Could migration routes be traced back to where birds evolved in ancient times? (1 Viewer)

[Jaysan]

Hello, penny for your thoughts. Migration is generally North-South. One that's traditionally explained be temperature and availability of food. However, there are some birds like the Amur falcon which migrate East-West too, which doesn't make sense. I wonder if the place a bird migrates to has its origins to where they originally evolved in Pangea.

As an example, I've attached the current distribution of the common and spotted sandpipers, and the map of pangea with current continents labelled on it. If you trace the regions where the common sandpiper is distributed back to pangea, its on the right hand half of the continent. Spotted sandpiper distribution seems to be the left hand side.

I know this may sound ridiculous. But is there any good explanation to where a bird

 

[lgonz1008]

You have the right idea, but sadly speciation and geological times don't work this neatly.

Pangaea is a supercontinent that was already splitting apart before the first dinosaurs that could be considered avian dinosaurs (or birds) roughly 175mya. Thanks to limited but preserved fossil record, we know certain bird families or groups did not evolve until much later.

Best example would be that the first galliforms and waterfowl evolved towards the end of the Cretaceous, while more "advanced" bird families hummingbirds and motmots originally evolved in the Eocene rainforests of present day Germany. This one is pretty cool to think about, while penguins were always limited to Antarctica and the Subantarctic regions since the down of their range as they are today, some bird families originally evolved in continents that are on opposite sides of the world from where they are only found today. Which is why hummers and motmots, mostly Neotropical families, trace their origins to modern day Europe, and also why species that contrast each other like Kagu and Sunbittern, are each other's closest relatives. They are leftovers of a bygone era from times when the ice caps changed the world.

However, you were right in some parts, just a closer time frame, birds like the Sandhill Crane are known to have lived in California at least for part of the year since before the last glacial period thanks to the remains of the La Brea Tar Pits, and these birds still winter in California to this day.

Another example, which is personally my favorite, is the Kirtland's Warbler, beautiful songbird that breeds only in certain forest of the Great Lakes region in the US and winters in some Bahamian islands. Weird thing is, while the bird has lost a lot of it's wintering ground due to habitat destruction, in the US, scientists have tried to reintroduce the birds to forests that fit the criteria the birds need in the region to help with population growth, but none did. The reason? Turns out that these birds evolved to only breed in the forests that were not destroyed by the last glaciers that encroached North America over 10,000 years ago. So even though these glaciers have disappeared and more breeding habitat is technically available, the bird will only breed in the zone that the glacier formerly did not destroy their jack pine forest habitat. Sadly, in the Bahamas, they have lost wintering grounds from rising sea levels since and human disturbance in the present, so not a great future. But its still amazing how this bird has been morphed to live in a world that no longer exists, as that world was one where it shared its habitat with mastodons and giant beavers, while today it mostly needs to worry of humans not cutting down the last places it has to live.

 

[chowchilla]

Most of our migratory birds go from south to north in winter, so it seems odd to me that there is an assertion that the opposite is the case.

There is also altitudinal migration, which is why Tableland species come into town in the winter from higher elevations. Australia also has a lot of nomadic species where entire populations of some birds move around the continent mostly in response to food and nesting availability. At the end of the day, the more classic migration is in response to similar pressures, but isn't the only solution to a species survival.

 

[Jaysan]

Most of our migratory birds go from south to north in winter, so it seems odd to me that there is an assertion that the opposite is the case.

There is also altitudinal migration, which is why Tableland species come into town in the winter from higher elevations. Australia also has a lot of nomadic species where entire populations of some birds move around the continent mostly in response to food and nesting availability. At the end of the day, the more classic migration is in response to similar pressures, but isn't the only solution to a species survival.

I was probably unclear. North-South, in the northern hemisphere. So, the reverse in the Southern hemisphere. Essentially, warmer closer to the equator. Altitudinal migration - probably works in the same way, higher colder, lower warmer.

 

[Jaysan]

You have the right idea, but sadly speciation and geological times don't work this neatly.

Pangaea is a supercontinent that was already splitting apart before the first dinosaurs that could be considered avian dinosaurs (or birds) roughly 175mya. Thanks to limited but preserved fossil record, we know certain bird families or groups did not evolve until much later.

Best example would be that the first galliforms and waterfowl evolved towards the end of the Cretaceous, while more "advanced" bird families hummingbirds and motmots originally evolved in the Eocene rainforests of present day Germany. This one is pretty cool to think about, while penguins were always limited to Antarctica and the Subantarctic regions since the down of their range as they are today, some bird families originally evolved in continents that are on opposite sides of the world from where they are only found today. Which is why hummers and motmots, mostly Neotropical families, trace their origins to modern day Europe, and also why species that contrast each other like Kagu and Sunbittern, are each other's closest relatives. They are leftovers of a bygone era from times when the ice caps changed the world.

