Evidence of effects of human disturbance on alert response in Père David's deer (Elaphurus davidianus)

To understand effects of human disturbance on alert response of Père David's deer, we carried out an experiment in the Dafeng Père David's Deer Reserve (32°59′–33°03′N, 120°47′–120°53′E), China. In the spring and summer, we observed alert responses (including stare, walking away, and flee) of deer and recorded the intensity of tourist disturbance in a small display pen using a laser‐range finder to measure the alert distance of a free‐ranging group in a large enclosure. We also recorded the pattern of head orientation when deer were resting in these two deer groups. After statistical analysis, we found that: 1) in small pen, the frequency of alert response was significantly different among different intensities of human disturbance; strong disturbance resulted in higher frequency of alert response; 2) stare distance in the free‐ranging group in summer was significantly longer than that in spring, but the distance of walking away and the distance of flee showed no significant difference between the two seasons; and 3) in free‐ranging group, there was no significant directional difference in head orientation, whereas in display group, there was a significant directional difference in head orientation. We suggest that: 1) under the captive situation, human disturbance may be one of the factors that affect alert response in Père David's deer; and 2) Père David's deer adopted different alert response to adapt to human disturbance under different circumstance. We recommended that relationships between alert response and human disturbance should be considered in ex situ conservation of this field extinct deer. Zoo Biol 26:461–470, 2007. © 2007 Wiley‐Liss, Inc.     

Reproductive biology of captive Arabian oryx (Oryx leucoryx) in Saudi Arabia

Reproductive data on captive Arabian oryx (Oryx leucoryx) were collected from June 1986 through April 1992 at the National Wildlife Research Center (Taif, Saudi Arabia). Oryx females are polyestrous. The estrous cycle averaged 22 days and mean gestation length was 260 ± 5.5 days (S.D). Sex ratio at birth was unbiased and mean weight was 6.5 ± 0.7 kg (S.D.), with no difference between sexes. Under captive breeding conditions, births occurred throughout the year. Females gave birth to a single calf at any time during the day and produced 1.03 young per year. Abortion rate was 3.6%. Mortality rate of young was 6.1% before weaning at 3 months of age. The interbirth interval averaged 295 ± 42 days (S.D.), with 53% lasting between 270 and 279 days. Females reached sexual maturity at the age of 13 months. © 1996 Wiley-Liss, Inc.     

Seasonal Changes of Reproductive Behavior and Fecal Steroid Concentrations in Père David's Deer

From July 1997 to September 1997 and from March 1998 to July 1998, we studied reproductive behaviors of Père David's deer in Dafeng, China. During the field behavioral observations, we collected fresh voided fecal samples from the Père David's stags and hinds periodically and kept those samples under −20°C until laboratory analysis. We analyzed the fecal testosterone, estradiol, and progesterone concentrations in those samples using radioimmunoassay. During this study, we also recorded 17 types of male reproductive behaviors and nine types of female reproductive behaviors. Reproductive behaviors and the fecal steroid concentrations showed overt seasonal fluctuations. There were statistically significant correlations between some male reproductive behaviors, such as anogenital sniffing, urine sniffing, urine spraying, wallowing, bellowing, antler adorning, Antler swags mud, chasing, herding hinds, chin resting, mounting and copulating, with the fecal testosterone concentrations. These results suggested that seasonal reproductive behaviors in stags are strongly associated with circulating testosterone. We also found that some female reproductive behaviors fluctuate corresponding with changes in fecal estrogen concentrations. Although there was no direct evidence to confirm the correlations between female reproductive behaviors and fecal estrogen in our experiment, we could not rule out that reproductive activities of hinds were largely related to ovarian estrogen secretion, and estrogen is necessary for inducing female reproductive behaviors.     

