Comparative analysis of weight gain, hand/wrist maturation; and dental emergence rates in chimpanzees aged 0–24 months from varying captive environments

Abstract

Variability during the first 2 years of growth and development is examined in captive chimpanzees. The mixed longitudinal study of 175 animals compares curves of weight, hand/wrist maturation, and dental emergence for groups within the sample which differ in sex, rearing circumstances (mother-reared versus hand-reared), and colony (Primate Foundation of Arizona, White Sands Research Center, and The University of Texas M.D. Anderson Cancer Center Department of Veterinary Sciences in Bastrop, Texas). Comparison of LOWESS fits of the curves, using a conservative jack-knife approach, reveals trends toward significant differences between colonies for weight (with 4 comparisons reaching significance) and between rearing groups for maturation (1 reaching significance). Results of a full versus reduced model approach show the same trends, for which significance is reached in a higher number of comparisons. The latter approach also indicates possible effects of sex and environmental differences on dental emergence rate. Difficulties with both approaches are discussed. It is concluded that the results are suggestive of significant sex and environmental effects on the variables monitored, justifying further analysis and continuation of the study. The study is significant in 1) providing norms specific to sex and rearing and colony environments with which individual colony animals may be compared in the assessment of their development and in 2) providing a standard, based upon data from a larger and more varied captive chimpanzee population than previously available, with which the dental emergence status and hand/wrist maturation of fossil apes and hominids may be compared.

Molar development in common chimpanzees (Pan troglodytes)

“…Finally, it has been suggested that nonhuman primates that are born and raised in captivity show more rapid skeletal, dental, and sexual development than wild animals (e.g., PhillipsConroy and Jolly, 1988;Kahumbu and Eley, 1991;Marzke et al, 1996;Kelley and Smith, 2003;Zihlman et al, 2004). Zihlman et al (2004) demonstrated this for ages at maxillary molar eruption in chimpanzees, and Phillips- Conroy and Jolly (1988) found the same results for maxillary and mandibular teeth in wild and captive baboon populations.…”

“…Assessments of the skeletal and dental development of chimpanzees have been underway since before the beginning of the twentieth century (Keith, 1899;Selenka, 1899), continuing today in both captive and natural environments (e.g., Kraemer et al, 1982;Goodall, 1986;Anemone et al, 1991Anemone et al, , 1996Kuykendall, 1996;Marzke et al, 1996;Zihlman et al, 2004). Hominoid dental development and tooth emergence have historically been valued because they offer insight into theories of life history and phylogeny (Zuckerman, 1928;Krogman, 1930;Schultz, 1935;Bennejeant, 1940;Clements and Zuckerman, 1953;Gavan and Swindler, 1966;Gavan, 1967), as well as the absolute ages of individuals that are still developing their dentitions (e.g., Garn et al, 1959;Bailit, 1976;Dean and Wood, 1981;Smith et al, 1994).…”

Environment influences morphology and development for in situ and ex situ populations of the black-footed ferret (Mustela nigripes)

“…Long bones develop from the epiphyseal growth plates at the proximate and distal ends (Hinchliffe & Johnson, 1980); cartilage cells at these growth plates transduce mechanical stimuli into extracellular matrix production (Lovejoy et al, 1999). These stimuli are believed to simultaneously build bone, yet prevent the epiphyses from ossifying prematurely (Marzke et al, 1996). The result is that bone architecture is modelled in response to the environment such that bone is built in areas subjected to stress and reabsorbed in areas without stress, a phenomenon known as Wolff's Law (Wolff, 1891;Salter, 1970).…”

A longitudinal study on hand and wrist skeletal maturation in chimpanzees ( Pan troglodytes ), with emphasis on growth in linear dimensions

“…Within the systems of growth, development and maturation, skeletal maturation is probably the least studied system in chimpanzees (exceptions are Watts 1971;Marzke et al 1996, on infants younger than 24 months of age; Matsuzawa et al 1990, on wild chimpanzees; Hamada et al 1998). Based on radiographs collected at the Yerkes laboratory, Watts (1971) presented the chimpanzee norm of RUS skeletal maturation based on the TW1 method.…”