Birds, Vitamin E, and the Race Against Time: A Guest Post

A reposting of an original article by Alyssa DeRubeis

The long and tapered wings on this young
Peregrine Falcon means it was built for some
serious speed! Photo by Alyssa DeRubeis.

Maybe you’ve been put under the false assumption that humans are cool. Don’t get me wrong; our bodies can do some pretty neat physiological stuff. But I’m gonna burst your bubble: humans are lame. Just think of how fast we can run compared to a Peregrine Falcon in a full stoop: 27 MPH versus 242 MPH.

Keep thinking about all the cool things birds can do. It doesn’t take us long to realize that our feathered friends are vastly more fascinating compared to humans. Now that you’re finally admitting defeat, I ask that you read on.

The most amazing avian physiological feat is the ability to travel long distances seasonally (a.k.a migrate). Between poor weather conditions, preventing fat loss, and staying alert, migration is not easy by any means. However, birds can cope with all of these things by assimilating and using antioxidants like vitamin E.

Here’s a classic bird migration scene: thousands of Tundra Swans, geese, and ducks congregate on the Mississippi River in Minnesota. Here, they rest and refuel before continuing their journey south. Photo by Alyssa DeRubeis.

Let’s talk a little bit about bird migration. It’s a two-way street, where a migratory bird will (usually) fly north as soon as possible to rear its young, and then fly south where it can stay warm and eat all sorts of goodies. During these two bouts of intense exercise, the birds produce free radicals, which are types of atoms, molecules, and ions that can harm DNA and other important stuff inside the body. This is where vitamin E comes in to save the day, because this vitamin, along with vitamin A and carotenoids, are antioxidants. They drive away bad things like free radicals from birds’ bodies; some scientists suggest that they may even reduce risks of cancer! In the case of migrating birds, antioxidants can make this migration headache a lot more bearable.

Well, that’s great. But where do these antioxidants come from? The short answer is avian nom-noms, but it’s one thing to eat something with an antioxidant in it. It’s quite another to actually be able to assimilate and use this antioxidant. Okay…so where do the birds get this ability from? It’s parentals!

Anders Møller from the University of Paris-Sud, along with his international team including Clotilde Biard (France), Filiz Karadas (Turkey), Diego Rubolini (Italy), Nicola Saino (Italy), and Peter Surai (Scotland), pointed out that there is little research looking at maternal effects on our feathered friends. Møller hypothesized that maternal effects (the direct effects a mother has on her offspring) play a critical role in migration: If mothers put a lot of antioxidants in their eggs, the chicks will be able to absorb antioxidants better later in life. This would give these birds a competitive edge because they will migrate in a healthier condition and arrive to breeding grounds earlier.

This male Barn Swallow on the left must’ve gotten back pretty early for him to have landed himself such a beautiful female. Thank you, Vitamin E! Photo by Alyssa DeRubeis.

In the early 2000s, Møller and his five colleagues collected 93 bird species’ eggs. The crew was able to analyze how the natural differences in antioxidant concentrations (put in by the mother) related to the birds’ spring arrival dates in 14 of them. They found that vitamin E concentration, but not vitamin A concentration, was a reliable predictor of earlier arrival dates.

This European posse took it a step further by injecting over 700 barn swallow eggs with either a large dose of vitamin E or a dose of corn oil (which contains a small amount of vitamin E). It was soon evident that the chicks with more vitamin E were bigger than chicks that received less vitamin E, thus already giving the big chicks a competitive edge over their less vitamin E-affiliated brethren. The researchers kept track of the eggs that hatched out as males in the following spring via frequent mist-netting sessions (a bird-capturing technique). Guess what? The fellas with higher vitamin E concentrations arrived earlier on average by ten days than those with lower concentrations!

Sweet. But what does it all mean? First off, vitamin E is crucial for migratory birds because it allows them to process antioxidants more efficiently. In fact, another study done by Møller, Filiz Karadas, and Johannes Emitzoe out of University of Paris-Sud suggested that birds killed by feral cats had less vitamin E than birds that died of other reasons. Furthermore, the early birds get the worm. Events such as insect hatches—vital for baby birds—now occur earlier in the spring as temperatures rise (read: climate change). Plus, if you’re a male arriving at the breeding grounds early, you get to pick the best spots to raise your offspring.

