I understand why they would migrate to avoid our winter but why bother coming here at all with the risks it involves
I believe the main reason is the daytime length here during summer. They have many more daylight hours available to them when feeding and raising their young than they would have nearer the equator where daytime and night time are generally nearer 12 hours each all year round. They move back south as the cold weather creeps in here and the insects they feed on diminish (in the case of Swallows).
My bird photos HERE
It will be very much an environmental thing as to why these birds migrate many thousands of miles, not just to raise young, but for food and also to provide food for other species!
Nature can be harsh and many don't make the long migration, and either through ill health or otherwise die, or more likely, as they pass over the continents, become prey to larger birds.
The cycle of life, which helps to keep numbers in sensible proportions (until man intervenes) while supporting other species.
Flickr Peak Rambler
In reply to Dave - CH:
Dave - CH said:Not ponds then Mike? You're, of course, absolutely right about the rigours of migration. Here, swifts no sooner arrive than they start to show up in rescue centres. We saw our first just a week ago; two arrived in the centre I volunteer at last Thursday alone. Very hard life being a bird.
I think the ponds bit may be for Paul, unless, as I often heard many years ago by an ex Royal Navy friend, terming seas and oceans as large ponds...
She's often say she had been across the pond to some exotic country....
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