However, you were right in some parts, just a closer time frame, birds like the Sandhill Crane are known to have lived in California at least for part of the year since before the last glacial period thanks to the remains of the La Brea Tar Pits, and these birds still winter in California to this day.

Another example, which is personally my favorite, is the Kirtland's Warbler, beautiful songbird that breeds only in certain forest of the Great Lakes region in the US and winters in some Bahamian islands. Weird thing is, while the bird has lost a lot of it's wintering ground due to habitat destruction, in the US, scientists have tried to reintroduce the birds to forests that fit the criteria the birds need in the region to help with population growth, but none did. The reason? Turns out that these birds evolved to only breed in the forests that were not destroyed by the last glaciers that encroached North America over 10,000 years ago. So even though these glaciers have disappeared and more breeding habitat is technically available, the bird will only breed in the zone that the glacier formerly did not destroy their jack pine forest habitat. Sadly, in the Bahamas, they have lost wintering grounds from rising sea levels since and human disturbance in the present, so not a great future. But its still amazing how this bird has been morphed to live in a world that no longer exists, as that world was one where it shared its habitat with mastodons and giant beavers, while today it mostly needs to worry of humans not cutting down the last places it has to live.

Thanks for the detailed reply. Need to digest before I comment.

Just about the Kirtland's warbler. I'm reading "A world on the wing" by Scott Weidensaul where he mentions that it's not just Jack pine forests but large areas of new growth of Jack pines that are critical for its nesting. He quotes how following the large Mack Lack fire (1980, over 24,000 acres), the birds started colonising areas of regeneration. And that its no longer on the endangered list as of 2019. There is also mention of expanding winter range from the Bahama's into neighbouring islands (Cuba/Hispaniola). So, there may be some light at the end of the tunnel.

 

[lgonz1008]

Thanks for the detailed reply. Need to digest before I comment.

Just about the Kirtland's warbler. I'm reading "A world on the wing" by Scott Weidensaul where he mentions that it's not just Jack pine forests but large areas of new growth of Jack pines that are critical for its nesting. He quotes how following the large Mack Lack fire (1980, over 24,000 acres), the birds started colonising areas of regeneration. And that its no longer on the endangered list as of 2019. There is also mention of expanding winter range from the Bahama's into neighbouring islands (Cuba/Hispaniola). So, there may be some light at the end of the tunnel.

Wasn't aware of the winter range expansion, but I'm glad to hear it since at least Cuba is not that far off from Bahamas and the Western Part of the islands has plenty of habitat that cannot be taken over by population growth and has minimal human disturbance.

 

[jurek]

Hi,
Basically, supercontinent Gondwana broke up in stages between 180 and 23 million years ago. It was when birds as a group just appeared, no bird species alive existed yet, and few recognizable modern bird groups existed yet.

Modern bird migrations could be traced to Ice Ages (the last one was 115 to 10 thousands (not m!) years ago. Migrations of some birds can reasonably be relics of the Ice Ages, for example Northern Wheatear which migrates from Alaska south-west and from Greenland south-east to wintering grounds in Africa. However, there are known cases where birds changed their migration routes in historic times, for example Bewick's Swan from South-Eastern Europe and West Asia to Western Europe. So migrations can be very flexible, too. And it is practically impossible to verify any of such ideas by proper scientific proof, since we almost never know migrations in the distant past.

However, over millions of years there must have been lots of changes of climate and changes of migration strategies and routes. For example, models of climate and vegetation during the peak of the last Ice Age suggest that several birds currently nesting in NW America had almost zero breeding habitat then. Did they stay and bred on their wintering grounds? Tens of millions of years earlier, today Antarctica had no ice cover, and probably there lived warm-loving birds of species unknown to us and long extinct, which probably migrated in a way unknown to us.

 

[Jaysan]

Hi,
Basically, supercontinent Gondwana broke up in stages between 180 and 23 million years ago. It was when birds as a group just appeared, no bird species alive existed yet, and few recognizable modern bird groups existed yet.

