Captive Propagation Research Articles

The limitation of conventional breeding programs and the need and promise of assisted reproduction in nondomestic species

The traditional concepts of captive propagation as a means to preserve biodiversity have limitations that are now well recognized. Too little space and a limited understanding of how to create optimal artificial environments prevent all but a few traditional breeding programs from meeting their ultimate goal of safeguarding targeted species. In order to achieve reasonable success we must be prepared to integrate new technologies in assisted reproduction with traditional propagation strategies and to view captive and noncaptive animals as a single resource. Methods such as cryogenics, artificial insemination and the transfer of in vivo- and in vitro-derived embryos have already been demonstrated for a limited number of endangered species. These techniques will likely be the foundation of broadly-based breeding programs for the conservation of many nondomestic animals in the future.

Effects of environmental enrichment on reproduction

AbstractAlthough there have been few demonstrations of a direct empirical relationship between environmental enrichment and reproductive success in captive animals, indirect and anecdotal evidence indicates the importance of physical and temporal complexity for reproduction. We discuss three major mechanisms through which environmental enrichment that specifically increases the complexity of an animal's surroundings may influence reproductive physiology and behavior: developmental processes, modulation of stress and arousal, and modification of social interactions. In complex environments developing animals learn that performing active behavior produces appropriate functional outcomes. Learning to control their environment influences their ability to adapt to novel situations, which may profoundly influence their reproductive behavior as adults in breeding situations. Chronic stress may compromise reproductive physiology and behavior; enrichment reduces stress by providing increased opportunity for behavioral coping responses. However, some degree of acute stress may be beneficial for reproduction by maintaining an animal's level of responsiveness to socio‐sexual stimuli necessary for sexual arousal and reproductive activation. Finally, environmental enrichment may influence reproductive success by stabilizing social groups, reducing aggression and increasing affiliative and play behaviors. It is concluded that multi‐variate multi‐institutional behavioral research in zoos will play an increasingly important role in the successful captive propagation of many species by closely examining relationships between environmental variables and reproductive potential of individual animals. © 1994 Wiley‐Liss, Inc.

Personality assessment in the gorilla and its utility as a management tool

AbstractGoals of the Gorilla Species Survival Plan (SSP) include increased captive propagation, maintenance of genetic diversity, and consideration of the psychological well‐being of the population. The SSP Propagation Group has attempted to accomplish these goals through recommendations based on assessment of genetic, behavioral, and demographic variables. A need is recognized for the development of a methodology to assess behavioral variables that contribute to the success of animal moves. Personality profiles have been used in the past to aid animal management decisions in laboratory settings. This paper describes personality assessment techniques, reviews historical perspectives on primate personality assessment, and reports on a study to assess gorilla personality.The Gorilla Behavior Index (GBI), a subjective assessment instrument consisting of behaviorally based adjectives, was completed for 298 of 303 captive gorillas over 1 year of age. The results were subjected to common factor analysis, resulting in the identification of four main factors: extroverted, dominant, fearful, and understanding. Frequency distributions were calculated illustrating the ranges of each factor. Potential management uses for the GBI scores are discussed. © 1994 Wiley‐Liss, Inc.

Successful intrauterine insemination of Eld's deer (Cervus eldi thamin) with frozen-thawed spermatozoa.

This study tested the efficacy of assisted reproduction (synchronization of oestrus and intrauterine artificial insemination (AI)) in contributing to the captive propagation of an endangered species, the Eld's deer (Cervus eldi thamin). Semen was collected from males preselected on the basis of under-represented genotype. Motility of spermatozoa after thawing from ejaculates diluted with BF5F extender (8% glycerol), frozen on dry ice in 0.5 ml straws and stored in liquid nitrogen was 60-70%. Intravaginal progesterone-releasing devices (controlled internal drug release, CIDR-type G) were inserted into 20 adult Eld's deer hinds for 14 days. In all hinds, semen (7.5-10 x 10(6) motile spermatozoa per uterine horn) was deposited by laparoscopy performed 70 h after removal of the CIDR device. Ovarian activity, before and after AI, was monitored by analysing pregnanediol-3 alpha-glucuronide (PdG) concentrations in voided urine collected three to seven times per week. During the period of CIDR device insertion, urinary PdG profiles were equal to, or above, normal luteal phase concentrations in all hinds. Within 48 h of device withdrawal, PdG concentrations returned to baseline values in 17 of the 20 females, and the onset of behavioural oestrus occurred at this time in 12 hinds. On the basis of sustained increases in urinary PdG, 9 of the 20 hinds were diagnosed as pregnant by 90 days after AI, all of which delivered offspring after a mean gestation of 241.1 days (range, 235-245). Seven singletons (two females, five males) were born alive and survived, and one singleton and one set of twins were stillborn (three females).(ABSTRACT TRUNCATED AT 250 WORDS)

