共查询到20条相似文献,搜索用时 31 毫秒
1.
Setchell Joanna M. Lee Phyllis C. Wickings E. Jean Dixson Alan F. 《International journal of primatology》2002,23(1):51-68
We report on 14 years of reproductive data for semifree-ranging mandrills (Mandrillus sphinx) in Gabon, and we explore relationships between female rank, age and parity, and reproductive strategies. Most births (61% of 132) occurred during the wet season in Gabon, between January and March. Female rank and parity were unrelated to the timing of parturition. Gestation lengths average 175 days (SE = ±1 day; N = 61) and were similar irrespective of female rank, parity, or sex of offspring. Birth sex ratio did not differ significantly from unity (52% male), and was unrelated to maternal rank or parity. Stillbirths and neonatal mortality tended to be more common among lower-ranking females than among either mid-ranking or dominant females. Median age at first birth is 4.71 years, at a median body mass of 7.6 kg, ca 5 years before females attain their adult body mass (median 12 kg). Age at first reproduction is significantly correlated with dominance rank, with dominant females giving birth on average 1.3 years earlier than lower-ranking females do. Interbirth intervals (IBI) average 405 days (range 184–1159 days, N = 103), and are independent of the sex of the offspring. Infant death within 6 months shortened IBI to 305 days. Increasing age and parity are also associated with short IBI, as is higher rank. Maternal rank and parity appear to influence reproductive success in female mandrills, but there is no apparent differential maternal investment by sex. 相似文献
2.
Thebirth season of Formosan macaqueM. cyclopis during our study started in February and ended in August with a peak in the second half of April and the first half of May.
The average birth rate was 82%±21 for 114 females with four years of breeding records. Our study reports that a time span
of one year between births can be considered as the norm for the wildM. cyclopis. Of the 288 inter-birth intervals (IBI), 88.5% showed a 1-year interval (mean 364±SD 29 days); 11% showed 2-year interval
(727±36 days); and 1% (2 females) had 3-year interval (range 1030–1040 days). The IBI for females that had infant loss within
six months of life were the shortest. But there was no significant difference from that of females that had stillbirth (p>0.9) and infant that survived for first six months of life (p>0.06). However, among 255 cases of 1-year IBI, stillbirth or following infant loss within six months of life did significantly
shorten IBI for ten days (F
1,253=5.74,p<0.05). 相似文献
3.
Tong Jin De‐Zhi Wang Qing Zhao Li‐Jie Yin Da‐Gong Qin Wen‐Zhong Ran Wen‐Shi Pan 《American journal of primatology》2009,71(7):558-566
Understanding the reproductive parameters of endangered primate species is vital for evaluating the status of populations and developing adequate conservation measures. This study provides the first detailed analysis of the reproductive parameters of wild white‐headed langurs (Trachypithecus leucocephalus), based on demographic data collected over an 8‐year period in the Nongguan Karst Hills in Chongzuo County, Guangxi, China. From 1998 to 2002, a total of 133 live births were recorded in the population based on systematic censuses. Births occurred throughout the year, but the temporal pattern was highly correlated with seasonal variation in temperature and rainfall, with the birth peak coinciding with the dry and cold months of November–March. The average birthrate was 0.47±0.13 births per female per year and mortality for infants younger than 20 months was 15.8%. From 1998 to 2006, 14 females gave birth to 41 infants in four focal groups. The average age at first birth for female langurs was 5–6 years (n=5) and the interbirth interval (IBI) was 23.2±5.2 months (median=24.5 months, n=27). Infants are weaned at 19–21 months of age. The IBI for females with infant loss before weaning was significantly shorter than those for females whose infants survived. It appears that birth seasonality in the white‐headed langurs is influenced by seasonal changes in food availability. The timing of conceptions was found to coincide with peak food availability. The reproductive parameters for white‐headed langurs reported here are quite similar to those reported for other colobine species. One major difference is our observation of lower infant mortality in Trachypithecus. Am. J. Primatol. 71:558–566, 2009. © 2009 Wiley‐Liss, Inc. 相似文献
4.
