Friday, November 29, 2013

Friday Roundup: This Week's Wildlife Links (November 29th, 2013)

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    You may have noticed that no blog post appeared on Wednesday. I started the three-posts-a-week format in May of 2013 and have been happy to see a resulting increase in traffic and comments. But, this is a blog and not a newsletter and I am going to free myself from this structure and expectation (see above). Changing to a more unpredictable format should also make the e-mail notifications more useful. Have you subscribed yet?

Okay, onto this week's links:

Plastic debris and its effects on seabirds (Monday's guest post by Dr. Alex Bond).

The truth about snakebite: a breakdown of actual risk and bite outcomes.

You may remember that a few months ago I linked to an article about a Grizzly that killed and ate a Black Bear in Alberta. He is up to his old (but different) tricks again. With video.

Want some more bear cam? Check out these Polar Bears of Churchill, Manitoba.

The world's most skillful predator: a newt?

Zelda, the wild Turkey of Battery Park in New York City.

Illinois blows their chance to study Mountain Lions dispersing into the state.

Bonobos, seemingly secure in their remote jungles, are not so secure. Not far away, the Okapi is now endangered.

Notorious wildlife smuggler, the Lizard King, is at it again.

Learning to like the snake in the cellar.

Wind turbines kill more than 600,000 bats each year.

There has been a lot of talk lately about how demand for shark fin soup in China has plummeted. These reports might have been a little optimistic.

You may recall the former Animal Planet host that pled guilty to illegally selling critically rare lizards. He recently stated that he agrees with the rest of us: That was a stupid thing to do.

On a safari for exotic lizards in Los Angeles.

Did I miss an interesting wildlife link from this week? Provide it below

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Monday, November 25, 2013

Plastic for Dinner: Marine Debris and its Effects on Seabirds --Guest Post--

Plastic Dinner. Photo by Alex Bond.
    Imagine carrying around several kilos (or pounds) of plastic in your stomach, unable to rid yourself of it, and gradually adding pieces day by day.  This is what many marine animals go through every day.  Millions of pieces of plastic enter the world’s oceans each day, and once it’s there, it doesn’t go away.  Instead, it breaks into smaller and smaller pieces.  But every piece of plastic ever produced by humanity exists in some form or another today. And it will for years to come.

    Seabirds mistake floating plastic for food (pieces of squid, fish eggs, small invertebrates), and ingest them everywhere from Tristan da Cunha (the most remote island in the world; in the South Atlantic Ocean) to the Canadian Arctic.  Aside from the obvious physical damage from eating (often large) bits of plastic, plastic floating in the ocean acts like a sponge to sop up hydrophobic contaminants (those that don’t like water), like PCBs, DDT, and newer chemicals like polybrominated diphenyl ethers (PBDEs, used as flame retardants).  Once in a bird’s stomach (which is warm and acidic), the outer layers of the plastic, with the tag-along contaminants, enters the bird’s body.

Thick-billed (L) and Common Murre (R).
 Photo by Alex Bond.
    In Canada, we know very little about which species ingest plastic, in what quantities, and the influences of this behaviour.  About 2 years ago, while chatting with some colleagues in Newfoundland, someone mentioned that there were data sheets from about 1200 Thick-billed Murres (Uria lomvia) used in a study of diet in the mid-1980s.  Murres (both Thick-billed, and Common (Uria aalge)) are harvested legally in Newfoundland and Labrador each winter (and are rather delicious!).  Back in the 1980s, scientists worked with harvesters to examine the contents of murres’ stomachs, and better understand what murres ate outside the breeding season; they made note of any plastics they found.

    In the mid-1990s, some other folks did the same thing, using about 400 murres to look at what changes the 1992 groundfish moratorium had on murres’ ecology and diet. Thankfully, they also recorded ingested plastic.

    We pulled together these original datasheets, and 15-year-old spreadsheets, along with our own sampling of about 50 birds in 2011-12 to try and understand if murres’ rate of plastic ingestion had changed over time, and whether there were differences between the two species, and between adult and first-winter birds. The bottom line is that about 7-8% of murres, regardless of species or age, contain at least some plastic. And, this has been the case since the 1980s.  This is surprising for two reasons:

    First, murres dive for their food. Deep. Up to 180 m deep.  We don’t expect to find a lot of plastic there, since most of it is concentrated at the surface.

