Sunday, October 30, 2011

The realm of miss-ID

Last week while at Van Wagner's Beach (Jaeger-watching) - I had one of those eye-opening experiences that I actually really enjoy.

Cheryl Edgecombe, myself and a few others were busy searching the waves during the strong NE winds. We eventually picked up on two Jaegers, not far, yet not close (outside the wave tower). One was a monster, pretty clearly a Pomarine Jaeger in its own right. The other?

Well the other was visibly smaller... But after years of watching here, and also having them "up close" in the zodiac, I knew size wasn't all it is made out to be with Jaeger ID. Check out these birds below:


Here's two Pomarine Jaegers seen "up close" from the zodiac in recent years. Both were so unbelievably monstrous, their bulk alone clinched the ID of POJA:



Yet we have seen multiple "other" POJA's that were not nearly as large as the above birds. 



So how reliable is size? Just because the second Jaeger is visibly smaller, does it automatically mean it's a different species? I sure don't think so. So I watched the two birds behaviour.  They were "flying together" - but not just "flying together" - they were reallly flying together. Following each other very close, doing some seemingly playful interactions, no true "chases", never breaking apart very far.....

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So there it was. I started loudly proclaiming to Cheryl how after these "close encounters" with Poms over the years, my lack of trust in the "different size = different species" ID, and the fact that the two birds were closely "hanging out" with each other, that I had little doubt that those two birds were both, in fact, Pomarine Jaegers. 
The one "clearly" was, so must be the smaller bird!


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And isn't that just where things threw me for a loop? The birds did a 180 and returned our way. Yet this time they were considerably closer to shore, and providing excellent looks. There was the monster Pomarine, a very nice bird indeed (no photos unfortunately), here's my chance to study the second bird:

-Smaller size
- tail projections obvious 
- limited white on the underside of the primaries
- very few white primary shafts (barely visible)
- funny lemon collar behind the head

----- waaaait a minute

(not thee bird)

there it was, plain as day with a really good scope view. A Juvenile Long-tailed Jaeger directly associating with this juvenile Pomarine Jaeger. Of course the size difference was obvious before ,but really? A Long-tailed Jaeger? Perhaps the strangest thing really was how "buddy buddy" the LTJA and POJA were together... I ran to grab my camera, but we did not see those two birds again. 


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So there I was, right after explaining why I thought they were probably 2 POJA's before, I suddenly had a POJA and LTJA together. It may sound odd to those who never want a bird ID to escape them, but it was one of those moments I really enjoy when birding that reminds you no matter how much you think you know about a given topic, you're going to be wrong sometimes! (and other times, you're really just doing educated guesswork!)

One of the things that makes Jaegers so much fun!



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