Friday 7 November 2014

A Meadowlark Appears

About a month ago I came across an abandoned field somewhat close to my house that I had previously been unaware of - my immediate impression was that it might be a good spot for sparrows and meadowlarks. I've since checked it 3-4 times, purposefully criss-crossing the field in hopes I'd flush something up. During my first visit there were sparrows everywhere - but none of them were unexpected species. The next couple visits turned up nothing. This morning I happened to be passing by that same field and had meadowlarks on my mind. Wishful thinking of course. But today was one of those days where a dream came true and within a minute of walking out into the field I saw the distinctive shape of a meadowlark flutter towards the ground with its prominent white outer tail feathers.

Even with that 2-second look I was confident enough to send out the text messages. Less than a minute later I had a few "on my way" replies. I flushed the bird once more (it wasn't visible on the ground) and confirmed my previous 2-second view that it was a meadowlark. Lisa was the first person to arrive, she eventually got great photos of the bird in flight - one would think the photos would make the identification straightforward, but it isn't so easy. Even Pyle acknowledges "that this is one of the most difficult in-hand species identification problems" - this is coming from a guy who has probably held hundreds of them in his hand. Today we're stuck with one bird and distant photos.

Without having heard the bird vocalize I had to go to school... photos started streaming into my inbox a couple hours later and things were looking very interesting. Thankfully Lisa de Leon, Ken Knowles, and John Williams all got excellent photos and have been kind enough to let me post them here to help sort out the ID. See Lisa's post for more photos.


Jared Clarke and I have been trying to sort out the ID since this morning. We haven't made any conclusive identifications yet - but, I hate to say it, I don't think this bird is identifiable without hearing it - the few useful plumage characteristics that are described in the literature fail to separate this bird into EAME or WEME - instead the features are intermediate between the two species. In the mean time, here's a compilation of the most useful photos and information that we have gathered.

To start, the most reliable way to separate these two species is by their voice. At this time of year the birds will only call - thankfully the calls are quite distinctive. However,  I'm not sure if anyone familiar with the different calls actually heard the bird today.

The Eastern Meadowlark call is described more as a "dziit" versus a "pluk" from the Western Meadowlark. To me the EAME call is more like a fart!


Included here are 7 photos of todays bird (thanks again to Lisa, Ken, and John!)

EDIT: In my original post I made a noob mistake by reversing the numbering of the rectrices. It didn't really change what the outcome of the discussion was, but probably confused some people! It should all be fixed now...

One of the main plumage characteristics described to separate WEME from EAME in the fall is the extent of white on the rectrices (tail feathers). Meadowlarks have 12 rectrices - they are numbered from inside to outside:

The next photo shows that R6, R5, and about half of R4 are white, while there is a small white area on R3.

Here is a scan of Pyle's diagram of meadowlark tail patterns. EAMEs range from figures A - C, WEMEs range from B - D. So there is obviously quite a bit of overlap. However, the only really expected sub-species of EAME in our area (S. m. magna) has the least amount of white in the rectrices compared to the other sub-species - figures B-C are the only relevant ones for the expected sub-species of EAME.

 Our bird falls somewhere between C and D - much closer to D in my opinion - because it has a small white area along the shaft of R3, and the outer edge of R4 is dark.

This photos shows the dark outer edge to R4.

Another useful resource for studying the Newfoundland Meadowlark has been this website. A feature they point out is the extent of dark along the centre portions of the middle rectrices. EAMEs have more extensive dark areas that are all connected along the centre, while WEMEs have lighter areas that separate the individual dark bars.

This feature is very hard to pick out from todays photos - and considering the wide variation I would say it's best not to make a judgement on what we're seeing. The next two photos come closest to revealing the central rectrix pattern.

A study by Lanyon et. al in 1996 involved hybridizing Western with Eastern Meadowlarks. The resulting rectrices are shown below with Eastern at the top, Western at the bottom, and the hybrid of the two species in the middle.

Our bird fits best with the hybrid combination... the dreaded hybrid...
This is not meant to say that the Newfoundland bird is a hybrid. But certainly indicates that it isn's a "slam-dunk" Western Meadowlark.

This study can be found here.

An important quote from this study:
"Extensive overlap in all mensural characters and in the amount of white in the rectrices precludes the use of these characters for identifying all but the "extreme" specimens."

Other plumage characteristics often talked about are the malar and flank patterns.

Malar pattern is pretty much useless in the Autumn. For what its worth, the malar area on todays bird is buffy. Not white, not yellow.

Flank streaking on Easterns averages heavier and more merged - again, an unreliable feature from what I've been reading.

From all this, I would say that this bird isn't 100% identifiable based on plumage characteristics. Vocalizations are a hope. That won't happen tomorrow though with 100+ km/h winds!!

FWIW, several out of the province birders with a lot more experience with meadowlarks have unanimously said they "think" that it's a Western Meadowlark.