Wood-warblers, such as this Palm Warbler, must get back to their northerly breeding grounds in a timely fashion in order to hit the insect hatch for da babies. Photo by Alyssa DeRubeis.

Obviously, there’s an advantage to up the vitamin E intake and get a head start as a developing embryo. In an egg, most nutrients come from the yolk…which comes from the mother. The healthier the mother, the more vitamin E she will put in her eggs. And vitamin E isn’t produced internally; birds must consume it. While Møller’s paper on maternal effects states that vitamin E can be found widely in nature, a separate study found no apparent association between vitamin E and avian diet. Hmm. So then where DO birds get vitamin E from? Is it a limiting resource? Is there competition for it?

Clearly, we’ve got some questions and answers. As the field of “birdology,” advances, we will learn more and keep humans jealous of birds for years to come.


REFERENCES

1. Møller, A., Biard, C., Karadas, F., Rubolini, D., Saino, N., & Surai, P. (2011). Maternal effects and changing phenology of bird migration Climate Research, 49 (3), 201-210 DOI: 10.3354/cr01030

2. Møller AP, Erritzøe J, & Karadas F (2010). Levels of antioxidants in rural and urban birds and their consequences. Oecologia, 163 (1), 35-45 PMID: 20012100

3. Cohen, A., McGraw, K., & Robinson, W. (2009). Serum antioxidant levels in wild birds vary in relation to diet, season, life history strategy, and species Oecologia, 161 (4), 673-683 DOI: 10.1007/s00442-009-1423-9

Birds, Vitamin E, and the Race Against Time: A Guest Post

A repost of an original article by Alyssa DeRubeis on February 6, 2013

The long and tapered wings on this young
Peregrine Falcon means it was built for some
serious speed! Photo by Alyssa DeRubeis.

Maybe you’ve been put under the false assumption that humans are cool. Don’t get me wrong; our bodies can do some pretty neat physiological stuff. But I’m gonna burst your bubble: humans are lame. Just think of how fast we can run compared to a Peregrine Falcon in a full stoop: 27 MPH versus 242 MPH.

Keep thinking about all the cool things birds can do. It doesn’t take us long to realize that our feathered friends are vastly more fascinating compared to humans. Now that you’re finally admitting defeat, I ask that you read on.

The most amazing avian physiological feat is the ability to travel long distances seasonally (a.k.a migrate). Between poor weather conditions, preventing fat loss, and staying alert, migration is not easy by any means. However, birds can cope with all of these things by assimilating and using antioxidants like vitamin E.

Here’s a classic bird migration scene: thousands of Tundra Swans, geese, and ducks congregate on the Mississippi River in Minnesota. Here, they rest and refuel before continuing their journey south. Photo by Alyssa DeRubeis.

Let’s talk a little bit about bird migration. It’s a two-way street, where a migratory bird will (usually) fly north as soon as possible to rear its young, and then fly south where it can stay warm and eat all sorts of goodies. During these two bouts of intense exercise, the birds produce free radicals, which are types of atoms, molecules, and ions that can harm DNA and other important stuff inside the body. This is where vitamin E comes in to save the day, because this vitamin, along with vitamin A and carotenoids, are antioxidants. They drive away bad things like free radicals from birds’ bodies; some scientists suggest that they may even reduce risks of cancer! In the case of migrating birds, antioxidants can make this migration headache a lot more bearable.

Well, that’s great. But where do these antioxidants come from? The short answer is avian nom-noms, but it’s one thing to eat something with an antioxidant in it. It’s quite another to actually be able to assimilate and use this antioxidant. Okay…so where do the birds get this ability from? It’s parentals!

Anders Møller from the University of Paris-Sud, along with his international team including Clotilde Biard (France), Filiz Karadas (Turkey), Diego Rubolini (Italy), Nicola Saino (Italy), and Peter Surai (Scotland), pointed out that there is little research looking at maternal effects on our feathered friends. Møller hypothesized that maternal effects (the direct effects a mother has on her offspring) play a critical role in migration: If mothers put a lot of antioxidants in their eggs, the chicks will be able to absorb antioxidants better later in life. This would give these birds a competitive edge because they will migrate in a healthier condition and arrive to breeding grounds earlier.

This male Barn Swallow on the left must’ve gotten back pretty early for him to have landed himself such a beautiful female. Thank you, Vitamin E! Photo by Alyssa DeRubeis.

