NZ506559A - Animal control substance dispenser having a transmitter and both the lure dispenser and the control substance dispenser under electronic control - Google Patents

Abstract

An animal population control device includes: a) a lure dispenser for delivery of an attractant substance or lure for a target animal such as a stoat; b) a control substance dispenser for delivery of a control substance for the target animal; c) a triggering mechanism for actuating the control substance dispenser and d) electronic control means configured to control one or more of: i) actuation of the lure dispenser dependent on the time or day and/or temperature; ii) actuation of the control substance in response to triggering of the triggering mechanism of at least a predetermined magnitude and/or for at least a predetermined length of time and/or over a predetermined spatial distance; iii) actuation of the control substance dispenser such that after one actuation of the control substance dispenser the control substance dispenser is no re-actuated for at least a minimum time delay and iv) actuation of a transmitter to transmit data from the device to a remote receiving station. Addition to 506559

Description

INTELLECTUAL PROPERTY OFFICE OF N.Z. 2 1 NOV 2001 RECEIVED NEW ZEALAND PATENTS ACT, 1953 No: Date: COMPLETE SPECIFICATION IMPROVEMENTS IN OR RELATING TO ANIMAL POPULATION CONTROL DEVICES We, THE HORITUCLTURE AND FOOD RESEARCH INSTITUTE OF NEW ZEALAND LIMITED, a New Zealand company and Crown Research Institute (under the Crown Research Institutes Act 1992) having a place of business at Corproate Office, Tennant Drive, Private Bag 11030, Palmerston North, New Zealand, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: IMPROVEMENTS IN OR RELATING TO ANIMAL POPULATION CONTROL DEVICES TECHNICAL FIELD This invention relates devices for controlling populations of animals. In particular, although not exclusively, the invention relates to a device for population control of stoats.

BACKGROUND ART NZ Patent No. 270011 discloses a device and method for administering an active substance to an animal. Suitable substances include those which can control the population of the animal, or a substance to vaccinate the animal against disease. Particular animals of concern are possums.

The device can be positioned above the ground in such a manner that it forms a fluid trail, and the device is capable of dispensing an active substance within a carrier substance when the dispenser detects the presence of an animal. The animal is preferably detected by pushing on a barrier, the barrier restricting access to the source of the carrier substance.

It would be advantageous to provide an animal population control device which is of particular use in controlling stoats. Stoats are a serious predator of birds, and are probably the main influence in driving some species toward extinction. Stoats are very difficult and expensive to control by conventional methods. Their strong preference for fresh control substance makes the provision of poisoned control substances through aerial dropping or bait stations impractical. Trapping can be effective, but conventional traps need to be reset manually, and this makes trapping too costly to be a practical control method over large areas of land.

It is an object of at least a preferred embodiment of the present invention to provide an animal population control device which is particularly suitable for controlling the population of stoats, and/or to at least provide the public with a useful choice. An alternative object of at least a preferred embodiment of the present invention is to provide an animal population control device which achieves one or more of the following: • High incidence of lethality to target animals when poisons are used, thus avoiding generation of learned control substance-shyness; • High efficiency of use of expensive poisons, through reduced over-consumption; • Inaccessibility of poisons to birds, dogs and children; • Effective pest control at low population density; • Remote monitoring of catch rate, defects and re-invasion; • Detection of theft of the device; • A life of several years in the field without attention, thus reducing the high labour costs of maintaining control substance stations and conventional traps.

SUMMARY OF THE INVENTION In accordance with an aspect of the present invention, there is provided an animal population control device including: a lure dispenser for delivery of an attractant substance for a target animal; a control substance dispenser for delivery of a control substance for the target animal; a triggering mechanism for actuating the control substance dispenser; and electronic control means configured to control one or more of: actuation of the lure dispenser dependent on the time of day and/or temperature; actuation of the control substance dispenser in response to triggering of the triggering mechanism of at least a predetermined magnitude and/or for at least a predetermined length of time and/or over a predetermined spatial distance; actuation of the control substance dispenser such that after one actuation of the control substance dispenser the control substance dispenser is not reactivated for at least a minimum time delay; and actuation of a transmitter to transmit data from the device to a remote receiving station.

The electronic control means is suitably configured to actuate the lure dispenser at predetermined intervals. Preferably the animal population control device further includes a temperature sensor, the electronic control means being configured to prevent dispensing of attractant substance should the temperature be below a predetermined threshold. This may minimise the likelihood of blockage by preventing dispensing of attractant or lure substance when the temperature is too low, when the viscosity of the lure substance would be too high.

Advantageously, the triggering mechanism includes a rod or bar connected to a movement sensor to detect movement of the rod or bar by an animal. Preferably, an artificial egg is attached to an end of the rod to attract a target animal. The movement sensor may be configured to emit a signal having a characteristic quantity which varies dependent on the force applied to the rod or bar, and the electronic control means is configured to determine from the characteristic quantity of the signal whether the animal is of a size at least similar to the target animal and actuate the control substance dispenser if the animal is of such a size. Suitably, the electronic control means is configured to actuate the control substance dispenser when the movement sensor emits a signal for at least a predetermined time period.

In an alternative embodiment, the triggering mechanism comprises an first infrared emitter and sensor at a spatial distance from a second infrared emitter and sensor to provide two beams, and the electronic control means is configured to actuate the control substance dispenser when both beams are broken by an animal. Preferably, the first emitter and sensor are spaced at approximately 100mm distance from the second emitter and sensor.

In a more preferred embodiment, there are two infrared emitters and sensors at each position to provide four beams, and the electronic control means is configured to actuate the control substance dispenser when all four beams are broken by an animal.

One or both of the lure dispenser and the control substance dispenser may comprise a gas-pressurised aerosol container.

Preferably, each of the lure dispenser and the control substance dispenser comprises a gas-pressurised aerosol container, and the animal population control device suitably includes an actuator for actuating the lure dispenser and control substance dispenser, the actuator including a motor in driving engagement with a crank which is operably connected to a valve of the lure dispenser and a valve of the control substance dispenser, wherein rotation of the crank by the motor in one direction causes actuation of the lure dispenser, and rotation of the crank by the motor in the opposite direction causes actuation of the control substance dispenser. The motor is advantageously an electric servo motor.

Alternatively, the animal population control device includes an actuator for actuating one or both of the lure dispenser and the control substance dispenser, the actuator comprising a contractile wire attached between the respective dispenser and a fixed member, which wire is adapted to contract when a current is passed therethrough to cause a valve of the dispenser to be operated.

The animal population control device may alternatively or in addition include an actuator for actuating one or both of the lure dispenser and the control substance dispenser, which comprises a motorised valve pusher having an electric motor, a reduction gear train and a valve activating gear, the activating gear having an engagement portion for engagement with a valve of the respective dispenser such that upon actuation of the motor the valve of the dispenser is operated.