Selected aspects of Lemur variegatus reproductive biology

Results from data collected during the 1978–1979 breeding season on the reproduction of Lemur variegatus at the San Diego Zoo provide information which generally supports previously published reports on this species. Comparison of selected results from these data to a larger data base of which they are a part makes it possible to resolve some of the discrepancies between reports. Certain aspects of the reproductive biology of this species may then be generally characterized with confidence: The onset of seasonal breeding as evidenced by estrous behavior begins as early as mid-December in the northern hemisphere and may continue through March; genital changes associated with estrus in females last 9.85 ± 1.67 days (± SD); female receptivity occurs 7.0 ± 1.53 days after the onset of these genital changes and lasts 12-24 hours, during which breeding occurs; gestation averages 99.47 ± 4.19 days; the peak birth season is April–May; litters normally contain two to three offspring, with full-term neonates weighing an average of 104.63 ± 19.10 grams. In addition, L variegatus appears to be highly resistant to the impact of captivity on both its reproductive physiology and behavior, as indicated by the 100% breeding success of the diversely reared and managed groups of study animals.     

不同年龄麇鹿角的脱落时间与形态特征比较

鹿角是大部分鹿科动物的第二性征.麋鹿仅雄性具角,且角枝向后分杈,呈多回分支状,形态特征与其他鹿科动物不同.针对麋鹿的脱落时间、角型特征、外部形态与年龄关系等问题,2008年12月～2009年3月在北京麋鹿苑对麋鹿角进行了标记、收集与测量.结果 表明:解角期持续时间长短与种群年龄结构有关;麋鹿角的重量、角基周长、主干长度、后枝长和角宽5个变量与年龄显著线性相关,其中重量和角基周长与年龄的相关性最显著.麋鹿角并不完全是每增加1岁就增加1个分枝,依据鹿角分枝数只能对年龄进行大致判断.     

Pulsatile secretion of LH during the periovulatory and luteal phases of the oestrous cycle in the Père David's deer hind (Elaphurus davidianus)

Changes in the secretion of LH during the oestrous cycle were studied in 5 tame Père David's deer in which ovulation was synchronized with progesterone implants and prostaglandin injections. Plasma LH concentrations were measured in samples collected at 15-min intervals for a 36-h period, starting 16 h after the removal of the progesterone implants (follicular phase), and for a further 10-h period 10 days after the removal of the progesterone implants (luteal phase). In all animals, there was a preovulatory surge of LH and behavioural oestrus which occurred at a mean time of 59.6 h (+/- 3.25) and 69 h respectively following implant removal. LH pulse frequency was significantly higher during the follicular phase (0.59 +/- 0.03 pulses/h) than the luteal phase (0.24 +/- 0.2 pulses/h), thus confirming in deer findings from research on domesticated ruminants. There were no significant differences between the follicular and luteal phases in mean plasma LH concentrations (0.57 +/- 0.09 and 0.74 +/- 0.13 ng/ml) or mean pulse amplitude (0.99 +/- 0.14 and 1.05 +/- 0.21 ng/ml) for the follicular and luteal phase respectively. The long interval from the removal of progesterone to the onset of the LH surge and the absence of a significant difference in mean LH concentration or pulse amplitude in the follicular and luteal phases resemble published data for cattle but differ from sheep in which there is a short interval from luteal regression to the onset of the surge and a marked increase in LH pulse amplitude during the luteal phase.     

