The bays give up their dead?

27 03 2015

Over much of this winter, I heard from Seanetters telling me they were finding what seemed like fewer dead birds on their beaches. This was mainly from the “hotspot” beaches that typically produce a few birds per walk throughout the winter, when bird mortality is generally highest. Many of these Seanetters went many weeks without finding any birds. Now, as spring advances, our northern cohort of Seanetters are seeing the opposite in many places–sometimes over a dozen birds dead on a stretch of beach. We are also hearing from nature centers and other groups who are receiving reports from the public about what seems like a spike in mortality. So is it?

Before I begin, I offer the caveat that we have not actually analyzed these numbers since they are only now coming in, but I can give some impressions and some hypotheses. First let’s look at what’s been turning up. On some beaches, it seems that a particular species dominates among the carcasses. Ray Bosse, walking along Buzzard’s Bay in Massachusets, found eleven Canada geese on his beach on March 22. Ray’s beach does not typically turn up many birds. Compare these snapshots from our database for Ray’s beach during the winter of 2014 vs. the winter of 2015:

RBosse_winter2015
RBosse_winter2014
2014 was a fairly typical year for Ray–a few birds here and there. 2015 looks a bit different. Ray found no birds from November though the end of February, and then an uptick began, culminating in that big day on the 22nd. Compare Ray’s numbers with those of Warren Mumford, walking in Chatham, MA, a part of the Cape facing out toward Nantucket. Warren’s beach is a fairly reliable producer of dead birds, though not in huge numbers all at once. Then, on March 25th, he too saw a sudden influx, finding 17 dead birds on his beach.

MA_27_winter2015
These kinds of spikes draw our eyes, but are they reflecting current, ongoing mortalities, or something else? To figure that out, we need to look at just what kinds of birds were found on each beach, and in what condition they were in. When we do this, we find some differences between beaches. On Ray’s big day in Buzzard’s Bay (a fine title for a morbid children’s book about bird carcasses), he found mostly one species–Canada geese (CAGO). Warren, however, found a grab bag of different species, basically representing the usual species that turn up on his beach: eiders, White-winged scoters, and gulls. When we see so many different species, it does not rule out a disease process, or other common cause of death, but it makes it far less likely. Few causes would impact everything from American Black Ducks to Herring Gulls to Common Eiders. The other point to consider is the condition of the carcasses. Warren’s birds, in addition to being all sorts of species, are in varied states of decomposition and degradation. Some are very weathered, and almost mummified. Others are intact, and look fairly fresh. This tells us that these birds did not die all at the same time.

WMumford7220-20399[1]

A weathered Common Eider carcass. Likely many months dead.

A much more recently dead juvenile gull.

A much more recently dead juvenile gull.

We appear to be seeing accumulated mortality over time, but revealed to us all at once.

In Ray’s case, the geese are all at just about the same level of degradation, suggesting they died within a much narrower timeframe. Multiple specimens of one species, and all dying around the same time raises our eyebrows a bit higher. For this reason, we are planning to collect a few of these geese and perform necropsies on them. The condition of the carcasses will preclude any advanced diagnostics, but we can hopefully look for signs of trauma, and also assess the nutritional state of the birds. It is very possible that the cause of death in these birds was starvation. The harsh winter, one in which many of our sheltered bays (and not so sheltered ones) actually froze over entirely, and massive snowfalls this year, severely reduced the available grass forage for the geese. It’s our current, working hypothesis. Even if the birds died over the course of a few weeks or even a month, the cold and the ice would have preserved them fairly well. They may even have been on the beach the entire time, just concealed by ice and snow and only now becoming visible. This effect might be expected to be even more pronounced in the bays where dead birds were entirely prevented from washing up by the extensive ice sheets from late January through just a week or so ago. On ocean facing beaches, where open water persisted all winter, are these spikes due to birds that were dead on the beach but hidden by snow? Or are these birds drifting in from other previously ice-locked areas?

What even the larger bays looked like this winter. How many dead birds could be locked in that ice?

What even the larger bays looked like this winter. How many dead birds could be locked in that ice?


If the ice-imprisoned carcass hypothesis is correct, then these high numbers of dead birds on many beaches may represent weeks or months worth of mortality all released at once for the finding as the ice and snow rapidly melt. I look forward to seeing what we find in the CAGO from Ray’s beach to see if we seem to be on the right track in our line of thinking. Watch this space for more news.

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DBQ, part deux

17 03 2015

I have feeling so very remiss about SEANET lately, not least because I cannot blog as frequently as I might like during the high teaching season. To partly make up for this, in this second installment of the most recent DBQ, I have labeled photos with orange arrows. This way, it will appear that I have been doing something more substantial than my usual.

The features I elected to label with orange arrows are not entirely arbitrary. When I looked at Bird B’s photos, my instant thought was “This is a loon.” Of course, that kind of bolt from the blue is insufficient to a DBQ answer, so I then took my usual next step, which is to ponder what it is about the overall Gestalt of this carcass that brought the word loon instantly to my lips. First, the sternum shaped (not labeled with an arrow.) It’s elongate, which, as Edward also pointed out, makes this not a grebe, which is the other pointy-beaked, white-under-winged group of birds one might consider for this i.d. Second, the small bit of patterning visible on the back feathers (shown with orange arrow).

