Sunday, 28 January 2018

Oh no the bridge is gone, but I'll still carry on

With the recent storms, a large quantity of debris including some pretty large Alder trunks have come down the river and collected at the bridge over the Avon as the Saxon Mill. So strong was the flood water that the stone support of the bridge has been broken. For safety, it has been closed meaning that my easy access to my patch has been changed to a much longer route. This means that I will be visiting my patch less often.

With the good weather today I got on my bike and ventured around and checked my camera. As I entered my patch I flushed a Woodcock (Scolopax rusticila) that lazily flew deeper into the bit of woodland. This was a portent of what was to come.

Thankfully my camera, at its new secret location, worked well and I got some great shots of Wood Mice, Badgers, Brown Rats, Magpies, Squirrels and Jays.The shots are so much better that I think I may be able to create a database of Badger faces and attempt to identify individuals.

Most excitingly was some footage of the Woodcock foraging for food.

Woodcock are secretive and well-camouflaged birds. I have never seen one on the ground stationary. I have always flushed them by accident, not knowing they were there or seen them flying at dusk. They have broad rounded wings that are very distinctive, forming deep beats as the bird flies.

In the clip you can see the Woodcock foraging. It uses its long straight beak to probe the leaf litter and soil for insects. They have very sensitive beak tips,

Mainly crepuscular (active at dawn and dusk) they lie up during the day using their cryptic plumage to hide away from predators unless disturbed like I did when they quickly take flight. 

On a separate note, I have now begun to analyse the data from my hedgerow camera study and will be filtering in results as and when I make them. 

Sunday, 7 January 2018

A winter visitor

After the rain and snow of late, a cold spell is now upon us and it has brought in an unusual and welcome bird to our garden - a pair of Brambling (Fringilla montifringilla).

I haven't seen a Brambling in years and even then it was a very fleeting glance, this time I got excellent views and time to photograph. Easily mistaken for a Chaffinch at a quick glance, this stunning little bird has so much more going on.

Diagnostically key is the black tipped yellow beak. A lovely peachy-red upper chest is complemented with the wing bars and primaries. Like many finches, there are hints of gold in the flight feathers.
The underside is white/buff with neat rows of black specks. On the back, an obvious white stripe down the back and the black and white shading at the neck are also diagnostic.

They are charming birds and in the cold had fluffed themselves up on occasion to look like round pop poms of feathers with little beaks sticking out.

Common in large flocks many Bramblings come to this country from northern Scandinavia in the winter. They breed in the birch forests of Norway and Sweden.

Most often recorded in gardens in March there are peaks in the years they appear. Previous good years for Brambling were 2008, 2011 and 2013. They are more commonly seen in flocks often with other ground feeding finches such as Chaffinch feeding on Beech Mast although checks on my patch around the beech trees revealed none.

Friday, 5 January 2018

A tasty treat

Following the theft of my trail camera in November I have been forced to call to a close my long-term monitoring project on the birds and mammals using a hedgerow. Although this has saddened me, I was hoping to amass 5 years of data, 3 and a half will have to do.

I now have a new camera with greater security and stronger fixings/locks and a new more discreet location to use. I have decided in this case I will still operate on an ongoing 24/7 basis recording where possible but this time I will bait the camera to see what species are attracted. This is something I have been wanting to do for awhile but would have skewed the data with the old survey.

I started running the project over New Year and have already started getting footage of Wood Mice, Brown Rats, Foxes, Grey Squirrels and Badgers. My first bait attempt was two Ham Bones bought from the supermarket designed for dogs.

Magpie picking at the bone

Brown Rat passing by

A Wood Mouse on the bone, tiny compared to the rat!
The most interested in the bones were the Magpies that spent a lot of time picking at them. Interestingly Wood Mice and Grey Squirrels were both recorded feeding on them.

Unusually the Foxes seemed interested but didn't partake this was due to their unfamiliarity of the setup. They are clever creatures and were well aware of the camera and were spooked enough by its presence to avoid it.

Lastly and most excitingly are the Badgers and boy are they showing evidence of behaviour, first of all, they solved the problem of continually visiting the bone - just take it with you.

Secondly, I manage to get two 10 sec clips which have been put together to show a badger foraging. You can see how it snuffles through the leaf litter using its powerful sense of smell to root out food. Given the large amount of rain and the nearby flooding it's no surprise that worms were abundant, The clip shows that the badger gets the scent of the worm and then dives in. The earthworm makes a bid for freedom trying to burrow away however once the worm is in the badger's jaws it expertly pulls it out and devours it.

Wednesday, 27 December 2017

Pecking order

Amidst the slushy snow that arrived overnight the birds in my garden struggled against the cold. Whilst I ate my breakfast I watched with interest as each species behaved differently. Sometimes it is just be watching the commonest of birds the most interesting things can be observed.

