Sunday 17 March 2024

Dead Duck - Food for someone

 When you are an avid patch worker you might assume that things become stale, but the reverse is true. I have been visiting and recording wildlife on my patch since 2002 and recording them on Trail Cameras since 2016. Ecosystems are dynamic places constantly changing and all the hours I have spent down there have barely scratched the surface of animal behaviour.

Whilst out changing out my memory cards on Friday morning I came across the carcass of a bird. It was close to the bird feeding station and not far from the backwater. At first, I thought it was a crow but as I got closer, I could see it was a duck, one of the domestic hybrid Mallard that frequents the river. On closer examination, I could see that it was lying on its back. The head seemed to be missing and the breast muscles had been eaten away on either side revealing the keel.  There was very little blood suggesting that it had been dragged to this location and the remaining meat was still fresh and red, there was little smell and no decomposition. There was a general carpet of some down and feathers that looked pulled rather than plucked. I reckoned it had been killed that night or early in the morning.


Who was the culprit? I had two animals in mind straight away. The way the bird had been eaten so neatly suggested a mammal predator. Avian predators such as buzzards would hold the prey down with their talons and rip the meat free from the carcass creating jagged tears, additionally, they tend to pluck birds leaving discarded feathers with intact shafts, foxes by comparison bite through the feathers. My number one suspect was an otter. It could easily have taken a duck sleeping on the backwater or from the undergrowth and then dropped it here.

I knew that my Mostela camera wasn’t catching much footage so I relocated this camera to watch the carcass to see what appeared later. I left the camera in place until today (Sunday) and returned to collect it. The duck was gone, and I had 839 photos and videos to examine.

To my delight, my suspicion was confirmed. The first interest in the carcass was an otter arriving at 21:06 (The mostela camera was 1 hour ahead). It went directly to the carcass and began feeding. It sat comfortably pulling chunks off and gulping it down with slappy chops for initially 8 minutes before something spooked it and it dashed away. It almost immediately returned settling in to feast for a further 4 minutes before slinking off. It returned at 23:58 and spent a further 4 minutes eating. This meant that it spent in total, 16 minutes eating and seemingly enjoying its meal.


To see a full 11 minute video click here

With the otter gone a wood mouse appeared (3:25 am) and pottered about for 8 minutes.

Daytime on the 16th of March brought a woodpigeon and blackbird that seemed unfussed by the carcass. At 19:15 a fox appears and casually starts to feed. It feeds on the main carcass and around it until 19:21, at this point, it picks up the remains and drags it off. I suspect it took the remains to cache it somewhere. I doubt the carcass was picked clean and so there was still food available that it could access later. This suspicion is validified somewhat by its return 10 minutes later whereupon it continues to scavenge any and all scraps still available. It did this sporadically leaving and returning until 20:41 and then again in the early hours of the 17th.


For a full video of the fox click here

I want to go over the footage in more detail to make sure it's the same individuals and comment a little more in the eating habits of the two species. As you can see the otter tends to settle down comfortably to eat. It rips chunks from the carcass and devours them with large bites. The fox however acts more like the scavenger it is. It doesn't seem to settle as well, preferring to stand and feed. It keeps a wary eye out and varies its feeding from the caracss to remains scattered across the site.

Saturday 9 March 2024

GardePro Wildlife Cameras - Are they any good?

 

This winter’s heavy rain and inevitable flooding have proved costly to my wallet and my camera-trapping project. The once-in-a-25-year flooding took out 3 of my good trail cameras. Cameras I believed would never be touched succumbed to the deluge, the one in the mostela actually floated off and into some undergrowth.

In all my years I have been camera trapping I have always invested in Bushnell Cameras, which I have found to be the most reliable for long-term studies. They are not overly battery-hungry and have great resolution. The electronics work well, and they have few malfunctions. As a backup, I have trusted Browning, which are solid and reliable and within the same price bracket as the Bushnell’s. I have experimented with LTL Acorns, which are on the lower end of the price range but found them not worth the price. Their electronics were temperamental, and the image quality was not as good as the Bushnell’s or Browning’s.



