Birth Timing for Mountain Lions (Puma concolor); Testing the Prey Availability Hypothesis

We investigated potential advantages in birth timing for mountain lion (Puma concolor) cubs. We examined cub body mass, survival, and age of natal dispersal in relation to specific timing of birth. We also investigated the role of maternal age relative to timing of births. We captured mountain lion cubs while in the natal den to determine birth date, which allowed for precise estimates of the population birth pulse and age of natal dispersal. A birth pulse occurred during June–August. Body mass of cubs was related to litter size and timing of birth; heaviest cubs occurred in litters of 2, and those born after 1 July. Cubs born within pulse months exhibited similar survival to those born out of the pulse. We found that cubs born April–June dispersed at younger ages than those born after 1 July. There was less variation in birth timing for 1^st litters of females than older females. We hypothesize that cubs born after the peak in births of neonate prey are advantaged by the abundance of vulnerable prey and those cubs and mothers realize an evolutionary advantage.     

首例圈养大熊猫产后出血的治疗及初生幼仔长途运输初探

中国保护大熊猫研究中心雅安碧峰峡基地的一只雌性大熊猫分娩后发生产后出血,采取促进子宫收缩、减少出血、利用抗菌素药物防止感染的原则对母兽进行治疗,4d后恢复正常。治疗期间取出两只初生幼仔,利用自制人工保温箱将幼仔成功地从雅安长途运回卧龙进行人工育幼;并对母兽进行育幼行为培训以保持母性行为,母兽康复后主动接受幼仔成功哺育成活。     

大熊猫超轻初生幼仔的成功哺育

大熊猫初生幼仔体重较轻,仅为正常母体体重的千分之一,平均144.9±40.59 g(张志和和魏辅文,2006).初生体重在70 g以下的幼仔,常被称之为超轻体重幼仔,初生体重超轻、身体瘦弱活动无力,产后无叫声或叫声小是其主要特点.对于体重超轻初生幼仔的育幼,目前有1993年对一例初生体重为61 g的幼仔,在产后两周内采用胃导管喂母初乳、之后采取人工与母兽交替哺育的方法养育存活以及2000年对一只58 g幼仔进行全人工育幼存活7 d的报道(钟顺龙和何光昕,1997,侯蓉等,2000).2006年成都大熊猫繁育研究基地的一只雌性大熊猫产下一对双胞胎,其中一仔初生体重仅51 g,经人工辅助哺育存活,该幼仔是圈养条件下育成的初生体重最轻的大熊猫.现将该例的育幼情况报道于后,以供参考.     

Reproductive life history of South African cheetahs (Acynonyx jubatus jubatus) at the San Diego Zoo Wild Animal Park, 1970–2005

We analyzed 35 years of data from a captive breeding program of cheetahs to determine basic reproductive life history characteristics of females. Breeding females ranged in age from 2.7–10.5 years. Sixteen females and over 13 males produced 129 cubs in 36 litters, with an average litter size of 3.6. Older females produced significantly fewer cubs per litter than younger females, but cub survivorship was comparable across female ages. Sex ratio was balanced at birth and 71% of infants survived the weaning period. Given that the reproductive output of captive cheetahs in our study is similar to that in other zoologic institutions and to cheetahs in the wild, we suggest that reproductive deficits in captive cheetahs arise from the inability of some pairs to breed, due to a lack of mating preference, rather than from a species‐wide problem. Zoo Biol 0:1–8, 2006. © 2006 Wiley‐Liss, Inc.     

Maternal rank is not correlated with cub survival in the spotted hyena, Crocuta crocuta

