Emiliano Donadio, Steven W. Neotropical ungulates are poorly understood with regard to age-specific mortality and how it relates to different mortality causes. Further, low survival rate in 1 calendar year was associated with low mean birth mass during that year, but not with population density and forage quality in the previous year.
How environmental factors e. La influencia de factores ambientales e. Knowledge of how food and predators influence mortality is key to the processes that determine ungulate numbers.
For instance, decreasing forage quality and availability predispose malnourished individuals to starvation e.
Furthermore, forage shortage depresses pregnancy rates e. Food and predators differentially affect discrete aspects of ungulate populations. Losses to malnutrition typically affect young and old animals more than others reviewed by Gaillard et al.
Losses to predation depend on the interaction between individual traits of the prey and the hunting mode of the predator. Cursorial and ambush predators tend to select young and old individuals Hornocker ; Mech et al. However, ambush predators may kill prime individuals if prey occur in groups and the success of the attack depends on proximity rather than prey characteristics Logan and Sweanor In 1 Peruvian population, exposure, lightning, calf losses to culpeo foxes Lycalopex culpaeus , and predation on adults from unknown agents explained natural mortality Franklin ; Hofmann et al.