Slide1
Can you make out the faint, light colored chevrons tipping the otherwise dark feathers? That’s a loon thing. What kind of loon though? We have at least some of the head to work from, though the mandibles have parted ways from the upper beak, complicating matters. Still, take a look at this helpfully labeled photo:
Slide2

Here, we can see a v-shaped white patch at the base of the upper bill. This is quite suggestive to me of a Red-throated Loon, as no other loon has such extensive white on the face, especially in the region extending up the forehead from the bill base. Without the usual hallmark of the RTLO though–the jaunty and somewhat smugly upturned look to the bill–it’s not a slam dunk i.d. As Edward pointed out, the upturned appearance of the bill of RTLO is largely due to the shape of the mandible, the upper bill being actually quite straight, as in this specimen. Alarmingly though, Edward suggested Bird B might be NOT a RTLO, but an Arctic Loon! We have never, in the history of SEANET, gotten one of those. Given this dearth, I am tempted to heed that old vet school warning about jumping to rare diagnoses: “When you hear hoofbeats, think horses, not zebras.” But then I am whipsawed by indecision when I consider all my rotations in zoos, and the memorable day I got to blow dart a zebra with its vaccinations. And then, coming out of my reverie, I remember about identifying Bird B again.

I perused the internet for some nice photos to share with you, and I found one by someone else in the world who likes to photograph rotten old carcasses! Here is a mostly skeletal Arctic Loon (known in other parts of the world as a “Black-throated Diver”:

800px-The_remains_of_a_Black-Throated_Diver_I_255618814

Photo by Miika Silfverberg via wikimedia commons

You may note that this species has what looks almost like a droopy, downturned bill: just the opposite of what we see in a RTLO. And here is a cartoon version of the birds by L. Shyamal, which gets across the main aspects of their patterning:
410px-GaviaArctica.svg

I argue that our Bird B has more white on the face than an Arctic Loon would. Add that to the extreme rarity of that latter species in our neck of the woods, and I think I am right. But I love to argue and debate, so if anyone can convince me this is something other than RTLO, bring it on!!!





DBQ answers

12 03 2015

Occasionally, I feel daunted when writing up these supposedly correct DBQ answers. Actually, most of the time I feel daunted. I am hardly an expert birder, and while my confidence in identifying our bread and butter dead bird species–loons, herring gulls, scoters–is high, when it comes to rarities, I often stumble. I was feeling additionally daunted, momentarily, by the international nature of our Bird A. Then, I very quickly remembered that we study seabirds here at SEANET, and seabirds scoff not only at international borders, but at the very idea that the Atlantic Ocean would be a barrier to their travels. For truly sea-faring birds, the Atlantic, or the polar oceans in the aggregate, are home turf, and many of their ranges are, in fact, circumpolar. Overall, the suite of species we see washing up on our beaches on the east coast tends to match what turns up on Scottish beaches, or Danish ones, better than what turns up on our west coast friends’ beaches in California or Washington. So, somewhat less daunted, I considered Bird A (which, full disclosure, came pre-identified for me by Edward, who sent the picture.)

**update: feeling MORE daunted now, after spending an hour writing up a fabulous breakdown of the identification here, and then losing it to a computer crash on my less than stellar work machine. So, here is the brief and aggravated version of the lyrical prose piece I labored over and lost:**

Bird A options: one of the jaegers, or one of the skuas. n.b., we Americans call jaegers jaegers and skuas skuas. Europeans call the whole lot skuas, which seems sensible since the four species that are candidates in a case like this are all actually in the same genus, Stercorarius. The birds we call jaegers here, specifically the pomarine and the parasitic, are both smaller, more delicate birds than the south polar and great skuas, not that one can say much about overall daintiness from this headless carcass. One thing that does leap out at me about Bird A is the tail, which is fairly short and blunt. This contrasts rather well with the longer tails of the jaegers, though juvenile jaeger tails are substantially shorter than those of their esteemed elders. Lest ye lose hope though, here’s a helpful bit of information: while juvenile jaegers do have short tails, they also have gray legs with black toes! A very dapper combination. The gray can be very extensive (see photo below of a jaeger that got a lot of attention in Texas), or run only just beyond the tarsal (“ankle”) joint, but our Bird A has no gray in evidence anywhere on the legs or feet, which appear entirely black (aside from that bit of silver jewelry its sporting).

A jaeger that caused an identification kerfuffle on Kirby Lake in Texas.

A jaeger that caused an identification kerfuffle on Kirby Lake in Texas.

So, not a jaeger then. Let us conclude that it is a skua. What kind of skua? The call generally comes down to plumage color, with South Polar Skuas being grayer, and Great Skuas browner overall, but with the dreaded exceptions, overlaps, and light and dark morphs. Terrible stuff. I can convince myself that I see some warm brown tones at the tail base and a bit along the wings, but mostly, I am persuaded by the fact that Edward sent me this picture with the note, “Great skua. Found on Texel Island, ringed in the Shetlands.” If there are field marks I am missing here that might help, please enlighten me!