Joseph Saragusty Robert Hermes Frank Gritz Dennis L. Schmitt Thomas B. Hildebrandt 《Animal reproduction science》2009,115(1-4):247-254
Sex allocation theories predict equal offspring number of both sexes unless differential investment is required or some competition exists. Left undisturbed, elephants reproduce well and in approximately even numbers in the wild. We report an excess of males are born and substantial juvenile mortality occurs, perinatally, in captivity. Studbook data on captive births (CB, n = 487) and premature deaths (PD, <5 years of age; n = 164) in Asian and African elephants in Europe and North America were compared with data on Myanmar timber (Asian) elephants (CB, n = 3070; PD, n = 738). Growth in CB was found in three of the captive populations. A significant excess of male births occurred in European Asian elephants (ratio: 0.61, P = 0.044) and in births following artificial insemination (0.83, P = 0.003), and a numerical inclination in North American African elephants (0.6). While juvenile mortality in European African and Myanmar populations was 21–23%, it was almost double (40–45%) in all other captive populations. In zoo populations, 68–91% of PD were within 1 month of birth with stillbirth and infanticide being major causes. In Myanmar, 62% of juvenile deaths were at >6 months with maternal insufficient milk production, natural hazards and accidents being the main causes. European Asian and Myanmar elephants PD was biased towards males (0.71, P = 0.024 and 0.56, P < 0.001, respectively). The skewed birth sex ratio and high juvenile mortality hinder efforts to help captive populations become self-sustaining. Efforts should be invested to identify the mechanism behind these trends and seek solutions for them. 相似文献
5.
René E. van Dijk Jan Komdeur Marco van der Velde István Szentirmai Xutong Yang Richard Ffrench-Constant Tamás Székely 《Journal of Ornithology》2008,149(4):521-527
Despite the growing literature on facultative sex-ratio adjustment in chromosomal sex-determining vertebrate taxa (birds,
mammals), the consistency of results is often low between studies and species. Here, we investigate the primary and secondary
offspring sex ratio of a small passerine bird, the Eurasian Penduline Tit (Remiz pendulinus) in three consecutive years. This species has a uniquely diverse breeding system, in which the male (and/or the female) abandons
the nest during egg-laying, and starts a new breeding attempt. This allowed us to test (1) whether patterns of parental care,
i.e., male-only care, female-only care or biparental desertion, influence offspring sex ratio, and (2) whether the offspring
sex ratio is repeatable between successive clutches of males and females. Using molecular markers to sex 497 offspring in
176 broods, we show that (1) offspring sex ratio does not depend on which parent provides care, and (2) the offspring sex
ratio is not repeatable between clutches of a given individual. The overall primary and secondary offspring sex ratio at a
population level is not different from parity (54 ± 6% males, and 50 ± 3% (mean ± SE), respectively). We suggest that ecological
and phenotypic factors, rather than individual traits of parents, may influence offspring’s sex, and conclude that there is
currently no evidence for a facultative adjustment of offspring sex ratio in the Penduline Tit. 相似文献
6.
Maternal Investment of the Virunga Mountain Gorillas 总被引:1,自引:1,他引:0
Andrew M Robbins Martha M Robbins & Katie Fawcett† 《Ethology : formerly Zeitschrift fur Tierpsychologie》2007,113(3):235-245
The Trivers & Willard hypothesis (TWH) predicts that females with more resources should bias their maternal investment toward offspring of the sex that is most likely to benefit from those additional resources. This paper examines the sex allocation of 61 female mountain gorillas (Gorilla beringei beringei) of the Virunga volcanoes, Rwanda from 1967 to 2004. Like most highly dimorphic, polygynous mammals, mountain gorillas are expected to show greater variance in reproductive success among males than females, so mothers in good condition should bias their investment toward sons. Using dominance rank as the indicator of maternal condition, the TWH was tentatively supported by our results with interbirth intervals (IBI). Dominant mothers had longer IBI following the birth of sons, relative to the longer IBI that subordinate mothers had with daughters. In contrast, maternal condition did not have a significant effect on birth sex ratios. We also found no significant relationships with other variables that might influence birth sex ratios (e.g., maternal age, parity, or group size), and the overall birth sex ratio was not significantly different from a 50:50 split. Collectively, our results suggest that female mountain gorillas do not control the sex ratio of their offspring at birth, but they may adjust their subsequent maternal investment. This conclusion is consistent with recurring questions about whether any adjustments in birth sex ratios occur in primates. 相似文献
7.
