Living With Wolves

Restoring Yellowstone’s aspen with wolves

Wolves (Canis lupus) were reintroduced to Yellowstone National Park in 1995–1996. We present data on a recent trophic cascade involving wolves, elk (Cervus elaphus), and aspen (Populus tremuloides) in Yellowstone’s northern winter range that documents the first significant growth of aspen in over half a century. Results indicate reduced browsing and increased heights of young aspen during the l...

Dancing With Wolves: Today's Lone Wolf Terrorists

Comparison of serum hormone levels of captive and free-living maned wolves Chrysocyon brachyurus.

Serum hormone levels were compared between captive and free-living maned wolves and seasonal variations of sex hormones were studied. Blood samples were collected from 16 male and 26 female adult animals from Brazilian zoos, and from 30 male and 24 female free-living adults to determine serum progesterone and testosterone by radioimmunoassay. Serum testosterone concentrations varied (P < 0.05) ...

Populational genetic structure of free-living maned wolves (Chrysocyon brachyurus) determined by proteic markers.

Electrophoretic analysis of presumptive twenty gene loci products was conducted in hemolisates and plasma samples of twenty-eight maned wolves (Chrysocyon brachyurus) from an area in northeastern São Paulo State, Brazil. The area sampled was divided into three sub-areas, with the Mogi-Guaçu and Pardo rivers regarded as barriers to the gene flow. The polymorphism degree and heterozygosity level ...

The Wolves of Yellowstone

Perhaps no other large predator is more deeply embedded in our psyche than the wolf. Vilified throughout history in both legend and literature, humans had effectively eradicated wolves from Europe by 1850. In the United States, the government declared a war of extermination against gray wolves (Canis lupus) beginning in the early 1800s. Hunters, ranchers, and farmers eagerly enlisted, using let...