In the most preferred embodiment, the actuator for the lure dispenser comprises the motorised valve pusher, and the actuator for the control substance dispenser comprises the contractile wire.

The lure dispenser and/or the control substance dispenser may comprise a pump attached to a reservoir, preferably in an Aairless pump@ arrangement in which no air enters the reservoir as the contents are pumped out.

Either or both of the control substance dispenser and the lure dispenser advantageously include a metering attachment to release a predetermined amount of substance upon actuation, thereby minimising substance wastage.

The electronic control device is suitably configured to prevent reactuation of the control substance dispenser for a period of at least five minutes following an actuation thereof to minimise the chance of overdose.

Preferably, the animal population control device includes a digital camera and data storage means, and the electronic control means is configured to actuate the camera to take a photo of the animal immediately following actuation of the control substance dispenser. The electronic control means is preferably configured to actuate the camera a second time several minutes after the actuation of the control substance dispenser, to confirm that the control substance has been consumed. The device may further include an illuminator, which is preferably an infrared illuminator.

The electronic control means may include a plurality of electronic timers connected with logic links. Alternatively, the electronic control means may include a microprocessor.

The microprocessor is suitably configured to record the number of control substance dispensing events. The microprocessor may further be configured to record the number of times the triggering mechanism indicates an animal is active for at least a predetermined length of time.

In a preferred embodiment, the microprocessor is configured to actuate the transmitter to transmit data relating to triggering events and duration of activity to a remote receiving station at predetermined intervals. The predetermined interval may be a regular interval such as once per day, once per week, or once per year.

The microprocessor may be configured to actuate the transmitter to transmit a signal at short intervals if blockage or exhaustion of the control substance dispenser or lure dispenser is detected, or theft of the device is detected.

The animal population control device preferably includes a housing, the triggering mechanism being located inside the housing, the housing being sized to allow an animal smaller than or approximating the size of a target animal to enter the housing, while preventing an animal substantially larger than a target animal from entering the housing. A bifurcated tube may extend from the lure dispenser, such that lure is dispensed both into the interior of the housing, as well as to the exterior of the housing to attract target animals.

The animal population control device optionally includes a sound generator to generate a sound to scare off the animal a predetermined time after actuation of the control substance dispenser. Preferably, the predetermined time is sufficient to allow ingestion of the control substance by the animal following actuation of the control substance dispenser. The electronic control means may be configured to actuate the sound generator at predetermined intervals to deter nesting in the device. The noise may be ultrasonic, or may mimic the sound of a predator.

Other features which may be present in preferred embodiments of the present invention include: • A mechanism for dispensing lure continuously or intermittently; • A mechanism for making triggering by non-target animals unlikely; • A timer to determine the times at which the lure is discharged, which may be varied according to the time of year or time of day; • A container for edible active substance, which prevents contact between the control substance and the atmosphere except when the container's discharge valve is opened, and also prevents dissolution of pressurising gases in the control substance; • An edible control substance, formulated to be attractive to target animals, which is in the form of a liquid or a paste; • A formulation for animal population control or vaccination which may be part of or mixed with the control substance; • A temperature sensor to prevent the discharge of lure or control substance when the temperature is such as to make the discharge of the control substance unreliable, for example when the temperature is low enough to make the viscosity of the control substance unacceptably high; • A data logger to record the duration of animal activity within the device after a dispensing event has occurred; and/or • A control substance additive to discourage revisiting when the control substance contains a slow acting poison or a non-lethal treatment.

This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

The invention consists in the foregoing and also envisages constructions of which the following gives examples only.

BRIEF DESCRIPTION OF DRAWINGS Further aspects of the present invention will now become apparent from the ensuing description which is given by way of example only and with reference to the accompanying drawings in which: Figure 1 shows a top diagrammatic view of a device in accordance with a preferred embodiment of the present invention; Figure 2 shows a side diagrammatic view of the device of Figure 1 at section A-A; Figure 3 shows a detailed view of the arrangement of the control substance discharge mechanisms at section A-A; Figure 4 shows a detailed view of the arrangement of the control substance and lure discharge actuator at section B-B; Figure 5 shows a detailed view of an alternative discharge actuator for the control substance and/or lure; Figures 6 to 8 show alternative dispenser arrangements; Figure 9 shows a diagrammatic view of an alternative arrangement of components; and Figure 10 shows a diagrammatic view of the components of Figure 9 at section C-C.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The ensuing description is given by way of example only.

In Fig 1, a plan view of an animal population control device in accordance with a preferred embodiment of the invention is generally indicated by arrow 1. Fig 2 shows a side elevation view approximating the cross section A-A. The dispenser package 2 is contained within a cover 19, shown in outline. Within the package are indicated a lure container 3, control substance container 4, control substance metering attachment 5, valve actuator 6, electronics module 7, radio transmitter 8, battery pack 9, movement sensor 10 linked by a rod 11 to an artificial egg 12, control substance-valve actuator lever 13, lure valve actuator lever 14, camera 15, and camera illuminator module 16.

The electronics module 7 includes a timer and microprocessor (not shown) that calculates times at which lure should be released according to a software program embedded in the microprocessor. The electronics module contains an on-board temperature sensor (not shown) which allows the microprocessor to override the lure-release program should the temperature be so low that there is a risk of unreliable operation of any part of the dispenser.

When the microprocessor determines that it is time to dispense lure, it sends a signal to the valve actuator 6 that causes its crank 40 (Fig. 4) to rotate in such a direction that the link rod 41 pulls on the actuator lever 14. This, turning about pivot 42, depresses the lure valve cap 43, causing the valve in the lure aerosol can 3 to open, discharging lure through the tubing 44. This tubing bifurcates to two orifices (not shown), one of which discharges to the outside of the cover 19, and the other to the interior of the cover, where some is deposited on the egg 12.

When an animal enters the cover by either of the two entrance holes that are in positions generally indicated by arrow 20, it is likely to be attracted both by the artificial egg 12 and the lure which is deposited on or around it. If the animal moves the egg, it also moves the connecting rod 11 and the movement sensor 10. Rod 11 passes through the wall of the package 2 by means of a flexible grommet 22.

The movement sensor 10 emits a signal of magnitude correlated with the strength of the movement. This signal is conveyed to the electronics module 7, and if the magnitude, duration or other characteristics are such as to indicate that the animal is likely to be of a target species, and the temperature is not too low, the microprocessor will then provide a signal to the actuator 6 that causes its crank 40 to rotate in such a direction that the link rod 45 pulls on the control substance valve actuator lever 13. This, turning about fulcrum 21, forces the control substance metering attachment 5 downwards towards the base 30 of the package 2 (Fig. 3), depressing the stem 31 of the valve (not shown) and thereby opening the valve. A metered volume of control substance, typically approximately 1 ml, flows from the valve through hole 32 and drops onto the egg 12.