The effect of temperature on the development of immature stages of the predator Cheyletus malaccensis Oudemans, produced by either fertilized or virgin females, was studied at 17.5, 20, 25, 30, 32.5, and 35°C, 80 ± 5% relative
humidity, in complete darkness, and fed Tyrophagus putrescentiae (Schrank). The population maintained at 15°C failed to reproduce. The thermal data obtained were used for the estimation
of the thermal requirements (developmental thresholds, thermal constant, optimum temperature) of this predator by a linear
and nonlinear model (Logan type I model). Upper and lower developmental thresholds ranged between 37.4–37.8 and 11.6–12.0°C,
respectively. Optimum temperature for development was estimated at between 33.1 and 33.5°C. The thermal constant ranged between
238.1 and 312.5 degree-days. Based on the data of the total pre-imaginal period, immatures’ survival peaked at 25°C. Arrhenotokous
parthenogenesis (haplodiploidy) is confirmed in the species: virgin females always produce males, whereas fertilized females
give rise to offspring of both sexes. Survival of the immature stages and offspring sex ratio were not significantly influenced
by temperature. 相似文献
8.
The Siberian chipmunk, Tamias sibiricus, was introduced into the suburban forest of Sénart in the late 1970s where it naturalised. Juvenile dispersal of this solitary
ground-dwelling squirrel is not known, while it is an important component of the invasion process. From 2003 to 2007, mark–recapture
techniques were used to determine how dispersal movements differed between year, cohort, sex and body mass. Distances moved
were calculated between the location of first capture during the year of birth and the arithmetic centre of the trapping locations
obtained the next year. Excluding heaviest individuals, e.g. 80 g, that must have already dispersed and thus lowered the estimation
of averaged distance moved, our results shows that the dispersal distance in juvenile males (168 ± 24 m, n = 39) was greater than in females (83 ± 11 m, n = 66), with no effect detected for either year or cohort. Juveniles are thus involved in the spread of this ground squirrel,
bearing in mind that movements estimated may have been underestimated due to the use of capture–mark–recapture methods on
a limited trapping area. 相似文献
9.
MICHAEL E. BERGER 《African Journal of Ecology》1972,10(3):159-164
A study of the population structure of olive baboons {Papio anubis (J. P. Fischer)) was conducted near Rumuruti and Nanyuki in the Laikipia District of Kenya during 1969. The overall male: female ratio was 96:100 for all animals captured. The sex ratio of immature baboons favoured males, while adult females outnumbered adult males. Male baboons demonstrated an increased mortality during the juvenile stage primarily due to exploratory behaviour. Female baboons demonstrated an increased mortality incurred during the first pregnancy or birth early in the adult stage. About 50 % of adult females had an infant offspring, while about 75% had a juvenile offspring. Adult female baboons in their native environment produce an offspring every 2.5-3.0 years. No birth peak was discernable and births occurred throughout the year. 相似文献
10.
Bruna Larissa Maganhe Laura de Oliveira Camilo Rodrigo E. Kurokawa Hugo Gallo Neto Eduardo Gomes Sanches 《Journal of fish biology》2023,102(1):119-127
Endemic to the south-west Atlantic Ocean, the shortnose guitarfish (Zapteryx brevirostris) is a small species, classified as endangered by the IUCN. Although reproduction in captivity has been successful for some species, a range of factors can limit the success of captive breeding programmes for elasmobranchs. In Brazil, the Ubatuba Aquarium was the first public aquarium to reproduce small-sized elasmobranchs. Since 2018, at least five parturition events have been recorded for Z. brevirostris at the institution. From a total of 13 live neonates that rearing was attempted, the mean ± standard error of weight, total length (TL) and disc width at birth were 17.47 ± 1.6 g, 13.25 ± 0.7 cm and 6.53 ± 0.2 cm, respectively. The mean weight as well as mean TL were higher for females at all births, with 26.15 g and 15.07 cm for females in comparison with 17.09 g and 13.94 cm for males. Considering the increasing risk of extinction that the species is facing, age and growth studies are fundamental for the success of conservation, improving the knowledge of Z. brevirostris life cycle so that a more efficient and sustainable management can be carried out. This study provides important data, as well as directions for captive breeding of the species. 相似文献
11.