Reproductive success in female spotted hyenas, Crocuta crocuta,is positively correlated with social rank. High-ranking femalesare known to produce more offspring, but the effects of maternalrank on early cub survivorship have not been investigated. Cubmortality was examined over a 4-year period in one clan of wild-livingspotted hyenas in Kenya. Data were obtained for 100 cubs in63 litters produced by 27 adult females. Survivorship of cubsfrom birth through their first year was examined as a functionof litter size, sex of cubs, and maternal rank. Overall, cubmortality was high (61%). Contrary to expectation, singletoncubs did not survive better than twins, and there was no differencein survivorship between female and male cubs. High-ranking motherswere not more successful at raising twins or daughters thanwere low-ranking mothers. There was no correlation between cubmortality and maternal rank. Peaks in cub mortality coincidedwith life stage events, including mean age of arrival at a communalden, and age at which cubs began visiting kills. Documentedcauses of mortality included intraclan infanticide, disease,orphaning, predation by lions, and a mechanism of filial infanticidethat has not been previously described in this species: selectivelitter reduction by mothers via partial litter abandonment.No instances of facultative or obligate siblicide were detected.During this study, association between rank and number of cubssurviving to 1 year of age appeared to be due to differencesin reproductive output and not differential survival of cubswithin their first year.     

Maternal nutrition, egg quality and breeding success of Scottish Ptarmigan Lagopus mutus

Samples of Ptarmigan eggs were hatched in captivity. They had been taken from ground adjacent to study areas where the wild birds' breeding success by early August, and their food plants, were measured.
Almost all deaths of chicks in captivity occurred within a few days of hatching and examination postmortem showed no specific cause. The proportion of chicks which died in captivity before 15 days of age varied markedly between years and study areas. These variations occurred in parallel with variations in breeding success in the wild populations from which the eggs had been taken. It was concluded that the survival of chicks both in captivity and in the wild was determined in part before the eggs hatched.
Variations in breeding success from year to year were correlated with the number of days that the food plants had been growing before the hens finished laying. Breeding success in the wild and chick survival in captivity were better for a 'rich' area overlying some base-rich rocks than for a 'poor' one overlying granite and with less blaeberry. It was inferred that, as in Red Grouse, maternal nutrition affected breeding success through the quality of the eggs.     

Early life social and ecological determinants of global DNA methylation in wild spotted hyenas

Environmental factors early in life can have lasting influence on the development and phenotypes of animals, but the underlying molecular modifications remain poorly understood. We examined cross‐sectional associations among early life socioecological factors and global DNA methylation in 293 wild spotted hyenas (Crocuta crocuta) in the Masai Mara National Reserve, Kenya, grouped according to three age classes (cub, subadult and adult). Explanatory variables of interest included annual maternal rank based on outcomes of dyadic agonistic interactions, litter size, wild ungulate prey density and anthropogenic disturbance in the year each hyena was born based on counts of illegal livestock in the Reserve. The dependent variable of interest was global DNA methylation, assessed via the LUminometric Methylation Assay, which provides a percentage methylation value calculated at CCGG sites across the genome. Among cubs, we observed approximately 2.75% higher CCGG methylation in offspring born to high‐ than low‐ranking mothers. Among cubs and subadults, higher anthropogenic disturbance corresponded with greater %CCGG methylation. In both cubs and adults, we found an inverse association between prey density measured before a hyena was 3 months old and %CCGG methylation. Our results suggest that maternal rank, anthropogenic disturbance and prey availability early in life are associated with later life global DNA methylation. Future studies are required to understand the extent to which these DNA methylation patterns relate to adult phenotypes and fitness outcomes.     

Aviation noise does not impair the reproductive success of farmed blue foxes

The aim of our study was to assess the effects of aviation noise on reproduction and cub mortality in farmed blue foxes. Eighty artificially inseminated blue fox vixens (45 primiparous and 35 multiparous) were exposed to aviation noise on 5 days when they were pregnant or had cubs. The noise during the exposures varied from 85 to 121 dB (L(AFmax)). Vixens (45 primiparous and 34 multiparous) on a farm without flight action acted as controls. Cubs were counted 1, 3, 7, 14 and 49 days postpartum and at the beginning of July. Litter size (cubs per whelped vixen), reproductive performance (cubs per mated vixen) and cub losses (lost cubs per whelped vixen) were analyzed from both experimental farms (A and C). The flight action had no effect on reproductive success. Reproductive performance in primiparous vixens was 4.2+/-3.8 and 4.3+/-3.6 cubs (ns, Mann-Whitney U-test) in the control and aviation group, respectively, while in multiparous vixens the corresponding figures were 7.1+/-4.4 and 7.3+/-3.8 cubs (ns). In general, litter size declined from birth to weaning (in primiparous vixens from 8.1+/-3.8 to 5.4+/-3.2 cubs, and in multiparous from 9.7+/-3.8 to 7.2+/-3.8 cubs, P<0.001, GLM for repeated measures). The decline was greater in primiparous than in multiparous vixens (P<0.01). There were no differences in total cub losses between the experimental groups (ns). Accordingly, the present results show that exposure to severe and repeated aviation noise does not impair the reproductive success of farmed blue foxes.     

