Mammals and landscape connectivity conservation
Increasing agricultural expansion and land use is having severe impacts on persistence of wide ranging species. Mortality of such species disproportionately occurs outside of reserves that are intended to protect them. The Cerrado of Brazil provides a prime example. It comprises the world’s most diverse tropical savanna and is also one of the world’s most threatened regions. The Cerrado is home to hundreds of endemic species and comprises the primary habitat of the maned wolf, a wild canid found only in the grasslands of central South America. The majority of the maned wolves’ range is under conversion for agricultural production. This prompted us to ask how the mosaic of land uses outside of nature reserves and national parks affects the viability of wide-ranging species such as the maned wolf.
We conducted a population assessment and monitoring the stress, nutritional, and reproductive impacts associated with maned wolf use of protected areas and their surrounding landscape. Their diets and parasite loads were also examined. Simultaneously, we conducted a presence-absence survey of other wide-ranging fauna that co-occur with maned wolves, puma, jaguar, giant armadillo, giant anteater, tapir.
Where we worked
The 1200 square kilometer Emas National Park (ENP) in southwest Goias State, Brazil, is considered one of a few major strongholds for maned wolf populations. ENP is also home to more endemic and endangered Cerrado species than any other park in the biome, and is recognized for being one of the few places in South America that still contains its entire large mammalian fauna. However, conversion of the surrounding area to farmland has been recent, rapid, and intense, transforming the Park into an island in a sea of agriculture.
Private landholders are currently required to set aside 20-30% (depending on the State) of their farm as natural habitat. There is ongoing debate about whether they should be allowed to purchase set aside land outside their farms instead of maintaining natural habitat within their farmland. Our study aimed to assess differential impacts of these land use decisions by examining how the type of land mosaic best promotes or reduces species viability.
We employed novel, noninvasive methods pioneered by the Center for Conservation Biology to examine the population status and physiological health of the wolves in ENP and the surrounding region, as well as survey for several other wide-ranging species. Specially-trained scat detection dogs are used to rapidly and non-invasively acquire unbiased scat samples of maned wolves, puma, jaguar, giant anteater, and giant armadillo across a diversity of habitat conditions. Dog-handler teams located scat samples over 800 km2 of national park and 3300 km2 of private farm and ranchland during field seasons in 2006 through 2008. Habitat data were collected every 20 minutes, sample locations and track logs were maintained by GPS, a spatial database was created and linked to each sample encountered, and rare events such as wildlife sightings were noted. DNA extracted from these samples was used to confirm the species, as well as assign gender and individual identities. Hormones measured from the same samples were used to assess the animal’s stress levels, nutritional status and reproductive health. Diet contents as well as parasite load were also examined from these samples. These data collectively determine how abundance, distribution and physiological health of individuals vary across these landscapes. For more information read the following paper by Vynne, C. et al. 2010. Effectiveness of Scat-Detection Dogs in Determining Species Presence in a Tropical Savanna Landscape. Conservation Biology.
All six species were found inside and outside of Emas National Park (ENP). However, the jaguar was almost entirely restricted to the immediate vicinity of the Park and thus is at most risk from isolation. Maned wolves make extensive use of the landscape mosaic surrounding ENP and established pairs were found using areas up to tens of kilometers from any protected area. For more information please see the following paper by Vynne et al. 2011. Resource Selection and Its Implications for Wide-Ranging Mammals of the Brazilian Cerrado. PLoS One.
The maned wolves have a much more diverse diet inside the Park than when they occur on surrounding farmlands and ranches.
Maned wolves harbor a plethora of parasite species. Mike Kinsella, our collaborator for this component of the project, has identified 13 different species and many individual samples with multiple types of parasites.
The giant armadillo (IUCN Vulnerable) shows a clear preference for open habitats in this region, with open cerrado, grasslands, and marsh edges being the most commonly used areas. There is some evidence of individuals using altered landscapes (pastures and agricultural edges). However, we found no evidence of burrow digging or scat samples from armadillos in croplands or pasture further than 100 meters from natural habitat. This is particularly important since open habitats are nearly non-existent outside of protected areas in this region.
