A couple of osprey questions

Unknown said:

A coup,e of osprey questions.

1. Why do they come to the UK when there are warmer places to visit?

2. Why have some of the UK birds been a lot earlier than previous years?

1. I think that the generally accepted scientific reasons are that firstly, if they stayed and bred in West Africa they would face interspecific competition for nest sites and prey with other raptors e.g. African fish eagle. Secondly, due to latitude, sunrise and sunset does not vary greatly in Africa, whereas in Scotland, particularly in mid-Summer when the male must catch many fish each day to feed his growing offspring, sunrise can be as early as 4.00 am and sunset as late as 10.00 pm. These extra hours of daylight must be invaluable to the male in his search for food for his family.

2. Statistics tend to show that birds tend to arrive earlier as they get older - perhaps they are learning each year the best routes / stopover points as they complete a successful migration. However, in my opinion, a much more important factor is weather conditions on migration. If there are either strong easterly winds and/or heavy rain on migration then an individual may well decide to rest until the wind, which might carry it across the sea (and hence its demise) abates, and in the case of heavy rain it will seek shelter to prevent soaking of its feathers. In addition, the Osprey will have difficulty fishing in heavy rain.

Hope this helps.

Unknown said:

1. Why do they come to the UK when there are warmer places to visit?
2. Why have some of the UK birds been a lot earlier than previous years?

I'll take a stab, IMHO, but I am sure you will read additional reasons here!
1) Ospreys (especially males)  are faithful to their natal nesting area, called philopatry. Those reared in UK will try to return.
2) Early return could be attributed by some to earlier warming, or also favorable weather patterns.

May I ask a question.  Do Ospreys get the sticks for the nest from the ground or do they break them off trees like crows do?

Anthony B said:

May I ask a question.  Do Ospreys get the sticks for the nest from the ground or do they break them off trees like crows do?

Both :-)

Unknown said:

1. Why do they come to the UK when there are warmer places to visit?
2. Why have some of the UK birds been a lot earlier than previous years?

I'll take a stab, IMHO, but I am sure you will read additional reasons here!
1) Ospreys (especially males)  are faithful to their natal nesting area, called philopatry. Those reared in UK will try to return.

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Spot on! Females tend to breed much further from their natal sites than males = nature's way of reducing the risk of inbreeding. Having been on the planet for millions of years these birds have most things worked out by now............ except sometimes how to cope with what mankind throws at them.

Some people think Ospreys are a matter of life and death. I don't like that attitude. I can assure them it is much more serious than that. 

Unknown said:

Ospreys (especially males)  are faithful to their natal nesting area, called philopatry. Those reared in UK will try to return.

It should also be said that any male.migrating north, seriously risks joining the UK breeding population if they happen to fly over EJ alone on her nest - whether they happen to be from the UK or not!  LG's naming of Odin suggests this happened to him.

Thank you for all the responses. You learn something new everyday!