Laboratory Spawning and Rearing of the Endangered Fountain Darter

Abstract Survival of the fountain darter (Etheostoma fonticola), a U.S. federally listed endangered species, may depend on captive propagation. Studies were conducted to determine the effect of temperature on spawning and to develop methods for culture. The fountain darter spawned and produced viable offspring in aquaria at 27, 24, 21, 18, 15, 12, 9, and 6°C. The fish also spawned at 3 and 30°C but did not produce viable eggs. Daily egg production of individual fish held at 27, 21, 15, and 9°C was variable. The mean critical thermal maximum for the fountain darter was 34.8°C. Early life stages, 4–14 mm long, were offered a variety of live protozoans, rotifers, and microcrustaceans. Food selection varied with fish size and food size. Fountain darters reached sexual maturity in about 180 d when maintained at 21°C. Three-year-old darters produced viable offspring, and several lived longer than 4 years. Tricaine methanesulfonate was an effective anesthetic at 60 mg/L but was fatal to subadults at 100 mg/L.

Progress in Restoration of the Mauritius Kestrel

In the 1970s, the Mauritius Kestrel (Falco punctatus) was the most endangered bird of prey in the world, at one time with only two known pairs surviving in the remnant native forest of the Black River Gorges (ca. 4,000 ha). At the end of the 1991–1992 breeding season, a minimum of 30 nesting pairs and more than 170 individuals were distributed in four separate forested areas, thanks mainly to manipulation of the reproductive potential of the wild pairs, to captive propagation, and to reintroduction (restocking). Since 1984, 139 young have been reared from 618 eggs laid by captive kestrels, and 147 from 265 wild eggs incubated and hatched in the laboratory; 235 young kestrels have been released on Mauritius by hacking and fostering. Adjustments in feeding and nesting habits of kestrels hacked and released outside the Black River Gorges in areas dominated by exotic vegetation and agriculture have allowed these kestrels to survive and reproduce in an array of previously unused habitats. Now that the kestrels have been released from dependence on the remnant and dying native forest, a viable population of more than 100 nesting pairs should be achievable in a few more years.

Genetics and morphology of Yaqui chub Gila purpurea, an endangered cyprinid fish subject to recovery efforts

Federally endangered Yaqui chubs Gila purpurea are restricted to the Rio San Bernardino, a small headwater tributary of the vast Rio Yaqui basin of Sonora, México, and Arizona, United States. The species faced almost certain extirpation in the United States during the late 1960s when its remaining habitats went dry. Just prior to that event in 1969, individuals were successfully transplanted into nearby Leslie Creek. Captive propagation was later used to produce fish to re-establish populations in its native range after habitats were reclaimed and protected. We present the history of conservation efforts which include numerous transfers of differing numbers of fish between captive and ‘wild’ stocks. We examined the effects of these recovery efforts on the genetic and phenotypic structure of populations. Genetic and morphological differentiation were respectively assessed using allozyme electrophoresis and principal components analysis. Considerable genetic stability was indicated, with observed variations attributable to documented or inferred changes in population sizes. Morphology also remained uniform, both temporally and spatially, with no evidence of changes attributable to recovery manipulations or ecophenotypic responses to novel environments. Yaqui chubs exhibit high fecundity and quickly establish large effective population sizes, life history characteristics which likely account for the minimal effects of population manipulations.

F10 pandalid shrimp: Sex determination; DNA and dopamine as indicators of domestication; and outcrossing for wild pigment pattern

AbstractDomestication becomes significant in captive propagation of high‐fecundity animals which sustain significant mortality rates. The domestication process typical of higher vertebrates has been observed in the coonstripe shrimp, Pandalus danae, which were reared through 10 generations for study of protandric hermaphroditism. The research protocol of repeated handling, for determining sex and carapace length, rendered escape responses maladaptive. Domesticated, F10 shrimp showed significantly greater band‐sharing in genomic DNA than wild shrimp, and the domesticated shrimp had only 5.5% of the dopamine levels in haemolymph found in wild shrimp. For both parameters, outcrossed shrimp (wild X domestic) had intermediate values. The outcrossed shrimp looked entirely wild, yet had behavioral and metabolic attributes of domestic shrimp. For such nonendangered species, domestication may be as desirable as it is unavoidable. It appears necessary, however, to perform outcrossing in order to maintain the wild form. © 1993 Wiley‐Liss, Inc.