In the early 2000s, Møller and his five colleagues collected 93 bird species’ eggs. The crew was able to analyze how the natural differences in antioxidant concentrations (put in by the mother) related to the birds’ spring arrival dates in 14 of them. They found that vitamin E concentration, but not vitamin A concentration, was a reliable predictor of earlier arrival dates.

This European posse took it a step further by injecting over 700 barn swallow eggs with either a large dose of vitamin E or a dose of corn oil (which contains a small amount of vitamin E). It was soon evident that the chicks with more vitamin E were bigger than chicks that received less vitamin E, thus already giving the big chicks a competitive edge over their less vitamin E-affiliated brethren. The researchers kept track of the eggs that hatched out as males in the following spring via frequent mist-netting sessions (a bird-capturing technique). Guess what? The fellas with higher vitamin E concentrations arrived earlier on average by ten days than those with lower concentrations!

Sweet. But what does it all mean? First off, vitamin E is crucial for migratory birds because it allows them to process antioxidants more efficiently. In fact, another study done by Møller, Filiz Karadas, and Johannes Emitzoe out of University of Paris-Sud suggested that birds killed by feral cats had less vitamin E than birds that died of other reasons. Furthermore, the early birds get the worm. Events such as insect hatches—vital for baby birds—now occur earlier in the spring as temperatures rise (read: climate change). Plus, if you’re a male arriving at the breeding grounds early, you get to pick the best spots to raise your offspring.

Wood-warblers, such as this Palm Warbler, must get back to their northerly breeding grounds in a timely fashion in order to hit the insect hatch for da babies. Photo by Alyssa DeRubeis.

Obviously, there’s an advantage to up the vitamin E intake and get a head start as a developing embryo. In an egg, most nutrients come from the yolk…which comes from the mother. The healthier the mother, the more vitamin E she will put in her eggs. And vitamin E isn’t produced internally; birds must consume it. While Møller’s paper on maternal effects states that vitamin E can be found widely in nature, a separate study found no apparent association between vitamin E and avian diet. Hmm. So then where DO birds get vitamin E from? Is it a limiting resource? Is there competition for it?

Clearly, we’ve got some questions and answers. As the field of “birdology,” advances, we will learn more and keep humans jealous of birds for years to come.

REFERENCES

1. Møller, A., Biard, C., Karadas, F., Rubolini, D., Saino, N., & Surai, P. (2011). Maternal effects and changing phenology of bird migration Climate Research, 49 (3), 201-210 DOI: 10.3354/cr01030

2. Møller AP, Erritzøe J, & Karadas F (2010). Levels of antioxidants in rural and urban birds and their consequences. Oecologia, 163 (1), 35-45 PMID: 20012100

3. Cohen, A., McGraw, K., & Robinson, W. (2009). Serum antioxidant levels in wild birds vary in relation to diet, season, life history strategy, and species Oecologia, 161 (4), 673-683 DOI: 10.1007/s00442-009-1423-9

Bottlenose Dolphins: The Ultimate Sea Bully? (A Guest Post)

By Kayla Fuller

Imagine this situation: you’ve brought your favorite lunch to work. Everyone is jealous of your food, continuously eyeing it up. A few coworkers, who have brought in disappointing lunches in comparison, approach and demand that you hand it over. After you refuse, they beat you until your body lies lifeless and they take your lunch anyway.

Woah, woah, woah… that took a dramatic turn!

Photo of a harbour porpoise, taken by AVampireTear (Wikimedia Commons)

But for harbour porpoises in the northeastern Atlantic, this fight for food has become a reality, and bottlenose dolphins are the suspected culprit. In 1996, Harry M. Ross (SAC Veterinary Services, U.K.) and Ben Wilson (University of Aberdeen, U.K.) documented fractured rib cages, damaged internal organs and joint dislocations of deceased harbour porpoises in the northeastern Atlantic. Why would bottlenose dolphins be causing such damage? Who could ever associate such a cute and cuddly creature with a horrific crime like this?