After a few seconds, sufficient to ensure a discharge of the full metered volume of control substance, the microprocessor signals the actuator 6 to return to its neutral position, the valve stem 31 is no longer depressed, and the valve closes. This action allows the metering attachment to recharge. The microprocessor will not issue any further signals for discharge of either lure or control substance until the end of a programmed waiting period of at least 5 minutes, and preferably about 30 minutes. After the discharge the microprocessor increments a counter to record that a dispensing event has occurred.

The animal, finding attractive control substance appearing before its nose, consumes the control substance by licking on and around the egg. At some time shortly after the control substance is dispensed the microprocessor will briefly turn on the camera illuminator 16, and signal the digital camera 15 to record a low-resolution photograph.

While the animal is feeding it will continue to move the egg and the movement sensor 10. If movement continues for more than a programmed interval, perhaps ten seconds, the microprocessor increments a second counter to record that persistent activity, presumed to be feeding, occurred.

Eventually, finding no more control substance forthcoming, the animal will leave the dispenser. Because the control substance may contain either poison, an appetite depressant or a substance that causes aversion, the animal is unlikely to return for a second dose.

At programmed intervals the microprocessor will briefly provide power to the radio transmitter 8 so that it can transmit the counts associated with dispensing events.

Fig. 3 also illustrates a method of attaching the control substance container 4 to the metering attachment 5. The metering valve (not shown), the stem of which is indicated by arrow 31, is contained within a small aerosol can 33. The can 33 is glued or otherwise sealed to a collar 34, and pierced by a hole 35. The stem 36 is the stem of a second aerosol valve (not shown) that provides closure for control substance container 4. Stem 36 is of slightly larger outside diameter than hole 35, but fits within the larger-diameter hole 38. Collar 34 is pressed against stem 36 so that the valve of container 4 opens and control substance flows through hole 35 to fill the metering can 33. Collar 34 is held in this position by a clamping means (not shown) so that the valve of container 4 is permanently open. Leakage of liquid control substance is prevented by O-ring 39.

Figure 5 shows an alternative discharge actuator which may be used to discharge the lure or the control substance. A lure or control substance canister 100 has a valve stem 102 which is located in a stepped aperture that penetrates the wall of an outer container 103. One end of a wire 105 composed of contractile material such as nitinol is attached to the wall 103 by a bracket 106 and a fastening clamp 107. The opposite end of the wire 105 passes through an aperture adjacent TO one end of an actuation lever 108, and is attached thereto by a fastener 109. The opposite end of the actuation lever 108 is pivotally connected to the wall of a container 103 via a pivot 110. An adjustable pusher screw 111 extends through the actuation lever and is located against the base of the canister 100.

Electrical wires 112 are attached to the fastening clamp 107 and fastener 109, which are in electrical connection with the contractile wire 105. When current is passed through the wires 112 and thereby through the contractile wire 105, wire 105 contracts, causing the actuation lever 108 to turn about the pivot 110, pushing the adjusting screw 111 against the base of the canister 100. The compression between the canister 100 and the valve stem 102 causes the valve of the canister to open, discharging a portion of the contents of the canister through the aperture 104.

The valve of the canister is preferably of a type which provides a metered discharge for each compression, for example 100 microlitres in volume.

When the current through the contractile wire 105 is discontinued, the wire 105 cools and expands, allowing the valve to close again.

The wire 105 contracts by about 5% of its length when heated above a certain transition temperature, typically about 70° C, by passing a current therethrough. It has been found that a wire 105 having a diameter of300 microns will reach the transition temperature in about 1 second when a current of about 2 Amperes is passed therethrough, and will expand again as it cools below the transition temperature. The 300 micron wire is capable of contracting against a loading of approximately 40N, which is sufficient force to open an aerosol dispenser valve, with movement of approximately 2mm. The use of levers increases the force available from the wires, allowing the use of small diameter wire that requires less heating current. It will be appreciated that the current level and length of time will vary depending on the wire diameter. It has been found that having the wire contract by at least 1% of its length may be sufficient for actuation of the dispenser.

An alternative embodiment could be provided in which the canister is stationary and the valve is moved by the contractile wire. However, it has been found by having the valve stationary and the canister moving, a good seal is easily provided around the valve stem, so that the container 103 can be hermetically sealed from the external environment.

An advantage of using contractile wire for dispenser actuation is that its operation is silent, and will therefore not scare the animal.

Figure 6 shows an alternative arrangement for actuation of the dispenser valve by the contractile wire, and an alternative arrangement for the dispenser discharge nozzle. Container 201 is an aerosol can with standard 90-degree valve tip 213. Tip 213 penetrates a wall 203 surrounding the container through an aperture 204, and is glued or sealed into the aperture. A contractile wire 205 is connected to brackets 206 and 208 by fasteners 207 and 209 respectively. Bracket 206 is fixed to the wall 203. Bracket 208 is able to slide along the wall 203, and the wall prevents movement perpendicular to the axis of the wire. The contractile wire is pre-tensioned by an extension spring 210, which is fastened to the bracket 208 and to the wall 203. An adjusting-screw 211 is adjusted to make light contact with the container 201. When a sufficiently large current is passed through electrical leads 212, the wire 205 contracts and by means of the screw 211 pushes the container 201 against the valve tip 202, so that the valve opens and a spray emerges from nozzle 202. Some of the spray goes into the air, and some deposits on the surface of wall 203, providing a residue of odour. The wall 203 may be partially coated with an absorbent surface to enhance the longevity of the residual odour. When the current ceases, expansion of wire 205 allows resetting of the valve mechanism.

Figure 7 shows an alternative arrangement for actuation of the bait dispenser. Container 301 is a pressurised container of aerosol type. Valve 302 is a metering valve such as the type supplied by the Lablabo company. A contractile wire 305 is connected to brackets 306 and 308 by fasteners 307 and 309 respectively. Bracket 306 is fixed to the wall 303, but bracket 308 is able to slide along the wall 303. The contractile wire is pre-tensioned by an extension spring 310, which is fastened to bracket 308 and to the wall 303. An adjusting-screw 311 is adjusted to make light contact with the container 301. When a sufficiently large current is passed through electrical leads 312, the wire 305 contracts and by means of screw 311 pushes the container 301 against the dome 313, which is prevented from moving by the wall 303. This compression opens an internal valve and allows liquid from the container 301 to fill the space under an elastomeric diaphragm (not shown) inside the dome 313. When the current ceases, expansion of the contractile wire 305 results in a relaxation of force on the dome 313, and another internal valve (not shown) allows the liquid under the dome to discharge through tube 314, which penetrates the wall 303 at point 304.

