TY - JOUR
T1 - Ontogenetic Development of Sexual Dimorphism in Body Mass of Wild Black-and-White Snub-Nosed Monkey (Rhinopithecus bieti)
AU - Li, Yan Peng
AU - Huang, Zhi Pang
AU - Yang, Yin
AU - He, Xiao Bin
AU - Pan, Ru Liang
AU - He, Xin Ming
AU - Yang, Gui Wei
AU - Wu, Hua
AU - Cui, Liang Wei
AU - Xiao, Wen
N1 - Funding Information:
This work was funded by the National Natural Science Foundation of China [#31860168 and #31260149], Yunnan Natural Science Foundation [#202001BA070001-227], Science Research Foundation of Yunnan Education Bureau [#2020J0543], and Ten Thousand Talent Plans for Young Top-notch Talents of Yunnan Province [#YNWR-QNBJ-2019-262].
Publisher Copyright:
© 2023 by the authors.
PY - 2023/5
Y1 - 2023/5
N2 - Sexual dimorphism exists widely in animals, manifesting in different forms, such as body size, color, shape, unique characteristics, behavior, and sound. Of these, body mass dimorphism is the most obvious. Studies of evolutionary and ontogenetic development and adaptation mechanisms of animals’ sexual dimorphism in body mass (SDBM), allow us to understand how environment, social group size, diet, and other external factors have driven the selection of sexual dimorphism. There are fewer reports of the ontogenetic development of sexual dimorphism in body mass in Rhinopithecus. This study explores the ontogenetic development pattern of SDBM in wild black-and-white snub-nosed monkeys (R. bieti), and the causes resulting in extreme sexual dimorphism compared to other colobines. A significant dimorphism with a ratio of 1.27 (p < 0.001) appears when females enter the reproductive period around six years old, reaching a peak (1.85, p < 0.001) when males become sexually mature. After the age of eight, the SDBM falls to 1.78, but is still significant (p < 0.001). The results also indicate that males had a longer body mass growth period than females (8 years vs. 5 years); females in larger breeding units had a significantly higher SDBM than those in smaller ones (2.12 vs. 1.93, p < 0.01). A comparative analysis with other colobines further clarifies that Rhinopithecus and Nasalis, which both have multilevel social organization, have the highest degree of SDBM among all colobines. The large SDBM in R. bieti can be explained through Bergman’s and Rensch’s rules. Overall, environmental adaptation, a distinctive alimentary system, and a complex social structure contribute to R. bieti having such a remarkable SDBM compared to other colobines. In addition, we found that females’ choice for males may not be significantly related to the development of SDBM.
AB - Sexual dimorphism exists widely in animals, manifesting in different forms, such as body size, color, shape, unique characteristics, behavior, and sound. Of these, body mass dimorphism is the most obvious. Studies of evolutionary and ontogenetic development and adaptation mechanisms of animals’ sexual dimorphism in body mass (SDBM), allow us to understand how environment, social group size, diet, and other external factors have driven the selection of sexual dimorphism. There are fewer reports of the ontogenetic development of sexual dimorphism in body mass in Rhinopithecus. This study explores the ontogenetic development pattern of SDBM in wild black-and-white snub-nosed monkeys (R. bieti), and the causes resulting in extreme sexual dimorphism compared to other colobines. A significant dimorphism with a ratio of 1.27 (p < 0.001) appears when females enter the reproductive period around six years old, reaching a peak (1.85, p < 0.001) when males become sexually mature. After the age of eight, the SDBM falls to 1.78, but is still significant (p < 0.001). The results also indicate that males had a longer body mass growth period than females (8 years vs. 5 years); females in larger breeding units had a significantly higher SDBM than those in smaller ones (2.12 vs. 1.93, p < 0.01). A comparative analysis with other colobines further clarifies that Rhinopithecus and Nasalis, which both have multilevel social organization, have the highest degree of SDBM among all colobines. The large SDBM in R. bieti can be explained through Bergman’s and Rensch’s rules. Overall, environmental adaptation, a distinctive alimentary system, and a complex social structure contribute to R. bieti having such a remarkable SDBM compared to other colobines. In addition, we found that females’ choice for males may not be significantly related to the development of SDBM.
KW - environmental adaptation
KW - multilevel social organization
KW - Rhinopithecus bieti
KW - sexual bimaturism
KW - sexual selection
UR - http://www.scopus.com/inward/record.url?scp=85159098723&partnerID=8YFLogxK
U2 - 10.3390/ani13091576
DO - 10.3390/ani13091576
M3 - Article
C2 - 37174611
AN - SCOPUS:85159098723
SN - 2076-2615
VL - 13
JO - Animals
JF - Animals
IS - 9
M1 - 1576
ER -