DeGusta D, Milton K (1998) Skeletal pathologies in a population of Alouatta palliata: Behavioral, ecological, and evolutionary implications. International Journal of Primatology 19:615-650. [PDF]
Abstract -
We examined the pathological conditions in a sample of 200 Alouatta palliata skulls recovered from Barro Colorado Island (BCI), Panama to investigate the prevalence of disease and injury in a free-ranging monkey population. A total of 45 individuals (22.5%) have some type of non-dental pathological condition, indicating that illness and injury are relatively common in this population. Ten individuals, all older adult males, exhibit clear signs of antemortem trauma in the form of healed fractures. We attribute the trauma primarily to fighting, and its frequency (16.4% of adult males) contradicts previous assertions that BCI howlers are non-aggressive. Nine of the 37 scorable immature individuals (24%) have signs of a larvae infestation, supporting the suggestion that ectoparasites play an important role in BCI howler mortality. Other pathological conditions in the sample include shifted muscle attachments, periostitis, arthritis, neoplasm, periapical abscesses, and facial deformity, as well as various dental abnormalities.