COMPARATIVE-ANALYSIS OF WEIGHT-GAIN, HAND WRIST MATURATION, AND DENTAL EMERGENCE RATES IN CHIMPANZEES AGED 0-24 MONTHS FROM VARYING CAPTIVEENVIRONMENTS/

Variability during the first 2 years of growth and development is exam ined in captive chimpanzees, The mixed longitudinal study of 175 anima ls compares curves of weight, hand/wrist maturation, and dental emerge nce for groups within the sample which differ in sex, rearing circumst ances (mother-reared versus hand-reared), and colony (Primate Foundati on of Arizona, White Sands Research Center, and The University of Texa s M.D. Anderson Cancer Center Department of Veterinary Sciences in Bas trop, Texas). Comparison of LOWESS fits of the curves, using a conserv ative jackknife approach, reveals trends toward significant difference s between colonies for weight (with 4 comparisons reaching significanc e) 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 enviro nmental differences on dental emergence rate. Difficulties with both a pproaches are discussed, It is concluded that the results are suggesti ve of significant sex and environmental effects on the variables monit ored, justifying further analysis and continuation of the study. The s tudy is significant in 1) providing norms specific to sex and rearing and colony environments with which individual colony animals may be co mpared in the assessment of their development and in 2) providing a st andard, based upon data from a larger and more varied captive chimpanz ee population than previously available, with which the dental emergen ce status and hand/wrist maturation of fossil apes and hominids may be compared. (C) 1996 Wiley-Liss, Inc.