Tag: birds

Gruesome but amazing falcon behaviour

August 28, 2015 • 7:45 am

JAC: In lieu of our usual dollop of living creatures in “Readers’ wildlife photographs,” I’ll post this contribution by Matthew.

by Matthew Cobb

Eleonora’s falcon (Falco eleonorae) is a kind of hobby with a wingspan of about 1 meter which breeds on Mediterranean islands and overwinters in Madagascar. It’s a rather fine-looking bird, as this photo by Jürgen Dietrich from Wikipedia shows:

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Outside of the breeding season, Eleonora’s falcon mainly eats insects, but when there are babies about they will take larger prey, including other birds. A short paper has just been published in Alauda, the journal of the Société d’Etudes Ornithologiques de France, which reveals that in one population of this species, predation can take on quite a gruesome aspect.

As reported on Morrocanbirds and another of other sites (I haven’t been able to read the original article), the discovery is part of a long-term study of a population of this falcon off the Moroccan Atlantic coast by Moroccan scientists. According to the article, the birds will sometimes catch their prey and then, rather than feeding it to their chicks straight away, they store them, alive, sometimes having removed the flight feathers of the poor victim.

The Morrocanbirds piece includes two grim photos by Abdeljebbar Qninba of doomed birds, the first of a chiffchaff sans tail and wing feathers, the second of a common whitethroat peering from its prison:

Many birds in temperate regions will stash the bodies of their prey for later consumption. In the case of the shrike or butcher bird, this can become quite macabre, with bodies impaled on spikes. Eleanor’s falcon appears to have taken the process a step further – in the heat the Moroccan coast, any stashed body would rapidly dry out. By disabling and imprisoning the prey for a while (it is not clear what is the maximum duration – at least a matter of days), their food will stay fresh for longer…

Here’s a picture of an adult brooding a pair of eggs, from here. It looks pretty cross.

Of course, this is no different from the behaviour of many hymenoptera, which paralyse their prey (generally caterpillars, but in some cases spiders), lay eggs inside them or next to them and then wall them up in a hole or a pot, where the victim is slowly eaten alive by the maggots…

To paraphrase Miranda from The Tempest, and with only a touch of irony:

Oh, wonder! How many goodly creatures are there here!

How beauteous nature is!

O brave new world that has such creatures in ‘t!

Reference: Qninba, A., Benhoussa, A. Radi, M., El Idrissi, A., Bousadik, H., Badaoui B. & El Agbani, M.A. 2015. Mode de prédation très particulier du Faucon d’Éléonore Falco eleonorae sur l’Archipel d’Essaouira (Maroc Atlantique). Alauda 83(2): 149-150.

More about that bird (and readers’ wildlife photographs)

May 31, 2015 • 7:45 am

by Greg Mayer

The unidentified leucistic bird in the photos sent by my Wind Point correspondent have generated a lot of interesting discussion (as well as a heart-rending tale from one of our regular commenters). Most of the debate has been grackle vs. cowbird. When I first saw one of the pictures (the third of those I posted), I thought it was a crow, but zooming out showed it was much smaller. My correspondent had suggested cowbird, and that was my suspicion too, due to the brown ‘hood’. But as several readers pointed out, the bill is not conical and finch-like like a cowbirds. I should also say the native habitat is deciduous forest– sugar maple, basswood– with prairie/savanna not far off, but far from the more coniferous northern forests of Wisconsin, which makes something like a gray jay highly improbable on distributional grounds.

Several readers have commented on the enlargement and jpeg artifacts interfering with deciphering. I’ll ask my correspondent if he has the original files in a more lossless format, but in the meantime here are the pictures not enlarged, which may aid in identifying the bird. The size of the bird is easier to judge with more context, and, in the third picture, you can see that it was in company with a grackle. (My correspondent thought the other bird was a starling, but the light mark near the head is not its bill; IIRC, he had other photos that when we checked showed it was a grackle. The presence of the grackle might lean one toward the leucistic bird being a grackle, but icterids often occur in mixed species flocks.

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I’ll add some bird photos sent by three readers. From Stephen Barnard, who seems to see every U.S. bird in Idaho, we have a pair of American white pelicans (Pelecanus erythrorhynchos), which are in fact known to breed in parts of the state:

This is a mated pair. The males grow a weird “horn” on their beaks during breeding season. These are very large birds and voracious fish eaters, so I chase them away from the creek whenever I see them.

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And some photos from England by reader Mal Morrison:

A few photos taken over the last couple of days on Roborough Down, which is land between Plymouth and Dartmoor in Devon. The first couple is of a Linnet (Carduelis cannabina). The next is, I think, a Corn Bunting (Miliaria calandra) although I’m open to correction not having seen one before. The last is a Meadow Pipit (Anthus pratensis) with its breakfast.