Figure 8 shows an alternative dispenser type for bait. Container 401 is an unpressurised Aairless@ type container, containing liquid bait in a flexible bag (not shown). A piston pump unit 402 is attached to the container 401. A contractile wire 405 is connected to brackets 406 and 408 by fasteners 407 and 409 respectively. Bracket 406 is fixed to the wall 403, but bracket 408 is able to slide along the wall 403. The contractile wire is pre-tensioned by an extension spring 410, which is fastened to the bracket 408 and to the wall 403. An adjusting-screw 411 is adjusted to make light contact with container 401. When a sufficiently large current is passed through electrical leads 412, the wire 405 contracts and by means of the screw 411 pushes the container 401 against the piston pump unit 402, which is constrained from moving by the wall 403. The compression of the pump forces liquid from the container 401 through the tube 413, which penetrates the wall 403 at point 404.

Another alternative discharge actuator which may be used to discharge the control substance and/or lure is a motorised valve pusher (not shown). The valve pusher includes a small electric motor and a reduction gear train connected to a cam-like nozzle activating gear. The nozzle activating gear has an engagement portion which is located against the nozzle of a canister. When the motor is operated, the reduction gearing causes the engagement portion to depress the nozzle of the canister, causing it to dispense. The nozzle is spring loaded, such that once the operation of the motor is stopped, the nozzle releases from its depressed position. Such a valve pusher is described in United States Patent Number 6,036,108 to Chen.

The advantage of using a motorised valve pusher is that its power requirement for actuation is approximately 1/10th of that of the contractile wire. However, the motorised valve pusher does create some noise, which may scare the animal.

Accordingly, the currently preferred embodiment utilises a motorised valve pusher for controlling the discharge of scent lure, which would generally occur 2-10 times daily (and usually when the animal is not present) and the contractile wire to discharge the control substance. This provides a good balance between power consumption and the risk of scaring away target animals.

Mode of Operation In the following description the control substance is described for convenience as containing poison, but it should be understood that it may alternatively contain contraceptives, vaccines, bacteria, viruses, vitamins, or other substances.

In one example of the invention the dispenser is contained within a tunnel-shaped cover. It may be fixed to the cover in such a way that it can easily be exchanged in the field for a replacement dispenser. The entrances of the tunnel are sized to exclude animals that are larger than the target animals.

Lure and control substance are contained within separate corrosion resistant aerosol cans. Deterioration of the control substance and the lure is minimised by holding both in reservoirs that prevent contact between the contents and air except at the point of discharge. A volume-metering device is attached to or incorporated into the control substance can.

A microprocessor controls timing and sensing operations. Timed release of pulses of lure attracts animals to the device. Movement of an animal within the tunnel activates a detection means. The detection means causes the release of an attractive poisoned control substance close to the animal's nose, providing a strong stimulus for the control substance to be eaten.

Excessive consumption of the control substance by a single animal is prevented by a time delay that prevents repeat discharges of the control substance for a duration sufficient that the animal will wait long enough to gain a second dose. The control substance may also contain a substance that reduces the animal's appetite before the time delay expires. It may also contain a substance that creates an aversion, so that if the treatment is a deliberately non-lethal one, such as a contraceptive, the animal will avoid the dispenser in the future.

After consuming the control substance offered, the animal will depart from the tunnel, leaving it clear for repeat operations. The poison will be selected so that the effect is not so fast as to disable the animal while it is still in the tunnel. Additional chemicals may be added so that the animal is positively motivated to leave the tunnel, for example by generating thirst.

The event of dispensing control substance will be recorded in the memory of the microprocessor. Also recorded may be the duration of the animal's activity while it is consuming the control substance, for example as a count of the number of times when the dispensing event is followed by less than ten seconds of activity, and a count of the number of times when the dispensing event is followed by more than ten seconds of activity. The latter case can reasonably be assumed to represent full consumption of the control substance, and the former can be assumed to represent an incident when the animal has been frightened away by the dispensing event or is not interested in the control substance. It should be understood that more detailed recording of the activity might also be carried out.

At intervals of perhaps a day or a week the records of events and activity duration may be transmitted by radio to a base station, perhaps through a relay station. The data thus transmitted will be very useful to the managers of the operation in indicating the level of infestation of pest animals in the area and the rate of change in their population, which is essential information for efficient management. Such information is obtained in normal practice by means of visits to the area to carry out manual trapping or inspection of indicator footprint tunnels, which may take many days and is very expensive when the areas are remote.

Radio transmission can also be used to alert the operation management to abnormal events such as exhaustion, malfunction, or theft of the device. In the event of such an abnormal event the transmitter may transmit at a much shorter interval, for example every two seconds, to aid location and recovery of the device.

Management may require assurance that the animals that are consuming the control substance are in fact the target ones. This could be a very important point for acceptance of the device in circumstances where the aim of the population control operation is to protect an endangered species from a predator. Suspicion that members of the endangered species may fall victim to the device could prevent its use. To provide the necessary assurance, a camera can be incorporated into the device. To avoid startling the animals the camera will preferably be able to take pictures with infrared light, which low-cost digital cameras can do. The dispenser unit will be equipped with an infrared illuminator, for example a cluster of light-emitting diodes sited above the control substance dispensing point, that is turned on briefly by the triggering event and is timed to coincide with an exposure being taken by the camera. The pictures will preferably be downloaded from the camera during a visit to the device. The need for camera evidence of exclusion of non-target species will only be occasional, so the labour costs of visiting the unit will not be a significant part of the overall operational costs.

An acceptably long battery life for the device, for example five years, can be practically obtained from a small and relatively inexpensive battery designed for longevity, for example a lithium cell.

Current consumption by the microprocessor, detector and camera while on standby need only be a few microamperes. Current consumption during actuation of the lure and control substance valves and during radio transmission may be between one and three amperes depending on the wire diameter, but these events are so short and infrequent that a small batteiy pack will have adequate capacity.

Detection of the Animal/Triggering Mechanism Reliable dispensing of liquid control substances over long periods of time requires that the dispensing mechanism be robust enough to overcome blockages that might result from solidification of residual amounts of control substance remaining after a previous dispensing event. This robustness requires that substantial forces are involved in the dispensing mechanism. Such forces are not generally available from use of the body weight of small animals weighing between one hundred grams and one kilogram. For control of such small animals is it desirable that the dispensing mechanism should be actuated by a powered system in response to detection of the presence of an animal.

In the preferred embodiment the detection means that senses the presence of an animal is a motion sensor that produces an electrical signal in response to the animal's movement. The preferred sensor type is a piezo-electric device, but other sensor types may be used, for example a motion-sensitive switch, a force-sensitive switch, a load cell, a strain gauge, a sensor that detects a change of infrared light level, or a heat sensor. The output of the sensor will preferably be modifiable by electronic or mechanical means so that signals produced by wind or by small non-target animals (for example, mice, insects, birds) can be ignored. This will protect those non-target animals and also prevent the wastage of control substance that would occur if they were to consume it.

