Impaled Moth (1 Viewer)

[jeffnsue]

Attached is a photo taken on my phone as I was searching for Irish Lady’s Tresses on Benbecula. It shows an Elephant Hawk Moth impaled on barbed wire. In my limited experience the only UK predator I know to do this is one or other of the shrikes. As the moth flies in May/June it can not be an overwintering shrike that is the culprit, leaving only Red-backed Shrike as a possibility. It is said that a Schedule 1 bird is breeding at the site which I took to be Red-necked Phalarope but who knows, could there perchance be a conspiracy of silence.

Enquiries of Scottish Natural Heritage regarding alternative culprits drew a blank, and an email exchange with a local naturalist did put a damper on things when he reminded me that shrikes don’t fly at night and suggested that the moth may have impaled itself by accident. That argument overlooks the fact that the moth would have been lying up during the day and could have been taken by a predator in daylight hours.

Perhaps it’s not easy to see from the photo, but this did not happen by accident and in my experience moths do not generally fly backwards onto spikes of barbed wire. Can anyone with more wisdom than me shed some light on this mystery.

Jeff Hodgson

 

[Corvus cornix]

Hi,

I can't explain how the moth became impaled on the wire, it's not possible to see from the photo exactly how it was impaled. As you say, a Shrike would be the obvious candidate, but I know they don't breed there.

I know the site in question, and there is a Schedule 1 species that breeds there, but not a Red-necked Phalarope or a Red-backed Shrike.

The only possibility I can suggest is that the moth was caught in strong winds and blown onto the wire by sheer chance. It may seem a bit of a long-shot, but I can't think of another scenario.

Cheers.

 

[Sangahyando]

Hi,

I can't explain how the moth became impaled on the wire, it's not possible to see from the photo exactly how it was impaled. As you say, a Shrike would be the obvious candidate, but I know they don't breed there.

Couldn't it just be a non-breeding RBS, though? Aside from other explanations, of course.

 

[Nutcracker]

It needn't be a breeding pair of shrikes, a single unpaired shrike on passage could also account for it. Perhaps most likely Red-backed, but Woodchat and Lesser Grey are also possible.

I don't know the site, but my guess for a local breeding Schedule 1 bird would be Corncrake.


Edit: cross-posted with Sangahyando

 

[jeffnsue]

I really can’t think it happened by accident or as a result of strong winds, after all a barbed wire spike is a pretty big and blunt thing if you’re a moth.

I understood the Schedule 1 bird to be Red-necked Phalarope but saw no sign of those birds, I guess it’s late in the season now, nor did I hear or see Corncrake

JMH

 

[Corvus cornix]

The Corncrakes haven't had a particularly good year, this year. Not sure about the Phalaropes, but I think the wet summer has affected most breeding species up there.

Cheers

 

[Gladiator96]

Are you sure it's impaled? Don't think there's a 'spike' going through it (compare with the one in the background). Maybe it just died in a weird position.

 

[Paul Chapman]

There are some specialists on the Rare Bird Information forum after the Savannah Sparrow hoax that could help on two & three prong barbed wire. Was it that species?

Presumably the white wispy filaments apparently coming out of the abdomen are the remnants of the cobweb it was once caught in?

All the best

 

[Andy Hurley]

Being familiar with the wind up in Bebecula, it could have been picked up and impaled by the wind. I'm not saying it was, mind you, but fully grown adults have been picked up and dumped by the wind, my wife included.
I think that a Red-backed Shrike is far more likely. They are called Neuntöter in German, because of their habit of impaling their food on thorns in their "larder". Legend has it that they have to kill (töten) at least nine (neun) animals before they can start eating, hence the name.

 

[Daniel Martin]

I think Paul has it with cobweb strands. I wouldn't necessarily say its been impaled.

 

[Paul Chapman]

The more I look at it, the more it has the look of a pristine desiccated spider victim rather than a bird victim.

All the best

 

[Farnboro John]

I looked at the other barb in the photo and it clearly shows that where the moth is, a barb is right through it. The spider is a late-comer to this party. I'm in the passing shrike camp.

John

 

[Paul Chapman]

I looked at the other barb in the photo and it clearly shows that where the moth is, a barb is right through it. The spider is a late-comer to this party. I'm in the passing shrike camp.

John

Could be:-

https://www.flickr.com/photos/maholyoak/5873871546/

http://www.outdoorphoto.community/gallery/showphoto.php?photo=185804&title=shrike-larder-i&cat=548

But do you agree that those are elements of spider's web? It's a big old moth for a shrike to capture it without damaging its wings etc.

All the best

 

[halftwo]

Am I right in thinking that large moths have filaments in their abdomens ? If a Shrike had pulled at the rear it might leave these.

 

[Paul Chapman]

Am I right in thinking that large moths have filaments in their abdomens ? If a Shrike had pulled at the rear it might leave these.

Not really no. Some moths have hairy abdomens which they sometimes use to encircle egg masses and the like - Small Eggar, Gypsy Moth, etc but Elephant Hawk-moth is not really one of those. Having seen a number of bird victims in and around traps over the years, I would just expect to see more damage if it was a bird victim.

That said - it is all guesswork and I doubt even CSI Benbecula could provide a clear answer. 3

All the best

 

[Farnboro John]

Could be:-

https://www.flickr.com/photos/maholyoak/5873871546/

http://www.outdoorphoto.community/gallery/showphoto.php?photo=185804&title=shrike-larder-i&cat=548

But do you agree that those are elements of spider's web? It's a big old moth for a shrike to capture it without damaging its wings etc.

All the best

They could be spider's web. I didn't feel I could contradict what had already been said, put it that way. I did wonder if it was a wind-blown strand of sheep's hair.

I should have thought it fairly obvious that without being thoroughly tied down with spider silk, a big moth like that wouldn't stay in one place for very long. If not impaled, and only held by a few strands, it would blow away with the first serious wind. You can see from the lack of colour over most of it (the sheltered bit has some left) that some fairly serious weather has battered it, wind and probably rain as well - but it is still where it was put.

As for damage in capture by a bird, what more natural than being fairly undamaged by a shrike? Their modus operandi is to catch and impale, not to start dismantling immediately, and the natural grab on a big moth is the fat body. If the shrike got its bill tip in, the mark would be hard to detect but the moth held securely until pinned on the fence.

That's my two penn'orth anyway.

John

 

[Paul Chapman]

They could be spider's web. I didn't feel I could contradict what had already been said, put it that way. I did wonder if it was a wind-blown strand of sheep's hair.

I should have thought it fairly obvious that without being thoroughly tied down with spider silk, a big moth like that wouldn't stay in one place for very long. If not impaled, and only held by a few strands, it would blow away with the first serious wind. You can see from the lack of colour over most of it (the sheltered bit has some left) that some fairly serious weather has battered it, wind and probably rain as well - but it is still where it was put.

As for damage in capture by a bird, what more natural than being fairly undamaged by a shrike? Their modus operandi is to catch and impale, not to start dismantling immediately, and the natural grab on a big moth is the fat body. If the shrike got its bill tip in, the mark would be hard to detect but the moth held securely until pinned on the fence.

That's my two penn'orth anyway.

John

Perhaps:-

http://www.123rf.com/photo_7912347_humming-bird-moth-caught-in-spider-s-web.html

All the best

 

[Farnboro John]

Perhaps:-

http://www.123rf.com/photo_7912347_humming-bird-moth-caught-in-spider-s-web.html

All the best

That one is fully coloured so it hasn't been there very long, which was part of the point I was making.

Speculation is fun, isn't it?

John