Here then is a photo essay of the birds in my garden this morning (Apologies for the picture quality but it was cold and so most pictures were taken through the patio window!).

The first bird I saw was the Pied Wagtail. We only ever see the wagtail in the winter months. We can get up to two at a time but never more, unlike the town centre which can get small flocks of between 20 and 30 that all roost together. For such a small and seemingly cheerful bird, it was interesting to note that today he was near the top of the pecking order. Usually placid and cautious he guarded the ground feeder where the seeds were zealously seeing off Blue Tits, Sparrows and even the Robins.

The usually feisty Robin would normally be chasing the smaller birds off however a second Robin seemed to take all its attention. Robins are well known for their aggression between each other. Even in this cold weather, they had made the decision that it was more important to defend territory and then feed itself. This shows some measure of long-term planning, its energy levels were high enough that the pay off in the long run of having access to a stable food source was more important than the short term food gain and the possible loss of the food in the future.

Here you can see the Robin in an aggressive pose with tail up low beak and wings out.

Also on a territorial defence footing were the Blackbirds, at this time of year there is a large influx of Blackbirds from the continent. Our native birds are joined by individuals from Scandinavia, the Low Countries and Germany.
Whereas the Robins fought consistently the Blackbirds were able to tolerate each other's presence a little more only chasing each other off if they got too close to each other.

The usual bully boys, the Feral Pigeons, Starlings and Woodpigeons all relaxed their aggressive behaviour and focused instead on feeding. They have large bodies more insulated from the weather but have strong flight muscles that need refuelling, in this case, they opted to eat rather than chasing off competitors of other species.

The ubiquitous House Sparrows seemed to behave no different than normal. They whizzed around like a mix of a squadron of fighter jets and a horde of excited children. Chattering and squabbling and diving into feed whenever a feeder was free. The picture below shows a male with his feathers plumped up against the cold. Birds do this to trap a layer of air next to the skin that creates effective insulation against the cold.

The Hedge Sparrow or Dunnock likewise did not change behaviour, skulking around the edges bothering no one and being bothered by no one.

The last two species to mention are two rare visitors to the garden, both with different strategies, the Goldcrest and the Blackcap. Both are warblers although the Blackcap is considered more of a spring/summer bird.

The Goldcrest is a specialist of conifers and is tiny in comparison to the other birds. It remained cautiously in the leylandi darting quickly from branch to branch. Their small size means they have a high metabolism and must feed nearly constantly to ensure they can survive each night. They have dainty beaks that they use to hunt out hibernating insects and spiders in the branches.

Like the Goldcrest the Blackcap is insectivorous. It can usually be seen hunting green caterpillars in the spring, but insects are scarce in the winter. Like many warblers, Blackcaps are actually migratory and spend the winter in the Mediterranean or North Africa however they are many that have started to overwinter in the UK. Some might not be British birds but individuals moving south from Scandinavia. Like many birds they can change their diet, Sparrows feed their young insects but feed mainly on seed themselves whilst in this cold spell the Blackcap could be seen pecking at peanuts and taking seed from the grounder. Seeds are excellent food in this weather, containing important energy stores like fats and oils. Its is because of well stocked gardens that this usually summer only visior can now stay all year round.

These were not the only birds to visit today, Blue Tits, Great Tits, Chaffinch and Goldfinch all entered into the web of politics which is the English garden, vying for space and food.

What is on exhibition here is a model called Optimum Foraging Theory, something I studied in detail at University. It dictates the optimum time to feed, how long to feed and what to feed on, It guides organisms by causing them to evaluate costs and benefits of their actions. What is interesting is that their motives may seem strange to us, perhaps nonsensical but survival is the name of the game and each has adapted itself to ensure it lives to see another day.

Tuesday, 26 December 2017

My patch - a year review

Another 12 months has passed on my patch making it now 15 years since I first started making records. The Saxon Mill never ceases to amaze me. Each year new species are discovered and new pieces of interesting behaviour recorded. There is still so much I do not know.
I know for instance that my hour-long counts each week are but the tip of the iceberg. What resident species have I yet to record? Where are many of my resident's nesting?

This year I recorded 58 species of bird in my small patch over 53 approx 1hr-1hr 30min visits, 4 species of mammal, 9 species of dragonfly and 14 species of butterfly.

Interesting sightings this year include the first sighting of a Little Egret in April and a Sedge Warbler in May.

The counts of Banded Demoiselles were huge this year, 612 (208 in 2016).

So whats in store for 2018... well in terms of wildlife, who knows - the sky is the limit, but I do have some targets.

- I plan to start a new trail cam experiment using baited camera traps.
- Find more nests
- Focus a little more on insects like moths

Either way its going to be fun.

