Tuesday 29 July 2014

Sunning birds



Male Blackbird gets down and out (c.OOS)

Not surprisingly, given the great warm weather of the past month, I've noticed a few incidences of garden bird behaviour that involves individuals suddenly adopting strange positions around the garden.  Though at first sight, it might look like the bird is in trouble and the heat has got to it and they have literally flipped, the accepted theory is that deliberate posturing to attract the heat of the sun, is a tactic to enhance feather maintenance.

Blackbirds are often caught sunning: either flat out as above with both wings spread and the tail flat out, together with a glazed look and open bill, panting, or keeled over to one side with tail and one wing fanned to the suns rays.  Panting relieves excess heat.

 I was lucky to see a juvenile Robin adopt similar postures, in the same part of the garden: it looked for all the world like a flattened, crumpled up leaf.

A juvenile Robin does its fallen leaf impression (c.OOS)

The birds must take a risk with predators when adopting this behaviour, as they are  slightly dazed looking, though it is clearly worth the risk

The sunning behaviour serves to maintain the flight feathers of the birds and  may also play a role in activating preen oil.  This in turn leads to a dispersal of ectoparasites that are hard to reach with the bill in normal circumstances.. I always said it.. you cant beat a good scratch, or in this case, a good oiling in the sun, high factor of course!

Same bird sits up, panting (c.OOS)

Thursday 17 July 2014

Starlings, pollen and Phormiums

Juvenile Starling ( c. Dick Coombes)
There's lots of interest from members of the public in exotic looking birds sporting a luminous orange head: apart from the flame coloured crown, the birds are fairly drab, greyish or beige in colour without any other distinctive markings evident.

They are of course, young Starlings, the most recently fledged birds are the plainest, later on in the summer the lines of pale spots on dark ribbons of plumage brings the birds closer to the more familiar autumn/winter plumage.

Starlings beak is well suited to accessing the long flower tube (c. Dick Coombes)
The exotic looking orange head and crown on starlings is a residue of pollen, picked up by the birds in the course of foraging for nectar from the Phormium or New Zealand Flax as it is also known.  The plant has tough, leathery, sword shaped leaves which can grow to 3 meters long, though cultivars of Phormium tenax are neater and sport a range of leaf colour combinations.  The rigid flower stalks can add up to 5 meters on the height of a plant.  The tube like flowers are bright red and produce large  quantities of nectar to attract birds such as starlings ,whose beak seems to be ideal in shape and length for accessing the flowers.

(c. Dick Coombes)
As well as Starlings, House Sparrows are known to visit the plants, I wonder have you noticed any more species availing of this source of food? 

Special thanks to my colleague, Dick Coombes, who photographed these birds on the North Wexford coast recently.

Thursday 3 July 2014

Subsidies for Seed Eaters



Ken Thompson, writing recently in the Daily Telegraph, cited some very interesting data concerning urban birds and differences in garden bird populations across the bird families.

Why, for instance, do Finches frequent bird feeders more readily than say buntings ( Yellowhammers and Reed Buntings) ?


Yellowhammer: an increasingly scarce seed eater (c. David Dillon)

Birds have had to adapt to our modern landscape, a built up urban sprawl with green areas dotted about and usually enclosed by hard landscape. Firstly, he cites a European study that suggests it is about brain size: Finches have bigger brains than Buntings and might adapt more readily to the modern, urban landscape.

A UK study found other reasons why some bird families might thrive in urban conditions: Generalists find it easier than specialists, and Yellowhammer would fit the latter category, despite being a seed eater, they are closely associated with larger seed crops such as Oats and Barley and their distribution closely reflects this preference. 

 Here in county Wicklow we are surrounded on two sides of our acre by two big fields of spring sown Barley: definitely Yellowhammer country, the Elder bushes on the boundary of our acre are enlivened daily by the distinctive song delivered right through the summer months.  In  winter Yellowhammers fly over our garden en route to their night time roost, though they are never tempted to join the flock of Chaffinches under the bird feeders, despite the fact that they form loose mixed flocks in the winter stubbles. Next winter, I am tempted to provide a sack of Oats, specifically for Yellowhammers, just to see if it makes a difference to this iconic farmland bird.


Adult Robin (c.OOS)

So,  the winners are likely to be generalist seed eaters, rather than insect eaters.  The UK bird food market is estimated to be worth stg.£200 million per annum with the vast majority of this is aimed at seed eaters.

As I watched the Greenfinches and Great Tits camp on the sole peanut feeder, I felt heartened by the sight of other birds patrolling the mixed beds and grassy areas: a family of Blackbirds and 4 or 5 Robins were sticking to what they like best: a mixed diet of insects and soft  fruit..( I've given up on actually tasting our own Strawberries, but will need to cover the ripening Blackcurrants for jam making).  


Juvenile Robin: same shape, but different plumage! (c.OOS)


Ken Thompson is a plant ecologist and is the author of 'No Nettles Required, the truth about wildlife gardening'. (eden project books)