The preferred motion sensor is configured to emit a signal having a magnitude corresponding to the force applied to a rod or bar, and the electronic control means is configured to determine from the magnitude of the signal whether the animal is of a size at least similar to the target animal and actuate the control substance dispenser if the animal is of such a size. However, the emitted signal could have some other characteristic quantity which varies dependent on the force applied to the rod or bar, and the electronic control means could be configured to determine from the characteristic quantity of the signal whether the animal is of the desired size. For example, the characteristic quantity may be the frequency of the signal which could increase with an increase in force applied to the rod or bar.

In the preferred embodiment the sensor is contained within a package situated near the top or roof of the tunnel, and is linked by a suspension rod to an attractive object that is close to the floor of the tunnel. The object may for example resemble an egg, which is attractive to many predators, particularly stoats. They and other predators are very likely to investigate and attempt to move an egg, increasing the likelihood that the animal will trigger the sensor, and also increasing the likelihood that the animal will linger long enough in the device to notice the control substance that is dispensed. Preferably the control substance will be dispensed onto the egg, so it is readily noticed by the animal and is also readily accessible to it.

While particular types of detection/triggering mechanisms have been described above, other types may be utilised. The presently preferred triggering mechanism utilises infrared light beams, provided between emitters and sensors on opposite sides of the tunnel. A preferred embodiment provides a pair of emitters and sensors spaced approximately 100mm apart within the tunnel. More preferably, rather than one emitter and sensor at each position, there may be two or more emitters and sensors at each position, to reduce the chances of getting false positive triggering due to emitters or sensors being obscured inadvertently, for example by dirt. The emitters (and optionally the sensors) are switched on for an interval of approximately 0.1-0.2 milliseconds (one microprocessor instruction cycle) every 250 milliseconds. In that interval, the microprocessor checks the output from the light sensors and will trigger only if there is no light received by any of the sensors. It will be appreciated that having the sensors spaced apart enables the microprocessor to determine whether the animal is of a desired size, ie a rat or stoat, or is a smaller non-target animal such as a mouse.

If, when the emitters are switched on, light falls on a sensor, an output pulse is produced by the sensor of the same duration as the light pulse. The sensors are connected in parallel, so that if any of the sensors receives light there will be an output pulse from the combination. When such a pulse is produced, an elevated voltage is maintained by analog electronic means for about 1 millisecond so that it is available at an input port of the microprocessor several instruction cycles after the pulse, for reading as a high state. If the voltage level at the input port is detected as high, the microprocessor determines that there is either no animal or that the animal is too short. Only if all sensors produce no output is the control substance dispenser triggered.

The voltage level presented to the microprocessor input is affected by the length of time the light sensor(s) receive light and by the intensity of the received light. Gain and threshold controls may be provided between the sensors and the microprocessor to adjust for light-level variations due to stray sunlight and other spurious signals such as those caused by insects crossing the beams.

Due to the short period of time between each pulse of the emitters, the microprocessor can alternatively be configured so that if all beams are broken at almost the same time, the control substance dispenser will be triggered.

Battery conservation may be enhanced by operating the microprocessor in a low power mode for most of the 250 milliseconds between the emitter/sensor pulses. The microprocessor need only be operated in full power mode for about 10 milliseconds every 250 milliseconds, including pulsing the emitters, checking the response, actuating the control substance dispenser as applicable, and recording data or performing a data transmission as applicable.

In an alternative embodiment the sensor that detects the presence of the animal is a movement detector that is mounted below a flexible floor, that may for example be made of rubber. The rubber floor is sealed to a rigid base of the device, but the middle part of the floor is suspended above the base by spacers or springs or a resilient pad to allow transmission of the animal's movement to the movement sensor. Small movements of the floor will produce an electrical signal in the sensor element that will trigger the dispensing operation.

Other types of triggering mechanisms which enable the sensing of any parameter that distinguishes presence of an animal from non-presence may be used, such as a mechanism that detects force exerted against a door or lever or jaw pressure from an animal biting on an object; detection of infrared radiation (body heat), sound, capacitance (proximity sensing), conductivity, or a change to a microwave field. Discrimination between target animals (eg rats, stoats) and non-target animals (eg mice) can be determined on the basis of the degree of the change of parameter.

Control Substances and Lures Preferred control substances (the edible substance containing the poison or other treatment agent) include liquid egg, dairy products such as butter oil or cream, fish oils, plant oils, blood extract and sugar-containing gels. Generally a preservative will be added, but other preservation and sterile packaging methods such as ultra-high-temperature pasteurisation or irradiation may used. Control substances may be thickened and/or emulsified to improve their stability, attractiveness to the animal and increase the ease with which the animal can ingest all of the offered control substance. Additional chemicals may be added to enhance the desire of the animal to eat the control substance. Poisons maybe micro-encapsulated to reduce emission of volatile components and thereby reduce the likelihood that the target animal will detect them. Other chemicals may be added to cause distress to the animal a short time after eating the control substance, so that it will be discouraged from returning to the dispenser for a second dose, which would be wasteful of control substance. This will be useful if it is necessary to use a poison that takes a long time to have an effect, for example an anticoagulant. It will also be useful if the treatment given to the animal is a non-lethal one, for example a contraceptive or sterilizing agent. The chemicals added to the control substance may generate thirst.

In the preferred embodiment the lure (the attractant scent) is dispensed from a separate container from the control substance. The lure is likely to be a low-viscosity volatile liquid, whereas the control substance is likely to be a non-volatile liquid with high viscosity, preferably in a thickened or gelled form. The lure may be any known attractant, for example a pheromone, a pheromone primer, urine of prey species, fruit odour, or any other type. The lure is dispensed under the control of a timer and microprocessor so that the lure emissions can be adjusted in frequency or duration according to the time of day, season of the year, temperature, or any combination of these factors, as calculated by the microprocessor. For example, the lure may be released at greatest frequency when the target population is most susceptible to attraction, or at the time of day when the animal is most likely to be active. The lure could be dispensed using a volume-metering device as is preferred for the control substance dispenser. The microprocessor will preferably be equipped with a temperature sensor, and lure release and control substance release may be suppressed when the temperature is so low that control substance discharge might be unreliable.

Dispensing of lure will preferably be disabled during the delay period that follows a dispensing event, so that an animal feeding on control substance will not be frightened away by a lure dispensing event.

In the preferred embodiment the lure may be sprayed in several directions simultaneously, by means of tubing connected to the valve of the lure container and the use of one or more tee-pieces in the tubing. Preferably the lure will spray outside of the dispenser cover and also inside the cover in the vicinity of the attractive object. Spray may also be directed towards the entrance of the cover so that a trail is laid from the outside to the inside, thus encouraging entry by animals attracted to the lure.

An alternative means of achieving the desired result that some of the lure should be deposited within the dispenser unit, while another part should be dispersed into the air, is to arrange the lure discharge nozzle so that part of the spray deposits on a surface of the dispenser unit.