Genetic resource banks for conserving wildlife species: justification, examples and becoming organized on a global basis

The cryopreservation of germ plasm and embryos combined with assisted reproduction play a continuing, vital role in sustaining and improving animal agriculture. It only is logical that similar types of technologies could be useful for preserving other forms of bio- and genetic-diversity, many of which are under the threat of extinction. The benefits of genetic resource banking for conservation purposes are even more profound than for domesticated livestock. In addition to preserving genetic vigor and enhancing captive propagation, these frozen repositories could provide a high level of insurance against further losses of diversity or entire species. Particularly important is that biological material could be recovered from free-living animals, stored and used without removing more individuals from native habitats. Three ongoing research projects at the National Zoological Park involving cervids, mustelids and felids are reviewed to demonstrate the potential of assisted reproduction for species preservation. Furthermore, rapidly evolving global strategies are discussed that will provide organization to the systematic collection, storage and use of germ plasm, embryos, blood products, tissue and DNA. Even given current restricted financial support for efforts, all evidence suggests that genetic resource banks will be contributing significantly to the conservation of rare wildlife species as we enter the 21st century.

Potential contribution of cryopreserved germ plasm to the preservation of genetic diversity and conservation of endangered species in captivity

Demographic and genetic objectives of captive propagation programs for endangered species focus on establishing demographically secure populations that maintain adequate levels of genetic diversity. Long-term storage and utilization of cryopreserved germ plasm could extend the population's generation length and allow higher levels of genetic variation to be maintained in smaller populations. Since fewer breeding animals would be needed, more species would be “rescued” from extinction using the cage facilities currently available at existing institutions. Doubling generation lengths for callitrichid primates through use of cryopreservation could almost triple the number of species that could be rescued in world zoos. Additionally, long-term cryopreservation would allow for a third population, that of the frozen zoo. Three-way exchange of germ plasm from germ plasm banks to captive and wild populations would increase genetic diversity at reduced risk and expense. Advances in reproductive technology and better understanding of the reproductive physiology of these animal populations are necessary to permit routine application of artificial insemination and embryo transfer using frozenstored germ plasm.

Conservation prospects for lion‐tailed macaques in Karnataka, India

AbstractA substantial proportion of the wild lion‐tailed macaque population occurs in Karnataka State, India. In this paper, problems of protecting the macaques and their habitats are discussed. Fairly large portions of the Karnataka habitat remain available. These are free of large‐scale shrinkage in area, but are experiencing deterioration in quality due to pressures from enclaves of human settlements, from developmental projects, and from timber/minor forest produce extraction. Illegal hunting is another threat to the population. A pragmatic, cost‐effective approach to conservation of rain forest habitats, centered around protection of nature reserves, with the lion‐tailed macaque as a flagship species, as opposed to a strategy based on captive propagation, is advocated.

Observations on reproduction, hormones, copulatory behavior, and neonatal mortality in captive Lemur mongoz (Mongoose lemur)

AbstractThis study examines correlates of reproduction in Lemur mongoz, an endangered prosimian primate with a history of poor captive reproduction. Male testicular growth and regression were quantified via testicular indices (TI). Although TIs could be used to predict male breeding condition, they were not indicators of ability to sire offspring. Serum estradiol (E2) and progesterone (P) concentrations, along with vaginal cytology, were used to monitor female reproductive cyclicity. E2 and P profiles showed no abnormalities. An elevation of E2 with low P, approximately one estrous cycle length (31.4 days) prior to the onset of fertile cycles, was consistent with the phenomenon of ‘pseudoestrus’ observed in other lemur species. The copulatory pattern, consisting of thrusting, multiple intromissions, single or multiple ejaculations, and no copulatory lock, was more complex than expected for an animal with a supposedly monogamous mating system. The preference for natural arboreal substrata during copulation suggests that enclosure furnishings may influence copulatory behavior. A 30% neonatal mortality rate tempered recent success in breeding L. mongoz at the Duke University Primate Center (DUPC). Although infant sex and parity of the mother were not predictive of neonatal mortality, mother's natal status was, with captive‐born females having a 67% infant mortality rate, compared with 15% in wild‐caught females. Based on these observations, a number of factors, including housing, behavior, and photoperiod, may be relevant to successful captive propagation of L. mongoz. © 1992 Wiley‐Liss, Inc.

