Another morbid website, and goings on in the Gulf of Maine

19 05 2015

You may already be familiar with WHER, the Wildlife Health Event Reporter, where members of the public can submit their reports of sick, injured, or dead wildlife. Your SEANET beached bird data gets hoovered up by that very site, so you can see what birds your neighbors, or distant SEANET kin are finding. Now, there’s an additional tool out from USGS National Wildlife Health Center, conspiratorially named WHISPers. This site draws together wildlife mortality reports from government agencies and other partner groups. Though you, as an individual citizen (scientist) cannot contribute to this particular database, you can see what’s turning up. Here’s a screenshot of the results I got when I searched for events in my home state of New Hampshire:

Screen Shot 2015-05-19 at 10.25.57 AM

Cool, huh? One gets not only geographic information, but in many cases, a confirmed or suspected diagnosis. Take a look around the site when you have a chance.

Now, I abruptly turn to some happenings here in the northern SEANET reaches over the next couple weeks. First up is our annual pilgrimage to Appledore Island to band gulls for the ongoing work of our own Julie Ellis. Through the generosity of a private donor, I was able to select four worthy students from my institution, Northern Essex Community College, to join our Gull Team this May. They are packing their bags and borrowing binoculars in preparation for the trip, and truly, none of them have any idea what they’re getting into.

Finally, in June, I will be meeting with faculty and administrators from my college and from the Gulf of Maine Institute to discuss possible collaborations and partnerships for our students. This is an exciting prospect and I will, no doubt, have some news on that front as the summer progresses. Never a dull moment, Seanetters. Though sometimes I do wish for a bit of a breather…





Back in the game!

12 05 2015

My dear Seanetters and friends,

Thank you for your patience and forbearance during my teaching semester. Now, I am finished grading, and as a kickoff to the summer, I attended a 3 day workshop on forest stewardship here in New Hampshire. In addition to opening my eyes to a whole new way of seeing my environment, we were also introduced to the The Stewardship Network, a clearinghouse of volunteer and citizen science opportunities here in New England. If you’re in the area, and SEANET just isn’t enough citsci for you, I urge to check out the offerings on their site. I know I will be signing up for some of these programs and work days for sure.

TSN_logo_New_England_green

These activities already had me enthused to jump back into SEANET with both feet, and to top it all off, I received a request this week for a work up of our data from the winter of 2012-2013; you may remember that alcids were hit particularly hard that season, and I am contributing your data to a manuscript on the subject.

Total data immersion.

Total data immersion.

It’s a good thing I have enthusiasm for the project, because I certainly lack expertise in Excel, so the going is not swift, but it is steady. After that data is wrapped up and shipped off, it’s back to the mill for the backlog of regular old baseline data you all are diligently collecting.

So thank you for bearing with me, and I hope you’ll stick around here to see what we get up to this summer!





What we can glean from severed legs

6 05 2015

Now, for the final installment of this latest DBQ. Bird C was nothing more than a leg, mostly stripped of its flesh. Remember it?

Bird C: Severed,  skeletal leg found by Dennis Minsky on Cape Cod.

Bird C: Severed, skeletal leg found by Dennis Minsky on Cape Cod.

What we can see here is that the skin that is left on the lower leg is black, and there is one small hind toe with a fairly small nail visible. The bones we see here, from the top, are the femur, which meets the tibiotarsus at the knee joint, the tibiotarsus, bearing the tag and the tie, then the hock (ankle) joint, and finally, the tarsometatarsus, which has the black skin on it.

For our crack team of dead bird experts, this specimen was not particularly difficult, it’s clear. But for lesser mortals, let’s work through some possibilities as an exercise.

For me, that color leg brings to my mind two main possibilities since this leg is fairly large: loon and goose. What other traits would we expect were this a loon? First, the skin-bearing tarsometatarsus is extensively flattened side to side, giving it an almost blade like appearance head-on. Bird C looks to have a rounder leg that that. The toes are no help since they aren’t here, but we can use the proportions of the leg bones as well as a bit of knee anatomy.