The drastic reduction in giant anteater density in ENP has been a puzzle for the last decade. We now have more than 800 records of giant anteaters, providing an important baseline for monitoring how population density varies with fires or other causes of decline, as well as the likelihood that populations will rebound.
This work was part of the doctoral dissertation of Carly Vynne in the Center for Conservation Biology. We gratefully acknowledge the tireless efforts of our conservation canines, field and laboratory assistants, the Jaguar Conservation Fund, and of course the support of our donors: The Morris Animal Foundation, the TEAM Network of Conservation International, funded by the Gordon and Betty Moore Foundation, Conservação Internacional do Brasil, and the Biology Department at the University of Washington. A National Science Foundation Graduate Fellowship and a National Security Education Program Boren Fellowship to C. Vynne helped make this work possible.
- Vynne, C. and Kinsella, J.M. 2009. First Record of Entodiniomorph ciliates in a Carnivore, the Maned Wolf (Chrysocyon Brachyurus), From Brazil. Journal of Zoo and Wildlife Medicine. 40(2).
- Vynne, C. et al. 2011. Factors influencing degradation of DNA and hormones in maned wolf scat. Animal Conservation.
- Wasser, S., Smith, H., Madden, L., Marks, N. and Vynne, C. In press. Scent matching dogs determine number of unique individuals from scat. Journal of Wildlife Management.
- Furtado, M.M., Carrillo-Percastegui, S.E., Jácomo, A.T.A., Powell, G., Silveira, L., Sollmann, R. and Vynne, C. 2008. Studying jaguars in the wild: past experiences and future perspectives. CAT News, Special Issue 4 – The Jaguar in Brazil.
- Vynne, C. Machado, R., Marinho-Filho, J., Wasser, S.K. In press. Scat-detection dogs seek out new locations of Priodontes maximus and Myrmecophaga tridactyla in Central Brazil. Edentata.
- Silveira, L. Jácomo, A.T.A., Furtado, M.M., Torres, N.M., Sollmann, R., Vynne, C. In press. Ecology of the giant armadillo (Priodontes maximus) in the grasslands of central Brazil. Edentata.
- Mamede, S.B. and Alho, C.J.R. English translation by Vynne. C. 2008. Impressions of the Cerrado and Pantanal: A guide for the observation of the non-flying mammals.
Selected press coverage
- Sniffing dogs monitor and protect Brazil’s wildlife by detecting animal feces. Yahoo News India. May 13, 2008.
- Dogs trained to track movements of threatened wildlife. May 16, 2008. Tony Barboza, Los Angeles Times.
- Sniffing dogs detect feces to help monitor and protect threatened animals in Brazil. May 13, 2008. Science Daily.
- Quando o melhor amigo do homem é amigo do conservação. May 16, 2008. Organização para a Proteção Ambiental.
- Wasser, SK. 2008. Lucky Dogs: Single-minded dogs sniff out the scat of endangered animals, trumping more technical tracking methods. Natural History, October.
- For these dogs, are their new tricks saving species? 2008. Conservation International website.
- MacKay, P., D. A. Smith, R. A. Long, M. Parker. 2008. Scat Detection Dogs. In Noninvasive Survey Methods for Carnivores. R. A. Long, P. MacKay, W. J. Zielinski and J. C. Ray (eds). Washington, Island Press: 183-222.
- Researchers Use Dogs to Track Species in the Field. 2005. Biodiversity Hotspots: a newsletter covering the Biodiversity Hotspots. Fall 2005 edition. Available at www.BiodiversityHotspots.org.
- Vynne, C. 2008. Scat detector dogs seek out jaguar locations in and around Emas National Park – GO, Brazil. Jaguar News. No. 15, May 1. Newsletter of the Jaguar Conservation Fund.