Cub growth and maternal care in cheetahs

Using cub growth as an index, I examine the influence of maternalnutrition, litter size, and cub sex on maternal care in cheetahs(Acinonyx jubatus) and compare cub and litter growth rates withthose of other large feilds. Seventy-nine free-living cheetahcubs in 21 litters from 15 mothers were weighed at least oncebetween 6 and 48 days of age. Eleven litters were weighed atthe beginning and end of a 5-day observation of their mothers.The mean cub growth rate varied significantly between litters,due primarily to differences in maternal food intake. Growthdeclined sharply when maternal food intake was less than 1.5kg/ day, but did not increase with greater levels of food intake.Lower limits of growth rates may therefore have been set bythe mother's food intake, whereas upper limits may be set bythe intrinsic physiological ability of cubs to grow. Althoughmale cubs were heavier than female cubs in the same litter whenfirst weighed, major differences in growth rate between thesexes were not apparent at this stage. Both cheetah cubs andlitters grow fast relative to other large felids, and I arguethat this may be an adaptation to the high rate of cheetah juvenilemortality from predation.     

Reproductive parameters of the common genet <Emphasis Type="Italic">Genetta genetta</Emphasis> (Linnaeus, 1758) in Southwest Europe

We used information from 148 litters belonging to 119 different wild and captive female common genets (Genetta genetta) in SW Europe over a period of almost 50 years to study certain reproductive parameters. Data were obtained from a combination of sources including carcasses, live captures, telemetry-based studies, captive genets, and reports in the literature. The circannual pattern of breeding was fairly similar in both wild and captive genets, with births occurring in all months except December, albeit with a large peak in spring and a secondary peak in autumn. The sex ratio at birth was near to 1:1, and mean litter size was 2.16 ± 0.76 cubs/litter with a range of 1–5 cubs. Litters of two cubs were the most frequent both in wild and captive settings. In captivity, we have observed the births of replacement litters and double litters; however, we did not find evidence of wild females that having two litters in the same year. We conclude that the possibility of breeding at any time of the year is facilitated by the continuous spermatogenesis of the males and by the ability of females to enter into estrus after losing a litter prematurely and to breed twice in the same year.     

Survival and Conflict Behavior of American Black Bears after Rehabilitation

Wildlife agencies face difficult situations when orphaned or injured American black bear (Ursus americanus) cubs (<12 months old) or yearlings (≥12 and <24 months old) are captured. One option is bear rehabilitation, the care and feeding of cubs or yearlings in a semi-natural environment, followed by release. Unfortunately, the survival and movements of bears released from rehabilitation facilities are often poorly documented and the ultimate reasons for success or failure poorly understood. Our goal was to assess survival and post-release conflict of orphaned bear cubs and yearlings following release from a rehabilitation facility, Appalachian Bear Rescue (ABR), in Townsend, Tennessee, USA, from 2015–2016. We predicted that rehabilitated bears would survive at similar rates, die from similar causes, and engage in similar conflict behavior to wild conspecifics. We equipped 42 black bear cubs and yearlings from ABR with global positioning system-collars and released them in Great Smoky Mountains National Park or Cherokee National Forest, Tennessee and North Carolina, USA. Estimated annual survival using known-fate methods for all released bears was 0.93 ± 0.06 [SE]). Survival for 13 bears released as cubs was 0.64 ± 0.14, whereas none of the bears released as yearlings died within 1 year after release (n = 29). Survival of rehabilitated bears was similar to or higher than published rates for wild conspecifics. Three of 42 bears (7.1%) released from ABR engaged in conflict behavior up to 1 year following release, and those had spent time involved in conflict behavior with their mothers (e.g., approaching humans) prior to being orphaned. Despite not having the typical post-natal experience with their mothers, the bears in our study appeared to behave and survive similarly to their wild conspecifics. Rehabilitation is effective for managing orphaned or injured bears. Best survival occurred for bears released as yearlings; however, managers can maximize cub survival through fall releases when plentiful wild foods are available. © 2019 The Authors. The Journal of Wildlife Management published by Wiley Periodicals, Inc. on behalf of The Wildlife Society.     