Leg anatomy of loons. Note the proportionately short femur and the pointed projection at the knee joint.

Leg anatomy of loons. Note the proportionately short femur (f) and the pointed projection at the knee joint.

If you have ever seen a loon attempting to ambulate on land, you have witnessed an animal quite literally out of its element. With its legs set so far back on its body, the front heavy animals can manage only a couple labored steps at a time. In addition to having the legs set so far back, the birds’ short femurs offer limited ability to swing the leg with enough clearance above the ground. Why this absurd arrangement? Because of this:

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Click the image for more pics and a bit of video!

When you watch a loon in the water, it makes perfect sense. Legs set as far back as possible on the body works in the water the same way an outboard motor works on a boat: you want that propulsion system at the back of the craft. Unless you are like me and my hapless fisherman father when we tried (once) to use a trolling motor. We mounted it on the side of the boat and proceeded to describe large circles on the lake for an hour or so before giving up.
In the images of loons underwater, one cannot even see where the short little femur is on the body because it is snugged up under the thick feathers. The reason that femur is so short comes to down to a clever bit of physics. Though the femur is short, it is overlain by thick bands of quadriceps muscles. These are so beefy, they need extra attachment points where they insert at the knee. That reinforced structure is the spear-like projection, called the cnemial process, that juts up from the knee in the image of the hind limb bones. Muscle can attach along that whole length. When those strong muscles contract, though they are short, they pull on that cnemial process lever arm, and for a relatively small contraction distance, the tibiotarsus makes a very wide arc. That’s the kick you see in the video of the swimming loon.

You notice that the loon keeps its wings tucked in tight while swimming. This is in stark comparison with a wing-propelled diver like the Thick-billed Murre. These birds are a bit awkward in the air, seeming to be just on the brink of crashing. Their flight is labored, with their heavy bodies and proportionately small wings. But, as with the loons, all forms of locomotion are evolutionary trade-offs with others. In this video clip of murres underwater, you can see their short, pointed, stiff wings are just the thing for swimming. Note that their legs, on the other hand, just trail behind them, as they would during flight in the air. Their hind limb anatomy resembles a land bird much more than a loon since they did not evolve to use their legs and feet for swimming.

All this has not yet answered much about Bird C. Except that now, looking at the leg, we see the bones look similar in length, and proportional. This argues against a leg-propelled diver like a loon. So we could be looking at a wing-propelled diver, or, more likely, not a diver at all, but a bird that feeds like this:

Swan dabbling for food. (Photo by Etan Tal)

Swan dabbling for food. (Photo by Etan Tal)

In dabblers like this swan, as well as geese and the non-diving ducks, the birds are limited to the aquatic food they can reach from this absurd upturned position. The feet and legs do little more than help a bit with balance and orientation. A long neck helps with this, but it also helps to feed on immobile prey like plants. To catch more active foods, the ability to pursue is a major benefit.

Bird C–large sized, black legged, likely not a diver–seems too big to be a Brant, but too small to be a swan. The consensus on this one is Canada Goose, which is fitting given how many of them we’ve had reported this spring as the ice melts.

Now, my friends, I am off to learn about forest ecology and land management for several days, blissfully without internet. I’ll see you here when I get back!





Dead Bird Quiz answers

1 05 2015

This quiz didn’t throw our regulars off much at all, which is no surprise since they are a crack team. I agree with all three of our respondents, who all identified this as a Thick-billed Murre (TBMU). We hardly ever get Common Murres on SEANET beaches, but we must remain alert to the possibility. And sometimes, it can be tricky to differentiate the two. The northeast SEANET Field Guide uses measurements as the decisive factor, noting that, in the Common Murre, “bill depth at gonys <1/3 culmen.” The gonys is the point on the lower bill, which is particularly conspicuous in the Thick-billed. Living up to its name, the TBMU has a greater depth at this point. Overall, the bill looks different as well, having a much straighter appearance in the Common Murre. The feature I find particularly useful is the presence or absence of a light gape line running straight back from the corner of the mouth in TBMU. It is not present at all times or all ages, so its absence is not decisive, but its presence definitely indicates TBMU.

