圈养雌性大熊猫发情及排卵监测方法论述及展望

国内外专家学者为监测圈养雌性大熊猫Ailuropoda melanoleuca的发情程度和排卵时间,进行了大量多学科研究,方法学的研究重点为对大熊猫的适时配种有实际指导意义。生物化学、微生物学、光谱化学和组织学等领域的研究方法,由于学科关联度低、研究深度不够、费用较高、测试时间较长等缺点,对实践指导作用有限,仅可作基础性研究。而行为学、细胞学和内分泌学等监测方法的应用更多、成效更高。大量实践也证实了通过发情行为、外阴形态、阴道细胞角化率和雌激素监测可以取得较高的受孕率,获得较好的监测效果。综合运用行为、外阴形态与雌激素监测是目前最常用的手段。本文旨在介绍圈养雌性大熊猫发情鉴定和排卵监测方法的研究进展,论述各方法的实践效果,并探讨新方法的研究方向,以期更好把握大熊猫发情配种时机。     

雌性大熊猫发情行为的观察

1989、1990年对成都动物园和外地来园配种的5只正常发情大熊猫(年龄6—17岁,体况正常,其中1只为初情,其余的有过繁殖史),于每天活动量较大、人为影响较小的早晨和黄昏观察其行为和生理变化(外阴变化),并进行逐日记录,其中蹭阴、咩叫的描述及频率计算参照曾国庆等(1984)的方法。现将结果整理于后,为大熊猫适时配种提供行为参考。5只熊猫中有2只在咩叫高峰期自然交配,怀孕产仔,自然交配中的1只熊猫在咩叫高峰前两天作过一次人工授精,其余3只人工授精未怀孕。据观察雌性熊猫在发情期有蹭阴、咩叫两个高峰期,组成了发情高峰期,两者前后相差3—6…     

爱在卧龙

圈养大熊猫被认为是发情难、配种受孕难、育幼成活难的"三难"动物。根据科学统计有78%的雌性大熊猫不孕,有90%的雄性大熊猫不育。大熊猫性喜独居,发情后才愿意进行异性间的接触。雌性大熊猫每年只发情一次,且其择偶性极强,非见"白马王子"不抛"绣球"。由于这种天性使然,大熊猫种群的繁衍危机已迫在眉睫,为了挽救国宝,人工繁育己成重要手段。多年的实践证明,大熊猫人工繁育、移地保护是拯救大熊猫的重要战略之一。     

利用阴道粘液电阻值进行大熊猫排卵

对5只大熊猫发情配种期间阴道粘液电阻值进行了检测,结果发现4只发情表现正常的大熊猫发情配种期阴道粘液电阻值呈现相似的V字形变化曲线,V形曲线的谷底所代表时期恰好与尿雌酮峰值期吻合,其中3只大熊猫于秋后产仔,结果提示测定大熊猫发情配种期间阴道粘液电阻值可有效用于监测排卵,具有良好的应用前景。     

利用阴道粘液电阻值进行大熊猫排卵监测的研究初报

对５只大熊猫发情配种期间阴道粘液电阻值进行了检测,结果发现４只发情表现正常的大熊猫发情配种期阴道粘液电阻值呈现相似的Ｖ字形变化曲线,Ｖ形曲线的谷底所代表时期恰好与尿雌酮峰值期吻合,其中３只大熊猫于秋后产仔,结果提示测定大熊猫发情配种期间阴道粘液电阻值可有效用于监测排卵,具有良好的应用前景。     

大熊猫“佳佳”六月底发情配种、冬季产仔

大熊猫“佳佳”六月底发情配种、冬季产仔汤纯香,陈猛,张和民中国保护大熊猫研究中心汶川６２３００６大熊猫（Ａｉｌｕｒｏｐｏｄａｍｅｌａｎｏｌｅｕｃａ）是季节性单发情动物,多在春季发情一次。但随纬度和海拔高度不同也有差异。在野外,多于４至５月中旬发情配种...     