B. Louise Chilvers Bruce C. Robertson Ian S. Wilkinson Padraig J. Duignan 《Polar Biology》2007,30(4):459-469
Offspring birth mass and growth rate represent important life history traits, which influence many vital population and individual
characteristics, while offspring survival is a key factor in variation in female reproductive success. For a threatened population
of pinnipeds, such as New Zealand sea lions, Phocarctos hookeri, (Grey, 1844, NZ sea lions), understanding individual life history parameters and population dynamics is vital for their
management and conservation. This is the first study of the behaviour of females during parturition, pup birth mass and growth,
and pre-weaning survival of NZ sea lions, Enderby Island, Auckland Islands during austral summer breeding seasons, 2001/2002
to 2003/2004. Pregnant females arrived ashore 2.1 ± 0.16 days prior to giving birth. After parturition, mothers suckled their
pups for 8.6 ± 0.16 days before leaving on their first foraging trip. Male pups were born significantly heavier than female
(males 10.6 ± 1.4 kg, females 9.7 ± 0.9 kg). Pups lost on average 48 ± 0.14 g per day mass during the early postpartum period
(between birth and mothers first foraging trip). Pup mortality did not vary by pup sex, birth mass, date of birth or any maternal
characteristics however it varied significantly between years due to a bacterial infection epidemic (Pup mortality at 60 days:
2001 32%; 2002 21%; 2003 12%). The absolute growth rate per day for pups was 151 g/day over all years. Pup growth rate measured
as the slope of linear line fitted to pup mass by age was consistently higher for pups with heavier birth mass, male pups
and during the 2002 season. High offspring mortality and slow growth rates coupled with maternal foraging behaviour at their
physiological limits may reflect a threatened species which has limited ability for population growth in an environment which
is at the extreme of their historical range and impacted upon by fisheries. 相似文献
12.
Data presented in this paper are derived from the births and subsequent histories of red howler infants born in two habitats. Overall the sex ratio of infants at birth was about 1:1. Infant survivorship (at 1 yr) was about 80%, and 44% of infant mortality was attributed to infanticide by males. Survivorship curves indicated a dramatic sex difference, with far fewer females than males known to be alive at age 7 yr. However, this sex difference may be inflated because emigrant males are more easily identified than emigrant females, and females may be dispersing beyond the boundaries of the study area at a higher rate. Annual birthrate varied somewhat from year to year and was positively related to rainfall. Annual birthrate tended to be higher in the habitat with lower density and higher growth rate. Consistent with the trends, in annual birthrate, variation in interbirth interval length (TBR after births of surviving infants was related primarily to habitat differences and annual variation in rainfall. Season of birth and maternal age class had no effect on IBI. Infant sex had mostly nonsignificant effects on IBI. A small sample indicated that IBI's were significantly longer after the births of females who eventually became natal breeders than after the births of females who eventually emigrated. This difference might reflect differential parental (maternal) investment of some sort. 相似文献
13.
The European pond turtle Emys orbicularis, is an endangered species in Poland. The region of the Ilanka River, in the western part of the country (Lubuskie province),
is the most densely inhabited area by the species. Several populous sites are dispersed over the whole area of the province.
Over the past 10 years, 279 turtles were captured at 11 sites. In 218 individuals, those with a straight carapace length (SCL)
between 2.10–12.10 cm, sex was not determined; the remaining 61 with SCL 13.33–19.85 cm were sexed. Females had bigger bodies
and were heavier than males. The SCL of females was 17.10 ± 1.7 cm (average ± SD, n = 33), their body mass (BM) was 790.6 ± 228.7 g (n = 27), and in the case of males SCL was 15.44 ± 1.5 cm and BM was 554.2 ± 138.8 g (n = 28). SCL of the smallest egg laying female was 15.30 cm, and SCL of the smallest mating male was 13.33 cm. The colouration
of the turtles which undergoes change with age can be varied. 相似文献
14.
Kuze N Sipangkui S Malim TP Bernard H Ambu LN Kohshima S 《Primates; journal of primatology》2008,49(2):126-134
We analysed the reproductive parameters of free-ranging female orangutans at Sepilok Orangutan Rehabilitation Centre (SORC)
on Borneo Island, Sabah, Malaysia. Fourteen adult females produced 28 offspring in total between 1967 and 2004. The average
censored interbirth interval (IBI) (i.e. offspring was still alive when mother produced a next offspring) was 6 years. This
was shorter than censored IBIs reported in the wild but similar to IBIs reported for those in captivity. The nonparametric
survival analysis (Kaplan-Meier method) revealed a significantly shorter IBI at SORC compared with wild orangutans in Tanjung
Putting. The infant (0–3 years) mortality rate at SORC of 57% was much higher than rates reported both in the wild and captivity.
