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ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

Worcestershire Migration Log (2 Viewers)

Had an early morning checking for "Redditch" Stork and then stopped at 2 separate place at Lutley Wedge and 3 Wheatear. (2 previous attempts returned none)

No Wheatears in normal Redditch hotspot at north of the park.
 
Haven't any migrants to report, but I also find the topic so interesting. How did it all start, does anyone know? Could it have been as early as the first modern species evolving, when the continents were closer together, but drifting apart? What started out as small trips between seasonal habitats gradually grew to the huge migrations of today? Any suggestions?!!! Was anyone there?:-O

Hi Mary
the book in the link, would answer all the questions you would ask. A long read 600 pages but worth it.B :)John
http://www.amazon.co.uk/Collins-New-Naturalist-Library-113/dp/0007307314
 
The BTO also do a regular Migration Magazine to which individuals can subscribe as a supplement to their membership.
Of course, they also publish some fascinating articles on various migration-related subjects.
http://www.bto.org/science/migration
There's an archive here with several articles, most of which are free.
http://www.tandfonline.com/action/doSearch?quickLinkJournal=&journalText=&quickLink=true&type=simple&filter=multiple&stemming=yes&searchText=migration&=Search&publication=40001453&searchType=journal
 
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Many thanks for all your comments. I guess todays 'German' Blackcaps who now come here for winter are a good example of how it might have worked in some cases.
John.. the book will have to wait for a lottery win!
 
Many thanks for all your comments. I guess todays 'German' Blackcaps who now come here for winter are a good example of how it might have worked in some cases.
John.. the book will have to wait for a lottery win!

Yes, good example Mary - a case of 'positive feedback' reinforcing migratory patterns and resulting in a species exploiting a new opportunity which appears to have arisen due to an ongoing climatic trend (in this case generally milder winter weather) coupled with new feeding opportunities via bird-tables / winter feeding by humans. If these conditions reversed and people no longer put out food, I guess it wouldn't be long before different migratory patterns prevailed whereby wintering further south became more favourable and the Blackcaps wintering in north-west europe became 'deselected' via increased winter mortality rates.

Examples of where very similar species have evolved very different migratory strategies can be found among the Swallows of the African continent. This family is particularly well represented in Africa and it is probably where they first originated. Being among the most aerial of all birds, they have since radiated out across the globe. Two species in particular strike me as examples of how divergent behaviours in the distant past have led to what we see today:

Our Swallow (Hirundo rustica) is generally a VERY long distance migrant, as most people appreciate - wintering in South America, Southern Africa and Australia and spending the boreal summer as far north as the arctic circle.

The Red-chested Swallow (Hirundo lucida) closely resembles Hirundo rustica (so much so that it was formerly considered a subspecies) - but it is entirely non-migratory and stays in West Africa and Ethiopia throughout the year.

At some point in the past, the original Swallow 'superspecies' probably originated in this part of Africa but, due to competitive pressures, a portion of that original population found advantages / opportunities in moving north during the summer and south during the winter. This emerging behaviour allowed the overall population to increase as it could expand and exploit new niches (i.e. there was a net increase in the 'biomass' of the population). As generations went by, the pioneering migratory behaviour was subject to positive feedback and the frontiers of this portion of the population were widened further and further. Over time, physiological adaptations to migration took hold and phenotypic and genetic differences arose and the two populations became isolated, i.e speciation had occurred and this bifurcation was driven by migratory behaviour opening up new horizons.

BTW: The Ian Newton book is a great read but I wouldn't pay that much (£90+) for it, either - glad I got mine when it was only £19.
 
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Should Blackcaps and Chiff Chaffs be noted as I thought many wintered here.

Keith :t:

Info on Chiffs and Blackcaps are welcome as far as I'm concerned, Keith. Even though increasing numbers winter in this country the majority still migrate south.

Look out for 'pollinated' chiffchaffs with dark pollen on their faces - apparently this signifies birds which have recently fed on insects on mediterranean plants. I saw one such chiffchaff on my patch last spring.
 
Blimey thats a good tip....cheers.

I took this in October ..would it be one that would be overwintering or just late going.
Keith :t:
 

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Keith - you ca'nt say with any certainty, yes both CC and BC overwinter but are we talking about a few hundred birds as was the case in the 70's or a few thousand birds with the mild Winters that we have had over the last 30 years? Either way compared to the European populations of these birds (some 25-50 million pairs each) we must have several hundred thousand pairs in the UK so far and away the 99.9 recurring still migrate?