The behaviour of Przewalski's horses and its importance to their management

Przewalski's horses ( Equus przewalskii) are believed to be extinct in the wild; the current known population of 797 animals exists wholly in zoos. The Species Survival Commission of the International Union for Conservation of Nature and Natural Resources is proposing to reintroduce this endangered species into its former Mongogian habitat within the next decade. Knowledge of the behavior of harem-forming equids in general and of Przewalski's horses in particular, is of great importance to the captive propagation and eventual reintroduction of this species. Horses are rarely solitary by nature. Solitary captive animals are prone to pacing. Juvenile male feral horses ( Equus caballus) form bachelor herds upon dispersal from their natal band. Zoos can set up bachelor herds as a way of managing surplus males. The older, more dominant feral horse bachelors are the first to acquire mares. Bachelors do not generally obtain females until they are 4 or 5 years of age. The first females acquired are usually 1- and 2-year-old fillies dispersing from their natal band. Because of the age differential, the stallions are generally dominant to their mares. Behavioral impotence may result if captive stallions are given a harem at too young an age, especially if the harem contains older, more dominant, females. Typical harem sizes in the wild are 3–5 mares. Captive stallions with too large a harem may become either apathetic or aggressive toward their mares. Wild horses spend 60–70% of their time foraging. Captive animals may quickly consume their limited amounts of food and develop vices out of boredom. Provision of hay ad libitum reduces the amount of pacing seen in captive animals, and virtually eliminates coprophagy.

Captive breeding and reintroduction of the endangered masked bobwhite

AbstractEfforts to restore the endangered masked bobwhite (Colinus virginianus ridgwayi) to its former range have required 1) habitat acquisition, restoration, and preservation; 2) captive propagation; and 3) reintroduction of captive‐bred stock. In its role to recover the masked bobwhite, the Patuxent Wildlife Research Center (U.S. Fish and Wildlife Service) has refined captive breeding techniques; provided captive‐produced stock for release; conducted field research on the distribution, limiting factors, and habitat characteristics of this species; and developed release methods. Techniques for the husbandry and captive management, breeding, artificial incubation and hatching of eggs, and rearing of young of the masked bobwhite have been developed. Successful reintroduction techniques for the masked bobwhite have included prerelease conditioning and/or cross‐fostering of captive‐reared masked bobwhite chicks to a wild‐caught, related, vasectomized bobwhite species and their release to the wild as family units. In addition, the establishment by the U.S. Fish and Wildlife Service of the Buenos Aires National Wildlife Refuge in 1985 has further enhanced the potential for establishing a self‐sustaining population of the masked bobwhite in the U.S. Through continued releases and active management of habitat, therefore, it is believed that the masked bobwhite can become permanently established at the refuge to ensure its continued survival in the wild.

An automated assay for fecal estrogen conjugates in the determination of sex in avian species

AbstractRecently captive propagation of psitticines has become necessary in order to preserve and breed endangered species. As habitat destruction increases and importation restrictions become more stringent, the need for a reliable and noninvasive technique for sex assignment is essential to improve the productivity of breeding and raising birds in captivity. One aspect of breeding is the proper assignment of breeding pairs; however, sex identification can be challenging due to the lack of sexual dimorphism in approximately 30% of all avian species. Historically, visual, behavioral, surgical, cytogenetic, and endocrine methods have been utilized in sex identification of avian species; however, the practicality, safety, and reliability of these techniques have been questioned. Therefore, there remains a need for an accurate, simple, and non‐invasive method to identify the sex of monomorphic birds so that the formation of breeding pairs and the success of breeding programs is facilitated. The data in this study support the concept that an automated fluorescence‐immunoassay which measures fecal estrogen conjugates can have an 87% success rate in determining the sex of psitticines, as demonstrated with cockatiels, while offering the advantages of non‐invasiveness, simplicity, and speed.

