Hi Michael,
We've had sea-eagles take shearwaters (a Short-tailed and a Wedgie on separate
occasions) from behind the boat on pelagic trips out of Port Stephens NSW when
approaching the heads. The eagles have become quite habituated to meeting us as
we approach, due to the attraction of birds behind the boat.
Both birds were taken while preoccupied with foraging - the wedgie taken while
it was just under the surface.
Severe bruising on the back suggests a hit from a sea-eagle is a strong
contender for your S-tShear cause of death. In recent years I've found that
other birds seem to be very high on the sea-eagle's menu list, and they never
seem to miss an opportunity when it presents itself.
It seemed incredible to me that the birds were taken, since the sea-eagles on
both occasions were very conspicuously watching the seabird flock very closely
and only the gulls and terns appeared to overly concerned about their presence.
Allan Richardson
Morisset NSW
On 31/10/2013, at 10:54 AM, Michael Norris wrote:
> Many thanks to Mark Carey for his informed input.
>
> Not wanting to be alarmist or warmist, perhaps he can help with my vague
> recollection that about 5 years ago there were concerns about adverse
> conditions (algae?) in Alaskan waters attributed to climate change that may
> have affected the STSH. Along with that I’ve also vague memories of some bird
> species being significantly affected due to the changing composition of fish
> stocks.
>
> A friend did a couple of autopsies on birds along eastern Port Phillip with
> the following results:
>
> (1) In good condition. Well muscled. Stomach full. Partly digested small fish
> and interestingly 2 small octopus, about 2 inches long. Haemorrhage in the
> abdomen. Not quite sure where from but quite bruised along the back muscles
> (could see this when the abdominal contents were lifted out. Suspect the
> haemorrhage is part of the cause of death but not sure where it comes from?
> External trauma? Are there any predators that might attack them? No signs of
> external injury but difficult to see through all the feathers. No hooks or
> plastic present.
> (2) In very light condition. Stomach empty. Migration stress / starvation
> presumably.
>
> My guess is that the first bird may have been attacked by a Pacific Gull. Is
> that likely? Any other conjectures (the biggest fun in birding)?
>
> And I note it had eaten some small fish.
>
> Michael Norris
> ===============================
>
> To unsubscribe from this mailing list,
> send the message:
> unsubscribe
> (in the body of the message, with no Subject line)
> to:
>
> http://birding-aus.org
> ===============================
===============================
To unsubscribe from this mailing list,
send the message:
unsubscribe
(in the body of the message, with no Subject line)
to:
http://birding-aus.org
===============================
|