Great Skua field marks. I can't get enough of these composite images. And I think that raincoat clad person is going to meet a bad end.

Great Skua field marks. I can’t get enough of these composite images. And I think that raincoat clad person is going to meet a bad end.

As for Bird B, I reserve that for the next post since I am feeling chagrined about the tragic loss of my first post, and also, I enjoy keeping Ray Bosse, who found Bird B, in suspense.





Dead Bird Quiz: Transatlantic edition

6 03 2015

It’s an international accord! Nothing brings people together like dead birds, so here are two.

Bird A’s photos were sent in by Edward Soldaat. The carcass was found on the island of Texel in the Netherlands, and since we Americans are notoriously ignorant of world geography, here is a map:

Untitled3

Bird A, mostly upper surface.

Bird A, mostly upper surface.

Another of Bird A.

Another of Bird A.

Bird B comes to us from Ray Bosse in Massachusetts. It’s a similarly degraded specimen, though Ray’s is in an impressive number of pieces.

Bird B.Tarsus and Wing chord recorded on card in photo.

Bird B.


Partly the upper surface of Bird B.

Partly the upper surface of Bird B.





More trash talk

2 03 2015
The waste-to-energy plant (incinerator) in Haverhill, MA. I was apparently up in arms about as soon as it opened in 1989. I was nine.

The waste-to-energy plant (incinerator) in Haverhill, MA. I was apparently up in arms about as soon as it opened in 1989. I was nine.

I am always on the lookout for topics to write about here, and when I get a request from a reader for a specific post, I am both happy to oblige and relieved not to have to cast about for a theme. Seanetter Warren Mumford is a Cape Cod resident but was unable to attend the film screening of Trashed and subsequent panel discussion last week, and he asked me to provide a bit more of a synopsis on what occurred. If you’d like to view the film itself, you can stream it, or find it on iTunes. In general, it covers the end result of our global overconsumption of goods, and our tendency toward blindness as to where those goods end up. Landfills, incinerators, recycling plants all feature in the film, as do the places where our trash ends up inadvertently, including, I hardly need tell you, dear readers, the oceans. I was on the panel after the film primarily to speak to the impacts of trash (especially plastics) on marine wildlife. Jessica Donohue is a Research Assistant at SEA Education Association, and brought her expertise on sampling plastics directly from the oceans, and Dave Quinn, Regional Waste Reduction Coordinator for Barnstable County (Cape Cod), spoke to issues of recycling, composting, reusing, and attempting to reduce our overall waste stream wherever possible. The questions from the audience ranged widely from topics of contaminant induced infertility, to cancer clusters, to styrofoam recycling (very challenging, as it turns out), to composting and plastic bag bans.

Highly recommended.

Highly recommended.

I am currently reading the book Toms River by Dan Fagin, about the fate of a small town in New Jersey ravaged by the blithe dumping of chemical wastes from a dye manufacturing plant over multiple decades, so I have been, for the past week, more consumed than usual by matters of waste and waste disposal. Some of the discussion after the film screening centered around what we might do to combat this issue of our mountainous waste problem, and it seems to me fairly consistently the problem that we do not pay the appropriate price for what we use. The statistics in Toms River¬†on the volume of waste water generated per gallon of dye produced is appalling, and as I read, I considered what a poor job we do reflecting those true costs in the sticker prices on consumer goods. The environmental costs of cheap plastic bottles, bags, food containers, and so on, are not captured in the amount we pay, nor in the what the companies must pay to produce and distribute those goods. Dave Quinn brought up the idea of extending the responsibility of these manufacturers to encompass the entire lifespan of these products (or at least more of it since plastics stay with us for thousands of years). If the producers had to consider, and pay for, the ultimate disposal of their products or their products’ packaging, might things not turn out differently? Certainly we would expect the cost of that non-recyclable, non-reusable juice container to go up, and perhaps that would drive down demand for the most egregiously packaged items.

We discussed what consumers might do as well, and in the film, a small urban shop is featured where shoppers buy all items directly out of bulk bins and take them home in their own reusable containers. This shop was a lovely idyll, but I couldn’t help but bring up the issues of environmental justice and uneven access to high quality food, let alone to high quality food responsibly distributed. I tried not to be flip as I described my teaching work in the small, but rather depressed city of Lawrence, Massachusetts, where the underclasses may have access to no food at all save what they can get at the corner convenience store. This was by no means meant to discourage the opening of more environmentally minded retail shops, but simply to raise the issue that we have a very long way to go before they will be routine in places outside the liberal bastions of the posher cities or their suburbs. For my student population, it’s hard for me to get them to simply throw paper in the recycling bin rather than the trash can right beside it. This flabbergasts me, but it’s a good lesson in how little many of my students think about issues that keep me up at night. Trying to break down that barrier is part of why I teach.