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And, in Diana MacPherson’s part of Canada, the male (but not the female) hummingbirds have arrived from the south:

Male Ruby Throated Hummingbird (Archilochus colubris) fluffs feathers as he guards his nectar

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What bird is that? (and some readers’ wildlife)

May 30, 2015 • 9:00 am

by Greg Mayer

In the following photos, we have no problem spotting the bird– it sticks out like a sore thumb. Rather, the problem is the bird is not a nightjar– it’s pretty much the opposite in terms of background matching! We’ve recently paid some attention to color variation in squirrels, and reader Jason sent some especially marvelous photos of a multicolored gray squirrel from Toronto. We have here another case of distinctive color variation in a vertebrate. So distinctive, in fact, I’m not sure what kind of bird it is– can readers help me out here?

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The pictures were sent by my Wind Point, Wisconsin, correspondent,  who is an accomplished photographer, but the above pictures are much enlarged from originals shot through a glass window, hence the resolution is not as crisp as might be hoped for. The bird was in his yard in Wind Point, not far from Lake Michigan, and the pictures were taken on May 11.

I have an idea as to what it is, but I won’t say so as to not influence readers’ identifications. Please weigh in with your identifications below.

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JAC: I’m adding on to Greg’s post two pictures that will count, along with the leucistic bird above, as readers’ wildlife photos. They are by Stephen Barnard of Idaho, and show a great horned owl (Bubo virginianus) and a great blue heron (Ardea herodias):

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Nuttall Club in the New York Times

November 29, 2011 • 1:02 pm

by Greg Mayer

To show I don’t hold a grudge against birds, I’d like to point out that the New York Times today has a fine article by Cornelia Dean on the Nuttall Ornithological Club, the oldest ornithological society in the country, based at Harvard’s Museum of Comparative Zoology. Theodore Roosevelt, one of the few (only?) presidents to publish scientific papers, was a member.

Woodpeckers form the MCZ collection on display for the Nuttall Club. Top to bottom: imperial, ivory-billed, and pileated. MCZ photo.

The Club’s journal, the Bulletin of the Nuttall Ornithological Club began publishing in 1876, and in 1884 was taken over by the American Ornithologist’s Union as The Auk, which is to this day arguably the world’s premier bird journal, rivaled only by the British Ornithological Union‘s Ibis.

  Volume 1 of the Bulletin is available at the Biodiversity Heritage Library here, and the other volumes, also at BHL, are available here. (The BHL is a great resource for older biological literature. Its coverage is hit and miss, and its searches a bit clunky, but items it has are in high quality pdf scans. Whole volumes are scanned as single documents, so they have to be electronically ‘cut up’ to get single articles or numbers as pdfs.) The Auk is available through 2001 on another fabulous website, the Searchable Ornithological Research Archive (SORA), which contains pdfs of most North American ornithological journals up to about 1999-2008 (varying by journal).

The Club currently publishes two monograph series, Publications of the Nuttall Ornithological Club, and the Memoirs of the Nuttall Ornithological Club; several issues of both are on the shelf to my right as I type this.

Preserved protein from an 80-million-year old dinosaur support the dinosaurian origin of birds

May 6, 2009 • 6:16 am

In this week’s Science we find a paper by Schweitzer et al. (total of 16 authors!) that has a quite remarkable result. (See the one page summary by Robert Service here.)  The upshot is that protein-sequence data from an 80-million-year old duckbilled dinosaur supports the dinosaurian origin of birds.

This story has a bit of a tortuous background.  First of all, we’ve known for a long time that birds evolved from gracile theropod dinosaurs; the fossil and anatomical evidence is given in WEIT.  But for some folks, DNA-based data is more convincing than is the fossil record.  And molecular evidence is what Schweitzer et al. provided.

In 2007, her group published a paper purporting to show that fragments of the protein collagen (a structural protein found in blood vessels and connective tissue), taken from a 68-million-year old fossil of T. rex, showed that the protein sequence (which reflects the DNA sequence) was more similar to that of birds than to that of modern reptiles. This strongly suggests that birds evolved from a lineage of dinosaurs that had already branched off of the lineage that gave rise to modern reptiles.  This meant that birds and dinosaurs are each other’s closest relatives compared to say, turtles or iguanas. In fact, many systematists say that birds are dinosaurs, which is the conclusion you’re forced to if you’re a hidebound cladist.  I mentioned this paper in WEIT in footnote 11 on p. 237 (this was probably the last thing I put in the book). Of course this result was no surprise to paleontologists.

As recounted by Service, this result was sharply questioned by other researchers, who claimed that the protein sequence was due to contamination; many others thought it was hard to believe that any protein could survive for so many millions of years.  I was a bit depressed about this, because I had already put the result in my book and there was no opportunity to change it before publication.  Also, it was just such a cute result — the kind of new finding that gets our juices flowing as scientists.

