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Wednesday, January 30, 2013

Cold Case Costa's

Ten years ago I was struggling to learn how to identify female and juvenile hummingbirds. It wasn't easy then, and it's only slightly easier now. For the past 18 years I've kept a daily journal of what bird species I see at my oasis every day. Throughout December of 2002 I recorded seeing Anna's Hummingbirds. Then, on the 30th, I added the entry, "1 ANHU or COHU". The same for the following day. At some point during the next few days I was pretty certain it was a Costa's and reported it to someone. I don't remember to whom, but it was before I had a computer or used the internet.

In the year 2000 I had 2 Costa's at the oasis, one in September, and the other in December. With sketches accompanied by terrible photos, the Texas Birds Record Committee eventually accepted those sightings as official. At that time, they were only the 8th and 9th documented Costa's for Texas.

Photo taken January 4, 2003
On January 4, 2003, I photographed the bird with whatever film camera I had at the time. Around that same time,  I was contacted by Eric Carpenter, who was doing a Texas Big Year that year, had heard about my Costa's, and wanted to come add it to his year list. He arrived on the evening of the 5th, spent the night in my guesthouse, and did not locate the bird the following day. I had seen it the previous day, but when Eric was there the weather had turned bitterly cold and windy.

All we saw that day were Anna's. I was positive none were the same bird I had been calling a Costa's. No one but me ever saw the purported Costa's. Time passed, and my hectic life sped forward. At some point I sent my film off to some lab, and by the time I got it back, I had probably talked myself out of it being a Costa's. Both the 2000 year birds were juvenile males and had purple gorget feathers, but in different parts of the throat, so that I knew they were different individuals, so were easy to identify. There were no [purple] gorget feathers on the 2003 bird. I simply wasn't knowledgeable and confident enough to pursue the matter. A computer and digital camera would have made all the difference in the world. But in 2003, nothing in my photos told me it wasn't an Anna's.

 As is my habit, when I photograph a bird whose picture I want to paste into my day journal, I leave an empty place to add it later (when it comes back from the lab), with a notation of which species is to fill that space. In the case of this bird, I just sketched a hummer at a feeder to remind me. I had written Costa's as the page title, but at a later point changed that to "Broad-tailed." Bizarre, I know. Goes to show how confused I really was. No one could mistake that bird for a Broad-tailed. But ironically, that's what led me to "reopen the case."

Fast forward to the present. I was wondering if I'd ever had so many hummingbirds in January as I did this year. I checked my ebird entries to see, and noticed an entry for Broad-tailed in January of '03. I knew that had to be an error, so I pulled out my journal for that year and discovered my notations, such as "wings longer than tail," which could only be describing a Costa's. And if that wasn't proof enough, there was the above photograph covering the sketch, unmistakably a hummer of the family calypte, be it Anna's or Costa's. A few days ago I showed the photos to Kelly Bryan, the expert, and he says it's a Costa's. 

One thing that really messed me up in 2003 was that it was the only year I've ever experimented with keeping a journal in species order instead of chronological order. Disaster. So, apparently when I convinced myself that wasn't a Costa's, I used the rest of that page for my 2003 Broad-tailed sightings and changed the page heading. No actual Broad-tailed sightings were entered on the page until April. Then a few years ago, when I entered my old journal data into ebird, the Costa's went in as a Broad-tailed. By that time there had been nothing on the page that actually said "Costa's." (The December 30-31 of the previous year had merely said ANHU or COHU, and was in a separate journal, already archived and forgotten. Entering many years of data was daunting enough without taking the time to analyze the information contained in each entry. But that's not a good excuse, for sure. I can't even come up with a good excuse. Human error?

So now, in January 2013, I reported it belatedly to the TBRC. As luck would have it, Eric Carpenter is on the committee and remembers his visit well. If the committee does accept the report it'll have been the 13th Texas record (The one Kelly banded recently in Study Butte, once official, will then be the 35th Texas record.) 

While I do get an occasional juvenile male Costa's at the oasis, they've all had at least a couple of purple gorget feathers. Obviously, any without purple would have gotten overlooked by anyone but Kelly. He didn't make his first visit to the oasis until 2008.  Even the female that over-wintered near Study Butte/Terlingua a few years ago (2 winters in a row) had a few central purple gorget feathers. (See post label Costa's HU) The 2003 hummer was the only one I'd ever seen without any purple on it until this year's Study Butte one, which Kelly, not me, identified. 

Hopefully, the next one without purple on it won't get past me, even though as recently as my Oct 2012 juvenile male, it was Kelly who ID'd it, alas, not me. But I have a better excuse for missing that one. I had gotten to the oasis just before dark the night before, saw the Costa's, but without enough light to see the color of the gorget feathers. (It had lots of them.) Not getting good looks and seeing all the green on the sides I decided it had to be an Anna's. Then when Kelly arrived to band at daylight the next day, he immediately spotted it and knew what it was.

UPDATE: The TBRC did accept the ten year old sighting.

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