Seasonality of reproduction of wild Rhinopithecus bieti at Mt. Lasha, Yunnan, China

ORIGINAL ARTICLE

Seasonality of reproduction of wild black-and-white snub-nosed monkeys (Rhinopithecus bieti )at sha,Yunnan,China

Zhi-Pang Huang •Liang-Wei Cui •Matthew B.Scott •

Shuang-Jin Wang •Wen Xiao

Received:9August 2011/Accepted:22February 2012/Published online:10March 2012ÓJapan Monkey Centre and Springer 2012

Abstract Black-and-white snub-nosed monkeys (Rhin-opithecus bieti )inhabit one of the harshest habitats by any nonhuman primate.Reliable predictive cues to initiate reproduction may be particularly critical for R.bieti because they inhabit such seasonally energetically chal-lenging environments.To better understand the seasonal distribution of and predictive cues to reproduction,we collected breeding and birth data in a population of R.bieti at sha in Yunling Nature Reserve,Yunnan,China,from January 2008to May 2010,using a combination of 10-min instantaneous scans and ad libitum observations.We examined variations in temperature,rainfall,and food availability,as well as photoperiod differences between sha and the more northerly Xiaochangdu to identify environmental influences on the timing of reproductive events.Our data show the area exhibited distinct seasonal fluctuations in rainfall,temperature,and food availability.Mating occurred year-round,but peaked in August,coin-ciding with the end of the period of highest temperatures and food availability,and during the peak rainfall.

Copulation frequency peaked 1month after corresponding peaks in staple foods,rainfall,and minimum temperatures,and 3–4months after peaks in high-quality foods.Births were significantly seasonal,with a birth peak from mid-February to early April,and a mean birth date of 14March.Eleven births occurred in 41days in 2009,and 16births occurred in 52days in 2010.Births occurred during peri-ods of increasing temperatures and food availability.Our findings are suggestive of at least one environmental con-trol of conception timing,and support the notion that food availability during key reproductive stages is an ultimate factor for birth seasonality,but provide no supporting evidence for photoperiod during the conception season as a proximate cue to reproduction in R.bieti.

Keywords Black-and-white snub-nosed monkey ÁRhinopithecus bieti ÁBirth seasonality ÁReproduction ÁPhotoperiod ÁEnvironmental cues Ásha

Introduction

Most mammals exhibit some degree of reproductive syn-chrony so that species breed during optimal conditions (Bronson 1989;Bronson and Heideman 1994).Reproduc-tive events are triggered by internal physiological rhythms,as well as by a suite of environmental factors such as ambient temperature,rainfall,food availability,and pho-toperiod that reliably predict future conditions (Bronson and Heideman 1994).Often,though not exclusively,births are synchronized with seasonal shifts in food availability or temperatures,but shifts in the timing of births may also occur as a result of predation pressure,paternity confusion,and infanticide avoidance (Di Bitetti and Janson 2000).Seasonal breeders,or breeders that breed within a discrete

Z.-P.Huang and L.-W.Cui contributed equally to this work.Z.-P.Huang ÁM.B.Scott ÁS.-J.Wang ÁW.Xiao (&)Institute of Eastern-Himalaya Biodiversity Research,Dali University,Dali 671003,Yunnan,People’s Republic of China

e-mail:xiaowen.dali@

Z.-P.Huang ÁL.-W.Cui ÁS.-J.Wang

Key Laboratory of Forest Disaster Warning and Control in Yunnan Province,Southwest Forestry University,Kunming 650224,People’s Republic of China

L.-W.Cui ÁW.Xiao

Kunming Institute of Zoology,Chinese Academy of Sciences (CAS),Kunming 650223,Yunnan,People’s Republic of China

Primates (2012)53:237–245DOI 10.1007/s10329-012-0305-7