Control Substance Metering and Valve Actuation The control substance volume to be dispensed can be adjusted, or kept substantially constant in the face of viscosity variations, by adjusting the valve-open duration according to temperature. However, in the preferred embodiment the control substance will be dispensed in constant-volume aliquots by using a volumetric metering attachment. This will, on displacement of a valve, discharge a pre-set volume of liquid and then will prevent further flow until the valve is released to a reset or recharge position. The valve will be opened for a duration long enough that the metered dose can be fully discharged under all practical conditions. Should the temperature be so low that the viscosity of the control substance is too high to be discharged in the period that the valve is open, or so low that the propellant is at too low a pressure to ensure adequate control substance flow, the microprocessor can determine that control substance dispensing be disallowed at such a time.

Because the device will be required to operate for long periods in the field without inspection or maintenance, it is preferable that the valve through which the control substance is dispensed should remain free of blockage, despite any tendency that the control substance may have to polymerise or otherwise form a solid plug in the channels of the valve after long periods of non-use. It has been found that the valves used in standard aerosol cans are particularly resistant to blockage, because the only part of the liquid that is exposed to oxidation or evaporation after a dispensing event is in the short, straight passage between the elastomeric seal within the valve and the outlet end of the nozzle. Even if the liquid in that passage solidifies into a plug, it is readily ejected by the combination of flexing of the valve seal at the next discharge event, and the pressure of the propellant. However, for this ease of ejection to apply, there will preferably be no further barriers or passages between the end of the valve nozzle and the point at which the liquid is finally discharged from the dispenser package.

Preferably the valve actuation will involve high forces so that the valve mechanism will not be significantly hindered by any solidification of the control substance that may occur. In the preferred embodiment there is a novel valve actuating system that takes full advantage of the reliability and ease of clearance of the standard aerosol valve. The valve is opened by application to its stem of a strong force, about 30 Newtons, sufficient to provide full flexing of the internal seal of the valve with a movement similar to that for which they are designed.

Alternative valve systems are envisioned, for example the use of solenoid valves or a piston-pump dispenser.

In the preferred embodiment the control substance container will be an aerosol-type can, and the control substance will be ejected by means of a propellant gas. With some combinations of control substance and target animal it may be preferable that the gas should not mix with or dissolve into the control substance, because if it does the control substance will either be tainted by the gas or will have a fizzy mouth feel that may make it unattractive to animals. Separation of gas and control substance can be achieved by means of a flexible barrier bag (for example of a type supplied by CCL Container, Ontario, Canada). The gas squeezes the bag to provide the pressure required to force the control substance out of the valve. A further advantage of the use of a barrier bag is that nearly complete ejection of the control substance liquid can be obtained irrespective of the orientation of the can.

In the preferred embodiment the volume of control substance that is discharged in a dispensing event is determined by a metering system, for example of the types supplied by Spruehventile Gmbh., Wyhl am Kaiserstuhl, Germany; The Seaquist-Perfect Company or Caiy, Illinois, United States of America; or by the Lablabo Company of 74112 Annemasse Cedex, France. With all of these products, each cycle of depression and release of the valve results in discharge of a predetermined volume of liquid.

While in the preferred embodiment the containers for bait and lure described above are gas-pressurised aerosol devices, other types of containers may be used. A particularly preferred embodiment utilises an Aairless@ hermetically sealed pump dispenser for example of the type supplied by the Lablabo Company, which prevents the entry of air and microbes into the body of the dispenser. As no propellant is required in a pump type system, there is no need to provide a barrier between the propellant and bait. Such a pump may be used for either or both of the lure dispenser and control substance dispenser.

Dispenser Cover The outer cover of the device will preferably be one that is well accepted by the target pests. A preferred cover is from a range of general-purpose covers for traps and control substance stations, made by Philproof Pest Control Products, Hamilton, New Zealand. It is in the shape of a tunnel approximately 700 mm long, 150 mm wide and 150 mm high, except for a larger section 350x250x170 mm in the middle. The openings at the ends of the tunnel are sized to restrict access to animals smaller than a chosen size. This type of cover is effective in protecting non-target animals from control substances and traps within it. This cover is also weatherproof, can be pegged to the ground, and is strong enough to prevent damage if stood on by heavy animals.

Figure 9 shows an alternative arrangement of components that has been found satisfactory for an animal population control device. A lure dispenser compartment generally indicated by arrow 501, a bait dispenser compartment generally indicated by arrow 502, and a camera and electronics compartment generally indicated by arrow 503, are arranged under a cover which extends to the boundaries indicated by dashed line 504. The three compartments are formed from a single base component and closed by the single cover to form a sealed unit, as illustrated in Figure 10.

In Figure 9, lure is sprayed at predetermined intervals from nozzle 505. The spray is partially deposited on surface 506, and partially emitted into the air through passage 507. A animal of the size of the target species, attracted by the lure, will be unable to enter passages 507 and 508 because they will be too narrow. On searching for the source of the lure, the animal will be able to enter passage 509.

When the animal' s body prevents infrared light from emitters 510 from reaching detectors 511, the operation of the bait dispenser will be triggered, and an aliquot of bait will be dispensed at position 512, close to the animal' s nose. At the same time a photograph will be taken by infrared camera 513 through the lens 514. At some time later the camera may be programmed to take a second photograph to confirm that the bait has been taken.

Figure 10 is a cross sectional sketch of the device shown in Figure 9, showing how a single base component 601 can form the lure compartment 501, the bait dispenser compartment 502 and the roof of the entry tunnel 509. Circles 605 and 606 indicate cross-sections of the lure and bait containers. The base component 601 also forms the camera and electronics compartment (not shown). With the attachment of a cover 607 there is formed a container that can be completely sealed from the outside atmosphere. Cover 607 may be extended down to ground level as shown to allow the whole unit to be pegged to the ground through holes in the flange 608. Ground level is indicated by dashed line 609.

Event Data Recording In the preferred embodiment a count of the number of times the dispenser has been actuated is readily recorded in the memory of the microprocessor, for examination on an inspection, or for transmission by radio. When an actuation event occurs, only a single increment to the count is recorded until after the passing of a delay period, for example 30 minutes. During this delay period the microprocessor suppresses further dispensing actions and count increments, even if the movement sensor is detecting activity by the animal during that time.

The duration of the animal activity, for example associated with licking of the control substance, is also recorded in a simplified manner, for example by programming the microprocessor to test, whenever an activity signal is detected, if a time of greater than 10 seconds has elapsed since the first detection of activity and dispensing of control substance. If this test result is logically true, it is presumed that the animal is still present ten seconds after the dispensing event, and is consuming the control substance. This results in a second count being recorded in the microprocessor memory. When the record is examined, a total number of second counts that is substantially less than the total number of first counts would indicate that the control substance was unattractive to a significant number of animals, or that they were being frightened by the dispensing event. More sophisticated data classification systems are envisioned, but this example is a preferred compromise between information gathering and the cost of memory capacity.