    Second, plastic production has increased over time, and so we would expect an increase in the plastics in murres, but that wasn’t the case.  In general, there was more plastic ingested in the 1980s, and less in the 1990s (our 2011-12 sample was in the middle).

    What also makes this study important is that it’s one of the few studies that have looked at changes in plastic ingestion over time (in Canada, or elsewhere) with relatively large sample sizes (>40).  It’s still not perfect, since samples came from all across Newfoundland, so there could be subtle spatial differences that we couldn’t figure out, but it’s a heck of a lot better than what we knew before (which was, essentially, nothing).

    So while murres aren’t affected by plastics enough to cause problems (either to individual birds, or murre populations), other species aren’t so lucky.

    In Australia, about 95% of Flesh-footed Shearwater (Puffinus carneipes) chicks have plastic numbering tens to hundreds of pieces.  In many cases, it’s a likely cause of death for many chicks on Lord Howe Island in the Tasman Sea.

55.5 g of plastic/person on Qantas flight from
Sydney to Lord Howe Island. This adds up to about
2.1 metric tons/year. Photo by Alex Bond.
   Working on applied conservation can be challenging – not just because the work is hard, or the field sites remote, but because it’s easy to feel a sense of despair.  Humanity is not going to stop producing plastic.  And even if the last bit of plastic ever were made today, its legacy would be around for hundreds (and maybe thousands) of years. But I (and you) can do something.  We can use science to understand the effects of plastics on marine life, and to bring about better pollution control. 

     But one thing everyone can do is cut down on the new plastic we use - in everything from face wash with “microbeads” (plastic that goes down the drain) to packaging, and plastic bags to toys.

Photo by Donald Pirie-Hay.
Dr. Alex Bond has been studying the effects of pollution, climate change, and fisheries on marine birds since 2005, and has worked in Newfoundland, the Aleutian Islands of Alaska, and Australia. He is currently a Visiting Research Fellow at Environment Canada in Saskatoon, Saskatchewan, Canada. You can follow him on Twitter and visit his blog. The views in this post do not necessarily reflect those of his employer. 

Want to Learn More?

Bond, A.L., J.F. Provencher, R.D. Elliot, P.C. Ryan, S. Rowe, I.L. Jones, & G.J. Robertson S.I. Wilhelm (2013). Ingestion of plastic marine debris by Common and Thick-billed Murres in the northwestern Atlantic from 1985 to 2012 Marine Pollution Bulletin DOI: 10.1016/j.marpolbul.2013.10.005

Bond AL, & Lavers JL (2013). Effectiveness of emetics to study plastic ingestion by Leach's Storm-petrels (Oceanodroma leucorhoa). Marine pollution bulletin, 70 (1-2), 171-5 PMID: 23507234

Avery-Gomm S, O'Hara PD, Kleine L, Bowes V, Wilson LK, & Barry KL (2012). Northern fulmars as biological monitors of trends of plastic pollution in the eastern North Pacific. Marine pollution bulletin, 64 (9), 1776-81 PMID: 22738464

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Friday, November 22, 2013

Friday Roundup: This Week's Wildlife Links (November 22nd, 2013)

Paging Indiana Jones, do natural history specimens belong in museums or can they be sold to the public? What about Dodo bones? The author's conclusion is sometimes. What about dueling dinosaur fossils? Well, they didn't sell at auction. The San Diego Museum of Natural History changed their mind at the last minute and pulled their fossils out of the same auction.

This shark bit off more moose than it could chew.

A first-hand account of trying to find one of the rarest cats in the world. And succeeding. In Borneo.

An elusive cat closer to home. Long-form read of cougars outside Los Angeles.

What the United States can and should do to stop wildlife trade and the funding it produces for terrorist groups.

Speaking of, the fierce urgency of saving Asia's rhinos before it is too late.

Migration is a deadly time for raptors.

Beautiful pictures that are hard to look at. The Death of Majesty.

Did I miss an interesting wildlife link from this week? Provide it below

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Wednesday, November 20, 2013

Indigo Snake Found Last Week in Southwestern Georgia! --Guest Post--

    Like many other people these days I finally succumbed to the allure of social media and created a personal Facebook page; the main benefit for me is that it has allowed me to hear from lots of old friends. Another benefit is getting tagged in those, "Hey what is this critter?" posts I'm sure all other biologists probably get. Usually, the critter ends up being some spider in a garage or a tree frog in a toilet, but every once in a while there is a day when something really awesome pops up. This past Tuesday was one of those days! 