雄性麋鹿胆量和侵犯耦合与等级序位变化的关系

发情期的雄性麋鹿根据序位分为群主、挑战者和单身汉3个等级,序位变化是雄性麋鹿应对环境压力的直 观体现。本文利用胆量和侵犯2个行为指标在麋鹿生活史不同阶段的耦合强弱,来解释幼体时麋鹿序位发育、亚 成体时雄性序位定型及发情期时挑战者对群体序位的扰动。行为取样采用焦点取样法和扫描取样法相结合;分 析个体间行为样本流的非同步化水平,以同类型行为中较早发生、同步化率较低的判断为胆大;侵犯则结合攻 击行为和取胜指数来判定;粪样睾酮水平测定采用放射免疫分析法。结果显示雄性麋鹿幼体胆量和侵犯耦合与 等级序位呈负相关(r=-0.111 8,P=0.018 3);成体胆量和侵犯耦合与等级序位的波动呈正相关(r=0.917 9,P= 0.002 6)。从亚成体到成体:4头雄性麋鹿序位上升(胆量和侵犯耦合r=0.852 3,P=0.000 3),其中1头成为鹿 王;4头序位未发生改变(胆量和侵犯耦合r=0.482 9,P=0.006 3);3头序位下降(胆量和侵犯耦合r=0.251 7, P=0.003 5)。雄性麋鹿幼体睾酮水平与等级序位呈正相关(r=0.860 7,P=0.005 5);亚成体睾酮水平与等级序 位呈正相关(r=0.845 7,P=0.004 4);成体睾酮水平与等级序位呈正相关(r=0.954 6,P=0.001 8)。结果表明雄 性麋鹿发情期胆量和侵犯耦合强度与等级序位波动呈正相关;等级序位上升与睾酮水平升高有关。     

Reproduction in the slender loris (Loris tardigradus malabaricus)

A breeding colony of slender lorises (Loris tardigradus malabaricus) was studied to obtain data for comparison with other prosimian species, to contribute reproductive information for improving management of captive lorises, and to resolve some uncertainties in the literature regarding reproduction in the slender loris. At the Duke University Primate Center, a female slender loris reached sexual maturity at approximately ten months of age and conceived at one year of age. The length of the estrous cycle was 29–40 days, with copulation occurring over two consecutive days during estrus. Gestation length was 166–169 days. Litter size for each six births was one. Conception did not occur during an immediate post-partum estrus, but four months after birth, resulting in a 9 1/2-month interbirth interval. There was no evidence of reproductive seasonality. Lactation lasted between five and seven months. Reproductive rates of slender lorises are among the lowest of primates less than 500 g. Differences in reproductive parameters may exist between different subspecies of slender lorises.     

Predictors of reproductive success in female white-faced capuchins (Cebus capucinus)

Early investigations into variable reproductive success in nonhuman primates tended to focus on the benefits conferred by high dominance rank. However, the effect of high rank on individual reproductive success has been found to vary both intra- and interspecifically, requiring researchers to expand their investigations to include additional factors. Here we examine the age and rank of the mother, sex of the infant, group size, number of close kin, replacement of group males, and resource availability as possible predictors of female reproductive success in white-faced capuchins (Cebus capucinus) in the Santa Rosa sector of the Area de Conservación Guanacaste, Costa Rica. We examine the length of interbirth intervals (IBI) and infant survivorship as measures of individual reproductive success for the 31 adult females that resided in our three study groups between 1986 and 2007. The greatest predictor of IBI length was whether or not the first infant in the interval survived (number of matrilineal kin and resource availability were also significant predictors); while infant survivorship was most significantly predicted by the occurrence of a turnover in group males in the year following the birth of an infant (infant sex was also a significant factor). Based on these findings, we conclude that male and female reproductive strategies are at odds in this species, with male strategies strongly influencing female reproductive success.     

Reproduction in Coquerel's dwarf lemur (Mirza coquereli)

Most nocturnal Malagasy primates, as well as many diurnal species, are highly endangered in their natural habitat. Captive breeding programs have been established for many species, but detailed information on reproduction is only available for three nocturnal taxa: the mouse lemur (Microcebus murinus), the dwarf lemur (Cheirogaleus medius), and the greater dwarf lemur (Cheirogaleus major). In this study, we present data for another nocturnal Malagasy primate, Coquerel's dwarf lemur (Mirza coquereli), which has been propagated since 1982 at the Duke University Primate Center. Unlike all other Malagasy primates bred in captivity, M. coquereli cycles throughout the year, and is clearly less seasonal in its birth distribution than is C. medius or M. murinus. Estrous intervals ranged between 19 and 30.5 days. Estrus lasted no longer than 1 day. After an average gestation length of 89.2 days, litters of one or two were born. Females cycled for the first time between 8 and 15 months of age, and gave birth for the first time between 12.8 and 33.5 months of age. The earliest mating of a male leading to conception was observed at the age of 17 months. For males and females, an increase in daylength appears to trigger pubertal development. Males had seasonal changes in testicular volume which were not explained by covariation with body weight. Maximum testis size occurred in spring, when breeding activity was highest. The occurrence of year-round reproduction in M. coquereli, and the absence of seasonal fattening and/or hibernation, along with their specialized winter diet, may be correlated. © 1995 Wiley-Liss, Inc.     

