Black-and-White "Warbler": Warbler or Nuthatch? (1 Viewer)

[gthang]

I got a field guide to the Birds of New York (by Stan Tekiela) and I couldn't help but notice that the Black-And-White Warbler has the shape and size of a nuthatch, but is the only "warbler" that can go head-first down tree trunks, which is a feat only nuthatches can do.

This got me to thinking: Is the Black-and-White Warbler really a nuthatch? It has the signature eye-stripe that occurs on all 17 species of nuthatch (including the White-Breasted nuthatch). It also has the rear toe claw that is two times longer than the front toe claws, which is also a feature of nuthatches.

What do you guys think?

 

[lassa8]

It's probably just convergent evolution. Similar niches often result in similar morphologies. Form=function.

 

[Charles Harper]

.. or is it a Dairy Woodpecker?...

 

[gthang]

OK, so I went through other field guides and also noted that there's another warbler that forages like a nuthatch: Yellow-Throated Warbler.

Charles: Must you quote me??? (i'm sure i'm not the person who originally said it, but I used it quite a bit)

 

[crispycreme]

From Warblers, by Jon Dunn and Kimball Garrett (pg. 412):

Black-and-white Warbler is superficially similar to nuthatches (Sitta) because of creeping behavior but differs strongly from all New World nuthatches in having striped underparts and strong wing pattern, as well as a longer tail and thinner bill.​

Also note that the four N.A. nuthatches have straight or even slightly upcurved bills, where B&W Warbler's is slightly decurved.

(side note: we got the Red-breasted Nuthatch recently, giving us all three Western U.S. species )

((would it be asking too much to get the standard, muli-use, ubiquitous smiley face emoticon installed on here? ))

(((And the tongue-sticking-out face too!)))

 

[gthang]

Yeah, I know that the "warbler" has a decurved bill. But that's basically the only thing that makes it un"nuthatch"-like. Even being in its own genus (mniotilta) and calling it the Black-And-White Nuthatch will be more reasonable than calling it a warbler when it clearly isn't!

Also, have not seen a Red-Breasted Nuthatch, and as far as field guides go, Its too late to see them now (will have to wait until next winter....).

Most of the field guides I have say that the White-Breasted Nuthatch is the only nuthatch without the distinguishing eye-stripe found on the Red-Breasted, Brown-Headed, Blue, Pygmy, et al. But for some reason, one of the White-Breasted Nuthatches around here have eye-stripes:

 

[lassa8]

The genus Mniotilta falls under the family Parulidae (New World warblers), while nuthatches fall under the family Sittidae. While these families may be closely related (and the geneticist in me would love to make a phylogenetic tree based on DNA to find out, even if there is already one out there), there's no real justification to call a warbler a nuthatch based on a few morphological traits. There's more to classification than the few features you've been pointing out.

Also, every field-guide I have shows the same eye-stripe your nuthatches have. It's just not as pronounced as in the other nuthatches.

 

[Alastair Rae]

There's a bit more to classification than just plumage and behaviour. Although those are taken into account, species are usually grouped together by more structural similarities. The nuthatches, for example, have their own particulur toe arrangement.

 

[Edward]

It's probably just convergent evolution. Similar niches often result in similar morphologies. Form=function.

An even better example of this is in Australasia where the Sitellas (Neosittidae) replace nuthatches. Hard to believe that they are not closely related to nuthatches. See this
http://montereybay.com/creagrus/sittellas.html

E

 

[cuckooroller]

Black-And-White Warbler has the shape and size of a nuthatch, but is the only "warbler" that can go head-first down tree trunks, which is a feat only nuthatches can do.

This got me to thinking: Is the Black-and-White Warbler really a nuthatch?

What do you guys think?

Gthang,
There is another bird with a certain superficial resemblance to Mniotilta and for which I have seen a number of photos demonstrating it's penchant to sitta-like behavior going down trees head first. It is the last one listed in sequence for Dendroica, and then there is the one species of Catharopeza (haven't the slightest as to what it looks like), and then Mniotilta. It is Dendroica angelae (Elfin-woods Warbler), a Puerto Rican endemic. One of the reasons that bird taxonomy is still so mucked up is that before the advent of mtDNA hybridization techniques, the operators in the field could take into account only the morphology and behavior, etc. This has proven to be misleading as time and time again it has been seen that in certain ecotomes (in particular, insular) a small group of birds over time will differentiate and occupy all possible niches. Examples, Drepanidae in Hawaii, Vangidae in Madagascar, Darwin finches in the Galapagos, to name a few.