Avian behaviour heads and shoulders above bird list/'Energy Balance Sheet' outweighs anthropomorphic ideals......

 

A grey day (28th), with showers of rain persistent throughout the day did not promise much and looking through the list of sightings for the day, there was not anything that really stood out.  However, a list does not necessarily tell the whole story and represent the content of what was observed and today, the trip along the North Norfolk coast with Jason Nichols was a point in case!

There was no sign of the reported Iceland Gull at East Runton, but a Fulmar was good to see albeit briefly, as was a Cormorant attempting to consume a large fish, which at distance gave the impression of a flatfish species, but the shape of the fish on closer inspection (via some blurred magnified images) suggested something resembling a Sea Bass.

With not too much activity at the pond at Walsey Hills, a drive along Beach Road, Cley followed but just a lone Golden Plover bathing on the pool, Starlings and an Oystercatcher searching for food were noteworthy.

A look in the creeks and channels at Morston found a Greenshank, some very active Oystercatchers, constantly flying back and forth along the channel, several Common Redshank and a now depleted number of Dark-bellied Brent Geese.

Brancaster Staithe was eventful for two completely different reasons, or were they completely different?!

At least 30 Black-tailed Godwits were present, far more than seen in previous weeks here and these were constantly probing the mud with partially open bills, successfully finding and consuming what appeared to be small marine snails, which on occasions when there was too much mud attached to the prey, were washed in very small puddles of water.  

This washing of the prey before consuming by both species of Godwits (Black-tailed and Bar-tailed) has been seen many times before, especially here at the staithe.

The transfer of energy during these feeding processes is paramount for staying alive, in organisms that have to constantly search and find their own food if a local Tesco (or similar)  is not available, which basically rules out every other organism, except us, Homo sapiens (at least ‘Western Homo sapiens’!).  E/H values (Energy divided by Handling time) and Optimal Foraging Theory (basically, the process of choosing the highest calorific-gain food item, with respect to the effort made to capture and consume it) are ecological terms appropriated to these feeding processes alone; mating behaviour, holding territory, preening, bathing, heat-loss etc etc all have to be included in the ‘energy balance sheet’.

So, when you get the car stuck in this highly adhesive glutinous anaerobic mud (as my good friend Jason managed to do!) trying to walk around in this ‘odious mud soup’ in order to try and free the vehicle from its mud imprisonment should make you (if you have not already observed the drag on wader’s feet and legs as they search for prey) very quickly aware of the effort required to make your way through this sticky cocktail.  

So, based on the evidence presented thus far, do you think placing any objects on these animals (e.g. metal rings, plastic rings etc) helps them survive and keep the ‘energy balance sheet’ somewhere near neutral?  Any extra weight, however slight has an effect on performance and energy return (don’t be fooled by the BTO’s anthropomorphic claim on their website that a metal ring is the same as humans wearing a wrist watch), as does any extra mass in terms of basic physics, e.g. drag.

Further observations of birds feeding strategies observed here were also fascinating and to which the aforementioned applies.  

A Curlew was hunting by wading in the channel (as Jason described it ‘almost egret-like’) but the strategy here was not the usual probing with the long curved bill, based on feel, but hunting via sight and then moving in to capture the prey.  On two occasions the Curlew was seen to capture marine worms (presumably Blow Lugworm), which compared to its bill length were quite substantial and probably a good energy (E/H) return.

What the evidence for the presence of prey, below the water was that the Curlew was seeing is not something exactly determinable, but watching the methods and strategies animals use to hunt their energy values and in turn revealing (sometimes) what the ‘prey animal’ is that is also present in that environment is something I never tire of observing and trying to capture via photographic equipment.