Efficacy of intermittent or continuous administration of GnRH in inducing ovulation in early and late seasonal anoestrus in the Père David's deer hind (Elaphurus davidianus)

Père David's deer hinds were treated with GnRH, administered as intermittent i.v. injections (2.0 micrograms/injection at 2-h intervals) for 4 days, or as a continuous s.c. infusion (1.0 micrograms/h) for 14 days. These treatments were given early (February-March) and late (May-June) in the period of seasonal anoestrus. The administration of repeated injections of GnRH increased mean LH concentrations from pretreatment values of 0.54 +/- 0.09 to 2.10 +/- 0.25 ng/ml over the first 8 h of treatment in early anoestrus, and from 0.62 +/- 0.11 to 2.73 +/- 0.49 ng/ml in late anoestrus. The mean amplitude of GnRH-induced LH episodes was greater (P less than 0.01) in late (4.03 +/- 0.28 ng/ml) than in early (3.12 +/- 0.26 ng/ml) anoestrus, but within each replicate (early or late anoestrus), neither mean LH episode amplitude nor mean plasma LH concentrations differed significantly between the four periods of intensive blood sampling. On the basis of their progesterone profiles, 6/12 hinds had ovulated in response to treatment with injections of GnRH (1/6 in early anoestrus and 5/6 in late anoestrus), and oestrus and a preovulatory LH surge were recorded in all of these animals. Oestrus and a preovulatory LH surge were also recorded in one other animal treated in early anoestrus in which progesterone concentrations remained low. The mean times of onset of oestrus (91.0 +/- 1.00 and 62.4 +/- 0.98 h) and of the preovulatory LH surge (85.8 +/- 3.76 and 59.4 +/- 0.25 h) both occurred significantly earlier (P less than 0.001) in animals treated in late anoestrus. Continuous infusion of GnRH to seasonally anoestrous hinds resulted in an increase in mean plasma LH concentrations, but this response did not differ significantly between early (2.15 +/- 0.28 ng/ml) and late (2.48 +/- 0.26 ng/ml) anoestrus. Ovulation, based on progesterone profiles, occurred in 2/7 hinds in early anoestrus and in 4/6 hinds in late anoestrus. Oestrus was detected in all except one of these hinds. The mean time of onset of oestrus occurred earlier in animals treated in late anoestrus (66.2 +/- 0.32 h and 46.7 +/- 0.67 h, P less than 0.01). The administration of GnRH, given either intermittently or continuously, will induce ovulation in a proportion of seasonally anoestrous Père David's deer. However, more animals ovulate in response to this treatment in late than in early anoestrus (75% compared with 23%).     

Reproductive biology of captive alpine ibex (Capra i. ibex)

We studied the reproductive biology of alpine ibex bred at the Peter & Paul Wildlife Park, St. Gallen, Switzerland, from 1930 through 1943 and 1968 through 1983. Peter & Paul Wildlife Park had supplied most of the original stock used to reestablish ibex populations in the European Alps after they had become extinct. Ibex females were seasonally polyestrous. Their estrous cycle averaged 20 days, and their gestation period averaged 167 days. Females between 1 and 15 years of age on average produced 0.78 young per year; females between 3 and 13 years of age produced 0.99 young per year. The average age at which captive ibex females gave birth was 8.44 years. Sex ratio at birth was unbiased. More singletons than twins were born, but the proportion of twins born during the years 1968 through 1983 was higher than during the earlier study period. There were no differences in the survival rates of male or female and single or twin offspring.     