Factors influencing breeding success,ovarian cyclicity,and cub survival in zoo-managed tigers (Panthera tigris)

Understanding factors that influence reproduction and offspring survival in zoo populations is critical for management of threatened and endangered species. Examination of long-term data (1989–2011) compiled from the Association of Zoos and Aquarium's zoo-managed tiger breeding program provides the basis for a more thorough understanding of reproduction and scientifically based decisions for effective population management in this endangered felid. Biological and management-related factors that could influence tiger breeding success and cub survival were evaluated using logistic mixed models. Breeding success improved with female age until approximately age five, then declined thereafter. Experienced female breeders had greater breeding success than inexperienced females. Litter size was most predictive of cub survival, with average-sized litters (3–4 cubs) experiencing the highest proportional survival. Management-related factors, such as whether the breeding institution had a recent tiger litter and whether both animals were already located at the same institution, also influenced breeding success and cub survival. These results highlight the importance of institutional husbandry experience and the need to retain knowledge through staff turnovers to achieve optimal reproductive success. Using fecal estrogen data, frequency of ovarian cyclicity and mean cycle length did not differ by female age or parity; thus, lack of cyclicity and/or increased cycle duration are not likely explanations for declining breeding success with age. These results provide valuable reproductive information that should improve scientific management of zoo-based tiger populations.     

Rearing environment influences boldness and prey acquisition behavior,and brain and lens development of bull trout

Animals reared in barren captive environments exhibit different developmental trajectories and behaviors than wild counterparts. Hence, the captive phenotypes may influence the success of reintroduction and recovery programs for threatened and endangered species. We collected wild bull trout embryos from the Metolius River Basin, Oregon and reared them in differing environments to better understand how captivity affects the bull trout Salvelinus confluentus phenotype. We compared the boldness and prey acquisition behaviors and development of the brain and eye lens of bull trout reared in conventional barren and more structurally complex captive environments with that of wild fish. Wild fish and captive reared fish from complex habitats exhibited a greater level of boldness and prey acquisition ability, than fish reared in conventional captive environments. In addition, the eye lens of conventionally reared bull trout was larger than complex reared captive fish or same age wild fish. Interestingly, we detected wild fish had a smaller relative cerebellum than either captive reared treatment. Our results suggest that rearing fish in more complex captive environments can create a more wild-like phenotype than conventional rearing practices. A better understanding of the effects of captivity on the development and behavior of bull trout can inform rearing and reintroduction programs though prediction of the performance of released individuals.     

Effects of captivity,diet, and relocation on the gut bacterial communities of white‐footed mice

Microbes can have important impacts on their host's survival. Captive breeding programs for endangered species include periods of captivity that can ultimately have an impact on reintroduction success. No study to date has investigated the impacts of captive diet on the gut microbiota during the relocation process of generalist species. This study simulated a captive breeding program with white‐footed mice (Peromyscus leucopus) to describe the variability in gut microbial community structure and composition during captivity and relocation in their natural habitat, and compared it to wild individuals. Mice born in captivity were fed two different diets, a control with dry standardized pellets and a treatment with nonprocessed components that reflect a version of their wild diet that could be provided in captivity. The mice from the two groups were then relocated to their natural habitat. Relocated mice that had the treatment diet had more phylotypes in common with the wild‐host microbiota than mice under the control diet or mice kept in captivity. These results have broad implications for our understanding of microbial community dynamics and the effects of captivity on reintroduced animals, including the potential impact on the survival of endangered species. This study demonstrates that ex situ conservation actions should consider a more holistic perspective of an animal's biology including its microbes.     