The Husbandry and Captive Propagation of Forest Cobras,Naja melanoleuca

The Husbandry and Captive Propagation of Forest Cobras,<i>Naja melanoleuca</i>

The conservation of the fishes of Lake Victoria, Africa: an ecological perspective

The African Great Lakes are considered to be dynamically fragile ecosystems that are relatively resistant to minor changes with which they have co-evolved but vulnerable to major perturbations such as overfishing, the introduction of alien species and pollution. These lakes are inhabited by large species flocks of cichlid fishes which are characterised by a complex structure of interaction both between and within species, as is typical of mature ecosystems. Major perturbations, such as the disruption of trophic interactions through the introduction of alien fishes, may reverse the domination of relatively precocial, specialised forms and result in the creation of conditions that are conducive to the survival of more altricial, generalised forms with strong colonising abilities. The introduction of Nile perch and Nile tilapia, as well as other alien fishes, into Lake Victoria, combined with overfishing for the indigenous cichlid species, has resulted in marked changes to the fish communities and the fisheries that depend on them. The most important impacts of the Nile perch appear to be predation and aggressive effects whereas those of the tilapias include hybridization, overcrowding, competition for food and possibly the introduction of parasites and diseases. While the three proposed methods of conserving the indigenous flocks of cichlid fishes (captive propagation, reducing Nile perch stocks and closure of the haplochromine trawl fishery) all have merit, the changes that are occurring in Lake Victoria are basically irreversible. The highest priority should be to assist the governments of the riparian countries (Tanzania, Uganda and Kenya) with monitoring and research programmes and to support their policies of non-introduction of further alien fishes into any of the African Great Lakes so as prevent the same cycle of events from occurring, for example, in Lakes Tanganyika and Malawi. The diverse animal and plant communities of the African Great Lakes are a heritage of all mankind and it is the duty of every country to play a role in their conservation. It is therefore proposed that an internationally funded research programme should be mounted on the African Great Lakes on the scale of the tropical forest biome project of the IUCN.

Primate Ecology and Conservation.

The survival of primates in their natural habitats is of growing concern to primatologists, ecologists and conservationists. In this volume, research on feeding behaviour, nutrition and digestive physiology from captive and wild primates is presented. Correlates of the habitat and social organisation are discussed, and then integrated with the pressing problem of how to conserve primates. Broad issues of confrontation between human and non-human primate populations are considered in the light of conflicting priorities for land-use and development. The increased knowledge of what primates require for their survival is applied to problems of captive propagation as a means of reducing dependence on exploiting wild populations. The papers presented in this volume will stimulate discussion between ecologists, conservationists and those concerned with land-use management to establish realistic policies for primate conservation.

Training zoo biology in tropical countries: A report on a method and progress

AbstractIn 1987 the National Zoological Park inaugurated a Zoo Biology training program for developing country zoos, particularly those in the tropics where the threats to biological diversity are greatest. The program last 2 to 4 weeks, is targeted to mid‐level zoo managers, and aspires to improve the care and management of wildlife in zoos through in situ training. A host zoo in the foreign country is responsible for selecting and inviting trainees from other zoos in the country or region. Training activities include daily lectures, demonstrations, quizzes, problem solving exercises, and class projects. In addition, the class participates in creating an animal inventory for the host zoo, and endemic species are identified for studbook compilation and captive propagation projects. Most mid‐level zoo managers in tropical developing countries are college‐educated men in their thirties, and have on average less than 10 years of zoo experience. We evaluate our program, and discuss the problems confronting tropical zoos in the developing world. Finally, we suggest ways that zoos in developed countries can influence tropical conservation through training and education.

Neotropical primate conservation

The greatest threat to Neotropical primates is the loss of tropical forest for agriculture, ranching, commercial logging and hydroelectric projects. Hunting of primates for consumption or sale and live capture for the pet trade and for biomedical purposes is also a threat to certain species. Twenty-eight of the 76 Neotropical primate species are considered endangered and the highest density of endangered taxa occurs in Brazil's Atlantic forest, followed by Amazonia and Middle America. The most endangered Neotropical primate genera are Brachyteles and Leontopithecus, followed by some species of Ateles, Lagothrix, Saguinus and the Central American squirrel monkey ( Saimiri oerstedii citrinellus). Solutions to the problems of primate conservation are discussed, including habitat conservation, protection against poaching and international primate trade, education, research and captive propagation, and examples of successful conservation efferts are provided.