Saturday, 20 October 2018

Muntjacs abound

Whilst being a non-native deer species there is something endearing about this diminutive mammal. Small as a large dog these these oriental deer are widespread in the UK and a common sight on my trail cam.

They use the hedgerow as a dispersal conduit and can occasionally be seen foraging, in fact this past few weeks has seen a fair bit of activity of this species.

This first clip shows two interesting pieces of behaviour, it starts with the male becoming aware of something and then stamping his leg. This is an aggressive posture which he follows up with a bark like call. This continued for 13 minutes, I suspect it was a rival or perhaps more likely the Fox cub, the fox would register as a predator but its size and the size of the deer would not have meant the deer was under threat. The muntjac was just asserting himself, hes big and aggressive so leave me alone.

This week I actually got some views of a muntjac fawn. I saw a picture, as seen below that looked like a scene of family bliss -

You can see two adults and a tiny fawn perhaps only a week old, in fact the male pictured is not the father. Muntjac are able to breed all year round and the male has detected that the female is no receptive once more to mating. Video reveal him pursuing the female, smelling closely for receptiveness, this attention has spooked the fawn who dashes about in panic.

We next see the fawn and mother thankfully undisturbed again this morning.

Sunday, 16 September 2018

This weeks star - the Roe Deer

As you are aware the loss of the bridge has meant that I have only just been able to collect my camera and when I did I had over 2000 clips to analyse! I have finally finished ploughing through them and collating the information and I hope to be able to give you some insights in the next few posts especially regarding the presence of a Fox cub.

Today, however, I want to share with you several photos captured this week. They were taken at 11.10 am on the 11th September and show a young Roe Deer.

You can tell this is a young Roe Deer rather than a Muntjac for several reasons. Firstly the head lacks any of the correct markings, secondly, fur is of a different texture and colour. The muntjac has a more orangey colour and is smoother looking, in this case, the fur is coarser. Thirdly you can look at the ears, here the ears are more pointed and more upright whereas muntjac ears are rounder and stick out more from the side. Muntjacs are also shorter legged than this individual, lastly, there are diagnostic black spots on the rear legs.

It is also possible to tell that this is a young deer from its general appearance, the coat looks fresh but lighter than one would get in an adult, it is also possible to see faint white marks on the hin quarters when as a fawn it would have had spots. Last is the eye, juveniles generally have larger eyes in relation to their bodies, this is true for humans too. Eyes are proportionately larger at birth and it takes some time for an animal to 'grow into them'.

Sunday, 19 August 2018

Confessions of a Photographer

The post title says Confessions of a Photographer but I wouldn't really call myself a photographer. I am someone who dabbles in Wildlife Photography, I have taken some, in my opinion, good photos and photography is most definitely a hobby for me.

I enjoy being immersed in wildlife and I like the long-term value a nice picture of a wildlife experience can give you. That is why many of my blurry pictures of rare animals and birds can mean so much to me. They are by no means technical masterpieces but the capture a viewing.

I do of course try and take good photos and sometimes that takes a little work. Many professional photographers stage their work, and for me, that usually only involves removing stray twigs from eye line or where I hide. I am averse to heavy photoshop editing and will only ever crop, play with the light levels and perhaps do a little sharpening to an image.

In this particular case, I decided to make use of the fact that we are regularly getting Wood Mice visiting the garden to get a nice shot of a mouse. That nice shot is the one shown above. However, to achieve this shot I experimented with some staging.

At the moment the mice visit the bird table which isn't especially natural looking in aesthetic. So instead I built a stage. I used some wood to create a bridge between the table and the hedge and covered in natural material, moss, twigs, bark and brambles. I then baited this and waited for the mice to use it.

It took a little while for the mice to get used to the new bridge but pretty soon one ventured on and I got the shots. The two shots at the head of the post are the results, but even that still took time, I still had to compose correctly and focus right. Even now the focus of those pictures is a little out.

I make this post as a kind of warning of the shots you might see out there. People with more talent and time can create all manner of wonderful images with each tweak you lose a little of the naturalness and wonder. Some amazing photos are heavily photoshopped or even used stuffed animals. Of course, not all do this but it's important to be aware of the facts, modern technology has made photography achievable by all but it has also raised the possibility of erasing its veracity.

I am content with my limits, I want to see my subjects as natural as possible, I want to leave the animals with the option to take part, the ability to leave at any minute or to not even to show up. I also respect their right to peace and quiet. In this case, I waited only 20 minutes so as not to disturb them and to allow them to forage happily once I had a few shots in the can.

This was a fun experiment but do not expect me to roll out this for all shots, nature is best seen in its raw form.

Sunday, 5 August 2018

The 6th Mass Extinction

In the week of the 28th July, the New Scientist ran a very interesting article on whether life on Earth is really in crisis. It was called ‘Life on the Brink’ and explored why biodiversity is important and if we are currently in a sixth mass extinction event.

