The last female just died: A tale from Guam. By Joseph Topasna - a podcast by Liz Hadly

Why has the Pacific Island of Guam gone from sounding…like this...to a little more like this...

Hello again everyone!
My name is Joseph, and today I’m reporting to you all from the always beautiful Stanford University.
Before we dive in, first a little about me. You see, I was born on the island of Guam 18 years ago. The silence you got a brief glimpse of is extremely concerning for me. Many species of animals on Guam have disappeared forever- that’s the silence. For my generation of Guamanians, this pestilent silence has nowadays become common place. Sixty years ago my grandfather would have heard all of those beautiful birds. Where.have.they.gone?
Why has the island of Guam become a quieter place?!

Ope!
And it looks like we have caller! You're live caller #1, what do you have to say on the subject?
YARRRRRRR
Oh goodness me, not again. Make it quick captain yosef.
I have the answer to your question!!! NOW...
Come with me across the Pacific to peer at the answer in the form of an evolutionarily gifted predator.
It looks *pause* like this: It has…large unblinking eyes… elliptical pupils. It is the perfect hunter who, lacking appendages, will strike, and constrict its prey with its body. Then it will chew…and chew with its venomous rear fangs… until the helpless victim is poisoned, and ready for consumption.

OOOOOK, that's enough from you.
He's spot on though
What is this tank of nature? It’s the Brown Tree Snake.

The Brown Tree Snake’s home is Papua New Guinea and Northern and Eastern Coastal Australia. However, it has found new home. Research estimates that around the late 1940s, the Brown Tree snake was inadvertently transported in a cargo ship to the Island of Guam where it quickly found an abun dance of defenseless prey. The Brown Tree Snake targeted nearly every animal on Guam, including Guam’s 13 native forest birds. Of those 13 bird species, only 3 species of birds have survived. The lone bird you hear now is the Mariana crow. The last female crow on Guam died earlier this year, and there are only two male crows left.

We can’t let this silence spread across the Pacific to other islands. We, the public, must express our concerns about our beloved islands across the Pacific to let Governments know that we strongly support policies that control Brown Tree Snake populations, and prevent the Brown Tree Snake from being inadvertently transported once again.

So far, trapping snakes has been the most successful way to protect what birds remain. Proposed ideas like introducing predators to eat the Brown Tree Snakes hold little value since there are no other predators on Guam to eat those predators in turn. For example, if a predator like the mongoose were brought to Guam to eat the snakes, then Guam would just have a mongoose problem in place of its snake problem.

With that in mind, the greatest thing that Guam and other pacific islands can do (and have done) is invest in Brown Tree Snake prevention. Prevention measures are easy to enact--- Simple measures that include inspecting ship cargo, and any kind of shipment in and out of Pacific islands.

Everything aside though, we need to step back and realize that we can’t see the Brown Tree Snake as an evil animal. It is our fault, not the fault of the Brown Tree Snake, that Guam’s birds have become extinct. The animals of Guam, and the Brown Tree Snake played according to the rules--- they have all been living to the best of their abilities in their environments. And just because the Brown Tree Snake can do its job incredibly well, we can’t fault this skilled hunter for success.

You are the future, and now that you know how our simple, human mistakes impact the natural world, I invite you to remain conscious of human interaction with living and non-living environments. Collectively, it is an educated and conscious human population that will tend towards harmony with nature. Thank you for listening.

References
Stophlet, John J. 1946. Birds of Guam. The Auk 63: 534-40.
Savidge, Julie A., Fiona J. Qualls, Gordon H. Rodda. 2007. Reproductive Biology of the Brown Tree Snake, Boiga irregularis (Reptilia: Colubridae), during Colonization of Guam and Comparison with That in Their Native Range. Pacific Science, 61(2): 191-199.
Rodda, Gordon H., Julie A. Savidge 2007. Biology and Impacts of Pacific Island Invasive Species. 2. Boiga irregularis, the Brown Tree Snake (Reptilia: Colubridae). Pacific Science, 61 (3): 307-324.
D.F. Trembath, S. Fearn. 2008. Body sizes, activity times, food habits and reproduction of brown tree snakes (Boiga irregularis) (Serpentes: Colubridae) from tropical north Queensland, Australia. Australian Journal of Zoology 56: 173–178.
Brooks A. Kaiser, Kimberly M. Burnett 2010. Spatial economic analysis of early detection and rapid response strategies for an invasive species. Resource and Energy Economics 32 (4): 566-585.
Tyrrell, Claudine L., Michelle T. Christy, Gordon H. Rodda, Amy A. Yackel Adams, Aaron R. Ellingson, Julie Savidge, Kathy Dean-Bradley, Richard Bischof. 2009. Evaluation of trap capture in a geographically closed population of brown treesnakes on Guam. Journal of Applied Ecology 46: 128-135.
Mathies, Tom, Russel Scarpino, Brenna A. Levine, Craig Clark, and Julie A. Savidge. 2011. Excluding Nontarget Species from Brown Tree Snake, Boiga irregularis (Reptilia:Colubridae), Bait Stations: Experimental Tests of Station Design and Placement. Pacific Science 65(1): 41-57.
Wiles, G. J., Bart, J., Beck, R. E. and Aguon, C. F. 2003. Impacts of the Brown Tree Snake: Patterns of Decline and Species Persistence in Guam's Avifauna. Conservation Biology 17: 1350–1360.
Tarr, C. L. and Fleischer, R. C. 1999. Population boundaries and genetic diversity in the endangered Mariana crow (Corvus kubaryi). Molecular Ecology 8: 941–949.
Tomback, Diana F. 1986. Observations on the Behavior and Ecology of the Mariana Crow. The Condor 88 (3): 398-401.
Campbell, Steven R., Stephen P. Mackessy, Jennifer A. Clarke. 2008. Microhabitat Use by Brown Treesnakes (Boiga Irregularis): Effects of Moonlight and Prey. Journal of Herpetology 42(2): 246-250.
Kimberly M. Burnett, Sean D'Evelyn, Brooks A. Kaiser, Porntawee Nantamanasikarn, James A. Roumasset. 2008. Beyond the lamppost: Optimal prevention and control of the Brown Tree Snake in Hawaii, Ecological Economics, Volume 67 (1): 66-74.
Rodder, Dennis, Stefan Lotters. 2010. Potential Distribution of the Alien Invasive Brown Tree Snake, Boiga irregularis (Reptilia: Colubridae). Pacific Science, 64(1): 11-22.

Photo: By USNPS

Further episodes of Extinctions in Near Time: Biodiversity Loss Since the Pleistocene

Further podcasts by Liz Hadly

Website of Liz Hadly