Sunday, 24 December 2017

Whose been eating my birds?

The natural world is something I find incredibly relaxing and fascinating and sometimes it is easy to forget that although I get great solace in watching birds and animals they themselves are focused on eating to survive and avoiding getting eaten themselves.

One should avoid becoming oversensitive to the 'cruelty' of nature. In fact, cruelty is the wrong word, a fox isn't cruel catching a rabbit to eat. Cruelty should be replaced by reality. Predator/Prey relations are fascinating things, they are one of the prime movers in the evolution of species and the dynamics involved create amazing adaptations and behaviours.

Occasionally on my patch, I encounter a dead animal. It is surprisingly rare. This is because nature has the best recyclers in the world. If an individual isn't devoured in its entirety then a host of scavengers and decomposition can cause any carcass to disappear in an amazingly short time.

Today I found the remains of a black-headed gull. There seagulls frequent the fields in the winter sometimes in quite large flocks especially directly after the fields are ploughed. In December a few birds still visit the fields and it is one of those that succumbed to predation.

Nearly all the 'meat' had been removed by the time I found the bird lying in grassland adjacent to the crop field. Many of the feathers had been removed but there did not seem to be any wings present. Many experts are able to identify the predator from such remains and I am going to have a stab at exploring this myself.

The crime scene consisted of a single adult gull. Both wings and all primaries were missing. Both legs and skull were intact. It was surrounded by a mass of feathers including down and secondaries.
Each feather seemed to have been plucked rather than bitten. Most mammals bite through the feathers when getting to the flesh whilst birds like the sparrowhawk pluck them out, leaving the shaft of the feather intact.

The key suspects are Fox, Buzzard, Sparrowhawk, Peregrine, Kestrel. Let's examine each in turn.
The intact feathers and the fact that a fox would find it difficult to sneak up on a gull in the field seems to rule it out although as much a scavenger as a predator it could have moved the carcass.

Buzzards certainly have a wide and varied diet but are they agile enough to catch a gull? No, although an injured or sick one would definitely be fair game. Kestrels I think would be too small. They are fast and agile but suspect they wouldn't have the strength to take one down.

This leaves us with both a Peregrine or a Sparrowhawk. Both are viable candidates and occur on my patch. Of the two the Sparrowhawk is more likely as they are much more common on the site. They are ambush predators and could easily take a gull. Peregrines likewise have speed and strength on their side able to dive down and snatch birds from the sky.

Without forensics or witnesses to question I will never know the truth but I can narrow the field to these two raptors, both impressive predators in their own rights. The gull's gloomy end may well be bad for the gull but it means that the predator and all the decomposers can live on. In the words of Elton John - Its the circle of life.

Sunday, 17 December 2017

A dinosaur at the mill

Today in amongst the remains of the snow and approaching rain I made my usual patch visit. I was pleased to run into the Tit Flock, containing some goldcrest. The cold weather had no doubt brought them out from their solitary life in amongst the yews in search of wood. Safety is always greater in a flock and so they had joined the Great Tits, Blue Tits and Coal Tits flitting around the bridge.

Now the vegetation has died back it is once more easier to walk directly beside the river and it was here at the far end of the site that I came across a young cormorant perched above the water.

You can tell it is a juvenile because the front plumage is still so white.It will lose all these white feathers by its 2nd winter. The Cormorant is often seen as a coastal bird and indeed that is its primary habitat. In recent decades, however, the abundance of fish in rivers and lakes has resulted in many of them making inland regions their home.They can often be seen nesting alongside Herons. I have seen Cormorant fishing on the Avon before and know they frequent Brandon Marsh, Coombe Abbey and Draycote Water.

One of the interesting facts about cormorants is that their feathers are not waterproof. This is an amazing thing given their preference for fish. It is why after fishing you will often see them sitting with their wings out drying off.

I have always liked cormorants there is something primitive and ancient about them. If ever a bird looked like its dinosaur ancestors then cormorants do. It is something about the cold blue eye above the patch of yellow skin and hooked beak.

Cormorants are in the family, Phalacrocoracidae and closely related to Pelicans. They have a long lineage. They first appear in almost the same morphology in the fossil record as a species called Gansus yumenensis. It was found in sediments in China from the Early Cretaceous some 120 million years ago. A time in which they shared with dinosaurs like Iguanadons, Compsognathus and Utahraptor. The modern cormorant like the one pictured here was first in evidence during the late Paleogene 66 million years ago. 

The hooked bill helps catch and hold the fish and the feet are placed right at the back of the bird that makes movement on land awkward but makes them powerful and agile swimmers. They are a successful species able to live across much of the globe. It is always a treat to see one so far from the cliffs of the coast.