Replacing my damaged cameras was going to prove costly and unfortunately, repair was not an option. River water damage by direct immersion is not great for circuit board survival and the repair shop I sent it to was unable to save either of the two I sent.

Eventually, I decided to go against my instincts and have a look at some of the low-end mass-market models from less well-known manufacturers. After a bit of searching on Amazon I landed on a make called GardePro and in particular the A3S model. This camera costs as little as £80. It was a gamble, surely something so cheap couldn’t match the Bushnell’s.

The A3S model takes 32-megapixel images and 1296p video, with up to 100 foot no glow Night vision and 0.1s motion detection. In comparison the Bushnell’s I normally use take 30-megapixel images and 1080P at 60 fps with 80-foot no glow night vision and 0.2s motion detection. Both operate on 8 AA batteries and take standard SDHC memory cards.


So, after 2 weeks in the field, how does this model hold up?

Not bad. I am quietly impressed so far by this brand. The boxing is simple and functional, and the instructions are on par with what is usually shipped these days. On first impression, the build quality does feel cheap, something about the feel of the plastic and its strength. The buttons are large and the feel of the interface again seems cheap however one cannot fault its performance so far.

What makes GardePro better than Bushnell is the inclusion of a playback function on the screen, this enables me to check in the field very easily the operation and placement of the camera. I would not say that the battery life is much different from the other models and the image quality is excellent, as is its detection abilities.

You can see from the footage here that the images are crisp and the videos clear.

Daytime:




Night Time:




I am very impressed by this new manufacturer, it's early days as to their long use, but GardePro has certainly got me out of a hole and allowed my project to continue with minimal financial impact. This is a brand to watch.

GardePro - Website

Buy from Amazon


Monday 5 February 2024

Gorillas and Deer - Habituation as a tool for conservation

 This post is an amalgamation of two previous posts one on habituation and one on Virunga. Virunga was a powerful 2014 British documentary directed by Orlando Von Einsiedel that focused on the work of park rangers in Congos Virunga National Park and in particular the struggle to protect mountain gorillas. The habituation post related to my gradual acceptance of my present by the resident Doe and her two young females that have developed this year. Today I had my most intimate and relaxed encounter with them. They allowed me to sit some 40 metres away and grazed naturally mostly at ease, exhibiting natural behaviour. These two disparate things coalesce when considering another recent documentary, Silverback.

Silverback is a documentary by wildlife cameraman, Vianet Djenguet. The explores the themes surrounding the work of conservationists in the Kahuzi-Biega National Park in the Congo and their aim to habituate eastern lowland gorillas for tourism.

Through Vianet we are introduced to the dedicated rangers on the ground, the scientist managers, and the gorillas themselves. Conservation in Africa is difficult and complex, no one can deny the pressures on the local Congolese people living in a war-torn country and often this brings them into conflict with the local wildlife, poaching, and the bush meat trade are particularly disturbing but as a country develops most damaging is the loss of primary forest to make way for cattle, crops and development. The plan, which is already in action, is to habituate gorilla families so that tourists can safely be taken to view them. This tourist trade would provide valuable revenue to fund conservation measures like protecting land and show the local people the value of conserving wildlife around them.

Vianet joins the rangers for 3 months, during which they spent each day with a family of gorillas led by a Silverback called Mpungwe. Vianet started off wholly engaged in the project but slowly came to doubt the merits of the initiative as the knowing doubt that was in the back of my mind the whole time came to the fore.

There is considerable merit in the concept of involving local people in the management of their natural resources and given that all the people shown were from Congo exemplified this and removed any suggestion of the ‘white west’ dictating what the former colonies now do in their own country, but that is a whole other kettle of fish and a debate best saved for another time and place.

Mpungwe was a somewhat aggressive gorilla, but perhaps no more so than would be expected from someone who had lost his parents violently and is disturbed each day by a camera crew, and, here is the crux of habituation, the individual needs to be receptive and have the correct temperament. Mpungwe was not the first gorilla to be habituated, there had been successes elsewhere in the Congo but he seemed wholly unpredictable and unsettled by the whole affair for the techniques to be effective. Whilst there did seem to be some progress, a begrudging tolerance perhaps, Mpungwe seemed unable or perhaps more accurately unwilling to totally accept the presence of humans around his family.

