Communing over the dead: Seanetters and vultures

5 02 2015

Edward posted a comment on the last post that I think is quite useful, and thus, I share it here in its entirety. He writes first about the identity of the set of wings featured in that post, and I concur with his assessment that this is a female common eider.

First seen in Macrh, 2014. (photo: W. Mumford)

First seen in Macrh, 2014. (photo: W. Mumford)

“My first impression is female Eider Duck. The brown mottled wing coverts, the dull speculum with the white edges, the width of the sternum reminds me of an Eider. On the beach these wings can last for a long time, as proven by the pictures. But floating around in (sea) water they will last not very long. Maybe a week, most likely even much shorter. These pairs are most of the time the remains of a gull’s dinner and were consumed on land or close to the shore, in the tide line for instance and haven’t been floating around or just for a short time. When 588 was pictured for the first time I guess it was rather fresh, maybe a few days, a week, depending on the circumstances. Feathers still in good shape and condition and no discolouration at that moment. A good check is feeling the flexibility of the joints: still flexible in combination with feathers in a good state means fresh. The presence of red from blood is also a good indication for freshness. In dry periods the joints become stiff quite fast, and stiff joints but still good feathering means, not fresh, but not very old either. A good estimate requires experience and even then it is of doubtful reliability. It depends on so many factors: what was the weather in the days/weeks before: cold, dry, rainy, sunny, was it buried under the sand, was it scavenged or not, infested by maggots, etc, etc. But the latter pictures are definitely of wings that are dead for a long time and should not be counted in acute mortality events
We always cut the tips of the primaries when a carcass is counted to avoid the risk of doubling records. It is also a way to know whether a carcass is there for a longer period or not.”

The practice of marking primaries is one common to many beached bird programs, and, in fact, we at SEANET used to utilize that same method. We would prefer not to be putting any plastic out on carcasses of course, but when using the clip feathers method, we found that volunteers were having trouble detecting the cut feathers in subsequent surveys, sometimes because the feathers had not been cut aggressively enough, or because the cut had weathered and was hard to distinguish from normal degradation. It was surprisingly challenging. The bigger issue however, was needing a way to mark other parts of the body. We tried having walkers clip off a toe, but again, if the cuts were not aggressive enough, they were often dismissed as evidence of scavenging on subsequent walks. And we never really found a good way to mark heads and bills. Thus, we arrived at the cable tie method. Gaudy, yes. Plastic, yes. But reliably conspicuous, also yes. And the individually numbered metal tags are the only way to track an individual carcass over time, as we did with this eider. Still, it’s an issue that is a constant poke in the ribs for us.

It’s another snow day in New Hampshire, and my kids are pestering me for things, so I shall sign off. But not before I share with you this photo from Jerry Golub.

We are gathered together here today...to eat this gannet. (Photo: Jerry Golub)

We are gathered together here today…to eat this gannet. (Photo: Jerry Golub)

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