birding-aus Bulging crops

["Michael Todd" <>]

Secondly, my father found a dead feral pigeon in his house yard at Pearl
Beach (just north of Sydney).  The only mark or injury he could find on the
pigeon was a hole in its crop.  Apparently the crop was bulging and three
different types of small seeds were spilling out.  My father asked if a bird
could possibly fill its crop and then have the contents expand with
moisture, causing the crop to rupture.  Can anyone advise if this is
possible?  Or is it more likely the cause of death was from something
unrelated?

Hello Fiona,

 

I've sampled seeds from the crops of a lot of finches and I would think that it was unlikely that a bird could die from having the contents expand rupturing the crop. For starters, the seeds don't stay in the crop for very long. Off the top of my head (i haven't analysed this before- maybe I should!) after about an hour a half full crop would be just about empty, so I don't think that there is time for seeds to expand enough to rupture the crop. I am of course, assuming that pigeons would be much the same as finches in their crop function.

 

Regards,

 

Mick

 

Michael Todd
Finch Researcher,
Queensland Parks and Wildlife Service,
Pormpuraaw, Qld, Australia, 4871

-----Original Message-----
From: Johnson, Fiona <>
To: <>
Date: Wednesday, 5 May 1999 11:49
Subject: birding-aus Question - Terns and Pigeons

>Hello All
>
>I have a couple of
questions which I hope someone may be able to answer.
>
>Firstly, I
was on Heron Island (off-shore from Gladstone in Queensland) last
>week
and had a very brief sighting of a tern I wasn't familiar with. 
The
>story:  I was quite happily viewing a small group of terns
resting on the
>shoreline which included Black-naped, Lesser Crested and
Crested.  I had
>seen one Roseate in flight a couple of days before
but not since.  I
>suddenly noticed rich orange-red legs on two
smallish terns and my initial
>reaction was that I must have found some
Roseates.  However, when my field
>of view rose to their heads I
found that they had yellow bills with black
>ends (a bit more than just
the tips) and that their head pattern was black
>and white like Little,
although I thought the change from white to black on
>the forehead was a
bit blunter rather than deeply jagged like a Little's
>usually is. 
At this point, of course, a person ran through the birds
>putting them all
to flight and I never saw these two birds again.
>
>My question
is:  what were these birds?  I'm OK with breeding
plumage
>identification of most terns but not necessarily with
transitional or non
>breeding plumage.  What is smallish, has 
orange/red legs, yellow/black bill
>and black and white head?  I
didn't get a decent size comparison or any idea
>of plumage or wing/tail
length specifics (except it was pale - big deal.
>Aren't they
all?!).  I noted in Pizzey and HANZAB that there have been a
>couple
of historical records of Fairy terns on Heron Island with the
>suggestion
that they may have come over from New Caledonia.  Is it
possible
>that that is what "my" terns were, or is there a far
more obvious answer?
>
>Secondly, my father found a dead feral
pigeon in his house yard at Pearl
>Beach (just north of Sydney).  The
only mark or injury he could find on the
>pigeon was a hole in its 
crop.  Apparently the crop was bulging and three
>different types of
small seeds were spilling out.  My father asked if a bird
>could
possibly fill its crop and then have the contents expand with
>moisture,
causing the crop to rupture.  Can anyone advise if this
is
>possible?  Or is it more likely the cause of death was from
something
>unrelated?
>
>I look forward to hearing from anyone
on these two topics.
>
>Fiona Johnson
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