Modifying monofilament bins: it’s for the birds.

31 05 2012

Our friends at Menunkatuck Audubon down in Connecticut have come up with an ingenious way to retrofit their fishing line receptacles to prevent small birds from flying in and becoming trapped. I posted earlier about the issue of open pipes and tubes as a hazard to avian life, and Terry Shaw sent me step by step instructions on the solution they’ve devised. A classy and effective method, I think! If you want more details, drop me a line and I can get them to you.

I also have the pleasure of announcing that I will be headed down to Branford, CT to speak to the Menunkatuck Auduboners in September. I can’t wait; they’re a great group in a beautiful spot!

The retrofit: a simple hinged plywood cap.

Terry’s instructions in brief (for details, send me an email or post a comment):
I used 3/4″ plywood but any thickness or type of wood should work. If you have 1/2″ starboard that would be good. Make the circle about 1/2″ smaller than the opening somewhere near 6″ maybe 6 1/4″  then cut about 1/3—2/3 pieces.

I used paint i had left over it was marine interior cabin paint,  I think any white house exterior paint should work.
Add a zinc hinge from a hardware store.   I used a sheet metal screw for the handle, the same size can be used to mount into the plastic

Drill a hole in the plastic pipe big enough for the screw to slide through.

The finished product.

Oil and dispersant found in Minnesota pelican eggs

29 05 2012

American White Pelican colony. (Photo: Minnesota Public Radio)

I know most of the SEANET blog’s readership is not naive enough to think that the BP spill’s impacts were limited to the Gulf, but a study underway in Minnesota is now confirming its wide ranging effects, at least in pelicans. The massive American White Pelican winters in the Gulf but heads north to the upper midwest and prairie provinces of Canada to breed. Minnesota Department of Natural Resources biologists have begun sampling eggs in the state and testing them both for traces of petroleum and for the chemical dispersant Corexit used to break up the oil after the BP Deepwater Horizon spill. Over 90% of the eggs tested positive for petroleum and 80% for Corexit. The researchers point out that without a baseline prior to the spill, it’s impossible to attribute these levels directly to the BP disaster. Oil, in particular, is constantly entering the marine environment via spills large and small, many never officially reported. The birds could pick up oil through contaminated prey or directly from the environment. The situation with Corexit is a bit more intriguing; if the test for the compound is indeed highly specific, it would be interesting to know where else all these pelicans could have been exposed to it. I have no information on how wide ranging use of this dispersant is, and I look forward to the publication of the Minnesota results to see what they have to say on the subject.

Regardless of the source, the high prevalence of these contaminants in pelican eggs is troubling. Many petroleum based products act as carcinogens or as endocrine disruptors and need only be present in trace amounts to have profound effects. Just as pregnant women are urged to be vigilant about chemical exposure during the sensitive period of embryonic development, so too are these embryonic birds vulnerable to these foreign chemicals. The science of endocrine disrupting chemicals is still in its infancy, and it’s uncertain what long-term effects these contaminants may have on the populations of exposed seabirds. As usual, we humans are running a real-time, inadvertent experiment in the uncontrolled laboratory of the marine ecosystem. We’ll see what the Minnesota folks turn up from their piece of it when their study is complete.

Giant carnivorous mice?!

24 05 2012

House mouse atop its prize: the carcass of a petrel chick. (Photo: National Geographic)

Yes, they exist, and they may drive some seabirds straight to extinction. Researchers on Gough Island, way down in the southern Atlantic about half way between South America and Africa, have been studying the impacts of house mice on Atlantic Petrels. The petrels have been breeding on Gough Island for millennia, while the house mice are a more recent introduction brought there by, guess who? Yep, humans with boats. Since they were inadvertently dropped off on Gough, the mice have evolved much larger size than the average mouse gnawing a hole in your cereal boxes. The mice on Gough are now about ten inches long, not including the tail. This trend toward larger size is typical of small mammals marooned on islands over generations, and consistent with theories of island biogeography known as “The Island Rule”first posited by J. Bristol Foster in the 1960s.

The middle of nowhere: site of of the mouse induced carnage.

Now, these monster mice have multiplied as rodents are wont to do, and when their more typical sources of food run low, they turn to a massive, fleshy buffet: the large, immobile chicks of the Atlantic Petrel sitting in their underground burrows with no evolutionary defenses against the new comer mice. The mice simply eat the helpless chicks alive while the parents are out foraging.

The impacts are not slight–a study in Animal Conservation shows that millions of the chicks are being killed and eaten by mice every year, and a majority of their mathematical models project that the species will be driven into endangered, “Red List”status. Based on these numbers, an outcry is now rising for the extermination of the giant carnivorous mice. Gough is not the first nor the only island with a rodent problem, and all over the world, various strategies have been used to deal with invasive species. Poison is the most likely tactic to be used on Gough, and of course, it’s not without peril to non-target species, but with an infestation of this size and severity, there are few alternatives. It’s a problem of human making, and humans, being imperfect ourselves, have but imperfect means of fixing it. We’ll be rooting for the helpless, burrow-dwelling petrels and hoping the species itself won’t meet its end staring into the beady, heartless eyes of gigantic mice.

Dead Bird Quiz answers

22 05 2012

OK, so both of these birds are ducks. That was clear to everyone who responded to this quiz. But what sort of ducks? Bird A, which was merely a skeletal head, is definitely some kind of sea duck, what with that hooked beak tip and very thick ridges along the bill edges. Guesses on this one were Northern Shoveler and Common Eider. So let’s look at those two. The Northern Shoveler has an absurd looking bill, which makes up more than half of the total head plus bill length. As blog reader Wouter pointed out, it would be helpful to view the bill of Bird A from above to see if it’s wide enough to be a Shoveler’s. Well, Wouter, request granted! Here’s another shot of Bird A’s bill, showing that it’s pretty narrow, and helping us rule out the Northern Shoveler, whose bill would have a prominent, spatula-like appearance at its tip.