Well,  Schweitzer and her team persisted, and her new result supports the old one.  This time the group extracted protein fragments from the femur of a duck-billed dinosaur, Brachylophosaurus canadensis, collected in Montana. Great care was taken to prevent contamination.  They found that some of the elements in the demineralized bone bound to  antibodies made against bird collagen, indicating that collagen fragments similar in sequence to those of birds were present in the bone.  The same was found with antibodies for hemoglobin and two other structural proteins.

Some biochemical wizardry on bone extracts identified eight fragments of collagen, and their sequences (also determined in a separate lab to preclude contamination) were determined.  Sure enough, they were similar to the T. rex fragments that were questioned earlier, and were more similar to collagen sequences of modern birds than to those of modern reptiles. (See the phylogeny below.)  Note that there’s a small disparity between the fossil and biochemical evidence:  T. rex, as a theropod (the group that gave rise to modern birds), should be more closely related to modern birds than is B. canadensis.  This discrepancy might be an artifact of not having a complete protein sequence.

Let’s be clear: the phylogeny that we get doesn’t really tell us anything we didn’t know before.  Birds are highly-evolved dinosaurs, and that was already confirmed by the fossil record.  Still, it’s nice to have this molecular confirmation, and perhaps the most surprising result is the ability to determine the sequences of protein fragments that have survived for millions of years.  If this can be done with other fossils, we’ve suddenly gained the ability to solve many long-standing puzzles about ancestry and evolutionary relatedness.

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Phylogeny showing closer relationship between dinosaurs and birds (Gallus = chicken, Struthio = ostrich) than between either of these groups and modern reptiles (alligators and Anolis lizards).  Ergo, birds are dinosaurs.


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Brachylophosaurus canadensis, the duck-billed dinosaur whose proteins were sequenced.  Illustration by Julius T. Csotony from Science article.

Schweitzer, M. H. et al.  2009. Biomolecular Characterization and protein sequences of the campanian hadrosaur B. canadensis. Science 324:626-631.

More birdlike behavior in theropod dinosaurs

March 19, 2009 • 8:43 am

In WEIT I describe and show a picture of birdlike sleeping behavior in theropod dinosaurs: a fossil was discovered of a therpod sleeping with its head tucked underneath its forelimb (and tail curled around), a posture nearly identical to the sleeping posture of modern birds. Now an article has appeared in PLoS (Public Library of Science) showing even more birdlike behavior of theropods: “Bird-Like Anatomy, Posture, and Behavior Revealed by an Early Jurassic Theropod Dinosaur Resting Trace,” by Andrew R. C. Milner, Jerald D. Harris, Martin G. Lockley, James I. Kirkland, and Neffra A. Matthews, which you can find here.

It turns out that Milner et al. uncovered several sets of theropod tracks from fine Utah sandstone about 198 million years old. They show the impressions of theropods of the species Eubrontes gigante and Dilophosaurus wetherilli walking (and dragging their tails), as well as resting on both hind AND front legs. (Front-leg impressions are rare in theropods since they were obligately bipedal.) When the beast rested, it brought its hindlimbs (manus) together symmetrically (in line) and rested its forlimbs (pes) on the ground, with the hands pointing inwards (see the impressions in the original article showing handprints). The authors conclude that theropod hands always faced inwards when the arms were stretched out–a configuration identical to that of modern birds. Apparently the palms-in position evolved very early in the theropods, presumably to help them grasp prey.

The more we learn about theropods, the more we see that many of the features that were later co-opted in flight were “pre-adaptations”–that is, traits evolved for one use in the theropods that were later hijacked for flying by their bird descendants. Another such feature is feathers, which we’ll discuss tomorrow. Clearly, the evolution of birds from dinosaurs was not as mysterious and maladaptive as touted by creationists. As is usual in evolution, new adaptations are simply old ones that have been refashioned.

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Reconstruction of the theropod Dilophosaurus wetherilli resting after having walked on mud. Note inward-facing palms. See original paper for the tracks that led to this reconstruction. Drawing taken from Milner et al. paper.

More on the evolution of flight

January 30, 2009 • 4:51 pm

As I discuss in WEIT, the evidence shows that birds evolved from theropod dinosaurs–gracile, carnivorous beasts that walked on two legs. Some of the important evidence comes from Chinese fossils showing theropods with various types of feathers. The incipient stages of feather evolution appears to be filamentous feathers (T. rex might well have been covered with fluff!), implying that flight feathers originated as devices to help insulate the theropods. In a recent paper in Nature, however, F. Zhang et al. found a theropod fossil (Epidexipteryx hui), about 160 million years old, which had not only the downy feathers (feathers completely unsuitable for flight) but also four very long tail feathers that could not have been used for either flight or insulation. E. hui also showed a number of morphological features that seem to make it closely related to modern birds. The most likely explanation for these tail feathers is that they were ornaments–ornaments that evolved for either species recognition or via sexual selection. The evolution of flight, then, may have begun with feathers that were used for display. A somewhat fanciful reconstruction of the beast is shown below.

Epidexipteryx hui (reconstruction)
Epidexipteryx hui (reconstruction)