Selected dispensers in each population control area will preferably be fitted with cameras to confirm that non-target animals are not being treated. A digital camera, such as the "YAHOO" digital camera supplied by Tiger Electronics, Taiwan, can readily be triggered by the microprocessor in response to a dispensing event. This camera is sensitive to infrared light and has a built-in infrared illuminator. The picture may be transmitted by radio, or downloaded from the camera during an inspection. The electronic control means may be configured to activate the camera a second time several minutes after the actuation of the control substance dispenser, to confirm that the control substance has been consumed.

Radio Transmission The presence of the microprocessor electronics and associated battery pack means that the dispenser can be provided with a radio transmitter at modest additional cost. The transmitter can provide valuable information to the operators of the pest control program. For example, it can provide notice to a remote office when a predator invasion has occurred, or provide information on the daily, weekly or cumulative dispensing event count so that progress in pest control can be monitored. It can provide notice that the control substance container is nearing exhaustion, because the operator can count the total number of dispensing events, and knows the capacity of the control substance storage container. The radio can also provide a signal, perhaps in response to gross movement after the unit has been put in place, to indicate that the device has been stolen. All this information could greatly reduce the cost of monitoring the pest control operation.

The drain of the transmitter on the battery can be kept low by powering the transmitter only for a few seconds when it is reporting, and this might only be done on a daily or weekly basis. Should the transmitter be required to help guide the operator to its exact location (following scheduled completion of the population control program, exhaustion of consumables, or theft) the microprocessor could drive the transmitter more frequently, for example at the rate of several pulses per minute.

The transmitter may produce a frequency-modulated, amplitude modulated or even an unmodulated radio wave. In the latter case the simple data that is required to be transmitted could be encoded as a series of continuous-wave pulses, for example a simple identity sequence followed by a number of pulses corresponding to the dispensing counts. A range of 1 km for the transmitter would allow a hill-top relay station to collect and relay data from about 50 control substance devices spaced on a 300 metre grid.

The identity of the transmitting unit would be useful information, and several ways are envisaged for providing this information. An identity code could be generated by the microprocessor and communicated as additional data along with the event count data. Alternatively, an economical way of providing identity data would be for each dispenser unit to have a unique time of the day or week to transmit. With infrequent and short transmissions, and only a small number of transmitters per repeater station, the probability of confusion would be acceptably small.

Electronic Control Means While the above preferred embodiments have been described with reference to the use of a microprocessor, many of these tasks could be performed using alternative electronic control means such as a plurality of electronic timers with logic links between them, which may result in reduced costs. However, the use of a microprocessor provides the additional advantage of data accumulation and transmission.

Advantages of Preferred Embodiments There are a number of advantages of the preferred embodiments of the present invention described above.

Management advantages provided to the users of the preferred device include remote monitoring of catch rates, confirmation that control substance is consumed when dispensed, and confirmation that only target animals receive the control substance. These address significant problems with conventional poisoning operations, in that preferred poisons are not particularly fast-acting, and poisoned animals are not usually locatable, so results are hard to monitor.

Advantages provided by the use of a microprocessor include: Reliable triggering by lightweight or small target animals such as rats and stoats, and reliable avoidance of triggering by lighter or smaller non-target animals; Long life lure emission; Provision of an automatic discharge of the control substance at predetermined intervals (for example, monthly) to reduce the likelihood that the control substance nozzle will become blocked after a long period of inactivity; Remote monitoring of dispenser performance (labour saving); Recording of activity data and photographs for confirmation of species specificity; Theft protection; Control of time delay between dispensing events to minimise bait consumption; and Low temperature protection for lure and control substance.

The microprocessor can provide all of the above capabilities at a significant cost advantage.

The use of contractile wire enables silent actuation of the lure and/or control substance dispensers, so that target animals are not scared away upon actuation. It is estimated that previous motorised servo drive systems may have resulted in scaring off 5-10 % of target animals.

The preferred device allows reliable operation by small target animals such as stoats, but protects against triggering by very small non-target animals, for example mice and insects, which would result in waste of control substance and shortened field life for the device.

The preferred device provides a high level of reliability by reducing the likelihood that the control substance dispensing valve will block due to the solidification of control substance material in the outlet of the valve after long periods of non-use.

The preferred device prevents unreliable or wasteful operation of the control substance dispenser when the temperature is so low as to cause freezing or excessively slow flow of the control substance.

The preferred device which includes a tunnel may be used to provide an active substance for target animals such as ferrets, rats and stoats, while preventing access by larger non-target animals.

The preferred device discourages repeat visits and excessive consumption of control substance by the animal. This could occur if it is possible for an animal to return to the device after the post-triggering delay period has expired, which could occur in applications where the treatment delivered to the animal is a non-lethal one, for example a contraceptive vaccine, or where the poison of choice is one that takes several days to have an effect It will be appreciated that the above describes preferred embodiments of the present invention, and modifications may be made thereto without departing from the scope of the following claims.

Claims (43)

-29- What we claim is:

1. An animal population control device including: a lure dispenser for delivery of an attractant substance for a target animal; a control substance dispenser for delivery of a control substance for the target animal; a triggering mechanism for actuating the control substance dispenser; and electronic control means configured to control one or more of: actuation of the lure dispenser dependent on the time of day and/or temperature; actuation of the control substance dispenser in response to triggering of the triggering mechanism of at least a predetermined magnitude and/or for at least a predetermined length of time and/or over a predetermined spatial distance; actuation of the control substance dispenser such that after one actuation of the control substance dispenser the control substance dispenser is not reactuated for at least a minimum time delay; and actuation of a transmitter to transmit data from the device to a remote receiving station.

2. The animal population control device as claimed in claim 1, wherein the electronic control means is configured to actuate the lure dispenser at predetermined intervals.

3. The animal population control device as claimed in claim 1 or claim 2, further including a temperature sensor, the electronic control means being configured to prevent dispensing of attractant substance should the temperature be below a predetermined threshold.

4. The animal population control device as claimed in any one of the preceding claims, wherein the triggering mechanism includes a rod or bar connected to a movement sensor to detect movement of the rod or bar by an animal.

5. The animal population control device as claimed in claim 4, wherein an artificial egg is attached to an end of the rod or bar.

6. The animal population control device as claimed in claim 4 or 5, wherein the movement sensor is configured to emit a signal having a characteristic quantity which varies dependent on the force applied to the rod or bar, and the electronic control means is configured to determine from the characteristic quantity of the signal whether the animal is of a size at least similar to the target animal and actuate the control substance dispenser if the animal is of such a size.

7. The animal population control device as claimed in claim 6, wherein the electronic control means is configured to actuate the control substance dispenser when the movement sensor emits a signal for at least a predetermined time period.