The previous five mass extinctions stretch back 439 million years and it is worth considering each of these to consider the current status. We have fairly good data on previous extinctions in the fossil record. Marine invertebrate are particularly sensitive to extinction level changes and are consistent in the fossil record and so make for a good benchmark on which to measure changes.
The first mass extinction was the Ordovician-Silurian one peak occurring at the end of the Ordovician period and another in the Silurian. It was typified by the massive reduction in sea creatures such as Trilobites, Brachiopods and Graptolites. A reduction of about 85% of all species was thought to have occurred.
The Devonian extinction occurred 367 million years ago in the late Devonian period with 83% of species going extinct. It saw the loss of the armoured fish and the agnathan’s with them being replaced by modern fish.

The late-Permian mass extinction came in 245 million years ago and saw 96% of all species die out. It took place during a time of great continental upheaval. From this, the basal tetrapods were replaced by the Amniotes and allowed seed-bearing plants to become dominant over mosses, ferns and liverworts.

208 million years ago an increase in seismic activity led to extreme volcanic eruptions that had global effects on climate resulting in what we call the Triassic-Jurassic Mass Extinction. This series of extinction events over 18 million years resulted in 80% of all species dying out and led to the diversification of dinosaurs.

The final, most famous and most recent of the big five mass extinctions occurred 65 million years ago called the Cretaceous-Tertiary or K/T event that saw the end of the dinosaurs and pterosaurs along with a total of 76% species going extinct. The winners of this event were us, the mammals that diversified and proliferated greatly.

This brief history of extinction brings us to now and claims that we are living in the sixth extinction event. Extinction is a perfectly normal part of life evolution on earth. It happens regularly even outside of the main events this natural extinction rate is the background rate. It is calculated that if there are 10 million species and the average lifespan of a species is -10 million years then the extinction rate would be about 1 or 2 species every year.  During Mass Extinctions this rate is much higher, to put this in perspective with a high background extinction rate we would expect to see an extinction level in mammals of less than 1 species over 400 years but in fact we are saw 69 species going extinct. This is a strong indicator of mass extinction. Work by Jose Montoya states that the extinction rate is currently 1000x that of the background rate with many more species on the brink.

The problem with measuring extinction is that we do not have an accurate number for the total number of species on the planet, there are 91,000 on the IUCN list but this is a tiny proportion of all species extant on Earth. It is likely that 100’s of species have gone extinct before they have been recorded by science. We are all aware species number and population sizes on the whole are falling, although some species are bucking the trend, these will be the survivors of the extinction level event. A key issue in resolving the debate is the lack of data. Vertebrate taxa are pretty well documented but invertebrates, with the possible exception of the molluscs, is less well documented.

We lack rigid and robust data upon which to tie our theories and this is making it harder to push the agenda. Anecdotal evidence is abound to the reduction in insect splats of car windows in our youth to the lower numbers of butterflies seen. Work is ongoing but progress is slow, should funds be spent on studying the decline or working to combat it?

Perhaps the scariest thought is the cause of the extinction, most scientists agree it is happening, but instead of in previous causes, the cause was a meteor, major climatic change or volcanic eruption this extinction seems to be on us. The extinction rate seemed to accelerate from 1500 as the human population increased in number and spread across the whole planet. Many species have been hunted to extinction and with global warming altering the natural climatic cycle it is likely that many more will follow suit as the rate of evolution cannot keep pace with the selection pressures we are putting on species.

Don’t get me wrong, I m not trying to be all doom and gloom. Life on earth will go on. There will be survivors from the extinction event like last time, and in previous extinction events, recovery tales between 10 and 100 million years as the survivors radiate into all the newly vacated niches. The question is will human be one of the species to survive? The answer is probably yes, we are a resourceful and adaptable species but do we want to have the distinction of being the first species to extinguish the life of others? Given that the Dinosaurs thrived for millions of years it is not an auspicious start to a species as young as ours.

Sunday, 22 July 2018

Of mice and... moths!

This week our garden bird feeder was visited by some new visitors. I was sat out in the garden hoping to try out my new EchoMeter Touch 2 Bat Detector (review to follow) when I could hear something on one of the bird feeders on the pergola. Taking a closer look I saw a little Wood Mouse. He was joined later by two more.

Since their first sighting they have returned each night and last night was joined by another two that were visiting the bird table.

With the warm weather and a fully charged battery I have been making good use of my moth traps and this weekend got a manageable haul. I m still learning the species and so I do not want too many to overwhelm my ID skills.

I have reached about 50 individual species so far. I plan to do a full exploration of 'mothing' but for now here are some of what I have found.