This is one of those pictures you just dream of getting.
    An old friend, Leslie, send me a private message: "Hey, Roger! Apparently, you're still my go-to southern snake expert. This snake (on right) was picked up in southwestern Georgia near my family farm. Is it an indigo?! Here’s the story I got: The snake had come into the carport to get warm near a heat lamp. No, the snake was not harmed." 

    The first thing I noticed was that the snake was indeed unharmed. This was a relief because I always cringe when I open pictures of snakes that I am sent to identify; usually all that remains is a mangled corpse barely recognizable as a snake, let alone whatever species it was before dear aunt Mildred did a twelve point turn over it with the riding mulching mower.

    Second, Leslie’s identification of the snake as an Eastern Indigo Snake (Drymarchon couperi) is correct. This was particularly exciting because not only are Eastern Indigo Snakes Federally Threatened, but very few have ever been documented in southwestern Georgia. Getting the identification correct was certainly made easier because Leslie is a biologist and Mike (in picture, above) had obviously done his homework long ago, already having a good idea of what he had found before he asked anyone. At this point we can play the usual "Steen ID Challenge" and identify what features let us know that this is indeed an Eastern Indigo Snake. Feel free to leave your answers in the comments below. 

    The third thing that jumped out at me is that although we all have had people tell us that they have seen something strange or rare, without documentation it is just an anecdote. Mike had the good sense to grab a camera and snap a photo. 

    Needless to say after my initial excitement I knew that John Jensen from the Georgia Department of Natural Resources and Dirk Stevenson from the Orianne Society needed to be told about this find because this snake could represent a previously unknown population of Indigo Snakes, an exciting development for the future of this very rare species. I dutifully passed their contact information on to Leslie and encouraged her to make sure they were contacted. It took a few days but the proper authorities were contacted and the find is in the process of being officially documented.

    I feel it is appropriate to address the fact that although most people that are reading this blog post would probably jump for joy at finding an endangered species on their land, not everyone feels the same way because of fears associated with federal involvement. I would like to try and allay some of those fears now. First, the federal government is not immediately going to step in and confiscate your land if you find an endangered species on it. In fact, I don’t know of any cases where the government has seized someone’s land. Second, most federal agencies will acknowledge that because an endangered species was living on your property, however you had been managing your land likely must have been working to some degree for the species in question. As long as the land continues to be managed like it was before, they are probably not going to try to make you do anything much different

    In fact, if you find a federally listed species on your land, you will suddenly become eligible for assistance and advice from many interested government agencies and non-governmental organizations. In addition, these agencies and organizations will also likely be able to provide you with funding to help you to manage your land in a way that works both for you and also the rare species. Yes, there might be a catch that comes with that money, like a long-term agreement to not develop your land (i.e., a conservation easement) but if you truly care about the health of your land you will still come out ahead. 

    More than 90% of the land in Georgia (and in most of the other states east of the Mississippi River for that matter) is privately owned. Therefore private lands are key to the long-term conservation of imperiled species. Those of us working in conservation need to be mindful of this fact by appreciating private landowners that manage their land in a way that’s compatible with wildlife and also by respecting property rights. 

    I for one commend Mike on his great fortune in seeing a snake on his family land that most herpetologists only dream of finding in the wild. In addition his appreciation for the natural world was readily apparent in his decision to carefully move this snake out of his carport and to a safer location right nearby and photograph this snake rather than harm it. I look forward to hearing future reports about this location (which for obvious reasons shall remain secret…so don’t bother to pester David for a more specific locality) and its potential role in the understanding of Indigo snake biology and conservation. 

    My final thought was that I wanted to share this find with my other friends in the herpetological community so that they could enjoy this significant development in Indigo Snake conservation and to lend their voice in congratulating Mike for doing everything right. We all preach conservation and education, so here is our chance to congratulate someone for following that message. I hope that Leslie and Mike enjoy what follows in the comments section below!

Roger Birkhead is a biologist with the Alabama Science In Motion program. He received his Master's in herpetology from Auburn University in the same lab as David Steen. His Master’s research focused on the foraging behavior of Gopher Tortoises and their role as seed dispersers in the Longleaf Pine ecosystem. He also spent five years at the Jones Ecological Research Center and many previous years as a field technician working on many national forests and military bases in the southeast. In his spare time he enjoys being a dad, gardening and woodworking.

