How can you conserve a large carnivore when you don’t know how many of them exist? It’s a difficult task, and so a few scientists at the Jaguar Conservation Fund opted to put a number on their target population… only it’s not jaguars they were trying to pinpoint, it was the lesser known maned wolf.
The maned wolf is a quirky-looking wild dog relative that looks rather like an over grown red fox whose legs have been comically elongated. Or a skinny wolf on stilts. Though it is in the family Canidae, it’s not in the genus Canis as are true wolves… rather, it is in a related genus and is named Chrysocyon brachyurus. My reading of Tedford and Wang’s book, Dogs: Their Fossil Relatives and Evolutionary Origins, indicates that these researchers believe the South American canines, including Chrysocyon, evolved from a group closely related to, but separate from, Canis.
Today, the maned wolf lives in Brazil, Paraguay, eastern Bolivia and northern Argentina where mated pairs maintain territories from 30 to 80 square kilometers, according to the study. But the pairs do not hunt together, rather they go after prey individually. The largest portion of the animals range lies within Brazil in what’s known as the Cerrado or Brazilian savannah. This area is being rapidly converted to cattle ranches and agriculture, the authors state. Which poses a huge problem, because even though scientists suspect its numbers are declining, there is no baseline population measurements available for comparison.
So the authors used 13 years of telemetry data from the maned wolf’s use of a refuge called Emas National Park, plus private properties adjacent to the park, to characterize the first reliable estimate of the animal’s survival rate.
The authors radio-collared 72 maned wolves between 1995 and 2007 (63 adults, 9 sub-adults). They counted sightings of the collared animals as a “recapture” event, as well as recovery of dead animals, to perform a mark-recapture analysis. Each animal averaged about three years of study, and 23 maned wolves died over the course of the 13-year study.
Their results were inconclusive as to whether an animal’s sex had any bearing on its likelihood to survive. They found that 97 percent of 8-year old maned wolves survived to the following year, while only 28 percent of 12-year olds did. 63 percent of sub-adults lived to the next year, which they speculate may be a higher than anticipated rate because of rich resources available to maned wolves in the study area (relying on dispersal being a mechanism to balance limited resources).
Sollmann, R., Furtado, M., Jácomo, A., Tôrres, N., & Silveira, L. (2010). Maned wolf survival rate in central Brazil Journal of Zoology DOI: 10.1111/j.1469-7998.2010.00727.x