Photo of a bottlenose dolphin, taken by NASA (Wikimedia Commons)

Researchers Jérôme Spitz, Yann Rousseau, and Vincent Ridoux with the Center for Research on Marine Mammals: Institute for Coastal and Environmental Research at the University of La Rochelle in France become the judge and jury in this trial. Jérôme, Yann, and Vincent obtained 29 harbour porpoises and 25 bottlenose dolphins that had been beached and died in the Bay of Biscay (between Spain, France, and England). At the time of the study, more harbour porpoises were being found dead in the bay than in previous years. They hypothesized that bottlenose dolphins and harbour porpoises may have had similar enough diets to cause competition and violence between the two species.

Photo of a harbour porpoise that received injuries thought to be from a
bottlenose dolphin before death (circled), from Ross and Wilson (1996)

The researchers’ goal was to analyze stomach contents to directly see what each mammal was eating at the time of their death. To do this, Jérôme, Yann, and Vincent removed the stomachs from the harbour porpoise bodies and weighed them with all contents included. After weighing stomach casings separately, they calculated total weight inside of the animals’ stomachs. Then, they washed stomach contents through a filter to separate out larger matter. Now, if you have a weak stomach, this probably wouldn’t be the job for you. Jérôme, Yann, and Vincent separated food items within the stomachs into identifiable categories. It could sometimes be difficult to recognize whole animals in a stomach due to breakdown, so methods like pairing dismantled eyes or counting fish bones was necessary to identify them! This same process was repeated for bottlenose dolphin carcasses. From there, the scientists compared specimens for prey presence, abundance, mass, and size to see if there was overlap between diets of the harbour porpoises and bottlenose dolphins.

So what did they find? More food mass, a greater number of species, and a more diverse size range of prey was found in the stomachs of bottlenose dolphins in comparison to harbour porpoises. Although bottlenose dolphins have a habitat that includes more deep-ocean areas while harbor porpoises inhabit coastal surroundings, certain prey species were eaten by both. Since bottlenose dolphins are bigger and hunt in larger groups, they would logically be more dominant in a face-off over a common prey item. Why are they fighting more over the same foods? This shift could be a result of humans harvesting species from the ocean that are diet items for bottlenose dolphins. It could also be a result of warming ocean temperatures that could be changing the dwelling places of available food for bottlenose dolphins. This would explain why more habour porpoises are being attacked by these marine tyrants moving into shallower waters.

Poor porpoises, all they want to do is eat their lunch in peace. Who knows, maybe in the next few million years, we’ll see highly evolved harbour porpoises covered in spikes to ward off the dolphins. That’ll teach those bullies!


References:

Ross, H., & Wilson, B. (1996). Violent Interactions between Bottlenose Dolphins and Harbour Porpoises Proceedings of the Royal Society B: Biological Sciences, 263 (1368), 283-286 DOI: 10.1098/rspb.1996.0043

Spitz, J., Rousseau, Y., & Ridoux, V. (2006). Diet overlap between harbour porpoise and bottlenose dolphin: An argument in favour of interference competition for food? Estuarine, Coastal and Shelf Science, 70 (1-2), 259-270 DOI: 10.1016/j.ecss.2006.04.020

Birds, Vitamin E, and the Race Against Time: A Guest Post

By Alyssa DeRubeis

The long and tapered wings on this young
Peregrine Falcon means it was built for some
serious speed! Photo by Alyssa DeRubeis.

Maybe you’ve been put under the false assumption that humans are cool. Don’t get me wrong; our bodies can do some pretty neat physiological stuff. But I’m gonna burst your bubble: humans are lame. Just think of how fast we can run compared to a Peregrine Falcon in a full stoop: 27 MPH versus 242 MPH.

Keep thinking about all the cool things birds can do. It doesn’t take us long to realize that our feathered friends are vastly more fascinating compared to humans. Now that you’re finally admitting defeat, I ask that you read on.

The most amazing avian physiological feat is the ability to travel long distances seasonally (a.k.a migrate). Between poor weather conditions, preventing fat loss, and staying alert, migration is not easy by any means. However, birds can cope with all of these things by assimilating and using antioxidants like vitamin E.

Here’s a classic bird migration scene: thousands of Tundra Swans, geese, and ducks congregate on the Mississippi River in Minnesota. Here, they rest and refuel before continuing their journey south. Photo by Alyssa DeRubeis.