Relevant Scientific Articles

K.M. Enge, D. J. Stevenson, M. J. Elliot, & J. M. Bauder (2013). The historical and current distribution of the eastern indigo snake (Drymarchon couperi) Herpetological Conservation and Biology, 8 (2), 288-307

Monday, November 18, 2013

An Unstoppable Anaconda Invasion in Florida? What Slate Got Wrong.

Photo By Dave Lonsdale, Wikimedia
    Last week Slate ran a piece in their Wild Things blog entitled, “Green Anacondas in the Everglades: The Largest Snake in the World has Invaded the United States.” Obviously the sensational headline caught my attention as did the subtitle, which refers to this invasion as "unstoppable." However, after reading the actual article I realized that it was basically just a smattering of anecdotes. That makes for a fun story and some interesting conversations, but unfortunately it is too easy to interpret the article as news. Let me be clear: There is virtually no evidence that a population of anacondas exists in Florida.

    Curiously, Slate does not mention that the two individuals that provided the bulk of their anaconda information are affiliated with the Skunk Ape Museum in Ochopee, Florida (the facility is instead described as a “roadside zoo” or the “Trail Lakes Campground”). The Skunk Ape, if you’re not familiar, is the South Florida equivalent of Bigfoot. For what it’s worth, the official website of the Skunk Ape Museum unequivocally states that there are between 7-9 Skunk Apes living in the EvergladesNow, just because someone believes that there is a population of Skunk Apes living in the Everglades does not mean that we can or should discount everything they say, but it does indicate that they probably have different standards than most people when deciding what is circumstantial evidence and what is proof when it comes to determining whether an animal population exists.

    If you give the article a careful read, the entire premise that there is a breeding population of Green Anacondas (Eunectes murinus) in the Everglades boils down to: 1) ten years ago a juvenile Green Anaconda was found in the Everglades; the snake didn’t eat anything and died, 2) another Green Anaconda was later found in the region and finally, 3) lots of people around the Everglades have seen large snakes they did not identify but that possibly could have been Green Anacondas.

    I don't know about you, but this does not convince me that anacondas have invaded South Florida.

    The worst (and incredibly ironic) part of the article is that it repeatedly suggests that the well-publicized concern about the Burmese Python in Florida is largely a result of media-hype while the real problem (i.e., Green Anacondas) is overlooked. The fact that there is a large, reproducing population of Burmese Pythons in Florida is well-documented: thousands have been found including everything from juveniles to giant adults with 87 eggs inside. This population has been the subject of several large and ongoing research projects that have produced numerous scientific papers. For example, a recent paper in the Proceedings of the National Academy of Sciences described how mammal populations have crashed as the Burmese Python population expanded (and presumably, as they ate many of the mammals). 

    On the other hand, documentation of the Green Anaconda "invasion" basically consists entirely of the majorly hyped-up Slate article, which hints that the snakes can get as wide as hula-hoops (they can’t) and probably eat people.

    The irony boggled my mind. Because I only have very little first-hand experience with large invasive snakes, I contacted some of my friends and colleagues that study these Florida reptiles for their perspectives on the article. Unfortunately, I can’t repeat most of their reactions here (this is a family-friendly blog after all). But, fortunately Dr. J.D. Willson did provide a printable response. J.D. is an Assistant Professor at the University of Arkansas and has authored numerous articles about Burmese Pythons in Florida. Notably, he is also co-author of the new book, Invasive Pythons in the United States: Ecology of an Introduced Predator. I figured he could set the record straight.

J.D. replied, “Although there certainly has been a strong dose of sensationalism about the Burmese Python issue from the media, our research suggests that the problem is severe and should be considered a major threat to the Everglades. Over the past decade, Burmese Pythons have spread over an area of at least 4,000 square miles and including all of Everglades National Park and Big Cypress National Preserve. They also appear to have wiped out mammals such as rabbits, raccoons, and bobcats in the heart of the Everglades National Park. Over 2,000 of these snakes have been captured and our research shows that this is just a tiny fraction of the overall population…"

On the other hand…

“…We currently have no reason to suspect that anacondas are established in South Florida. This species certainly is kept in captivity and apparently escaped or released pets have been found. However, the small number of individuals that have been found were far apart and there has been no evidence of reproduction or of a ‘hotspot’ where sightings are concentrated.”