Reproductive timing in Eurasian otters on the coast of Norway

The seasonal distribution of reproductive phases in female otters and the recruitment of cubs were studied by using information from carcasses collected along the central and northern coast of Norway Relationships between available prey and female body condition were investigated Conception, partuntion and rearing of cubs, at least up to the age of 5–6 months, occurred successfully at all times of the year However, the main birth peak occurred in summer and autumn The frequency of all phases of the breeding cycle, from follicle enlargement to early stages of cub rearing, vaned consistently between seasons Food availability when the cubs were c 2 months old, and energetic demands on the female assumed to be greatest, was probably the main ultimate cause of the seasonal vananon in the recruitment of cubs Intrautenne mortality, possibly due to the seasonal vanation in body condition of females, and loss of litters, may have been important mechanisms in creaung the seasonal recruitment patterns Although the prey biomass on average showed seasonal vanation, the peak season shifted among years and locations It is argued that the availability of suitable prey for otters tend to be unrelated to the seasonal productivity in aquatic environments, due to species–specific growth and behavior of prey and restnctions on the hunting capability of otters Continuous reproduction with seasonal vanation in birth rates may have been maintained by selection for reproductive riskreduction in a nutritionally unpredictable, although generally seasonal, environment     

High juvenile mortality in cheetahs (Acinonyx jubatus) and its consequences for maternal care

Juvenile mortality in cheetahs was found to be extremely high compared to other large mammals, with approximately 72.2% of litters dying before they emerged from the lair at eight weeks of age. An average of 83.3% of cubs alive at emergence died by adolescence at 14 months of age, thus cheetah cubs were estimated to have only a 4.8% chance of reaching independence at birth. The instantaneous rate of mortality was highest immediately after cubs emerged from the lair. Before emergence, lion predation was the major source of this mortality, although some cubs died from starvation after they were abandoned by their mothers, or as a result of grass fires and inclement weather. After emergence, predation again accounted for virtually all cub mortality, with lions and spotted hyaenas taking approximately the same proportion of cubs. Overall predation accounted for 73.2% of cheetah cub deaths in this study, with 78.2% of these being killed by lions. The extent of maternal care, in the form of vigilance and antipredator behaviour, mirrored cub susceptibility to mortality and, in the case of vigilance, possibly also starvation. The probability of a cheetah mother responding aggressively to a predator was found also to depend on the species of predator. This study highlights the importance of the influence of juvenile mortality on patterns of parental care.     

圈养大熊猫催产素水平与母性行为之间关系

Maintaining a good cub-rearing relationship is of great significance for the healthy development of newborn giant panda cubs. Oxytocin plays a key role in this cub-rearing relationship development during the breeding period. To investigate the relationship between oxytocin levels and maternal behavior, we sampled the maternal behavior of 6 adult female giant pandas (3 in lactation group, 3 in non-lactation group) at Chengdu Research Base of Giant Panda Breeding from June to September 2019 by using the focal sampling method, and tested the urine oxytocin level of each individuals by using enzyme-linked immunosorbent assay. The results showed that the oxytocin levels were significantly higher in the lactation group (278. 86 pg/mg ±44. 42 pg/mg) than in the non-lactation group. For the two types of breastfeeding groups, the level of oxytocin in the multiparous female pandas (185. 64 pg/mg ±44. 61 pg/mg) was significantly lower than that in the primiparous female pandas (465. 30 pg/mg ±82. 39 pg/mg). Compared with the primiparous female pandas, the multiparous female pandas had more embracing cub behavior (77. 45% ±1. 24%) and feeding behavior (15. 22% ±1. 62%), but less licking cub (14. 26% ±0. 91%) and position adjustment behavior (1. 69% ±0. 29%). Finally, we found the licking cub behavior was significantly positively correlated with the oxytocin level in the lactation group, and the embracing cub behavior was significantly negatively correlated with the oxytocin level in the lactation group. The results indicate that primiparous female pandas show more maternal behavior, less individual behavior and higher oxytocin levels. The results of this study suggest that the different reactions of oxytocin in the two types of giant panda females may help to improve the refined and differentiated breeding techniques for captive giant pandas in the future.     

