Mystery Bird: Western Meadowlark, Sturnella neglecta

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[Mystery bird] Western Meadowlark, Sturnella neglecta, photographed at Carpinteria Salt Marsh in Carpinteria, California. [I will identify this bird for you in 48 hours]

Image: John Callender, 5 December 2009 [larger view].

Can you ID this bird? Can you identify what type of animal killed it? If so, share your comments.

Please name at least one field mark that supports your identification.

There is still some disagreement as to what killed this bird. The photographer says a raptor did it; a commenter claims a predatory mammal (coyote?) did it.

Review all mystery birds to date.

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A couple of (possibly helpful) hints:

* The longest feathers were around 4" to 5" in length.

* I foolishly contaminated the crime scene by picking up a number of feathers to show them to my companions, then put them back down before taking the photo. That batch in middle aligned from lower left to upper right was originally scattered around randomly, like the rest of them.

Escaped cockatiel!

Ahhh, not quite Dexter, but some forensics at last! Nice one John... just got home, have a project to finish, but keen to get started on this a little later...

By David Hilmy (not verified) on 14 Dec 2009 #permalink

John, this is a total shot in the dark... looking for a bird probably at least 8" (which discounts all the yellow-feathered warblers, etc.) that would probably look brownish above with streaked or dappled barring on the wings and with yellow on the breast or belly, documented for the Carpinteria Salt Marsh, and I am simply going to assume that the bird was killed on the ground perhaps because it tends to feed or nest there, so all I can think of would be a Western Meadowlark (Sturnella neglecta), perhaps caught and eaten by a coyote...?

By David Hilmy (not verified) on 14 Dec 2009 #permalink

Whoa, strike that coyote... the way a raptor plucks it's prey before eating totally slipped my mind, so I'm going to guess that this bird was caught and eaten by something like a Northern Harrier, an American Kestrel, or a Sharp-shinned Hawk... (still going with Western Meadowlark for dinner)

By David Hilmy (not verified) on 14 Dec 2009 #permalink

Hilmy- That's funny you say it might have been eaten by an American Kestrel because I was going to suggest it is and American Kestrel. That was before I saw the size of the feathers - Kestrels are small, but not that small. But then, I am very far from being an expert. I was going to say American Kestrel because of the broad, barred feathers reminded me of birds of prey, and it's the only bird of prey in North America I can think of with blue coloration. Someone enlighten me.

By cs shelton (not verified) on 14 Dec 2009 #permalink

It's the grey spotted frecklefart

Wow, been off-line for an upgrade for 8 days and come back to a pile of feathers!! Surely the yellow feathers are the key, I can't think of a raptor or grousey thing that would show these. So I'm with David Hilmy either an Eastern or Western Meadowlark. I think the giveaway is the feather on the middle left with an all white outer and barred inner web which is a Meadowlark tail feather, according to NatGeo field guide. Yes, plucked by a raptor.

Damnation, I forgot to say as it's California it must be Western.

I give up on the bird, but believe it was killed by a mammal, most likely a coyote. The ends of the feathers are blunt, suggesting that they were bitten off, not plucked.

By Judy Bass (not verified) on 15 Dec 2009 #permalink

@cs shelton:

The bright yellow feathers rule out any bird of prey -- at least in N.Am., and I think anywhere in the world. Barred flight feathers are common in birds of prey, but are also common in grouse, for example. Of course, the yellow rules them out completely as well.

As far as the blue color that you're referring to, that appears to be the down feathers and base to the body feathers -- all parts that you don't normally see. Male Kestrels would show blue primaries and orange tail feathers with a single dark bar, not brown like this. Female Kestrels don't have the blue. Both of them do have some blue on the head, and that could show up as body feathers, but again those bright yellow feathers don't fit.

The white flight feathers (especially the one at the bottom) strongly suggest Meadowlark, which would show bright yellow. I can't come up with another bird that should show the combination of barred wings and yellow color.

On the ID, I failed to call it in the field, even though several Western Meadowlarks flew overhead right where we were within minutes of our finding the pile of feathers. But I showed it to the significantly more-experienced birder who was leading our walk at the marsh, and he called it right away, and after he'd done so it seemed obvious, what with the yellow feathers.

On the question of what killed the bird, he pointed to the sheared-off ends of the shafts, and said that was indicative of a raptor kill. A red fox (which we have several of in the marsh, and one of which we saw not far from this pile of feathers) would pull out the feathers in bunches, while a raptor, he said, would neatly snip off the shafts individually, as had been done here.

In terms of what raptor would be the most likely killer, we have several that I've seen in the vicinity that I'd think would be potential suspects: Red-tailed, Cooper's, Sharp-shinned, Peregrine, and Merlin. The Red-tailed would seem to be on the large side to take out a meadowlark, and the Merlin on the small side, but I really don't know.

A little note on the presumed predator. From my experience, foxes (and I would assume coyotes also) tend to pluck feathers in mouthfuls and so we would expect to see damage to the plumes as well as the shafts; smaller mamals such as weasels will indeed bite through the shaft but so too do raptors, the sharp beaks of which might also leave holes in the shaft itself.

More clues would have been left by the condition of any bones- most raptors will decapitate their prey and damage to the breast bone is common, but the location will also leave us a hint: for example, merlins will pluck their prey on a prominent stone or fence whereas sparrowhawks have regular "plucking stumps" in nearby woodland (from Jon Hardey, Raptors: A Field Guide to Survey and Monitoring. Scottish Raptor Monitoring Group, 2006)

Although not discussing the method of plucking, the following article does discuss the difference in strategies between various raptors, suggesting that Accipitridae have evolved primarily to restrain large struggling prey while they are immobilised by dismemberment rather than relying upon impact as do the members of the Falconini and therefore one could perhaps expect a greater dispersement of feathers at "the scene of the crime"- John, as LFI, will have to judge by his initial observations.

In the Carpinteria Salt Marsh area, our predator therefore would come from one of the following: Northern Harrier; Sharp-shinned, Cooper's, Red-shouldered, or Red-tailed Hawks; White-tailed Kite; Bald Eagle; or even an Osprey- as opposed to a Peregrine, Merlin, or Kestrel.

Fowler, D.W., Freedman, E.A., and Scannella, J.B. (2009) Predatory Functional Morphology in Raptors: Interdigital Variation in Talon Size Is Related to Prey Restraint and Immobilisation Technique. PLoS ONE, 4(11): e7999. doi:10.1371/journal.pone.0007999

By David Hilmy (not verified) on 18 Dec 2009 #permalink