Early-flowering Goat Sallow is an excellent source of both nectar and the insects feeding on them. I watched 2 Chiffchaffs feeding on one ystda and any Chiffchaff whether overwintering or newly arrived would exploit this food source so i would'nt automatically associated a 'Nectar-head' as a newly-arrived bird but that just my opinion.

Personally i associate the arrival of migrants with the first singing birds as you have to start somewhere;)

Laurie:t:
 
Keith - you ca'nt say with any certainty, yes both CC and BC overwinter but are we talking about a few hundred birds as was the case in the 70's or a few thousand birds with the mild Winters that we have had over the last 30 years? Either way compared to the European populations of these birds (some 25-50 million pairs each) we must have several hundred thousand pairs in the UK so far and away the 99.9 recurring still migrate?

Early-flowering Goat Sallow is an excellent source of both nectar and the insects feeding on them. I watched 2 Chiffchaffs feeding on one ystda and any Chiffchaff whether overwintering or newly arrived would exploit this food source so i would'nt automatically associated a 'Nectar-head' as a newly-arrived bird but that just my opinion.

Personally i associate the arrival of migrants with the first singing birds as you have to start somewhere;)

Laurie:t:

I think the key point is that the pollen associated with the Mediterranean and Canary Isles plants is dark / almost black - unlike anything they might pick up here?? - but I may be wrong. I read about this phenomenon on the Portland and other websites last year - have a look at the following for example:

http://heyshamobservatory.blogspot.co.uk/2012/03/pollinated-male-chiffchiffs-and-female.html

The bird I saw had strikingly very dark head markings because of this.
 
Sorry Dave - i had'nt realised that a different colour pollen i.e from more Southern origins was meant. Good point and i would have thought fairly valid for new arrivals on a Southern coastline, i wonder how long the stuff lasts on birds further inland?

Now you have highlighted the possibility i shall look at the relevant spp at this time of year with my 'Nectar Eyes' wide open:eek!:

Cheers - Laurie:t:
 
2 Wheatear at Lutley Wedge this afternoon (3pm)

Managed to digiscope one from a distance

Stopped in Oakenshaw for Firecrest but no sign (4.30pm)
 

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Yes, good example Mary - a case of 'positive feedback' reinforcing migratory patterns and resulting in a species exploiting a new opportunity which appears to have arisen due to an ongoing climatic trend (in this case generally milder winter weather) coupled with new feeding opportunities via bird-tables / winter feeding by humans. If these conditions reversed and people no longer put out food, I guess it wouldn't be long before different migratory patterns prevailed whereby wintering further south became more favourable and the Blackcaps wintering in north-west europe became 'deselected' via increased winter mortality rates.

Examples of where very similar species have evolved very different migratory strategies can be found among the Swallows of the African continent. This family is particularly well represented in Africa and it is probably where they first originated. Being among the most aerial of all birds, they have since radiated out across the globe. Two species in particular strike me as examples of how divergent behaviours in the distant past have led to what we see today:

Our Swallow (Hirundo rustica) is generally a VERY long distance migrant, as most people appreciate - wintering in South America, Southern Africa and Australia and spending the boreal summer as far north as the arctic circle.

The Red-chested Swallow (Hirundo lucida) closely resembles Hirundo rustica (so much so that it was formerly considered a subspecies) - but it is entirely non-migratory and stays in West Africa and Ethiopia throughout the year.

At some point in the past, the original Swallow 'superspecies' probably originated in this part of Africa but, due to competitive pressures, a portion of that original population found advantages / opportunities in moving north during the summer and south during the winter. This emerging behaviour allowed the overall population to increase as it could expand and exploit new niches (i.e. there was a net increase in the 'biomass' of the population). As generations went by, the pioneering migratory behaviour was subject to positive feedback and the frontiers of this portion of the population were widened further and further. Over time, physiological adaptations to migration took hold and phenotypic and genetic differences arose and the two populations became isolated, i.e speciation had occurred and this bifurcation was driven by migratory behaviour opening up new horizons.

BTW: The Ian Newton book is a great read but I wouldn't pay that much (£90+) for it, either - glad I got mine when it was only £19.

Many thanks for your concise explanation, Woodchat, much appreciated.
 
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