Dark Arches

Scalloped Oak

A noctuid moth popping out to say hi

Sunday, 15 July 2018

Heat Wave and Birds
Unless you have been living under a rock for the past month you will be abundantly aware of the heat-wave Britain is currently experiencing. Normally I am writing about long winters or prolonged snow but warm weather can be as disruptive.

Birds lack sweat glands and so are unable to sweat to lower their temperature, instead, they must cool their body temperature via respiratory regulation and use behavioural changes. A bird’s natural body temperature is naturally higher than a mammal, between 37.7-43.50C.

If the temperature of the air exceeds 380C (which thankfully it isn’t in this heatwave) then birds actually undergo extreme stress which actually increases the body temperature until it dies. So to avoid this, birds undertake 3 cooling methods.

1.       Non-evaporative cooling – by raising feathers and spreading them out air is allowed to flow over the skin and cool the bird.

2.       Cutaneous cooling – as well as wind cooling the skin, can be cooled by water evaporating, due to the lack of sweat this is a lot slower but can be improved if the bird baths.

3.       Respiratory evaporative heat loss – This is seen as panting and many species of bird do this. By flushing their throat tissue with blood their allow heat to dissipate.

Birds will take behavioural changes such as seeking shade or sitting with their back to the sun, their feathers raised.

It is just as important in the summer to keep feeding the birds. Energy is needed to thermoregulate and sometimes heat waves cause scarcity of local resources. It is important to provide water baths and troughs for them to drink from, ponds are especially valuable. 

Sunday, 1 July 2018

The Humble Sparrow

Now a declining species in many parts of the UK Warwick is blessed with a decent sized population of the once ubiquitous House Sparrow (Passer domesticus). Many disregard this common bird as drab and boring but I find them charismatic and fascinating.

Their ever-present cheerful cheeps and squabbles fill our gardens all year long and this year I took a closer look when I began to notice a higher than usual incidence of mating.
Male Sparrow (c) M. Smith

 I first did a deep dive on the House Sparrow in 2012 when I was looking at comparing sparrow numbers in two different housing estates. I was looking to see if numbers were different between two adjacent estates, one built in the 1950’s and one in the 2000’s. My dataset was poor and the results were inconclusive, however, it did mean I read a lot about this bird.

The sparrow evolved in the Fertile Crescent (modern day Iraq and Iran) some 10,000 years ago. It spread widely with populations now found across the western Palearctic. In Britain, there is an estimated population of between 2,600,000 and 4,600,000 individuals which is believed to be an underestimate. This may seem a huge number but this is following a 45% decline in numbers between 1967 and 1999.

Female and Male Sparrow (c) M. Smith

Sparrows are mainly granivorous birds, only feeding their week-old young insects. This led the species being linked to agriculture and small villages where they nested in buildings. During the 19th century, the species was having such an effect on crops that local Sparrow Clubs were set up in every parish in an attempt to eradicate them.

Declines in the cities seemed to be linked initially to the disappearance of the horse but later was more closely linked to the types of building and housing. In natural habitats, House Sparrows are gregarious colony breeders, building nests in caves or old trees. Early housing with poor roofing provided excellent artificial nest sites. Pre-1919 buildings have been found to be favoured the most but with the advent of plastic fascias and smaller gardens, suitable nest sites have been declining since the 1960’s and markedly more so since the 1980’s.

Sparrows keep in good condition by dust bathing, here on the canal towpath. (c) M. Smith
The sparrow has become dependent on mankind and its dwindling numbers are caused by an increase in pesticides reducing chick food, herbicides reducing adult food, haymaking occurring prior to seed set, reduced spillage of grain and better storage of grain and an increase in predators like Sparrowhawks and cats. In fact, studies on cat predation have shown that 28% of prey taken by cats were sparrows. Squirrels are also frequent nest raiders and will often chew through nest boxes to get the nestlings.

Breeding takes part from February onwards with as many as 4 broods a year possible. Unlike their distant cousin, the Dunnock (Hedge Sparrow) House Sparrows are mate faithful. Nest are built in holes in buildings or trees. Dominance in males is marked by the breadth of the black bib and chest and mating can be solicited by both the male and the female. I have seen this, this year. Early in the season, I watched a male pester a female for 20 minutes. Calling intently and flitting closer and closer until the female relented and yet weeks later I watched another female on the fence actively encouraging to mate. In both cases coupling was quick but repeated, I counted 8 copulation with a 3 minute period.

The act (c) M.Smith

Clutch sizes tend to be between 3 and 5 eggs which are incubated for 11-14 days with an 11-19 fledging period. Young birds emerge all looking very similar to the female with males developing their characteristic caps later in the season. The young birds continue to be supported by their parents for awhile and beg for food by rapidly flapping their wings and calling. Eventually these young will join packs of other fledgelings and adults in small flocks that squabble together loudly.

Two fledgelings being fed by an adult male (c) M. Smith