The Problem

Animal pests destroy native wildlife and spread disease

The smaller invasive pests, such as rats, mice, stoats, ferrets, mongooses, mink and rabbits, are very hard to control. Aerial broadcasting of poison pellets can sometimes be used, but in most cases trapping or bait stations are required. Labour costs can be very high, especially when terrain is rugged or remote. Reinvasion or recovery of the pest population is a constant threat, requiring expensive ongoing monitoring.

Wary animals or difficult places = high costs

Monitoring

Effective ecosystem management requires monitoring of both pests and native species. The basic Scentinel logs animal weights and event data, but it also has add-on options that allow it to operate as a uniquely powerful animal monitor, with or without poisons: 

• Infrared digital camera
• RFID (PIT tag) reader
• Radio telemetry (cellular or UHF)
• Telemetered data from all stations delivered to a website data display

These add-on features provide:

• Early alert to invasions (telemetry)
• Measurement of population density (camera, RFID, logger)
• Confirmation of bait take (camera, RFID)
• Confirmation of protection of non-target species (camera)
• Easy checking on remote locations (telemetry)
• Observation of wildlife behaviour and condition (RFID, camera, weight logging)
• Quicker development of new features (bait and lure formulations, presentations) to suit target behaviour (all features)

Automated wildlife data collection

For examples of the kind of data readily collected with the Scentinel click here.

Tunnel shape

Tunnels are preferred in New Zealand for extra security against bird access and protection against debris. The current prototype is sized for ferrets, but smaller and  non-tunnel versions are being designed.

Inside/outside lure reduces wariness

The taster-lure (typically 0.5-1g per dose) is a thick mayonnaise-like liquid, rich in protein, fat or sugar and kept fresh in an aerosol-type canister. It is dispensed on a programmed schedule, typically daily. The taster-lure appears on the outside of the tunnel, where it can be easily accessed and tasted by animals without needing to enter the tunnel. But some of the lure flows through the slot and can only be reached by entering the tunnel. The prospect of finding more of the highly-palatable food helps to entice the animal inside.

Scent lures like pheromones can also be dispensed, in addition to the taster lure, in doses of about 25-180mg.

Weight detection and logging

The floor of the tunnel is a weighbridge that detects the animal's presence and determines its weight. The weighbridge features auto-taring to cope with debris accumulation, and weight smoothing to deal with animal movement. Weight data is logged. 

The sealed electronics package is under the weighbridge. In this cutaway model the aerosol canisters are visible above the weighbridge.

Feed delivery only to target animals, and only one dose per animal

If the animal is in the target weight range, the Scentinel dispenses a liquid feed, similar to the taster-lure, onto the shelf next to the lure. The feed potentially could contain toxin, contraceptive, vaccine etc. Aerosol spray delivery is also an option.

The feed dose is metered (0.5 to 3g currently available). With such a small quantity of highly-palatable feed complete consumption is usual, avoiding the learned aversion that would result from sub-lethal dosing.

There is a delay before another dose can be triggered, typically an hour (programmable), so an animal that has consumed one dose is unlikely to be able to consume a second one. In this time the animal will leave, clearing the Scentinel for the next visitor. By ensuring that only a single dose of poison is consumed by each animal, the Scentinel minimizes environmental release of toxin, secondary poisoning, and wastage of feed

In monitoring operations, when the feed is not toxic, the repeat-feeding rate can be restricted.

The Scentinel has provision for multiple feed types, potentially selectable according to animal weight, identity or the time-pattern of visitations. This could allow catchment area to be increased by using automated prefeeding to encourage the laying down of scent trails by target animals or by their prey.

Infrared camera

The optional infrared camera is triggered selectively according to animal weight. The camera provides high-accuracy species identification when the Scentinel is used as an animal monitor. When the Scentinel is used as toxic bait dispenser for pest control, the camera provides verification that non-target species are not being harmed. This is important when setting up an operation in a new environment.

Before-and-after pictures verify that the target animal has fully consumed the feed. This provides confirmation that the bait is effective for the species, and allows rapid testing of new baits and toxins on wild animals.

RFID logging of visits by individuals

Detection of subcutaneous RFID (PIT) tags is another option that can be added to the basic Scentinel. The identity of the individual is logged along with date, time, weight and optional picture data. The RFID reader is activated only in the presence of an animal, so does not waste power. Dispensing of feed (or one of several feed types) could be made selective for individuals.

Telemetry and internet access

Event records and images can be downloaded on-site, or by radio using brief scheduled transmissions. The Scentinel has optional GPRS (cellphone) or UHF radio modules. Tabulated data and images can be viewed from anywhere in the world through a secure web interface. (Click image or here for enlarged view of a sample display)