Modern bird migrations could be traced to Ice Ages (the last one was 115 to 10 thousands (not m!) years ago. Migrations of some birds can reasonably be relics of the Ice Ages, for example Northern Wheatear which migrates from Alaska south-west and from Greenland south-east to wintering grounds in Africa. However, there are known cases where birds changed their migration routes in historic times, for example Bewick's Swan from South-Eastern Europe and West Asia to Western Europe. So migrations can be very flexible, too. And it is practically impossible to verify any of such ideas by proper scientific proof, since we almost never know migrations in the distant past.

However, over millions of years there must have been lots of changes of climate and changes of migration strategies and routes. For example, models of climate and vegetation during the peak of the last Ice Age suggest that several birds currently nesting in NW America had almost zero breeding habitat then. Did they stay and bred on their wintering grounds? Tens of millions of years earlier, today Antarctica had no ice cover, and probably there lived warm-loving birds of species unknown to us and long extinct, which probably migrated in a way unknown to us.

Thank you. Stuff to read around.

 

[simple]

It is interesting thought for some species.

European Turtle Dove is perhaps a good example - most of the Sahara at one point would have looked much like their wintering grounds in the Sahel and there are of course resident populations of S. t. arenicola in NW.Africa . It is probably reasonable to suggest that migration started as population spread/dispersal from source populations across the Sahara? As the Sahara developed into something similar to what it looks like today it started to cut off northern breeders moving ever further north to occupy areas emerging as suitable and food rich due to retreating ice from perhaps more favourable wintering zones due to photo-period differences (daylight length)? Just a thought!

We often think of avian migration being triggered by food availability, warmers zones etc but whilst that is true possibly the biggest drive for species long distance migration is increased day length which in turn provides more opportunities for hunting / foraging and breeding / raising young.

 

[David_]

We often think of avian migration being triggered by food availability, warmers zones etc but whilst that is true possibly the biggest drive for species long distance migration is increased day length

No expert on this but as winters in Germany are getting warmer and more insects are available as food, more and more species are starting to winter here. Not saying day length is not a factor but food availabilty seems to be a bigger factor for at least some species.

 

[simple]

No expert on this but as winters in Germany are getting warmer and more insects are available as food, more and more species are starting to winter here. Not saying day length is not a factor but food availabilty seems to be a bigger factor for at least some species.

Hi David - Sure that would be true for shorter range migrants (although they are still triggered by daylight length) and of course as I say is still a factor but longer distance migrants (note I refer to long distance migrants in my post above) are more impacted by climate change issues as they are unable to shift their migratory timings to take advantage of changes and timings of food abundance.

Ospreys are a good example along the East Atlantic flyway where food on their breeding grounds is fairly is abundant (outside of areas that freeze) and accessible all through the year but they migrate largely to coastal sub-Saharan West Africa to take advantage of the daylight length not simply prey abundance (otherwise why don't they just stay put).

 

[lmans66]

This would be a fun project to work on but boy, what a project. Not only the weather but the fauna and perhaps how some fauna intermingled with other fauna etc...The Kirkland Warbler is a great example that has been brought up but multiple species are the same. Or, how about the evaluation of hummingbirds as that alone takes us into territory that weather alone might not track.

But a great idea.....I will be looking for your dissertation soon, jim

 

[Owene]

No expert on this but as winters in Germany are getting warmer and more insects are available as food, more and more species are starting to winter here. Not saying day length is not a factor but food availabilty seems to be a bigger factor for at least some species.

This is obviously happening but I think there is a difference between feeding yourself and feeding yourself and a growing chick. The further north you get you get hours of daylight that would just be unthinkable in the tropics. And insect species evolved to explode in population in that short time so barely have to take a break from feeding a chick during the 24 hours

 

[JTweedie]

I thought you might be interested in this paper:

Bird migration: When vagrants become pioneers

Unfortunately it's behind a paywall but I've contacted the author to ask if he can share the paper. My university library only has access up to a year ago, so I imagine that'll be the same for all universities.

The essence of the paper is that vagrant birds could be establishing new migration routes. It'll be interesting to read the paper to get the detail.

 

[JTweedie]

I thought you might be interested in this paper:

Bird migration: When vagrants become pioneers

Unfortunately it's behind a paywall but I've contacted the author to ask if he can share the paper. My university library only has access up to a year ago, so I imagine that'll be the same for all universities.

The essence of the paper is that vagrant birds could be establishing new migration routes. It'll be interesting to read the paper to get the detail.

Turns out the "paper" I got was just a summary of someone else's paper. However, the paper in question is about the Richard's pipit (Anthus richardi), a bird that breeds in Siberia and winters in southeast Asia, but is known in Europe.