The acceleration of reproductive aging in Nrg1flox/flox;Cyp19‐Cre female mice

Irregular menstrual cycles, reduced responses to exogenous hormonal treatments, and altered endocrine profiles (high FSH/high LH/low AMH) are observed in women with increasing age before menopause. In this study, because the granulosa cell‐specific Nrg1 knockout mice (gcNrg1KO) presented ovarian and endocrine phenotypes similar to older women, we sought to understand the mechanisms of ovarian aging and to develop a new strategy for improving fertility in older women prior to menopause. In the ovary of 6‐month‐old gcNrg1KO mice, follicular development was blocked in bilayer secondary follicles and heterogeneous cells accumulated in ovarian stroma. The heterogeneous cells in ovarian stroma were distinguished as two different types: (i) the LH receptor‐positive endocrine cells and (ii) actin‐rich fibrotic cells expressing collagen. Both the endocrine and fibrotic cells disappeared following long‐term treatment with a GnRH antagonist, indicating that the high levels of serum LH induced the survival of both cell types and the abnormal endocrine profile to reduce fertility. Moreover, follicular development to the antral stages was observed with reduced LH and the disappearance of the abnormal stromal cells. Mice treated with the GnRH antagonist regained normal, recurrent estrous cycles and continuously delivered pups for at least for 3 months. We conclude that endocrine and matrix alternations occur within the ovarian stroma with increasing age and that abolishing these alternations resets the cyclical release of LH. Thus, GnRH antagonist treatments might provide a new, noninvasive strategy for improving fertility in a subset of aging women before menopause.     

Demographic review of a captive colony of callitrichids (Callithrix kuhlii)

Although reports on colony demographics for a variety of callitrichid species are available in the literature, to date there has not been a detailed examination of Wied's black tufted-ear marmoset (Callithrix kuhlii). The purpose of this study is to present colony demographics for C. kuhlii from the University of Nebraska at Omaha's Callitrichid Research Center from 1991 to 2002. C. kuhlii are currently held in a number of zoological parks in the United States and abroad; however, the University of Nebraska at Omaha held the only breeding colony in North America. Here we report data on lifespan, sex ratio, litter size, and interbirth interval (IBI) for that captive breeding colony.     

Noninvasive analysis of fecal reproductive hormone metabolites in female veiled chameleons (Chamaeleo calyptratus) by enzyme immunoassay

The noninvasive technique of gonadal steroid metabolite measurement in feces for evaluation of reproductive activity has proven an effective and important tool for population management in various captive species, but has not yet been validated and used in reptile species. In this study, enzyme immunoassays (EIAs) were validated for the analysis of fecal samples from female veiled chameleons (Chamaeleo calyptratus) for estrogen (E2), testosterone (T), and progesterone (P) and their metabolites. High performance liquid chromatography and physiological methods (GnRH stimulation) were used for the validation of the assays. Biological events, such as skin color changes indicative of ovarian activity and oviposition, correlated with the cyclical pattern of E2, T and P metabolites in feces over a period of two reproductive cycles. This is the first study to report frequent longitudinal measurements of fecal hormone levels by EIA in a reptile species.     

Reproduction of the lesser kudu (Tragelaphus imberbis) at Dvůr Králové Zoo

Reproductive data on captive lesser kudus (Tragelaphus imberis) were collected from 1972 to 1990. The estrous cycles of two females were 21 and 22 days. Mean gestation length of 18 pregnancies was 244 ± 5.5 days (range = 235–256 days), and 71.2% of interbirth intervals (n = 146) were from 248 to 365 days. Births occurred throughout the year, but 55% were from September to December. Females always gave birth to a single calf (n = 215), and the sex ratio did not differ from unity. Neonatal weights (1–3 days postpartum) of 32 males and 28 females surviving at least 30 days were 6.4 ± 0.8 kg and 5.8 ± 0.7 kg, respectively. Males and females reached sexual maturity at the ages of 16 and 19 months, respectively. The oldest male lived to slightly more than 14 years, 5 months, and the oldest female to more than 18 years, 11 months. Males were fertile until at least 14 years and females minimally to 14–18 years of age; however, the maximum age of successful lactation was 13–14 years. © 1992 Wiley-Liss, Inc.     

