A comparison of adult body size between captive and wild vervet monkeys (Chlorocebus aethiops sabaeus) on the island of St. Kitts

Abstract

Weight and 34 morphological measurements were obtained from 103 vervet monkeys living either in the wild or in captive colonies derived from the wild populations on the island of St. Kitts in the Eastern Caribbean. All measures were taken during the same week, eliminating bias that might result from changing seasonal environmental conditions. Vervets on St. Kitts are all descended from a small number of individuals brought to the island approximately 400 years ago from West Africa, thus eliminating bias that might result from subspecific size differences. We conducted a principal components analysis (PCA) and compared individual traits between captive and wild adult animals. Morphological measures such as body, arm, and leg length did not differ significantly between animals living in the wild and animals in captivity. Weight and measures indicating condition-including body mass index (BMI), chest, thigh, and upper arm girth were all higher for animals living in captivity. More consistent available food is probably the cause of differences in measures reflecting condition.

Keywords: Adult body size; Captive; Vervet monkey; Wild.

Figure 1

PC1 and PC2 for female morphological variables.

Figure 2

PC1 and PC2 coordinates for female morphological variables with 95% confidence ellipses for captive and wild states.

Figure 3

PC1 and PC2 for female condition variables.

Figure 4

PC1 and PC2 coordinates for female condition variables with 95% confidence ellipses for captive and wild states.

Figure 5

PC1 and PC2 for male morphological variables.

Figure 6

PC1 and PC2 coordinates for male morphological variables with 95% confidence ellipses for captive and wild states.

Figure 7

PC1 and PC2 for male condition variables (with testes omitted).

Figure 8

PC1 and PC2 coordinates for male condition variables (testes omitted) with 95% confidence ellipses for captive and wild states.