8. The animal population control device as claimed in any one of claims 1 to 3, wherein the triggering mechanism comprises an first infrared emitter and sensor at a spatial distance from a second infrared emitter and sensor to provide two beams, and the electronic control means is configured to actuate the control substance dispenser when both beams are broken by an animal.

9. The animal population control device as claimed in claim 8, wherein the first emitter and sensor are spaced at approximately 100mm distance from the second emitter and sensor.

10. The animal population control device as claimed in claim 8 or 9, wherein there are two or -31 - more infrared emitters and sensors at each position to provide four or more beams, and the electronic control means is configured to actuate the control substance dispenser when all beams are broken by an animal.

11. The animal population control device as claimed in any one of the proceeding claims, wherein the lure dispenser or the control substance dispenser comprises a gas-pressurised aerosol container.

12. The animal population control device as claimed in any one of claims 1 to 10, wherein each of the lure dispenser and the control substance dispenser comprises a gas-pressurised aerosol container.

13. The animal population control device as claimed in claim 12, further including an actuator for actuating the lure dispenser and control substance dispenser, the actuator including a motor in driving engagement with a crank which is operably connected to a valve of the lure dispenser and a valve of the control substance dispenser, wherein rotation of the crank by the motor in one direction causes actuation of the lure dispenser, and rotation of the crank by the motor in the opposite direction causes actuation of the control substance dispenser.

14. The animal population control device as claimed in claim 13, wherein the motor is an electric servo motor.

15. The animal population control device as claimed in claim 11 or 12, further including an actuator for actuating one or both of the lure dispenser and the control substance dispenser, the actuator comprising a contractile wire attached between the respective dispenser and a fixed -32- member which will contract upon the passing of a current therethrough to cause a valve of the dispenser to be operated.

16. The animal population control device as claimed in claim 15, wherein the wire is a nitinol wire.

17. The animal population control device as claimed in claim 11 or 12, further including an actuator for actuating one or both of the lure dispenser and the control substance dispenser, the actuator comprising a motorised valve pusher having an electric motor, a reduction gear train and a valve activating gear, the activating gear having an engagement portion for engagement with a valve of the respective dispenser such that upon actuation of the motor the valve of the dispenser is operated.

18. The animal population control device as claimed in claim 11 or 12, wherein the actuator for the lure dispenser comprises a motorised valve pusher having an electric motor, a reduction gear train and a valve activating gear, the activating gear having an engagement portion for engagement with the valve of the lure dispenser such that upon actuation of the motor the valve of the lure dispenser is operated, and wherein the actuator for the control substance dispenser includes a contractile wire attached between the control substance dispenser and a fixed member which will contract upon the passing of a current therethrough to cause a valve of the control substance dispenser to be operated.

19. The animal population control device as claimed in any one of claims 1 to 10, wherein either or both of the lure dispenser and the control substance dispenser comprises a pump attached to a reservoir. 33. 506 559

20. The animal population control device as claimed m claim 19, wherein the pump and reservoir are hermetically sealed so that no air enters the reservoir as the contents are pumped out.

21. The animal population control device as claimed in any one of the preceding claims, wherein either or both of the control substance dispenser and the lure dispenser includes a metering attachment to release a predetermined amount of substance upon actuation.

22. The animal population control device as claimed in any one of the preceding claims, wherein the electronic control means is configured to prevent reactuation of the control substance dispenser for a period of at least 5 minutes following an actuation thereof.

23. The animal population control device as claimed in any one of the preceding claims, further including a digital camera and data storage means, and wherein the electronic control means is configured to actuate the camera to take a photo of the animal immediately following actuation of the control substance dispenser.

24. The animal population control device as claimed in claim 23, wherein the electronic control means is configured to actuate the camera a second time several minutes after the actuation of the control substance dispenser, to confirm that the control substance has been consumed.

25. The animal population control device as claimed m claim 23 or 24, further including an illuminator for the camera. INTELLECTUAL PROPEI OFFICE OF N.Z. 0 3 DEC 2001

26. The animal population control device as claimed in claim 25, wherein the RECEIVED -34- illuminator is an infrared illuminator.

27. The animal population control device as claimed in any one of the preceding claims, wherein the electronic control means includes a plurality of electronic timers connected with logic links.

28. The animal population control device as claimed in any one of claims 1 to 26, wherein the electronic control means includes a microprocessor.

29. The animal population control device as claimed in claim 28, wherein the microprocessor is configured to record the number of control substance dispensing events.

30. The animal population control device as claimed in claim 29, wherein the microprocessor is configured to record the number of times the triggering mechanism indicates an animal is active for at least a predetermined length of time.

31. The animal population control device as claimed in claim 29 or 30, wherein the microprocessor is configured to actuate the transmitter to transmit data relating to triggering events and/or duration of activity to a remote receiving station at predetermined intervals.

32. The animal population control device as claimed in claim 31, wherein the microprocessor is configured to actuate the transmitter to transmit data relating to triggering events and/or duration of activity to a remote receiving station at regular intervals.

33. The animal population control device as claimed in any one of claims 28 to 32, wherein the microprocessor is configured to actuate the transmitter to transmit a signal at short intervals if -35- blockage or exhaustion of the lure dispenser or control substance dispenser is detected, or theft of the device is detected.

34. The animal population control device as claimed in any one of the preceding claims, including a housing, the triggering mechanism being located inside the housing, the housing being sized to allow an animal smaller than or approximating the size of a target animal to enter the housing, while preventing an animal substantially larger than a target animal from entering the housing.

35. The animal population control device as claimed in claim 34, wherein a bifurcated tube extends from the lure dispenser, such that attractant substance is dispensed both into the interior of the housing, as well as to the exterior of the housing to attract target animals.

36. The animal population control device as claimed in claim 34, wherein the lure dispenser is arranged to dispense a portion of the attractant substance onto the surface of the dispenser, and the remainder of the attractant substance into the air.

37. The animal population control device as claimed in any one of the preceding claims, further including a sound generator to generate a sound to scare off the animal a predetermined time after actuation of the control substance dispenser.

38. The animal population control device as claimed in claim 37, wherein the predetermined time is sufficient to allow ingestion of the control substance by the animal following actuation of the control substance dispenser. -36-

39. The animal population control device as claimed in claim 37 or 38, wherein the electronic control means is configured to actuate the sound generator at predetermined intervals to deter nesting in the device.

40. The animal population control device as claimed in any one of claims 37 to 39, wherein the sound generator is adapted to generate an ultrasonic signal.

41. The animal population control device as claimed in any one of claims 37 to 39, wherein the sound generator is adapted to generate a noise mimicking a predator of the target animal.

42. The animal population control device substantially as hereinbefore described with reference to the accompanying drawings.

43. The animal population control device as claimed in any one of claims 1 to 41 substantially as herein described with reference to any embodiment disclosed. by IfiO _n