不同光照时长对麋鹿茸生长和繁殖季的溢出效应

光周期可影响鹿角脱落和新茸再生,麋(Elaphurus davidianus)冬至解角,冬季持续的光照时长改变对鹿茸生长速度、角形态发育及夏季的繁殖溢出效应尚未见相关报道。依托北京麋鹿苑2018年出生的同父异母雄性麋鹿12头,于2021年11月-2023年3月进行光照时长处理实验,依次分组为:自然光照(对照组)、缩短光照2h、延长光照3h和6h;记录实验麋鹿解角日期,红外测量新茸再生速度,测定脱落的麋角形态参数,并持续追踪记录翌年发情期等级序位、打斗、交配、繁殖绩效等参数。结果显示:持续缩短2h光照(6L∶18D)使麋鹿解角日期、角主干总长度、单角重量分别较对照组(8L∶16D),提前(8.5±0.4)d、缩短2.93cm(P ＜ 0.01,n=3)、减轻9.81g(P ＜ 0.01,n=3);延长3h光照(10L∶14D)使麋鹿解角日期、角主干总长度、单角重量分别较对照组(8L∶16D),推迟(10.5±0.3)d、增长5.47cm(P ＜ 0.01,n=6)、增加18.64g(P ＜ 0.01,n=6);延长6h光照(12L∶12D)使麋鹿解角日期、角主干总长度、单角重量较对照组(8L∶16D),分别推迟(13.5±0.6)d、增长10.43cm(P ＜ 0.01,n=6)、增加44.31g(P ＜ 0.01,n=6)。光照时长对麋角切片重量的影响差异极显著(P ＜ 0.01,n=6),缩短2h光照(6L∶18D)使麋角切片重量较对照组(8L∶16D)减轻(0.1230±0.0561)g/片;延长光照3h(10L∶14D)、6h(12L∶12D)使麋角切片重量较对照组(8L∶16D)分别增加(0.1200±0.0318)g/片、(0.3133±0.0618)g/片;冬季延长光照可明显增加夏季雄性麋鹿的交配机会和爬跨时长,增加发情持续天数、累积持续时间,增加查验母鹿发情、维护领地和圈群次数,提高交配成功率。综上所述,麋角脱落与光照时长之间密切相关,冬季持续光照时长变化对麋角脱落日期及繁殖产生了溢出效应,其机理仍需进一步研究,结果可为今后开展不同光照对麋角脱落及新茸再生多样化的分子调控机制研究提供理论支撑,可指导鹿科动物鹿茸产量提高、育种、保护与可持续发展。     

Reproductive biology and management of captive black-footed ferrets (Mustela nigripes)

A captive breeding program is being conducted with black-footed ferrets (Mustela nigripes), an endangered species. Results of 5 years of study are reported. Simple, but specialized, nontraumatic handling techniques allowed assessment of reproductive status with minimal stress, which was important in breeding management. Black-footed ferrets are sexually mature and may successfully reproduce in their 1st year. Proestrus lasts approximately 2-3 weeks. Duration of estrus in unbred females was 32–42 days; females usually bred within 20 days. Most breeding activity occurred during April. Mean gestation length was 42.7 days (±0.7, range 42–45 days), litter size averaged 3.0 kits (±1.4, range 1–6 kits), and weaned kits/litter averaged 2.4 (±1.7, range 1–6 kits). Weaning rate of kits was 80%. Sex ratio of kits was essentially 1:1. Productivity was greatest among females ?3 years of age. Rapid expansion of the captive population is possible and will be important for genetic management of the species and for achieving the primary goal of the recovery program, which is to return black-footed ferrets to the wild.