The authors refer to those birds that are known in small, but regular numbers outside their normal wintering ranges as "pseudo-vagrants", and that rather than actually being birds that are off course, actually make up small, viable populations on new migration routes or even from unknown breeding locations. Attaching dataloggers to seven birds, they recaptured three birds the following winter and found they'd summered in the western edge of their normal breeding range in Russia. 11 colour-ringed birds had also been recaptured on the wintering sites where they had been ringed. They suggest that this strong migratory connectivity supports their hypothesis that they're witnessing genuine migration rather than vagrancy.

 

[simple]

Vagrancy in Birds by Lees & Gilroy published by Helm recently is a great read!

Interestingly this hypothesises on the vagrancy of Yellow-browed Warbler being migratory pioneers - Ringing recovery of Yellow-browed Warbler in Andalucia confirms over-wintering in consecutive winters.

First published in British Birds

 

[jurek]

Interestingly this hypothesises on the vagrancy of Yellow-browed Warbler being migratory pioneers

This suggests that evolution has a sense of foresight, which it has not, being a random process.

Surely, a vagrant which lands in a good wintering site can start a whole new wintering population. However, this is likely outnumbered many times by vagrants landing in places worse than the original wintering ground, or completely unsuitable places and dying.

 

[simple]

This suggests that evolution has a sense of foresight, which it has not, being a random process.

Surely, a vagrant which lands in a good wintering site can start a whole new wintering population. However, this is likely outnumbered many times by vagrants landing in places worse than the original wintering ground, or completely unsuitable places and dying.

This is more the ethology of migratory behaviours and evolutionary selections, so it isn´t suggesting that at all.

Migratory birds are driven by instinct (photo-period change) as well as choices, food weather etc In the case of Yellow-browed Warblers it is a good example of adaptive migration and expansion leading to new colonisation which is exactly how birds spread across the globe. Interestingly Richards Pipits, Little Buntings and more showing similar tendencies of adaptive pioneering migratory expansion.

Interestingly vagrancy often happens with species that are more common place in their normal population areas and it is likely to some degree that randomisation of migration occurs more due to populations reaching carrying-capacity. Of course vagrancy just could be more common place due to numbers involved but it is more complex than that ...

In nature there are seldom successful examples of species that lack the ability to spread to new areas and almost all organisms have the ability for exploratory movements.

A mix of long and shorter (or perhaps normal) dispersal techniques tends to favour populations (Fraser et al 2001)

Rather than being pushed by adverse weather or faulty navigation a significant proportion of vagrancy is driven by individuals following urges to disperse to new areas (Newton 2008).

¨Vagrants represent the sensitive tentacles by which the species keeps aware of the possibilities of real expansion¨ - Grinnell 1922

 

[JTweedie]

Vagrancy in Birds by Lees & Gilroy published by Helm recently is a great read!

Interestingly this hypothesises on the vagrancy of Yellow-browed Warbler being migratory pioneers - Ringing recovery of Yellow-browed Warbler in Andalucia confirms over-wintering in consecutive winters.

First published in British Birds

I saw this mentioned on Twitter the other day. I'd forgotten about this thread, but good to see it mentioned here too.

 

[DMW]

This is more the ethology of migratory behaviours and evolutionary selections, so it isn´t suggesting that at all.

Migratory birds are driven by instinct (photo-period change) as well as choices, food weather etc In the case of Yellow-browed Warblers it is a good example of adaptive migration and expansion leading to new colonisation which is exactly how birds spread across the globe. Interestingly Richards Pipits, Little Buntings and more showing similar tendencies of adaptive pioneering migratory expansion.

Interestingly vagrancy often happens with species that are more common place in their normal population areas and it is likely to some degree that randomisation of migration occurs more due to populations reaching carrying-capacity. Of course vagrancy just could be more common place due to numbers involved but it is more complex than that ...

In nature there are seldom successful examples of species that lack the ability to spread to new areas and almost all organisms have the ability for exploratory movements.

A mix of long and shorter (or perhaps normal) dispersal techniques tends to favour populations (Fraser et al 2001)

Rather than being pushed by adverse weather or faulty navigation a significant proportion of vagrancy is driven by individuals following urges to disperse to new areas (Newton 2008).

¨Vagrants represent the sensitive tentacles by which the species keeps aware of the possibilities of real expansion¨ - Grinnell 1922

People almost universally use the word "adaptation" when talking about evolution through natural selection, when the actual process is abaptation. Organisms don't adapt to different conditions, rather the ones with heritable traits best fitted to those conditions are more successful. The concept of "adaptive migration" seems flawed on it's face, and several of your assertions seem extremely dubious.