Given your conclusion of no outside trauma, I would hazard a guess that it might have ingested some pesticides while getting nectar.

Systemic insecticides are suspected as a cause for bee ?colony collapse disorder?. Both seed and foliar applications appear to poison the pollen that bees need.
That being the case, I see reason to suspect that the nectar could also be poisoned.
This is not good.

It might have had a congenital condition, but the symptoms sound similar to being poisoned.


Christine Southwick
N Seattle/Shoreline
clsouthwick at pugetsoundbirds.org
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

On Thu, 21 Jul 2011, Allison Reak wrote:

> Date: Thu, 21 Jul 2011 11:30:40 -0700
> From: Allison Reak <areak at earthlink.net>
> To: tweeters at u.washington.edu
> Subject: [Tweeters] hummingbird death story and carcass
>
> A juvenile Anna's died at my feeder last night. It appeared quite sick and
> had trouble swallowing. It shivered constantly, kept its eyes closed most
> of the time, and repeatedly made a swallowing-retching-convulsive head and
> throat movement with its beak slightly agape and tongue protruding. I
> looked at the carcass with a magnifying glass, but didn't see any
> deformities on the bill, eyes, or feet. Its tongue looks clear and normal.
> It had a few grains of gold pollen on its face, so it had been feeding at
> flowers quite recently. Would anyone/place be interested in the carcass?
> It has been refrigerated.
>
> Over the course of three hours, numerous hummers tried to visit the
> feeder--or perhaps it was the same male and female repeatedly. I sat in a
> doorway, about 3 ft away, and scared the healthy birds away. The male or
> males would try to hit the juvenile's back and "thump" it off the perch.
> Their desire to attack the sick bird was almost greater than their fear of
> me, but my arm-waving prevailed. The female(s) would dash in and hover near
> it, chattering, but didn't go in for a hit. Finally, a persistent female
> zoomed to within about one foot of my face and hovered, which caused me to
> retreat into the house, and then she perched next to the little one for a
> while, making quiet chittering sounds. She stayed should-to-shoulder with
> the shivering bird for a few minutes, then moved to an adjacent perch and
> continued watching the sick hummer and me for a few more minutes, then fed
> and flew off. I was surprised to see maternal behavior over a long-fledged
> chick. She was willing to force me back into the house for access to that
> sick little bird.
>
> I cleaned the feeder, soaked it in a 10 percent bleach solution for an hour,
> then soaked it overnight in fresh water to leach the bleach smell out. It
> will be interesting to see if the hummers return this evening, or if they
> will avoid the feeder with the giant featherless monster who snatches young
> hummingbirds from their perches.
>
> Allison
> <areak at earthlink dot net>
>
>
>
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