The birth sex-ratio was significantly biassed toward females: 24 of the 27 sex-identified infants were females. The average
age at first reproduction was 11.6 years, which is younger than the age in the wild and in captivity. The high infant mortality
rate might be caused by human rearing and increased transmission of disease due to frequent proximal encounters with conspecifics
around the feeding platforms (FPs). This young age of first reproduction could be because of the uncertainty regarding estimated
ages of the female orangutans at SORC. It may also be affected by association with other conspecifics around FPs, which increased
the number of encounters of the females with males compared with the number of encounters that would take place in the wild.
Provision of FPs, which improves the nutritional condition of the females, caused the shorter IBI. The female-biassed birth
sex-ratio can be explained by the Trivers and Willard hypothesis. The female-biassed sex ratio could be caused by the mothers
being in poor health, parasite prevalence and/or high social stress (but not food scarcity) due to the frequent encounters
with conspecifics around FPs. 相似文献
15.
Three main hypotheses can explain the origin of the sexual size dimorphism: (1) the birth-size hypothesis, which states that
birth size of males is larger than that of females; (2) the growth-rate hypothesis, which states that males grow faster than
females; (3) the growth-length hypothesis, which states that males grow for a longer period of time than females. We examined
the factors that may contribute to sexual size dimorphism with growth data of striped skunks Mephitis mephitis Schreber, 1776 held in captivity in Manitoba (Canada), from 7 to 72 days of age. At seven days of age, the mass of male skunks
(mean = 79.7 g ± 13.9 SE, n = 37) was significantly larger than that of females (mean = 71.2 g ± 15.0 SE, n = 35) but the head and body length was not statistically different between males (mean = 110.3 mm ± 8.0 SE, n = 37) and females (mean = 95.3 mm ± 7.4 SE, n = 35). There was no difference in growth rate for mass or for length between sexes. We were not able to test for a difference
in growth length between sexes. Our results suggest that mass dimorphism occurs early in life. 相似文献
16.
Length‐weight relationship and reproductive parameters of Botia dario (Hamilton, 1822) in Assam,India
下载免费PDF全文
![点击此处可从《Zeitschrift fur angewandte Ichthyologie》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The length‐weight relationships, spawning season, sex ratio, size at first maturity and fecundity of Botia dario (Hamilton, 1822), also known as the Bengal loach, were analyzed based on 556 specimens collected from the wetlands of Majuli Island, Assam between June 2012 and May 2013. The sex ratio (M : F) was 1 : 0.68, differing significantly (P < 0.05) from a 1 : 1 ratio. Size at first maturity (Lm50) was estimated as 6.8 cm for males and 7.4 cm for females. Analysis of monthly variations in the gonado‐somatic index (GSI), the monthly proportions of macroscopic gonadal maturity, and the ova diameter suggest a prolonged spawning season of B. dario from May to August, with a peak in July for both males and females (GSI = 15.0 in females; 7.0 in males). Absolute fecundity varied from 2523 to 51 377, with a mean of 18 367 ± 1254 oocytes per ovary. A positive correlation was recorded between total fecundity and body weight (r2 = 0.678). 相似文献
17.
Carlos Fonseca António Alves da Silva Joana Alves José Vingada Amadeu M. V. M. Soares 《European Journal of Wildlife Research》2011,57(2):363-371
Reproductive tracts of 214 female wild boars collected in Central Portugal between October and February over the period 1997
to 2001 were examined. From this material, we were able to determine reproductive phenology (conception and birth periods)
as well as age and weight of sows at puberty, ovulation rates of adults, foetal sex ratio, levels of intrauterine mortality,
final litter size and postnatal mortality. Differences between year, region, age and body weight were analysed. A total of
66.8% of the females examined were gestating or lactating and 96.3% of these weighed >40 kg. The highest proportions of pregnant
sows were found in the adult age/weight classes (74%). None of the juvenile females (1 year old and younger) were lactating
and only 7% was pregnant. The average number of foetuses/female (4.1 ± 1.2SD) and that of corpora lutea per female (4.6 ± 1.7SD)
increased from lighter and younger to heavier and older wild sows. Foetal sex ratio was biased towards males (1.3:1). Observed
intrauterine mortality rate (9.7%) and postnatal mortality (6.3%) were among the lowest recorded in European wild boar populations.
The productivity rate of the Central Portuguese wild boar population was calculated as 1.1 young per individual in the population.