Aerial view of Bird A’s head.

Northern Shoveler: comical bill appears longer than the head itself.

What about Alicia’s suggestion of Common Eider then? Certainly, there are some similarities there, but if you look at the shape of the nostril, the Common Eider’s is elongated and placed lower on the side of the bill than our Bird A, whose nostril is very close to the top edge of the bill, and has a more open, almost triangular shape. So where does that leave us? I would posit that Bird A is a White-winged Scoter. The nostril shape and position are right, and while the demarcation between feathered area and bill is mostly obliterated, I can persuade myself that the profile of that line would have been consistent with WWSC. What do you think, Seanetters?

Bears some similarities to Bird A, but note shape and position of nostril.

Is this our bird? I would say yes!

Bird B is an easier case, and Wouter and I both agree, this is a Long-tailed Duck. The pinkish band on the bill marks it as a male, and the white neck followed by a wide black band on the breast, and then a white belly tell us this bird is still in its winter plumage, and had not yet acquired the full breeding plumage seen later in the year. Like many ducks though, the LTDU undergoes some complex interrupted and partial molts, changing its appearance almost continuously from April to October. What a pain for Dead Bird Quiz devotees, huh?

Long-tailed Duck in winter/spring.

Dead Bird Quiz to boost my spirits

17 05 2012

My weekend trip to Cape May, NJ for a SEANET training has now been canceled. Unable to drum up sufficient interest, the good folks down there at the Wetlands Institute will give it another try later this year. So, to distract myself from my sadness, I’m posting one of my favorite things: a Dead Bird Quiz. And one of these specimens is one I found myself! Bird A was nothing but a skeletal head attached to a strand of vertebrae. Bird B was mostly intact, though its head was crushed. Measurements for Bird B are provided in the photo, partly in the bizarre scrawl of my five year old son. It was his birthday yesterday, and this dead bird was my gift to him.

Guesses please!

Bird A: Found by Janet Kurz in North Carolina last week.

Bird B: Found by yours truly, Sarah Courchesne, yesterday in Massachusetts.

Seabird and dolphin die-offs in Peru: some answers?

15 05 2012

Silvia Oshiro/Getty images

Late last year, nearly a thousand dolphins and over 1500 seabirds turned up dead on the shores of Peru. Months later, a frustrating lack of answers prevails. While the initial fear was that all the animals were dying of a single cause, it now appears that the dolphins and seabirds were afflicted with separate issues. Still, the results as they have been presented in the media are incomplete and conflicting. The matter of the seabirds seems more settled–disruptions in the usual flow of nutrients via the cold Humboldt Current have driven the massive anchoveta shoals into deeper waters where seabirds, especially shallow divers like Brown Pelicans, can’t hunt them. The birds necropsied were mostly emaciated, supporting the theory of a collapsed prey base.

The mystery of the dolphin deaths, however, has generated more controversy. Many environmentalists have charged that offshore seismic testing for oil and gas wells has injured and disoriented the animals. But Peruvian environmental ministers stated that necropsies on the animals showed no evidence of characteristic seismic injuries. Carlos Yaipen-Llanos, of Peruvian marine conservation group Orca, however, reports “categorical” evidence of the animals dying from decompression sickness– in 30 necropsies he noted fractured bones in the dolphins’ ears, and blood and bubbles in their sinuses. Yaipen-Llanos suggests seismic testing could have scared the dolphins and caused them to surface too rapidly, leading to the damage.

These entirely opposing reports are further complicated by the findings in a study in the Proceedings of the Royal Society B. It appears that bubbles may form in the bodies of both live stranded dolphins, and post mortem in dolphins hauled up after drowning in fishing nets. The bubbles can be clinically silent, and it seems that dolphins and other marine mammals have a substantial degree of tolerance for this form of decompression sickness. While blood in the sinuses and fractured ear bones are a step well beyond bubble formation, the study does raise questions about the necropsy results out of Peru. Could the damage to the dolphins have been postmortem? Could it have been less than directly linked to decompression sickness? Peruvian government officials say they never received Yaipen-Llanos’ necropsy reports, and I can’t find the actual reports in any public venue either.

Over my time with SEANET, I have grown ever more leery of making blanket judgments about mortality events and their causes based only on second hand media reports of necropsy reports. Too many layers to the onion for me. So for now, I await more definitive results on the dolphin die-off, and will continue to follow any further developments in the seabird story as well. It’s all a classic tale of the convergence of environmentalists, industry, government and science. Let’s all root for a satisfactory resolution, and that fact may prevail!

Onward, ever onward for the Southeast Beached Bird Guide

10 05 2012

I work several jobs these days, including running SEANET, helping out with the Northeast Wildlife Disease Cooperative, and teaching college biology. Plus a little veterinary work on the side. It stems from my varied, sometimes scattered interests–I’m an artist! No, a teacher! No, a scientist! No, a writer! But once in a while, a project comes my way that brings them all together. Right now, that project is the Field Guide to Beached Birds of the Southeastern U.S. Through the generosity of the U.S. Fish and Wildlife Service, and the cheerleading of SEANET’s great friend John Stanton, I’m funded to do this book start to finish. I’ve compiled body measurements, written up descriptions of individual species, and am now working on the life size line drawings of each species’ bill.

I’m hoping this guide will be of equal use to Seanetters, and to people monitoring seabird mortality in other ways, whether on board fishing vessels or responding to the next oil spill. I’m hoping to have most of the content done by the end of summer, and from there, on to the presses! As soon as this new volume is available, you Seanetters will be the first to know, of course.