Thursday 29 November 2018

Bullfinches eating Guelder rose berries

A group of Bullfinches were feeding just outside Dalby Forest visitor centre this afternoon. We watched them from a window, just over them, and they seemed quite unaware of us, providing a great opportunity to watch this usually shy bird in action.
 Bullfinches are seed predators of many fruit trees. Blackbirds, Thrushes and Woodpigeons are seed dispersers, they eat the berry whole, digest the pulp and the seeds drop to the ground, undigested and prepared to germinate. This is the reason trees and bush species evolved fruits, as the way to disperse their seeds. In contrast, seed predators discard the flesh and eat the seeds inside each fruit. Many finches, like Hawfinches, Greenfinches and Goldfinches, are seed predators too.
Bullfinches favourite seeds include Honeysuckle, Rowan, Elder, Whitebeam and Blackberries, each ripening at different times of the year. Today, they were feeding on the bright red berries of the Guelder Rose, a late fruiting small tree. In their fantastic book "Birds and Berries", Barbara and David Snow document how bullfinches are one of the main seed predators of Guelder Rose.
 The bullfinches stretched to reach the berries (top shot) and used two techniques to get at the seed. They either opened up the fruit and picked the seed, leaving the flesh hanging from the bush or picked the berry and deftly extracted the seed. They will even hovering in front of the bunches of fruits to reach the most difficult ones.
A male picks a berry.
Female extracting a seed...
...and dropping the flesh.
There were not only bullfinches at the tree, a lone Robin, a seed disperser, was feeding on the berries, so even though there was a lot of seed predation going on, it's likely the Guelder Roses will manage to get some of their seed seeds to germinate.

More information
Snow, B. and D Snow 1988. Birds and Berries. T & AD Poyser. 268 pp.

Saturday 24 November 2018

A flock of Goosanders

I went to a local park today for a walk and found a flock of Goosanders in the lake. It is a fishing lake, frequented by anglers in the summer, but it was quiet today, and the Goosanders, had the fish to themselves. Goosanders are hard to count when they are fishing, as they are constantly diving -often one after the other- but I managed to count nine males and six females. I stayed away from the shore, half hidden on a tree trunk, as these ducks are wary of people. Soon after I started watching them, a male caught a large fish, another goosander followed it, interested, but the first one managed to keep it and swallow it.
Drake Goosander with fish.
 The Goosanders kept in a tight flock, when the fishing session was over they spent some time preening and flapping their wings and doing some exaggerated head shaking, which might also be related to courtship as the movement helps show their showy hairdos.
 
 
The fishing lake.
Shaking head looking straight up.
Drake Goosander.
The same drake. The photo shows the neck striations that form a 'bun' at the back of their head. 
Then a female went to the shore for a rest and a preen and one by one, several of the others followed her there, jumping awkwardly onto the edge. Their legs shone bright orange like Mallard's.