Common Murre

Common Murre

Thick-billed Murre

Thick-billed Murre

From these images, it appears that the bill on a TBMU is considerably shorter than that of a COMU. In fact, this can indeed be a useful factor when available. COMU culmen is reported in the range of 39-46 mm, while TBMU range from 30-38 mm.

For Bird B, where we have another beak in closeup, we have to first consider that the feathers at the base of the bill are partially missing and the remainder are matted down. This is common in birds that have been decomposing in the water, where feather and skin slip begin happening soon after death. It also makes it difficult to pick up on the feathering pattern in that area. Thus, we must go solely on the shape of the bill. The chisel-like shape, with the weight of the upper and lower bill appearing similar is reminiscent of a loon. But this appears too short, even for a Red-throated. That leaves us with the cousins of the loons, the grebes, and with something we might offer as an alternative hypothesis, an American Coot.

For prospects among the grebes, we have the Pied-billed, Horned, and Red-necked. When looking at our Bird B, we have both the color and the shape of the bill to go on. However, in dead birds, we must always remember that color can fade and shift with time, so if color and shape seem not to agree, best to defer to shape. And in this case, we have a very pale bill, but that may not be a true finding. As for shape, our Bird’s bill doesn’t look as stubby as a Pied-billed, nor as loon-like and spear-looking as a Red-necked. So, how about the mid-range option in grebes, the Horned?

Pied-billed Grebe. Don't rule it out; the black band is absent in non-breeding adults. (Photo: Factumquintus via wikimedia commons)

Pied-billed Grebe. Don’t rule it out; the black band is absent in non-breeding adults. (Photo: Factumquintus via wikimedia commons)

Red-necked Grebe. (Photo: USFWS)

Red-necked Grebe. (Photo: USFWS)

Horned Grebes have a dark bill when in breeding plumage, but a lighter gray one in the non-breeding season, as you see in the bird here. In that excellent photo, you can make out the whitish tip to the bill. I can’t claim to see that in our Bird, but, then again, all the color appears fairly well washed out of our bird’s bill.

Finally, just because it had occurred to me as the “out of left field option,” why is this bird not a coot? Laying aside the existential aspects of that question, the color of the bill in Bird B actually matches coot somewhat better than grebe, but our Bird B shows a clear flex point where the upper bill meets the head. In a coot, this would be a continuous slope, like such:

American Coot (Photo: Trisha Shears via wikimedia commons)

American Coot (Photo: Trisha Shears via wikimedia commons)

Additionally, a coot or moorhen has more of a droop to the bill tip, unlike our Bird B, which has a quite straight and self-respecting outlook on things.

So, we’ve got a TBMU and a HOGR. That still leaves the severed leg, but this post is overlong already and I have not yet had my supper. Next time, the i.d. revealed, and an anatomy lesson on wing versus leg propelled divers. Until next time, Seanetters.





Dead Bird Quiz: beaks and bits

28 04 2015
Aren't you feeling nostalgic for this? (Diana Gaumond, right, and a friend stand at the edge of frozen Cape Cod Bay.)

Aren’t you feeling nostalgic for this? (Diana Gaumond, right, and a friend stand at the edge of frozen Cape Cod Bay.)

I had a post in mind related to gulls, but I have been spending hours lately uploading pictures of all the dead birds and bits that were revealed on northern beaches when the snow and ice melted. The most recent walks on many of these beaches has been as if through a bird mausoleum. So I hope you will forgive me if I indulge in yet another dead bird quiz, since this one includes an opportunity for me to wax poetic about some interesting anatomic features of seabird legs.

Before I do that, please try your hand at these i.d.s, which I am sure will give you all no trouble at all.

Bird A: Found by Mary Myers on Cape Cod last month.

Bird A: Found by Mary Myers on Cape Cod last month.

Bird B: Another from Mary. This one found in April.

Bird B: Another from Mary. This one found in April.

Bird C: Severed,  skeletal leg found by Dennis Minsky on Cape Cod.

Bird C: Severed, skeletal leg found by Dennis Minsky on Cape Cod.