Reassessing the relationship between juvenile mortality and genetic monomorphism in captive cheetahs

Low levels of genetic heterozygosity are commonly considered a major threat to the survival of wild and captive populations. However, intense focus on genetic issues may obscure the importance of extrinsic factors influencing species' survival in wild and captive environments. A key example for this is the cheetah (Acinonyx jubatus), which is frequently cited as suffering from unusually high juvenile mortality and decreased fecundity in captivity due to genetic monomorphism at the species level. It has also been suggested that as a consequence of such extreme homozygosity, juvenile mortality rates of young from related vs. unrelated parents would not be expected to differ significantly. However, examination of current studbook data and breeding records of the North American captive population showed that juvenile mortality of young from related parents was significantly higher than that of young from unrelated parents, largely as a result of intrinsic causes, such as stillbirths and congenital defects, that may have a genetic basis. This indicates that in spite of the cheetah's homozygosity, effects of further inbreeding depression may still occur in the captive population, and deleterious recessive alleles are being segregated. Furthermore, juvenile mortality has declined over time and differs significantly among facilities, even when only young from unrelated parents are considered, suggesting that differences in management practices may be largely responsible for observed changes in mortality rate. Contrary to previous reports, cheetah juvenile mortality is not unusually high when compared to other captive-bred felids. In addition, cheetahs were found to have consistently higher litter sizes and the highest average number of surviving cubs per litter when compared to other captive-bred felid species. These findings cast doubt on the significance of overall homozygosity in this species for its juvenile survival and breeding performance and emphasize the key role of management practice in promoting breeding of endangered species. © 1996 Wiley-Liss. Inc.     

大熊猫母兽可根据幼仔的尖叫声辨别自己的后代

研究表明,群居哺乳动物具备通过叫声进行母幼识别的机制,而有关独栖动物的母幼识别机制鲜有研究。大熊猫(Ailuropoda melanoleuca)是典型的独栖动物,原始森林是保持野生大熊猫种群数量可持续发展的必要条件,其中的大型古树提供的育幼巢穴对大熊猫幼仔的存活至关重要。但是,近年来大型古树因受人为干扰而急剧减少,致使野生成年雌性大熊猫活动领域的重叠增大,在育幼期产仔大熊猫母兽对育幼巢穴的利用产生了竞争。大熊猫幼仔的体重约为成年大熊猫的0.1%,幼仔需要母兽高度关怀才能存活和成长。叫声是0-45日龄大熊猫幼仔向其母兽传递生理需求或所处状态的主要方式。然而,母兽能否根据幼仔的叫声识别自己的后代,目前尚无定论。本研究以274条大熊猫幼仔的尖叫声为例,首先对其进行个体独特性分析,然后通过叫声回放以及母兽对所回放的两种叫声的行为反应,验证大熊猫母兽能否辨别出其亲生幼仔。结果发现,尖叫声的17个声学参数中有14个具有潜在的个体判别能力(PIC>1);进一步的判别分析结果显示,基于这17个声学参数,78.5%的尖叫声被正确分配到对应的幼仔;叫声回放实验的结果显示,母兽在行为上更倾向其亲生幼...     

Modeling problems in conservation genetics using captive Drosophila populations: Rapid genetic adaptation to captivity

Long-term captive breeding programs for endangered species generally aim to preserve the option of release back into the wild. However, the success of re-release programs will be jeopardized if there is significant genetic adaptation to the captive environment. Since it is difficult to study this problem in rare and endangered species, a convenient laboratory animal model is required. The reproductive fitness of a large population of Drosophila melanogaster maintained in captivity for 12 months was compared with that of a recently caught wild population from the same locality. The competitive index measure of reproductive fitness for the captive population was twice that of the recently caught wild population, the difference being highly significant. Natural selection over approximately eight generations in captivity has caused rapid genetic adaptation. Captive breeding strategies for endangered species should minimize adaptation to captivity in populations destined for reintroduction into the wild. A framework for predicting the impact of factors on the rate of genetic adaptation to captivity is suggested. Equalization of family sizes is predicted to approximately halve the rate of genetic adaptation. Introduction of genes from the wild, increasing the generation interval, using captive environments close to those in the wild and achieving low mortality rates are all expected to slow genetic adaptation to captivity. Many of these procedures are already recommended for other reasons. © 1992 Wiley-Liss, Inc.