大熊猫发情期间阴道上皮细胞的角化率

大熊猫为单发情动物,仅在每年春季发情一次。因此,适时配种是人工繁育大熊猫的一个重要环节。到目前为止,人们对大熊猫配种时机的把握主要是根据自已的经验和大熊猫的行为变化。1991-1995年,笔者在进行大熊猫人工繁育研究中,对大熊猫发情期间阴道上皮细胞的角化率进行了观     

雌性大熊猫发情期与妊娠期尿液性激素的变化

用放射免疫法测定了两头雌性大熊猫发情期尿中雌二醇与孕酮含量及妊娠期尿中孕酮含量的变化。发情期开始,雌二醇量逐渐升高,在发情高潮期达高峰值。孕酮量则在发情高潮期下降,在发情后期上升。在发情高潮期雌二醇出现高峰的当日和次日配种,获致妊娠产仔。妊娠期尿中孕酮含量的变化特点是:在妊娠早期与晚期升高,晚期最高,妊娠中期停滞在低水平上波动,分娩前孕酮值迅速下降。     

外源激素诱导大熊猫发情排卵及受孕效果

圈养的适龄雌性大熊猫,通常每年会出现发情特征显著、一般、不显著等行为表现;但也有少数育龄雌性大熊猫有的年度根本就小发情。据本研究中心1991～1999年对16只育龄雌性大熊猫的59次发情行为统计,有19次发情行为不显著或一般;有3次属不正常发情,发情行为不显著或不正常所占的比例较大(约占35％)。     

圈舍环境对圈养大熊猫发情率的影响

发情率低是圈养大熊猫Ailuropoda melanoleuca饲养的难题之一,也是制约圈养大熊猫繁育的重要因素。近年来,随着大熊猫圈养技术的不断进步,圈养大熊猫的发情率有了大幅提高,但并未达到特别高的水平。对中国保护大熊猫研究中心2006—2012年参与繁殖计划的圈养成年雌性大熊猫种群的发情率进行统计发现,2009—2012年每年雌性大熊猫的发情率高达90%以上,较2006—2008年的发情率有显著提高。2006—2012年,该大熊猫种群的饲养和管理模式、食物结构都未变化,但从2009年起圈舍环境有明显变化。经分析,该种群发情率的变化与圈舍面积、圈舍地形、圈舍植被覆盖率和植物种类等因素变化有关。本研究为提高圈养大熊猫的发情率从改善大熊猫圈舍条件的角度提供了有效的参考。     

Dynamics of Male–Female Multimodal Signaling Behavior across the Estrous Cycle in Giant Pandas (Ailuropoda melanoleuca)

Giant panda courtship behavior includes multimodal signaling assemblages consisting of olfactory, vocal, and postural elements. While signaling is generally conspicuous, successful copulation is inconsistently achieved in captivity, even when female behavioral and physiological data indicate that ovulation is imminent. We set out to characterize these complex patterns of social behavior by observing interactions between 26 unique pairs of giant pandas housed in adjoining pens throughout the females' reproductive cycle. We categorized social behaviors from a transactional perspective and examined social exchanges via analyses of the relative frequency of social behaviors, and via the sequential relationship between male and female social behavior. From non‐estrus to peak‐estrus, we found that the relative frequency of female affiliative and sexual behavior increased and that the relative frequency of ambivalent and aggressive behavior decreased. Male behavior was fairly constant, except for sexual behavior, which increased during peak‐estrus, when it was facilitated by female sexual behavior. Sequential analysis of social interactions showed that preceding behavior had a significant influence over the other panda's response behavior primarily during peak‐estrus, suggesting that pandas are most responsive to conspecific signaling during the peri‐ovulatory period. However, behavioral momentum was a dominant feature of the intra‐individual transitions. Females maintained sexual, ambivalent, and neutral behavior during interactions significantly more than would be expected by chance, with male behavior bearing little influence once the behavior was initiated. A similar pattern was also observed in males, who maintained affiliative, interested, and neutral behaviors. Overall, our data suggest that the multimodal signals used by giant pandas during courtship do not consistently evoke a discrete, immediate response from receivers. Instead, signals appear to advertise reproductive condition and influence potential mates over longer timeframes, suggesting the potential tonic role of communication.     

