Mortality
Primary causes of mortality include habitat loss, human-introduced diseases, and indirect poisoning from prairie dog control. Annual mortality of juvenile and adult black-footed ferrets over a 4-year period ranged from 59% to 83% (128 individuals) near Meeteetse, Wyoming. During fall and winter, 50% to 70% of juveniles and older animals perish. Average lifespan in the wild is probably only 1 year but may be up to 5 years. Males have higher rates of mortality than females because of longer dispersal distances when they are most vulnerable to predators.
Given an obligate-dependence of black-footed ferrets on prairie dogs, black-footed ferrets are extremely vulnerable to prairie dog habitat loss. Habitat loss results from agriculture, livestock use, and other development.
Black-footed ferrets are susceptible to numerous diseases. They are fatally susceptible to canine distemper (Morbillivirus), introduced by striped skunks, common raccoons, red foxes, coyotes, and American badgers. A short-term vaccine for canine distemper is available for captive black-footed ferrets, but no protection is available for young born in the wild. Other diseases that black-footed ferrets are susceptible to include rabies, tularemia, and human influenza. Sylvatic plague (Yersinia pestis) probably does not directly affect black-footed ferrets, but epidemics in prairie dog towns may completely destroy the black-footed ferrets' prey base.
Predators of black-footed ferrets include golden eagles, great horned owls, coyotes, American badgers, bobcats, prairie falcons, ferruginous hawks, and prairie rattlesnakes.
Oil and natural gas exploration and extraction can have detrimental impacts on prairie dogs and black-footed ferrets. Seismic activity collapses prairie dog burrows. Other problems include potential leakages and spills, increased roads and fences, increased vehicle traffic and human presence, and an increased number of raptor perching sites on power poles. Traps set for coyotes, American mink, and other animals may harm black-footed ferrets.
Read more about this topic: Black-footed Ferret
Famous quotes containing the word mortality:
“When I turned into a parent, I experienced a real and total personality change that slowly shifted back to the “normal” me, yet has not completely vanished. I believe the two levels are now superimposed, with an additional sprinkling of mortality intimations.”
—Sonia Taitz (20th century)
“The mortality of all inanimate things is terrible to me, but that of books most of all.”
—William Dean Howells (1837–1920)