To persevere with the attempts at habituation, which is where the programme left us, risks causing Mpungwe more stress. Doctors live by the Hippocratic Oath, to first do no harm something that Ecologists and scientists should also live by even if it isn't codified in the same way.

Towards the end of the film Vianet seemed to be having second doubts, he acknowledged Mpungwe's discomfort and wondered if this was too high a price to pay. It's a valid point just as the technique of habituation is for tourism, but there is certainly an ethical line that needs to be explored. All of us need to rationalise how far we should go to safeguard a species. How far is too far and who decides?

I am uncomfortable with the concept of habituation, for me, it leads to a change in natural behaviour and desensitising a creature to man can be dangerous, this is less of a problem in this country with my deer per se but where active hunting is a problem then it could be deadly.  For my deer I want them to remain wild, and whilst some habituation makes it possible for me to observe them closer and get some great pictures anymore would be unjust and unfair, for Mpungwe it is much more complex, the rangers of Kahuzi-Beiga are trying to save a species and in the modern world that requires compromise. 

Saturday 3 February 2024

Pelagic Publishing - A Book Review

It's been a while since I have done a book review and so when I got a new wildlife book for Christmas and then decided to get a few more I thought I would like to look at Pelagic Publishing’s Data in the Wild Series. 



 Pelagic Publishing is fast becoming one of my favourite conservation publishers. It was founded in 2010 and has a steady output of conservation-focused texts that lean towards the practical application of ecology. 

 The internet provides us with a wealth of up-to-date information but nothing beats the ability to hold a book in your hands and browse the information. Statistics for Ecologists Using R and Excel and Community Ecology – Analytical Methods using R and Excel are two books that benefit from having a physical quality. When learning new software or manipulating your data in a spreadsheet it is so much easier to refer to a textbook than to constantly flick between a bewildering number of windows containing webpages, adverts, and YouTube clips to achieve your aims. Both these books explore simple and complex ecological themes providing step-by-step ways in which R or Excel can be used in analysis. Just from using these books I have managed to get a grip on R and can generate several statistical tests and output graphical representations. The books are backed up by trail data sets and web links marrying the physical with the virtual. 


 The other two books I have in the series are Measuring Abundance and Camera Trapping for Wildlife Research. The latter, I got a while ago and have helped shape and develop my ongoing camera-trapping project. Both books collate up-to-date information on their topics with relevant case studies and useful coding for use in R. In terms of level, the books are certainly not for the novice reader, you need an understanding of ecological theory and knowledge of mathematical notation and application. The books assume that you have this background and do not go far to explain in depth what the measures they are describing merely how to calculate them. 

Data in the Wild is an indispensable series for practical ecologists who are engaging in research. It helps focus on how projects are set up and aids in the analysis of data collected and presented. Pelagic Conservation Handbooks are a welcome addition to wildlife management and are a concise guide to habitat assessment and practical methods of management. I currently own the Woodland Survey Book which has helped me analyse and survey the woodland on my patch and as an extensive user of QGIS I am waiting with bated breath for their upcoming title, QGIS for Ecologists due this June.


Friday 5 January 2024

Water Water Everywhere!

 As was alluded to in the last post there has been a degree of flooding, and by degree, I mean a lot. There is always some winter flooding in January and December but this New Year it was exceptional. Floods and storm events can often characterised by their frequency the last time the river rose this much was in perhaps 1998, making this a once-in-25-year flood event.

This therefore is the largest flood in the time that I have been managing my patch. Flood water before New Year had already brought down a holly-weakened Alder and flattened my northern fence. This time the extent was much worse. 

I haven't been able to check on Otter Cam there is no way I can get anywhere near its location and given the height, the river rose to I am fairly sure the camera is no more. It rose so far that even the main cam was interrupted, it stopped recording on the 2nd January when the deluge reached its peak. You can see how the river rose in the following time-lapse video below.



Main Camera location showing much of the top soil stripped off revealing the stony base and the debris left by the floodwater.

