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.


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