Predators
Some aerial predators include hawks and eagles. Underground predators include rattlesnakes and bull snakes (Chance, 1976). Although some believe that burrowing owls prey upon prairie dogs, they do not usually. However, they do inhabit former prairie dog burrows (Hoogland, 1995).
Among the above- ground threats to prairie dogs are coyotes, foxes, badgers and bobcats (Chance, 1976). While badgers will often dig a prairie dog out of its hole, coyotes are less agressive predators that wait for a prairie dog to come above ground. Bobcats may be a danger to prairie dogs, especially if a prairie dog's territory is near a canyon. Because they are nocturnal bobcats are often a threat during the early morning and evening hours (Chance, 1976). The great plains grizzly bear, gray wolf, and mountain lion may also pose a threat to the prairie dog although they are endangered now (Chance, 1976).
Photograph courtesy of Doug Backlund
Photo courtesy of Doug Backlund
A special case of predation is the black- footed ferret, or Mustela nigripes. Because it is only found in South Dakota near prairie dog towns, it is believed that it is reliant on the prarie dog for food (Chance, 1976). Although some believe that the black- footed ferret may be able to slip into a prairie dog's burrow because of its small diameter, it often engages in predation of the prairie dog by digging into the prairie dog burrows (Chance, 1976).
Disease
In addition, prairie dogs are subject to the threats that come with other prairie dogs. These threats include the transmission of disease, such as bubonic plague, which is easily spread by the transfer of fleas within a prairie dog colony (DesertUSA, 1996). The plague can estinguish a whole colony (DesertUSA, 1996).
Infanticide
Another threat that comes along with communal living is the threat of infanticide, in which conspecifics may kill another prairie dog's young. Infanticide affects 39% of all litters and is thus a major threat to the life of praire dog young (Hoogland, 1995). There are two types of infanticide: infanticide by invading males from other coteries who hope to mate with females and infanticide by lactating females. This first type of infanticide is not surprising. In many species, males invade a nearby territory and kill the female’s offspring in the hope of mating with females. This occurance happens because females who do not have offspring stop lactating and thus come into estrus sooner (Hoogland, 1995). Thus, mothers without offspring are more likely to become impregnated by these invading males than mothers with offspring (Hoogland, 1995).
What is most surprising about infanticide within prairie dogs, however, is that most of the time the prairie dogs that commit infanticide are very close relatives (Hoogland, 1995). These relatives are often lactating females and the mothers, sisters, or aunts of the mothers of the victimized offspring. These lactating females kill a closely related female's offspring for a number of reasons. These reasons include the decrease in competition for a female and her offspring that comes along with infanticide, a nutritional gain (adult prairie dogs eat the young prairie dogs they kill), and increased foraging area due to a decrease in territorial defense by the victimized mother. In addition to these benefits, the killers also gain the benefits of possible helpers and a decrease in the likelihood that their offspring will be victims of infanticide. These benefits are due to the fact that victimized mothers now have no offspring to take up their time and have time to help other mothers with their motherly duties. Victimized mothers are believed to be less likely to kill because they stop lactating and lactating females are most often the females that kill other’s offspring (Hoogland, 1995). Thus, this last benefit is secondary to the others and probably helps cause infanticide to continue (Hoogland, 1995).