Prey ID

General birdwatching discussion, help with bird identification, and all other things relating to wild birds and birding in NZ that don't fit in one of the other forums.
sandyw
Posts: 19
Joined: Wed Dec 28, 2016 8:11 pm

Prey ID

Postby sandyw » Sun Dec 24, 2017 5:12 pm

I watched a white faced heron feeding at Foxton Beach yesterday. It took a range of prey including crabs, thin worms and this mouthful. It looked to be a fat pink worm as thick as a little finger and about 10 cm long, but the poor quality photo shows it has appendages of some sort. Anyone know what it is?
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DSCN6896.JPG (273.44 KiB) Viewed 2245 times
BombayDave
Posts: 88
Joined: Wed Aug 20, 2014 9:44 pm

Re: Prey ID

Postby BombayDave » Tue Dec 26, 2017 9:41 am

the muscle part of a razor shell
lloydesler
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Joined: Sun Jun 22, 2014 6:39 pm

Re: Prey ID

Postby lloydesler » Tue Dec 26, 2017 11:17 am

It's a Bamboo worm. These are polychaetes which feed on sediment. They withdraw to the bottom of their burrow when they detect movement so the heron must have had a light touch.
Cheers
Lloyd
sandyw
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Joined: Wed Dec 28, 2016 8:11 pm

Re: Prey ID

Postby sandyw » Sat Dec 30, 2017 8:46 pm

The bamboo worm seems to fit the bill, so to speak. Quite a juicy snack.
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David Riddell
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Re: Prey ID

Postby David Riddell » Sun Dec 31, 2017 8:18 am

Definitely a polychaete, but hard to be sure what species. It looks to me like there's a suggestion of fine, closely spaced parapodia (lateral appendages) visible around the middle of the animal, also perhaps a faint longitudinal stripe. The segments on a bamboo worm (Axiothella serrata) are very long, and the parapodia more widely spaced. If I had to stick my neck out I'd suggest a large nereid, maybe Nicon aestuariensis, which has a prominent blood vessel that looks like a stripe running down its back. Or it could be something like Glycera, which is a very muscular, active predator - the red colour's a good match.
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philbattley
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Re: Prey ID

Postby philbattley » Sun Dec 31, 2017 9:48 pm

Nicon is far and away the most numerous work in the Manawatu Estuary, and in their reproductive form condense considerably and become broader with more visible, tightly-packed segments (and hence parapodia). I've only seen a couple (and those were at Miranda) so can't vouch for their colour, but it's possible they are different to non-reproductive individuals. That's the most likely species anyway. I don't think I've ever sampled a Glycera or bamboo worm there.

Cheers, Phil

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