Let’s talk a little bit about bird migration. It’s a two-way street, where a migratory bird will (usually) fly north as soon as possible to rear its young, and then fly south where it can stay warm and eat all sorts of goodies. During these two bouts of intense exercise, the birds produce free radicals, which are types of atoms, molecules, and ions that can harm DNA and other important stuff inside the body. This is where vitamin E comes in to save the day, because this vitamin, along with vitamin A and carotenoids, are antioxidants. They drive away bad things like free radicals from birds’ bodies; some scientists suggest that they may even reduce risks of cancer! In the case of migrating birds, antioxidants can make this migration headache a lot more bearable.

Well, that’s great. But where do these antioxidants come from? The short answer is avian nom-noms, but it’s one thing to eat something with an antioxidant in it. It’s quite another to actually be able to assimilate and use this antioxidant. Okay…so where do the birds get this ability from? It’s parentals!

Anders Møller from the University of Paris-Sud, along with his international team including Clotilde Biard (France), Filiz Karadas (Turkey), Diego Rubolini (Italy), Nicola Saino (Italy), and Peter Surai (Scotland), pointed out that there is little research looking at maternal effects on our feathered friends. Møller hypothesized that maternal effects (the direct effects a mother has on her offspring) play a critical role in migration: If mothers put a lot of antioxidants in their eggs, the chicks will be able to absorb antioxidants better later in life. This would give these birds a competitive edge because they will migrate in a healthier condition and arrive to breeding grounds earlier.

This male Barn Swallow on the left must’ve gotten back pretty early for him to have landed himself such a beautiful female. Thank you, Vitamin E! Photo by Alyssa DeRubeis.

In the early 2000s, Møller and his five colleagues collected 93 bird species’ eggs. The crew was able to analyze how the natural differences in antioxidant concentrations (put in by the mother) related to the birds’ spring arrival dates in 14 of them. They found that vitamin E concentration, but not vitamin A concentration, was a reliable predictor of earlier arrival dates.

This European posse took it a step further by injecting over 700 barn swallow eggs with either a large dose of vitamin E or a dose of corn oil (which contains a small amount of vitamin E). It was soon evident that the chicks with more vitamin E were bigger than chicks that received less vitamin E, thus already giving the big chicks a competitive edge over their less vitamin E-affiliated brethren. The researchers kept track of the eggs that hatched out as males in the following spring via frequent mist-netting sessions (a bird-capturing technique). Guess what? The fellas with higher vitamin E concentrations arrived earlier on average by ten days than those with lower concentrations!

Sweet. But what does it all mean? First off, vitamin E is crucial for migratory birds because it allows them to process antioxidants more efficiently. In fact, another study done by Møller, Filiz Karadas, and Johannes Emitzoe out of University of Paris-Sud suggested that birds killed by feral cats had less vitamin E than birds that died of other reasons. Furthermore, the early birds get the worm. Events such as insect hatches—vital for baby birds—now occur earlier in the spring as temperatures rise (read: climate change). Plus, if you’re a male arriving at the breeding grounds early, you get to pick the best spots to raise your offspring.

Wood-warblers, such as this Palm Warbler, must get back to their northerly breeding grounds in a timely fashion in order to hit the insect hatch for da babies. Photo by Alyssa DeRubeis.

Obviously, there’s an advantage to up the vitamin E intake and get a head start as a developing embryo. In an egg, most nutrients come from the yolk…which comes from the mother. The healthier the mother, the more vitamin E she will put in her eggs. And vitamin E isn’t produced internally; birds must consume it. While Møller’s paper on maternal effects states that vitamin E can be found widely in nature, a separate study found no apparent association between vitamin E and avian diet. Hmm. So then where DO birds get vitamin E from? Is it a limiting resource? Is there competition for it?

Clearly, we’ve got some questions and answers. As the field of “birdology,” advances, we will learn more and keep humans jealous of birds for years to come.

REFERENCES

1. Møller, A., Biard, C., Karadas, F., Rubolini, D., Saino, N., & Surai, P. (2011). Maternal effects and changing phenology of bird migration Climate Research, 49 (3), 201-210 DOI: 10.3354/cr01030

2. Møller AP, Erritzøe J, & Karadas F (2010). Levels of antioxidants in rural and urban birds and their consequences. Oecologia, 163 (1), 35-45 PMID: 20012100

3. Cohen, A., McGraw, K., & Robinson, W. (2009). Serum antioxidant levels in wild birds vary in relation to diet, season, life history strategy, and species Oecologia, 161 (4), 673-683 DOI: 10.1007/s00442-009-1423-9