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Tetrapod Zoology

Tetrapod Zoology

Amphibians, reptiles, birds and mammals - living and extinct

Like Dinosaurs, Birds Can and Do Wrestle

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No time to finish anything new, gah. In desperation, here's a classic article from the Tet Zoo archives, originally published in March 2009. It has some minor updates.

Battling Great tits (Parus major). I don't know the name of the photographer but will add it when I find out.

I used to receive random unsolicited emails from an individual who strongly promoted the idea that birds could not not not not be dinosaurs, that the entire dinosaur family tree was screwed up beyond belief, that ‘dinosaurs’ had evolved from random assorted diverse archosaurs, that cladistics was rubbish, and that all mainstream palaeontologists were idiots [UPDATE; I still do]. For some reason, the study of dinosaurs attracts people with strong ‘fringe’ beliefs. This must be a by-product of popularity, as you don’t get this with temnospondyls, fossil ostriches, Eocene primates, corals or sea jellies (at least, as far as I know).

The famous 'fighting dinosaurs': Velociraptor (lying on its side) vs Protoceratops. Image by Yuya Tamai, licensed under Creative Commons Attribution 2.0 Generic license.

Anyway, said individual claimed that the ‘fighting’ specimen of Velociraptor [shown above; image by Yuya Tamai] provided compelling evidence for his assertion that feathers were indisputably absent in non-avialan maniraptorans. The Velociraptor is lying on its side, its left hindfoot jammed up against the Protoceratops's neck, its left hand is gripping the Protoceratops's frill, and its right arm is clamped shut in the Protoceratops's beak. Anyway, the fact that the Velociraptor in question is on its side, apparently grappling with this formidable opponent, was taken by said individual to show that feathers must have been absent. After all, said individual argued, feathers would get damaged and broken if their owner grappled in this fashion, and hence feathers are utterly incongruous with this sort of predation.

Needless to say this is all insane rambling nonsense. Like it or not, Velociraptor and kin really did have feathers: as if the presence of indisputable feathers in other dromaeosaur and maniraptoran specimens is not proof enough (e.g., Ji et al. 1998, 2001, Zhou et al. 2000a, b, Hwang et al. 2002, Norell et al. 2002, Norell & Xu 2005), the presence of quill nodes in Velociraptor (Turner et al. 2007) demonstrates once and for all that this animal was feathered [UPDATE: and, of course, numerous additional feathered non-avialan maniraptorans have been discovered since this was written].

Fighting European starlings (Sturnus vulgaris); image by Matthew Wills, from the Backyard and Beyond blog.

As it happens, the idea that feathered dinosaurs could not/cannot and did not/do not wrestle or grapple with prey is also absurd and woefully naive nonsense. Birds of many species often roll or squirm around on the ground (sometimes for protracted periods) when subduing prey or fighting. A series of photographs taken by Shelly Grossman, and appearing in various of Roger Tory Peterson’s books (e.g., Peterson 1968), show a Great horned owl Bubo virginianus fighting with, and killing, a snake. The owl is literally lying on its side, grappling with the snake on the ground and grabbing it in both its bill and feet. Perhaps even more impressive are those cases when birds – particularly passerines – get into territorial scraps and, similarly, roll around on the ground and wrestle with their feet. I’ve seen male Blackbirds Turdus merula do this but have never been quick enough to photograph it.

More battling starlings wrestling on the ground. Image from Flux & Flux (1993).

Due, it seems, to intense competition over nesting boxes, introduced starlings Sturnus vulgaris in New Zealand have been observed and photographed engaging in long, protracted wrestling bouts. The two combatants grasp each others heads in their feet and then try to dig their claws into the opponent’s eyes (Flux & Flux 1993). Even when picked up by people, the birds continue to fight, and some individuals die this way, locked in combat. For several fighting starling images in addition to the one used above, see this article on Matthew Wills's Backyard and Beyond blog. Bell (2002) reported a case in which two fighting New Zealand starlings fell off the edge of a roof while locked in wrestling combat, landed on another roof, and eventually fell off this too, then landing on the ground four metres below. They fought all the while, this going on for an incredible 45 minutes. There are other reports of this protracted terrestrial wrestling in the starling literature, but it isn’t unique to starlings. Taylor (1969) reported two male Bellbirds Anthornis melanura that were also found locked in combat, and there are other examples of this sort of thing in the literature. Wrestling Great tits Parus major are shown at the top of the article.

So, birds can and do wrestle, sometimes engaging in protracted terrestrial bouts of foot-gripping that literally involves the birds tumbling and rolling around on the ground. Ergo, the fact that non-avialan theropods like Velociraptor apparently engaged in this behaviour is perfectly concordant with the fact that they were feathered too. Birds are pretty metal, just like the dinosaurs they descend from.

And seeing as this article is partly a celebration of the dinosaurian nature of birds, I suppose it's as good a time as any to advertise the existence of the following t-shirt design. You can buy it here at the Tet Zoo redbubble shop.

The text says, at top: You know those small flying dinosaurs you see all over the place? ... and, at bottom: I think some people call them "birds".

Next: Katrina van Grouw and The Unfeathered Bird!

For previous Tet Zoo articles on interesting aspects of bird behaviour, see...

Refs – -

Bell, B. D. 2004. Prolonged aggressive encounter between two starlings below a prospective nest site. Notornis 51, 53-55.

Flux, J. E. C. & Flux, M. M. 1993. Nature red in claw: how and why starlings kill each other. Notornis 39, 293-300.

Hwang, S. H., Norell, M. A., Ji, Q. & Gao, K. 2002. New specimens of Microraptor zhaoianus (Theropoda: Dromaeosauridae) from northeastern China. American Museum Novitates 3381, 1-44.

Ji, Q., Currie, P. J., Norell, M. A. & Ji, S. 1998. Two feathered dinosaurs from northeastern China. Nature 393, 753-761.

- ., Norell, M. A., Gao, K.-Q., Ji, S.-A. & Ren, D. 2001. The distribution of integumentary structures in a feathered dinosaur. Nature 410, 1084-1088.

Norell, M. A., Ji, Q., Gao, K., Yuan, C., Zhao, Y. & Wang, L. 2002. ‘Modern’ feathers on a non-avian dinosaur. Nature 416, 36-37.

- . & Xu, X. 2005. Feathered dinosaurs. Annual Review of Earth and Planetary Sciences 33, 277-299.

Peterson, R. T. 1968. The Birds. Time-Life International, Nederland.

Taylor, R. H. 1969. Male Bellbirds locked in combat. Notornis 15, 63.

Turner, A. H., Makovicky, P. J. & Norell, M. A. 2007. Feather quill knobs in the dinosaurVelociraptor. Science 317, 1721.

Zhou, Z.-H. & Wang, X.-L. 2000a. A new species of Caudipteryx from the Yixian Formation of Liaoning, northeast China. Vertebrata PalAsiatica 38, 111-127.

- ., Wang, X.-L., Zhang, F.-C. & Xu, X. 2000b. Important features of Caudipteryx – evidence from two nearly complete new specimens. Vertebrata PalAsiatica 38, 241-254.

The views expressed are those of the author and are not necessarily those of Scientific American.

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