Intensified Non Sound Lure Behaviour

Recently we have been running extended trials with the sound lure targeting brush tailed possums with a new sound lure profile, and a decision was made to run at the same location without the sound lure for an extended period of time to chart the difference.    

There were several factors that occurred of note during this time.   Firstly there has been another successful capture at this location using the Timms trap, the second in three days, the first with and the second without the sound lure.    

The second is the heightened activity that we have seen where a trapped possum has remained in a trap for an extended period of time.  Typical of that occurring the activations on the camera and the interaction with the dead possum from other possums.  We are consistently seeing hundreds of activations at locations where typically we would expect twenty or thirty in an evening.   During this time we are seeing possums interacting with the dead possum, ripping fur off the dead animal and mating with it.      

This pattern repeated itself during this monitoring phase as over the five day of monitoring there was nearly a thousand activations.   Almost all of these occurred following the capture of the first possum where additional possums then came into the site and activated the camera by interacting with the possum.

In normal circumstances the trapped/dead possum would be removed in the following morning - however in this instance due to being absent from the location for five days it had to remain in the trap.    Three days of extreme heightened activity occurred with a variety of possums, including a mother and baby and a possum that had a distinct tinge of red or brown in the colour of its fut.

Also of note - the sound lure was not present and during the entire time there were no rat activations at the site - there has been numerous in the previous deployments including repeated large rat activations - these ceased for the duration of the five day only non sound lure deployment - there were no rat activity at all.

Finally New Zealand and our region has had a massive rainfall during the last three days of the deployment on the final day the water from the river, which is usually eight metres or so from the river to where the trap is located, had an unprecedented water level rise, as can be seen from the photograph on the left.   The affect that this has had on the activations will be investigated.
  
 

Third Night of Increased Activity: Possum/Rat Activations

In the third night of revised volume levels we have again seen an elevated level of activity at deployment site one.   This has been amongst some of the highest 'Winter' activations at the location in the past two years.   There has been numerous brush tailed possum visits to the site (three seperate occasions) large rodent activity (a rat that would be unable to access the rat box based on its size as it would not be able to fit into the trap area and various mice, including one that activated the trap).  The first activation shown left is of a brush tailed possum which has accessed the site, but not interacted any further with the location, it can be seen above the lens of the trail camera and is on the tree opposite the traps, as its fur can be seen above the camera.

The first set of activations at the site start at 10:00pm and last for over ten minutes and include twenty six activations (photographs) of the brush tailed possum.  Typical of the last view days the interest shown by the possum seems based around the sound lure unit, the small rat box, and it is not paying attention to the Timms trap which is immediately to the right as shown in the photograph.

The third set of possum activations during the night takes place starting at 1:01am and finishing at 1:08am.   Again in this brush tailed possum activity shows a repeat of what we have seen over the last few nights, the interaction is taking place with the unit, which is a baited rat trap, while the Timms trap, which is baited with pineapple is not interacted with.     The brush tailed possum climbs over the unit, looks inside and around it, while not investigating the other trap.

The final set of activations occur from 1:36am to 5:15am and rodent based activity - including a number of large rat photographs.   This location is adjacent to a river, and the rat box in use has a chicken wire entrance as opposed to a wooden tunnel, and based on the photographs one would assume that the rat would have some trouble entering the box, although not impossible (there is also a mouse that was trapped at some point during the night at the entrance to the trap although it is not obvious when this occurred).   The rats generally spend the time around the sound lure, although there is an interesting photo of it stretching on the Timms trap to give an idea of the size of the rat.    There are again numerous mouse photos as well.

In summary three nights of activity at this location have the following to note: 

• there is an absence of any domestic or feral cat activity, which has dominated this site in the past.   The cats have previously shown considerable interest in the lure, although this has lessened overtime (time frame here is two years) including when the lure was first used around the house the cats would interact directly with it, including spending time trying to get into the box etc.
• at the present time there have been repeated brush tailed possum interactions with the lure at this site, almost exclusively just the lure while the possum(s) ignores the traditional trap.   The possums appear not be scared away by the unit activation (based on the time that they spend at the site and the time that the lure is operating) and remains on site while the unit is activating
• rodent activity is also occurring at the site which is not deterred by the unit operating again based on the number of activations that are occurring and the operating cycle that the unit is running.

Brush Tailed Possum: Sound Lure compared to traditional trap

We have recently started using a new set up with a slightly more subtle set of sounds, with essentially a smaller speaker (although we can further reduce or set the sound volume level of the speaker and also have it operate at levels depending on the time of day or light level).

Yesterday was the first deployment of new unit and had a considerable number of activations in a single evening.   The second night of activations has seen an increased number of activations - and three seperate interactions with a possum/possums during the course of the night.   The first possum arrives at the site at 9:46pm - this possum ignores the Tims trap and proceeds to tip over the rat box where the sound lures is located.   The possum in this instance is photograph thirty seven times and spends a total of twenty five minutes at the location when the unit is repeatedly activating.   The possum interacts almost exclusively with the sound lure and ignores the traditional trap.

The second set of activations occur two and a half hours later.   The possum in this instance arrives just after midnight at 12:02am and remains on site for five photographs.   Again as with the first instance the interactions are exclusively with the rat box, now tipped over, with the sound lure operating from within it.    This possum is present at the site for a shorter duration than the first one and departs again by 12:03am.

