Thursday, April 30, 2015

Glorious Incertitudes: Olive Warbler and Yellow-breasted Chat

[Mt. Lemmon, AZ and Big Bend NP, TX. April 2015]

We, the human race, are afflicted with a compelling desire to understand all that surrounds us -- fundamentally, we want the world to make sense. We find order in the rhythms of nature and discover structure in the wonders of creation. 

Indeed, in the study of life on this planet, it gives us considerable satisfaction in classifying, sorting, and situating our fellow creatures into a tree of relationships based on shared characteristics and common attributes. But, this resulting taxonomy is not a static construct -- it evolves as new insights unfold.

As an example, consider the Olive Warbler -- at various times in its taxonomic life, it has suffered classification as a New World Warbler (Parulidae), Old World Warbler (Sylviidae), or Finch (Fringillidae). Neither placement was entirely satisfactory and it is now conveniently accommodated in its own taxonomic home: as the one species of a single genus in its own built-for-purpose family (Peucedramidae).  

However, such a bespoke taxonomic solution eludes another enigma -- the Yellow-breasted Chat. While humored as a Wood Warbler, it is clearly not; and, because its exact placement is a "TBD" (to-be-determined), its family is listed simply as incertae sedis ("uncertain placement").

Yet while accepting that both Olive Warbler and Yellow-breasted Chat may be plagued by taxonomic uncertainty, what is certain is that they are uniquely delightful species that attract keen interest from the birding community at large; and, thus, are surely deserving of coverage on this blog -- a feat made possible by a recent excursion to Southeast Arizona and Big Bend National Park (TX).

We start with the Olive Warbler:


Olive Warbler seen at Bear Wallow
Assessed at "Least Concern", the Olive Warbler is found uncommonly in the US mainly in Southern Arizona (and also in a tiny bit of SW New Mexico), however, its global range is much larger -- stretching all the way South to Nicaragua. 

Olive Warbler seen at Bear Wallow
Identification is straightforward -- a turmeric colored head, black mask, grey back, with white belly and two wing-bars. The female and juvenile is paler in coloration.


Olive Warbler seen at Bear Wallow
Found in montane habitat in coniferous forest, this distinctive, insectivorous songbird can often be heard before it is seen thanks to its loud "wheechy wheechy" song.


Olive Warbler seen at Bear Wallow
This particular individual was observed at Bear Wallow, Mt. Lemmon, in a mixed flock of foraging passerines.

Now the Yellow-breasted Chat:
Yellow-breasted Chat seen at Daniels Ranch
The Yellow-breasted Chat neither looks nor sounds like a warbler; it has a prominent, stout bill and at 7+" it is considerably larger than your typical warbler. In song, it doesn't warble -- making instead an assortment of harsh croaks and whistles.


Yellow-breasted Chat seen at Daniels Ranch
The chat ranges widely coast-to-coast across the US and down to Central America. For such a huge distribution, it is a surprise that the Chat is rarely seen -- but this is owing to the chat's secretive and skulking habits.


Yellow-breasted Chat seen at Daniels Ranch
This distinctive songbird was sighted at Daniels Ranch, Big Bend National Park (TX) which, in this blogger's experience, offers some of the best viewing opportunities for this enigmatic species.

At the intersection of Birding and Ornithology is the fundamental issue of the classification of species; however, this is a consideration that fades into the background when confronted by the striking personalities of these two iconic species of glorious incertitudes.  

1 comment:

  1. Another wonderful report, Hemant. An interesting story that will undoubtedly have another chapter.

    ReplyDelete