tar-sands extraction begins, but we hope our findings can 

 guide efforts to soften the blow of development. 



FAR FROM THE CHILLY ALBERTA muskeg, the Cerrado 

 of Brazil, a tropical savanna, is a biodiversity hotspot that is 

 home to thousands of endemic species. It's also among the 

 world's most threatened biomes. As with Alberta's tar sands, 

 the destruction is partly driven by humanity's unquenchable 

 thirst for fuel: vast fields of soybeans and sugarcane, grown 

 for biodiesel production, are replacing natural savanna at 

 a staggering pace. Landowners near Emas National Park, 

 a large preserve in the Cerrado, are required to set aside 

 20 or 30 percent of their land (depending on the location) 

 as reserves of natural habitat. But my graduate student 

 Carly Vynne and I suspected that the park and the private 

 reserves might be insufficient to sustain wildlife popula- 

 tions, particularly if the private reserves are located outside 

 huge cultivated fields, rather than within them to provide 

 stepping stones between patches of natural savanna. 



So Vynne and I have been using the dogs to monitor 

 how maned wolves move within the patchy landscape of 



Exploration for tar sands, a source of oil, mars a forest in northeast- 

 ern Alberta, Canada. If developers discover sufficient deposits in 

 an area, pipelines, extraction facilities, and additional roads soon 

 follow. Scat-detection dogs are helping to determine the effects of 

 such exploration on caribou, moose, and wolves. 



the Cerrado, with the secondary goal of studying distribu- 

 tions of puma, jaguar, giant anteater, and giant armadillo. 

 All five species have large home ranges and are reclusive, 

 so they're difficult to study; scientists know little about 

 whether and how each lives outside the park, and almost 

 nothing at all about the endangered giant armadillo. 



Over vast stretches of park and farmland, Vynne and 

 Mason, along with five other dog teams, have located an 

 impressive amount of scat from all five species, which 



gives us a pretty clear picture of where the animals spend 

 their time. Although the species differ in their behavior, 

 they all live both inside and outside the park in virtually 

 every type of natural habitat, but shy away from extensive 

 cultivated fields. With very few exceptions, the samples 

 discovered outside the park were in or near patches of 

 natural habitat, showing the importance of locating the 

 private reserves within farmland. We are currently ana- 

 lyzing hormones indicating emotional, reproductive, and 

 nutritional stress in the maned-wolf scat to see whether 

 the wolves' health is better inside or outside the park and 

 whether it's compromised when reserves are small and far 

 apart, as we predict. 



WITHOUT QUESTION, OUR DOGS' most surprising feat is 

 their successful tracking of whale poop. In our first whale 

 project, Rosalind M. Rolland, a marine scientist at the 

 New England Aquarium in Boston, Barbara Davenport, 

 and I used dogs to find the conspicuous scat of North 

 American right whales in Nova Scotia's Bay of Fundy. 

 The scat is orange, stinky, and floats. Soon enough, dogs 

 were locating it at more than four times the 

 rate achieved by multiple human observers. 

 They even detected a few samples from farther 

 than one nautical mile away. 



Then, two years ago, my graduate student 

 Katherine Ayres and I began a pilot study to 

 investigate why an endangered population of 

 orcas, or killer whales, in Puget Sound had 

 declined by 20 percent in the late 1990s and 

 had since recovered only slowly. We planned to 

 examine scat for toxins and for hormones indi- 

 cating emotional, reproductive, and nutritional 

 & stress, to determine the relative importance of 

 | three possible culprits: inadvertent harassment 

 I by commercial and private whale-watching 

 S boats, a decline in the whales' main food ot 

 E Chinook salmon, and PCB contamination, 

 g But orca scat is much harder to find and collect 

 § than right-whale scat. It's similar in color to 

 ° seawater, sinks quickly, and, being slimy and 

 fish-laden, is hard to remove from the water. 

 A dog, we hoped, would help us get to the 

 poop before it sank. 



We chose Tucker for the job, a happy-go- 

 lucky black Lab who hates to swim. Tucker 

 rides calmly on the boat's bow, sniffing air currents 

 wafting across the water. In spite of his fear of the deep, 

 he practically pulls his handler off the bow as soon as 

 he catches a whiff of orca scat. We steer into the wind, 

 toward the airborne cone of scent emanating from the 

 scat. If the boat exits the scent cone. Tucker loses inter- 

 est immediately. So we turn the boat perpendicular to 

 the wind until Tucker again tries to leap into the water; 

 then we steer back into the wind. And so we snake our 



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natural history October 2008 