Conception and birth periods did not differ significantly between the considered 4 years. Birth synchronisation was pronounced
in all the years, with a peak of births occurring in March. 相似文献
18.
Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), commonly called gram pod borer, is a serious pest of pulse crops in India and damages
chickpea (Cicer arietinum L). On average a 30% crop loss is reported. One of the potential natural enemies reported for its biological control is Campoletis chlorideae Uchida (Hymenoptera: Ichneumonidae), an idiobiont parasitic wasp that attacks second instar larvae of the pod borer. Male-biased
sex ratios hinder efforts to mass release parasitic Hymenoptera for biological control by making the production of females
costly. Parental age at time of mating is known to affect the progeny sex ratio in some Braconidae. In this view, we examined
the reproduction and survival of the parasitoid C. chlorideae in the laboratory [22 ± 4°C, 70 ± 10% R.H. and 10:14 h light:dark photoperiod]. All the nine (i.e. 3 × 3) combinations of
possible mating were made for males and females, being each of different age groups (0–12, 48–60 and 96–108 h old). Second
instar larvae of the pod borer were reared on chickpea and exposed to mated females of different mating age group combinations.
Results revealed that (a) newly emerged females (0–12 h old) mated to aged males yielded more progeny contrasted to the older
females inseminated by newly emerged males (0–12 h old). This implies that increased maternal age at mating caused greater
reduction in the progeny yield than that of paternal age; (b) the progeny sex ratio was lowest (0.344 ± 0.057) (mean ± SD)
when parents mated just after emergence (0–12 h old). It became more and more male biased as parents were deprived of mate
and was highest (0.666 ± 0.701) for 96–108 h old parents. The analysis of variance of the data shows that mate deprived males
caused greater contribution in the production of sons, resulting a male-biased progeny sex ratio. Our conclusion indicate
that newly emerged parasitoids (0–12 h old) are most fecund and should be used in rearing practices in order to enhance the
progeny yield, particularly with respect to daughters.
Handling Editor: Torsten Meiners 相似文献
19.
Ten years data on birth peak, birth rate and interbiith interval inPresbytis entellus of Jodhpur have been presented. Although Hangman langur females breed round the year, there is some concentration of births
during January–March while fewer births occur during October–December. It seems that provisioning and crop raiding together
may provide better feeding opportunities to breed year round. However, it remains unclear whether environmental factors allow
langur females to deliver more infants during January–March. During 1984–86 the birth rate was uniform for the whole population
(0.63). While there was a variation within the troops from year to year, data suggest that resident male replacements do alter
birth rate. It goes down when resident males are replaced frequently. The interbirth interval ranges between 7.0 and 76.5
months (average, 16.88 months;n = 112). Abortions and still-births reduced the interbirlh interval to 7.1 months (range 7.1-21.1; average, 11.4 months;n= 8) compared to the normal inlerbirth interval following infant survive its first 4.1 months of life (range 10.7-76.5 months;
average, 17.28 months;n = 86). However, infant loss under the age of 4.1 months did not reduce the interbirth interval except in two cases (range 7.0-51.8
months; average, 17.27 months;n = 18). Maternal rejection or weaning begins at about 8 months of age and lasts until infants are 12 months old. In this population,
the probability of twin births was worked out to be 0.79 per 100 births. 相似文献
20.
Mouyu Yang Dun Y. Sun Dietmar Zinner Christian Roos 《American journal of primatology》2009,71(3):266-270
In this study, we present data on reproductive parameters and birth seasonality of Guizhou snub‐nosed monkeys (Rhinopithecus brelichi). Our analyses are based on data from a small captive population collected over 15 years and on 5 years of observations of free‐ranging snub‐nosed monkeys. Captive females (n=4) mature at an age of 70.8±6.7 months and reproduce for the first time at 103.4±7.5 months. The mean interbirth interval was 38.2±4.4 months if the infant survived more than 6 months, which is longer than that in R. roxellana and R. bieti. In the wild and in captivity, births are very seasonal and occur only in a period from the end of March to the end of April. Our data suggest that population growth in Guizhou snub‐nosed monkeys is slow compared with the other two Chinese snub‐nosed monkey species. The risk of extinction is therefore particularly high in this species, given the small overall population size and slow population recovery potential. Am. J. Primatol. 71:266–270, 2009. © 2008 Wiley‐Liss, Inc. 相似文献