To put it in context the camera is located over 80 metres from the main river channel. To look at the situation in more detail I did a little analysis on QGIS starting with a Digital Elevation Model of the area. This shows the height of the terrain from sea-level in meters. I would have preferred a more fine-grained set of data, perhaps height in 25 centimeters but beggars can't be choosers.


My patch runs along the main river channel which I believe is deeper than is shown here. It was canalised and actually runs higher than the backwater shown. The backwater is I think the original river channel that was diverted to feed the mill. Normally flooding barely reaches the hedgeline where the Main Cam is. Otter Cam whilst closer to the backwater and river is actually on a tree at least 1.5 metres up, unfortunately I think the river rose more.

I used the DEM to create a profile across the river showing the normal water level and what looks like to be the height of the flood water on the 2nd January.

Patch Profile over 140m - Showing normal water height in the river (far left) and back water (centre). The hedgeline with the main camera is on the far right.


Estimated Flood Level - 140m cross section

So what does this mean for the wildlife? Well, it has thrown up one interesting fact. Normally the dominant rodent recorded on the camera is the Wood Mouse with the very rare sighting of a Field Vole. This is because the vole prefers more undergrowth than is present where the camera is, but when the water rose more voles were recorded as the water drove them from the vegetation and up the bankside.

Date

Number of Wood Mice Recorded

Number of Field Voles Recorded

28th December 2023

14

0

29th December 2023

29

3

30th December 2023

4

4

31st December 2023

4

0

1st January 2024

6

1

2nd January 2024

3

0


This devastation of my camera trapping will allow me to reassess how to move forward with the research and think about what cameras I will use and where. In some ways, this could prove costly but not as costly as it has been for the Saxon Mill pub. It was flooded out, something that has happened many times before but this time it was exceptional, you can see in the following photo how high the water rose by looking at the wet stone mark on the wall beside the entrance to the Riverside Bar.



 



Monday 1 January 2024

2023 - A patch round up

 So another year has been and gone, they are really starting to add up now. I started patch recording in 2002 and started getting good data in 2004. It means that I can start to see trends and patterns. 

I have so much data it takes time to process it all, it's taken me two days to process the Bird data from visits let alone my camera trail data. That project is on hold because Otter Cam is currently inaccessible due to flooding.

So how can I evaluate this year's recorded survey session on my patch, how about a series of numbers.

Number of Surveys: 49

Average length of survey: 77 minutes

Total time spent on the patch: 60.5 hours

In that time I recorded:

63 species of bird bringing my patch total to 93 species.

4 species of mammal

12 species of dragonfly

15 species of butterfly

Number of Bird Species each month

Number of Bird Species each year

Highlights this year are obviously the new species spotted namely Firecrest, Red Kite, and Great White Egret. 

Several species were not recorded at all but were relatively common:
Little Grebe (for the third year in a row)
Fieldfare
Kestrel ! once a breeding species
Mistle Thrush

Of course my Roe Deer have provided me with endless enjoyment

Roe Deer


 Grey Squirrel


Sadly foxes seems to have become scarcer and I no longer think the Badger sett is occupied but I will no more once I have analysed the trail camera data.

So 2023 was a mixed bag, with some gains and some losses. Over the next few months, I will dig into the data a little more to explore more of the trends, starting probably with the Little Grebe that used to overwinter here.


Sunday 10 December 2023

A Grey Squirrel thats a night owl?

 I am writing this blog post on a very wet Sunday afternoon. I have been lacking inspiration to post for a while now. No special creature has appeared no profound thought of ecological theory has struck. I have very much been struck in the rut of the change of seasons, the summer visitors have gone, and the winter ones seem not to be bothering to come at all this year. Last week the temperature did take somewhat of a dive, and this resulted in the return of the Marsh Tits to my patch, a small flock of Teal, a nice view of some Goosander, and a very fleeting view of an accidentally flushed Woodcock.

This past week the cold has evaporated to be replaced by rain, torrential downpours. Facebook happily reminded me that 6 years ago today we were under 6 inches of snow what a difference. I did see my first Redwings of the year, just three not the hundreds one would expect. From this introduction, you may assume that I am going to wax lyrical about climate change and the shifting of the season, but I feel I have done a lot of that already and I would imagine that most of my readers are not climate deniers. Instead, what piqued my interest were a few still shots from my main camera trap.