The third set of interactions with brush tailed possums occur at 12:55am and lasts until 12:57am.  A possum enters the trap  area and interacts exclusively with the sound lure, ignoring the traditional trap that is to the right.

Again we wish to stress that this is the first in a range of new testing and the location of the lure immediately next to sound lure is possibly not the most robust science, but there is a clear preference for the brush tailed possum in the instances from the last two days to target and interact with the sound lure trap within the rat box and to ignore the traditional Timms possum trap which is deployed adjacent to it.

Subtle Change in Speaker/Volume Levels: Further Possum Activity

We have modified several of the deployed units with the expressed purpose of checking and refining the volume levels of the speakers.   While we are currently conducting considerable trials in the effectiveness of the stoat based version of our units (thank you again Feral Control, Taranaki) we are also moving ahead with our brush tailed possum trials.

We have adjusted our speakers recently looking for something that is more subtle, particularly as we are seeing indications that possums are investigating everything and we believe that other animals that we want to target have a range of hearing more specific to a lower sound range.

Our first indications with our new version of the possum lure is again showing promise - on the very first night of trials we have had a sound lure unit, set up inside a rat box with a standard sound profile and had a Timms possum trap with fruit bait.   We have had a significant possum interaction with the unit - a brush tailed possum has appeared, spent time interacting with the unit - while it has spent time at the general site by far the most significant interactions have been between it and the sound unit, including repeated attempts by the animal to gain entrance to the box from the front and the back as shown in the photographs above.    It has taken fruit left at the site, eaten it, and been active at the site for forty minutes, including climbing over the rat box and investigating it extensively.   

We will be monitoring site one again, after a period of a break to determine what will happen with the new profile and how relative it will be for the trials.  We are also going to shortly create a specific possum sound lure trap.nz profile/project where we will be placing our results as we more forward with the final phase of our testing.

Please note due to a manual error in the camera setting the incorrect date and time have been displayed in the photographs that were taken overnight.   The correct date for the activations was the night of Saturday 10th of July/Sunday 11th of July.

Official Stoat Trial by Feral Control

 This week marks a significant step in the evoultion of the sound lure project, specifically our focus on stoats.   We have an external company, Feral Control, who are South Taranaki based who are running an official trial for us, focussing on stoats.    They have deployed four DOC 200/250 with our fully updated sound lure units, which are being placed in the field.

These units are being run and assessed independently of our project, where we will be concentrating on the results and comparing the results to the rest of the traps in the location.

We also have an additional trial being run for us by the Department of Conservation (DOC) as part of the trapping network on the local Mounga.

It has taken over two years for the project to reach this point where we are confident of the set up for the electronics, the weather proofing and the reliability of the units that we are producing, which we are looking now to deploy in a number of areas.   We will be updating the posts and information as the results come hand on this blog.

You can follow the trial by using trap.nz website and searching for "sound lure trial" and locating the South Taranaki trial.

Possum Activity and Interactions (Updated) June 2021

 

We are continue to monitor activity on a variety of local farm locations involving brush tailed possums, sound lures and interactions.

It is continuing to reinforce what we have been seeing recently over time and at a variety of locations - that the sound lures are proving effective at drawing possums to an area where we have been able to deploy Timms possums traps, which are now working effectively, with a number of successful catpures.

We are seeing that the springing of a trap is not proving to be a hinderance to additional possum activirty, if anything we are seeing heightened activity when there is a deceased animal in the trap, with numerous possum interactions with the dead animal.   

We believe that there is clear evidence that the lure, picture left, is drawing animals towards the areas of the lure, they are not frightened by the lure when in its vicinity (as evidence by the lure operating while they are present) and additional animals are being brought into the area once the first animal has been caught.   We have also recently seen the arrival of the New Zealand Hawk which has been feeding on possums that have been caught in the traps.   While this is not a focus for our investigation of sound lures it is proving some striking imagery.

Hawks in New Zealand are not considered a pest bird and while they are not a focus of our investigation we have seen then several times as part of our work - and them feeding potentially on trapped possums is safer for the animals than feeding on roadkill.

We have stated recently that we are going to be producing our final set of data for this project and essentially winding it down - we will be publishing our full results as we continue both this investigation and the stoat work that we have been looking at.

Possum Activity - Recent Notable Incidents

 

The following series of incidents and images are from a local student who has been experimenting with the sound lure on their local farm and using it in conjunction with a Timms trap.   As part of this sequence a possum is visible in the first photograph on the left.  The possum investigates the area around where the trap is set and then activates the trap.

In this incident the sound lure was adjacent to the trap not inside the trap as is in some local deployed variation.

Following this successfull pest removal there was heighten actvity at the site as a number of possums interacated at the trap site.    During this time the sound lure was still operating and additional possums were arriving at the sight (this has been witnessed before at various locations locally).

There were also additional activations from two other animals of note during the monitoring timeframe.   

The first of which, shown in the third picture, is of a feral cat that was pulled into the activation area and spent time investigating the site and the location.  

While we are not targetting feral cats at this location and it is not outside of the realms of possibility that the sound lure is responsible for this visit (it has been evident on numerous locations throughout trials that feral cats are showing interest in the noise being generated from the boxes or the sound lure).

The final photograph in the series shows a visit from a Hawk to a location on the same farm where another possum has been caught using a Timms trap with a sound lure in operation.

Shortly on this site we will be running a prolonged trial involving a double blind set up to montior and measure the effectiveness of the sound lure.