Photo By Trisha M Shears, Wikimedia
    Is it possible that there is a population of Green Anacondas prowling through the isolated marshes of the Everglades? Yes. When the author notes that even big snakes can effectively evade detection in the Everglades, he is completely correct. In addition, Burmese Pythons were already firmly established in Florida before there was indisputable proof that they represented a reproducing population. But there is really no compelling reason to think there is a Green Anaconda population in the Everglades; a grand total of four Green Anacondas have ever been confirmed in Florida, this despite a large-scale reporting and monitoring system that was recently put in place to track the presence of large invasive snakes there. If we use four animals as evidence of a population, for consistency we then also have to believe that just about every other exotic animal ever found in the state also represents an established population, with the possible exception of Skunk Apes.

    But what about all the large snakes people have reported seeing in the Everglades? This phenomenon is not unique to that region. Anyone that has spent any time answering snake questions knows that in general, people are not very good at identifying snakes and tend to exaggerate both their size and their potential to inflict bodily harm.

    Before closing, I want to address two specific points from the original article. First, the juvenile anaconda that was captured in the Everglades did not eat and later died. Is this compelling evidence that it was a wild snake and therefore that anacondas are breeding in the Everglades?

    Anyone that has experience with captive snakes knows that some are picky eaters, perhaps especially when said snake is an exotic species from a faraway land with unique habitats (like, for example, the Amazon). If we are to believe that a snake that did not eat is evidence that it is wild, should we then also believe that the only other individual Green Anaconda captured in the Everglades and mentioned in the article is actually an escaped captive because it did eat?

    Second, the original article argues that the Burmese Python invasion is no big deal compared to an invasion of Green Anacondas because fire ants kill pythons but not anacondas. Laboratory studies have confirmed that fire ants (i.e., Solenopsis invicta) are capable of penetrating reptile eggs, including those of Burmese Pythons. In addition, some have suggested that egg-laying reptiles are more susceptible to being killed by fire-ants than are reptiles that give birth to live young. Fire ants have even been implicated in the declines of some snakes in the southeastern United States, like Southern Hognosed Snakes (Heterodon simus) and Kingsnakes (Lampropeltis getula). But, these are just ideas. There is no evidence that fire ants are influencing the population growth of any reptile.

    To say with confidence that fire ants are limiting the population growth of Burmese Pythons we would need to have some kind of idea regarding how many young Burmese Pythons are being produced and how many are being killed by fire ants and this information is not available to us. The article notes that a single captive Burmese Python and her eggs were killed by fire ants and this is interesting. But, it does not suggest that the wild population is being affected at all. To put it another way, a paper published in 1989 identified 10 confirmed cases of fire ants killing human beings in Florida (and there surely have been more cases since that publication). I don’t think anyone would take that information and then suggest that fire ants are limiting human population growth.

    The possibility of Green Anacondas secretly prowling and reproducing throughout the Everglades is a fun topic to discuss around the campfire. But, it doesn’t stand up to scientific scrutiny. I wish Slate had made that clear.

Update 1/6/14: Slate has given me the opportunity to write more about how biologists differentiate exotic and invasive species, with a focus on large predatory reptiles, check it out!

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Some Relevant Scientific Papers:

Diffie, S., Miller, J, & Murray, K. (2010). Laboratory Observations of Red Imported Fire Ant (Hymenoptera: Formicidae) Predation on Reptilian and Avian Eggs Journal of Herpetology (44), 294-296 DOI: 10.1670/08-282.1

Dorcas ME, Willson JD, Reed RN, Snow RW, Rochford MR, Miller MA, Meshaka WE Jr, Andreadis PT, Mazzotti FJ, Romagosa CM, & Hart KM (2012). Severe mammal declines coincide with proliferation of invasive Burmese pythons in Everglades National Park. Proceedings of the National Academy of Sciences of the United States of America, 109 (7), 2418-22 PMID: 22308381

Rhoades RB, Stafford CT, & James FK Jr. (1989). Survey of fatal anaphylactic reactions to imported fire ant stings J Allergy Clin Immunol., 84, 159-162 DOI: 10.1016/0091-6749(88)90373-9