This particular camera trap has been situated in the same hedgerow recording 24/7 since 2015. This is my magnum opus, my long-term contribution to wildlife, and in particular mammal recording. My usual focus is on the Badgers, the local clan is seen less and less (I am very worried about them at present), but more recently the Roe Deer family and Otters have drawn my focus more. What has intrigued me most this week however is the ubiquitous Grey Squirrel.

Laying aside the obvious debate concerning its status as an invasive species, the demonic species that has devastated the native Red Squirrel, even though it is just doing its thing…survival, what drew my attention was some interesting behaviour.

It is easy to watch wildlife and become focused on the individual, websites, and books are filled with portraitures of birds and animals, and whilst delightful, I think I find the behaviour to be extra interesting. We are now into December and like I said we have had a cold snap now followed by rain. On the trail camera, I caught a few stills of a Grey Squirrel collecting leaves, it was noteworthy enough to add it… well to the notes section of my records.


Consistently for approximately an hour on the 28th of November in the early afternoon, a squirrel could be seen collecting beech leaves and taking them up the tree. This continued across the 7th, 8th and 9th of December despite the rain. This is obviously evidence that the individual is either building or remodelling its drey.

Squirrels live in dreys, collections of leaves and twigs sometimes lined with grass and moss. They are not a species that hibernate, and, in the winter, it provides, a warm refuge to retreat to between foraging expeditions. Dreys are built in the crook or v of branches in trees 2-20 metres off the ground, they appear roundish and nest-like, in fact, they can be confused with magpie nests although magpies are much messier.

Photo care of Rosser1954 on Wikimedia Commons CC-3.0 Grey Squirrel Drey.jpg

What interested me however was the timing of this event. I understand building it now, the weather has turned and the squirrel needs to shore up its existing drey or repair its old one if conditions are likely to worsen but this squirrel seems to be in quite a hurry often working in the night!


Squirrels are pretty much diurnal perhaps more active at dawn and dusk. Previous analysis of activity has indicated a rather broad daytime activity pattern on my patch. An aggregated count from 2015-2019 indicates activity occurring between 7 am and just past 5 pm so it surprised me to record the squirrel actively collecting leaves at 2.18 am, 5.40 am, 9.40 pm and 10.29 pm.



2.19 am and still collecting leaves!

A quick internet search suggests that squirrels are not nocturnal however I am one who on the whole eschews the internet as the font of all knowledge and so have fallen back on my books. My go-to bible in these situations is Harris and Yalden’s Mammals of the British Isles: Handbook, 4th Edition.

The Grey Squirrel account is written by J. Gurnell, R.E. Kenward, H. Pepper and P.W.W. Lurz and only has a paragraph on activity in which it states that they are less arboreal than Red Squirrels. Of note is a section on communication and senses. Seeing the squirrel in the dark I was concerned for its safety. It is predated by stoats, buzzards, and foxes. I have seen a vixen carrying a squirrel back to its litter, given that its usual life strategy is based on daytime activity just how vulnerable was this squirrel? The answer it appears is very, the book details the structure of the eye drawing the conclusion that the species can see in up to dim-light so fully nocturnal activity is very risky. Admittedly they have excellent hearing but their agility on the ground and up trees is based very much on vision.


I then considered the effect of the moon; a full moon could give enough light for the squirrel however from the 7th-9th of December the moon was a waning crescent with only 24% illumination on the 7th falling to just 10% on the 9th.

I will not get a definitive answer to this conundrum, nature does what nature does and most certainly does not follow the rules of the textbook. I considered that the individual could be pregnant and was forced to build/improve the drey for that, and births have been recorded right up until the end of November. Perhaps the mild spell allowed for a late pregnancy, but this is very much on the edge.

Animal behaviour is very much a cost/benefit game, and this squirrel obviously felt the need to put itself at risk and it would not do this if not for gain, unless this is one of those individuals that shape evolution, either making a mistake that inevitably leads to its predation and the end of its gene line or the pioneer that stakes out a new niche for all its kind.

It are these puzzles that make ecology such a fascinating topic to study.