The DBQ that just won’t die

16 04 2015

After posting the photo of the headless carcass with dusky reddish legs, it appears we now have a consensus on Bird B. The underwing of the headless carcass bears the classic pattern of an American Black Duck–white overall, with several distinct dark brown feathers at the wrist joint. With that in mind, looking back at the foot of Bird B, it looks like it too is very likely an American Black Duck. And in fact, when I posted the original DBQ, I was able only to access that single foot photo. Now that the database is fully up and running again, I found this photo as well:

Additional evidence as to the identity of Bird B. Open and shut case, with that speculum bordered in dark!

Additional evidence as to the identity of Bird B. Open and shut case, with that speculum bordered in dark!

And the case for Bird C was sealed by that additional photo–this bird was a Red-breasted Merganser.

I am in the last, thrashing weeks of the semester, readers, so please bear with me on the paucity of blog posts and the slowness of my email responses! Two weeks left until classes end and I turn my attention elsewhere. SEANET being a province of elsewhere, in case you wondered.





DBQ answers

9 04 2015

All respondents quickly recognized Bird A’s distinctive beak–heavy, straight and dark. This is a Common Loon. I wanted to show this picture mainly since it makes visible the very slight mismatch in length between upper and lower beak that one can rarely appreciate in a live bird at a distance. In fact, the upper bill does project just a small way past the lower (the bill is pictured upside down in our Bird A).

Bird B, found by Sue Bickford in Maine this month.

Bird B, found by Sue Bickford in Maine this month.

As for Bird B, where we have only a foot in this image, I was intrigued by the coloration here. The foot looks like a duck’s, and in fact, there are red or dark orange footed ducks in the world, namely scoters and mergasers. For more on that, see previous post on brightly colored feet. There are also terns and guillemots that may have red feet too, but our Bird B looks to have a duck foot to me. So Bird B here has a reddish looking foot. But something about it was bothering me. I could not quite square the color with the shape and proportion of the toes. I could not square this bird with a scoter, basically. Wouter and Edward had the same conversations in the comment thread as what went on in my mind–is this foot actually red, or has the desiccation process altered the original color? Then, fortuitously, I received a photo of a different bird: a headless carcass found by Louise Nelson, walking Plum Island in Massachusetts. The feet on this bird looked rather similar in proportions and color, and here we had more information on the rest of the bird, though not the head. But we Seanetters know not to ask too much. Here’s that bird’s picture:

Headless bird with vaguely red feet. If you squint? (Photo: L. Nelson)

Headless bird with vaguely red feet. If you squint? (Photo: L. Nelson)

To me, those feet also had a sort of dusky red hue to them, similar to Bird B. At the risk of dragging this out overlong, what do you think of that, readers? Are you convinced? And if yes, then what would that make Bird B? I have my thoughts, naturally.

Finally, Bird C, which generated some healthy debate as well. The two candidates were American Wigeon and Red-breasted Merganser (two votes for the latter, from Wouter and James Taft). Much hinges on how we interpret what we’re looking at in this case–the twisted up wreckage of these wings makes it challenging to sort out what’s upper wing, and what’s under, what’s covert and what’s secondary. Overall, a wigeon underwing is fairly light, with some brownish feathers along the margin of the wing’s leading edge. That is consistent with what we see in Bird C, but is also consistent with a Red-breasted Merganser’s underwing. A key difference, as both Wouter and Edward pointed out, is whether we are seeing a white speculum on the secondaries of the underwing or not. The merganser has one; the wigeon does not. I can see the problem though–might that white patch actually be not the secondaries themselves, but ┬áthe coverts, and the dark secondaries have gotten somewhat bunched up behind them?

Then we have that view of the very disheveled right wing, where all we can really make out is that there is a large white patch. Wigeon and merganser both have that. So, what to do? The answer–go back into the database and discover that Wendy Stanton actually took more than one photo of this specimen. Here’s the other:

SEANET gods' blessings on Wendy for taking this very illuminating photo.

SEANET gods’ blessings on Wendy for taking this very illuminating photo.

That helps rather a lot, no?








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