Saturday, 17 November 2012

The Common Pochard

Common Pochards, Aythya ferina, are common wintering ducks in the UK. I find intriguing that most of the birds in my local park are males. However, this is the case for the whole UK winter population, with males outnumbering females in a 2:1 ratio. In sites where supplementary food is given this biased sex ratio can be much more extreme (5:1). Females appear to migrate further south than males, and the reason for this could be that males are much more aggressive towards females than they are to other males. Confronted with this intraspecific competition, females move on to areas where there are fewer males. Males might benefit from shorter migration distances by coming back earlier than females to establish breeding territories.

  Pochards, unlike other birds, seem to have the same pattern of activity between day and night, they are cathemeral. Bouts of feeding are followed by bouts of sleeping day and night, and they are often found resting in flocks during the day (they still sleep about 50% of the time).

  In the winter, these diving ducks feed mostly on seeds and fuiting bodies of aquatic plants (Chara, Nitella, and Potamogeton being a large fraction of their diet). Their distribution is limited by their diet, as they require large bodies of water with good population of aquatic plants. They feed by diving and up-ending, and, they probably rely on the sense of touch to feed, which may explain they do not need light to feed.
One of the few photos I have got of a female Pochard, in the company of Tufted ducks.

2 comments:

  1. A very interesting and informative post, thank you - you really add to my knowledge.

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  2. Thank you Toffeeapple. I felt there must be something interesting about this gorgeous duck, photo first, research later...

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