Hormonal and behavioral relationships during estrus in the giant panda

Nonlactating female giant pandas experience a single estrus during the spring mating season. Although both hormonal and behavioral aspects of estrus have been reported on captive females, little is known about the relationship between them. Data were collected on a single captive female during three successive seasons, revealing a high degree of regularity in both estrogen profiles and the temporal pattern of associated behaviors. The birth of a live cub in the last of the three seasons, using artificial insemination, confirmed the time of ovulation as occurring shortly after a peak in urinary estrogen values. In this study, we examined the occurrence of female scent marking, rear presentations, chirp and bleat vocalizations, and the tail‐up display, and plotted their occurrence relative to the underlying estrogen values. We conclude that the role of estrogen in the expression of these behaviors is neither simple nor directly causal. Temporal associations indicate that a triggering rather than a maintenance function for estrogen is implicated. This analysis provides a clear identification of estrous behaviors, but in both the time and form of occurrence these behaviors most likely vary between females and seasons. Zoo Biol 20:537–543, 2001. © 2002 Wiley‐Liss, Inc.     

育幼经历对圈养成年雌性大熊猫尿液皮质醇含量的影响

为研究育幼期不同的育幼方式对圈养成年雌性大熊猫Ailuropoda melanoleuca福利状况的影响情况,了解圈养育幼模式可能引发成年雌性大熊猫的应激问题,完善育幼期大熊猫的饲养管理和兽舍参数设计,提高育幼过程中圈养大熊猫福利状况,选择成都大熊猫繁育研究基地育幼期采取不同育幼方式管理的成年雌性大熊猫为研究对象,利用...     

Behavior of giant pandas (Ailuropoda melanoleuca) in captive conditions: Gender differences and enclosure effects

The behavior of giant pandas (Ailuropoda melanoleuca) was studied under captive conditions. Both male and female pandas spent similar amounts of time engaged in eating and locomotion. Males performed anogenital‐marking more but rested less than females, which suggests a sexually dimorphic pattern of behavior. Furthermore, females housed in the seminatural environment spent significantly less time engaged in stereotyped behavior than did females housed in the traditional enclosure, indicating that an enclosure environment affects the behavior of giant pandas. These data illustrate the importance of careful management and facility design for captive giant pandas. Zoo Biol 22:77–82, 2003. © 2003 Wiley‐Liss, Inc.     

哺乳期圈养雌性大熊猫圈舍转移及其育幼行为变化

<正>大熊猫(Ailuropoda melanoleuca)为我国特有珍稀濒危物种之一,被誉为"国宝"。经过科研人员多年努力,圈养大熊猫"配种难、受孕难、幼仔存活难"等问题已基本被成功解决,圈养大熊猫种群数量正在快速增加(张和民等,2013)。目前我国已经建立了四川卧龙、成都和陕西楼观台3个较大的圈养大熊猫种群繁育基地。截至2013年底,圈养大熊猫种群数量已经达到375只(谢钟,2013)。快速增加的圈养种群,导致现存可供使用     

The Acute Phase Protein Ceruloplasmin as a Non-Invasive Marker of Pseudopregnancy, Pregnancy, and Pregnancy Loss in the Giant Panda

After ovulation, non-pregnant female giant pandas experience pseudopregnancy. During pseudopregnancy, non-pregnant females exhibit physiological and behavioral changes similar to pregnancy. Monitoring hormonal patterns that are usually different in pregnant mammals are not effective at determining pregnancy status in many animals that undergo pseudopregnancy, including the giant panda. Therefore, a physiological test to distinguish between pregnancy and pseudopregnancy in pandas has eluded scientists for decades. We examined other potential markers of pregnancy and found that activity of the acute phase protein ceruloplasmin increases in urine of giant pandas in response to pregnancy. Results indicate that in term pregnancies, levels of active urinary ceruloplasmin were elevated the first week of pregnancy and remain elevated until 20–24 days prior to parturition, while no increase was observed during the luteal phase in known pseudopregnancies. Active ceruloplasmin also increased during ultrasound-confirmed lost pregnancies; however, the pattern was different compared to term pregnancies, particularly during the late luteal phase. In four out of the five additional reproductive cycles included in the current study where females were bred but no birth occurred, active ceruloplasmin in urine increased during the luteal phase. Similar to the known lost pregnancies, the temporal pattern of change in urinary ceruloplasmin during the luteal phase deviated from the term pregnancies suggesting that these cycles may have also been lost pregnancies. Among giant pandas in captivity, it has been presumed that there is a high rate of pregnancy loss and our results are the first to provide evidence supporting this notion.     

