Smithsonian National Zoological Park l Friends of the National Zoo



Castelda Project

Determine how human development and habitat disturbance affect how canid species of the Brazilian species interact and coexist

The Cerrado is the largest savanna region in South America, and is biologically the richest grassland in the world. This ecosystem sustains over 1,200 species of birds, mammals, reptiles, and amphibians. Over the past 30 years, the Brazilian Cerrado undergone intense deforestation. Seventy percent of the Brazilian Cerrado has been converted into agricultural land such as cattle ranches and soybean and sugar cane plantation. These habitat changes hurt many populations; however, few studies have focused on how these alterations affect the dynamics of sympatric wildlife.

The Smithsonian Conservation Biology Institute in collaboration with Mammal Conservation Program of the Cerrado, the Hoary Fox Project, and Brazilian zoos are taking a multidisciplinary approach to improve our understanding of how human changes the Cerrado ecosystem affect the interactions among three canid species: the maned wolf (Chrysocyon brachyurus), the crab-eating fox (Cerdocyon thous) and the hoary fox (Psuedalopex vitulus).

Resource Competition Assessment

Radio-telemetry allows us to monitor home range, home-range overlap, and movement of these three sympatric canids in fragmented Cerrado environments. Anthropogenic factors (such as farming, ranching, and highway development) affect resource availability and species distribution, thereby indirectly increasing competition among sympatric species for those resources. The affect of inter-specific resources competition may be minimal for individuals living in large protected areas where resources are not limited, but the intensity of conflict can potentially increase in disturbed or isolated areas where resources are restricted.

Stress Hormone Monitoring

Stress responses play a key role in allowing animals to cope with changes in their environment. The responses to stressful or life-threatening situations of individuals involve the hypothalamic-pituitary-adrenocortical axis, which elicits glucocorticoid (GC) secretion from the adrenal cortex. GC metabolites can be measured in excreted feces and provides a non-invasive means in ecological and conservation studies for monitoring the well-being of wild animals without interfering with the animals’ normal activities. Our research group is developing field friendly methods to monitor stress hormone in the maned wolf, crab-eating fox and hoary fox.

Human-Canid Conflict Mitigation

The maned wolf, crab-eating fox and hoary fox are harassed and killed indiscriminately kill by farmers for being possible predators of domestic animals. These accusations are based on suspicions rather than science. In addition, these canids are chased and even killed by domestic dogs and fall victim to road traffic accidents (become road-kill). SCBI researchers and Brazilian collaborators can mitigate human-canid conflicts through community outreach and education that generating greater awareness in benefits of improved husbandry practices and the importance of the Cerrado ecosystem.