Sex Ratios of Wintering Pochard

[Darren Oakley-Martin]

Hi all,

I have been speaking to a very knowledgeable chap about the following problem.

Does anyone have any further information as to why there are a higher proportion of male to female Pochard, (Aythya rufina) wintering in NW Europe?

I have heard several theories, namely;

That males stay at their breeding grounds so it is easier for them to establish a territory,

Males outcompete females for food so females move further south.

Females are smaller, therefore require more southerly climes to retain body heat.

Females require a different food source, therefore, move south.

All of these theories seem to be flawed in some way.

many thanks

[Mike Pennington]

Hi all,

I have been speaking to a very knowledgeable chap about the following problem.

Does anyone have any further information as to why there are a higher proportion of male to female Pochard, (Aythya rufina) wintering in NW Europe?

I have heard several theories, namely;

That males stay at their breeding grounds so it is easier for them to establish a territory,

Males outcompete females for food so females move further south.

Females are smaller, therefore require more southerly climes to retain body heat.

Females require a different food source, therefore, move south.

many thanks


Hi Darren,

The first theory is the most widely accepted reason why males travel further than females in many species e.g. Long-eared Owl as well as many ducks.

As female owls are larger than males, this would suggest that the next two theories don't work. It may all be different with ducks, of course.

I have never heard of a difference in diet in Pochard, so that would rule out number four.

So I'd suggest number one is the most likely.

[Bluetail]

I don't think it's just Pochards by any means. It seems general in ducks for the females and immatures to move further than the adult males. I always thought it was a combination of your nos 1 and 2, but what do I know? Would be worth asking this question on uk.rec.birdwatching if you can stand the trolls there - I'm sure Malcolm Ogilvie would give you an answer.

[Rhion]

I don't think it's just Pochards by any means. It seems general in ducks for the females and immatures to move further than the adult males. I always thought it was a combination of your nos 1 and 2, but what do I know? Would be worth asking this question on uk.rec.birdwatching if you can stand the trolls there - I'm sure Malcolm Ogilvie would give you an answer.

Off topic, but why is Malcolm Ogilvie not on BF? He would be a great asset.

[Bluetail]

Off topic, but why is Malcolm Ogilvie not on BF? He would be a great asset.He certainly would. I've sometimes wondered whether he frequents the newsgroups not so much for pleasure as to counter the wild, anti-conservation propaganda by the two Animal Rights trolls there. The groups certainly need someone like him. Pure speculation on my part, of course, and if I asked I'm sure he'd tell me to mind my own business!

[Johnny1]

I think the same thing applies to Mallards, there's always more drakes than ducks. you often see several drakes fighting over one female. Maybe males outnumber females in most duck species?