No evidence for MHC‐based mate choice in wild giant pandas

Major histocompatibility complex genes (MHC), a gene cluster that controls the immune response to parasites, are regarded as an important determinant of mate choice. However, MHC‐based mate choice studies are especially rare for endangered animals. The giant panda (Ailuropoda melanoleuca), a flagship species, has suffered habitat loss and fragmentation. We investigated the genetic variation of three MHC class II loci, including DRB1, DQA1, and DQA2, for 19 mating‐pairs and 11 parent‐pairs of wild giant pandas based on long‐term field behavior observations and genetic samples. We tested four hypotheses of mate choice based on this MHC variation. We found no supporting evidence for the MHC‐based heterosis, genetic diversity, genetic compatibility and “good gene” hypotheses. These results suggest that giant pandas may not use MHC‐based signals to select mating partners, probably because limited mating opportunities or female‐biased natal dispersal restricts selection for MHC‐based mate choice, acknowledging the caveat of the small sample size often encountered in endangered animal studies. Our study provides insight into the mate choice mechanisms of wild giant pandas and highlights the need to increase the connectivity and facilitate dispersal among fragmented populations and habitats.     

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.     

Predicting reproduction in captive sea otters (Enhydra lutris)

The sea otter (Enhydra lutris) is a threatened species. It is also a popular exhibit animal in many zoos and aquariums worldwide. Unfortunately, sea otters reproduce successfully in only a small number of facilities. Pregnancies vary in duration, and are thought to involve a delayed implantation of about 2–3 months, followed by an implanted phase of 4–5 months. In this study we attempted to identify estrus and pregnancy states, and predict the date of birth in one female sea otter (Mali) housed at the Lisbon Oceanarium. We used different techniques to evaluate her reproductive status, including monitoring behavior to determine estrus, assessing weight changes to determine pregnancy and parturition date, and analyzing fecal hormone samples to determine estrus, pregnancy, and parturition date. During this study, Mali became pregnant four times. Her gestational length varied between 188–255 days. Weight increases >29 kg or 15% above baseline weight suggested pregnancy, and parturition was estimated to occur approximately 3 months thereafter. Fecal hormone (progestagens and estrogen) metabolite data gathered during two of her pregnancies showed that Mali's delayed implantation phase of pregnancy lasted 43–109 days (a typical duration in other sea otters is 100–110 days). Mali's implanted phase lasted a relatively long time (140–145 days compared to an average of 117 days in other sea otters). The combination of the three measurements was a powerful tool that enabled us to determine pregnancy and anticipate the arrival of a new sea otter pup. Zoo Biol 24:73–81, 2005. © 2005 Wiley‐Liss, Inc.     

Seasonal shifts in giant panda feeding behavior: relationships to bamboo plant part consumption

The giant panda (Ailuropoda melanoleuca) is classified as a carnivore, yet subsists on a diet comprised almost exclusively of bamboo. Wild and captive giant pandas use highly selective foraging behaviors for processing and consuming bamboo. These behaviors are for the first time quantified in captive giant pandas over a 5‐year period of time showing highly specific seasonal trends. Giant panda feeding behavior was recorded using live video observations of two giant pandas housed at the Memphis Zoo from November 2003 to June 2008. Leaf was the primary plant part consumed from June to December, whereas culm was consumed primarily from February to May, with both bears displaying similar seasonal shifts in plant part consumption. From May to June, leaf consumption increased significantly (P‐values<0.001); from June to August, leaf consumption remained high and stable. From December to March, leaf consumption decreased significantly (P‐values<0.001). Specific behaviors for bamboo leaf and culm consumption were also observed. Both bears formed wads of leaves before ingestion while feeding on leaf, but the male employed this feeding behavior more often than the female (54 and 33%, respectively). Both bears used similar culm‐stripping behavior (26 and 25%), used to remove the outer layer and isolate the pith for consumption. This study indicates that unique seasonal foraging behaviors observed in wild pandas are also apparent in captive animals in relation to plant part selectivity and feeding behaviors. Zoo Biol 29:470–483, 2010. © 2009 Wiley‐Liss, Inc.