Karen L. Bauman

Vitrification of oocytes from endangered Mexican gray wolves (Canis lupus baileyi)

Careful genetic management, including cryopreservation of genetic material, is central to conservation of the endangered Mexican gray wolf. We tested a technique, previously used to vitrify human and domestic animal oocytes, on oocytes from domestic dogs as a model and from the endangered Mexican wolf. This method provided a way to conserve oocytes from genetically valuable older female Mexican wolves as an alternative to embryos for preserving female genes. Oocytes were aspirated from ovaries of 36 female dogs in December and March (0 to 65 oocytes per female) and from six female wolves (4 to 73 per female) during their physiologic breeding season, or following stimulation with the GnRH agonist deslorelin. Oocytes from dogs were pooled; half were immediately tested for viability and the remainder vitrified, then warmed and tested for viability. All oocytes were vitrified by being moved through media of increasing cryoprotectant concentration, placed on Cryotops, and plunged into liquid nitrogen. There was no difference in viability (propidium iodide staining) between fresh and vitrified, warmed dog oocytes (65.7 and 61.0%, respectively, P = 0.27). Oocyte viability after warming was similarly assessed in a subset of wolves (4 to 15 oocytes from each of three females; total 29 oocytes). Of these, 57.1% of the post-thaw intact oocytes were viable, which was 41.4% of all oocytes warmed. These were the first oocytes from a canid or an endangered species demonstrated to have maintained viability after vitrification and warming. Furthermore, our results demonstrated that vitrification of oocytes with the Cryotop technique was an option for preserving female gametes from Mexican wolves for future use in captive breeding programs, although in vitro embryo production techniques must first be developed in canids for this technique to be used.

Factors Associated With Uterine Endometrial Hyperplasia and Pyometra in Wild Canids: Implications for Fertility

The ability to safely and effectively manage reproduction is central to the success of AZA captive-breeding programs. Although the AZA Wildlife Contraception Center routinely monitors contraceptive safety, there have been no studies that compare the effects of contraceptive use to separation of males from females, the other option for preventing reproduction. We used retrospective medical records and pathology reports submitted by AZA and related facilities for the seven AZA-managed canid species to assess rates of uterine pathology relative to female reproductive life histories. Our results showed that the prevalence of both pyometra and endometrial hyperplasia (EH) was associated not only with treatment with the two most common contraceptives (Suprelorin® and MGA implants) but also with the number of years barren (i.e., not producing a litter and not contracepted). Rates of pyometra and EH were especially high in African painted dogs and red wolves, but lowest in swift and fennec foxes. The number of years producing a litter had a low association, suggesting it could be protective against uterine pathology. A more recently developed Suprelorin® protocol using Ovaban® to prevent the initial stimulation phase, followed by implant removal when reversal is desired, may be a safer contraceptive option. These results concerning the relationship between reproductive management and uterine health have important implications for AZA-managed programs, since the unsustainability of many captive populations may be due at least in part to infertility. Managing a females reproductive lifespan to optimize or maintain fertility will require a reconsideration of how breeding recommendations are formulated.

Effect of semen collection method on sperm motility of gray wolves (Canis lupus) and domestic dogs (C. l. familiaris)

Genetic management of Mexican gray wolves includes semen banking, but due to the small number of animals in the population and handling restrictions, improvements in semen collection and cryopreservation rely on results from studies of domestic dogs. Semen collection from wolves requires anesthesia and electroejaculation, which introduce potentially important variables into species comparisons, as dog semen is typically collected manually from conscious animals. To investigate possible effects of collection method on semen quality, we compared semen collection by the traditional manual method and by electroejaculation (EE) in a group of dogs (n = 5) to collection by EE only in wolves (n = 7). Samples were divided into two aliquots: neat or diluted in Tris/egg yolk extender, with motility evaluated at intervals up to 24 h. There were no differences (P > 0.10) in sperm motility in either neat or extended samples at 24 h from EE dogs and wolves, although motility of the wolf neat samples declined more rapidly (P < 0.05). However, there were differences (P < 0.01) between EE and manually collected dog semen in motility at 24 h, in both the neat and extended samples. Therefore, general motility patterns of dog and wolf semen collected by EE were similar, especially when diluted with a Tris/egg yolk extender, but sperm collected from dogs by EE did not maintain motility as long as manually collected samples, perhaps related to the longer exposure of EE samples to more prostate fluid.

Time‐lapse infrared videography for animal behavior observations

Although videography has been used for many years to record episodes of animal behavior, the availability of increasingly complex equipment can make selection difficult. Most equipment developed for round-the-clock observations was designed for security surveillance, so informed purchasing, installation, and usage decisions need to be made to monitor animal behavior effectively. During 7 years of using video and infrared equipment for animal behavior research and monitoring in a zoo setting, we tested many models, evaluated options, and modified components. We now have well-integrated systems that are compatible with our video/computer review and analysis program. New equipment will continue to become available, but familiarity with basic features and applications can help to narrow the selection. Zoo Biol 17:535–543, 1998.

Melengestrol acetate implant contraception in addax (Addax Nasomaculatus) and Arabian oryx (Oryx Leucoryx)

Melengestrol acetate (MGA) implants were used for contraception in three addax and three Arabian oryx females housed at the Saint Louis Zoo. Serum estradiol and progesterone or fecal estrogen and progestin analysis and ultrasonography of reproductive tracts were used for monitoring changes before, during, and after MGA treatment. Follicular development and irregular uterine fluid accumulation were detected in all females during MGA treatment. Although housed with an intact male for all or most of the contraceptive period, no pregnancies occurred.One female addax may have ovulated, based on sustained elevated progesterone levels, and another showed continued follicle development, as seen by fluctuating estradiol concentrations. Reversibility was documented in two of the three addax that resumed reproductive cycles post-MGA-implant removal, whereas the third, a peripubertal female, did not cycle before, during, or after treatment. Addax females were lost to further follow-up after transfer to another institution, so the possibility of subsequent pregnancies is not known.All three Arabian oryx ovulated during the initial MGA treatment, but two of the three females had implants past the typical 2-year efficacy period. They had regular ovulatory cycles after implant removal, with mean cycle length of 27.5+/-1.5 days and mean luteal phase duration of 15.2+/-0.7 days. Reversibility was further shown in all three oryx by pregnancies after placement with a male approximately 2 years after MGA implant removal. Two produced healthy calves, but the third died owing to an unrelated terminal illness in the mother. Zoo Biol 26:299-310, 2007. (c) 2007 Wiley-Liss, Inc.

Reproductive behavior of the great hornbill (Buceros bicornis)

Great hornbills (Buceros bicornis) are a long-lived, monogamous species that forms strong pair-bonds, and mate compatibility is thought to be important for successful reproduction. Within AZA, great hornbills are listed as a red SSP. The population consists of a limited number of individuals that do not breed reliably, and improving reproduction is a top priority for the Coraciiformes TAG. To better understand mating behavior and evaluate mate compatibility, this study documented the behavior of pairs of great hornbills during and immediately after courtship. Using live observations, the study followed one female, an experienced and successful breeder, as she was paired with four successive males over 11 breeding seasons. Initially, males frequently vocalized, investigated the nest, and approached the female. As the female spent more time in the nest, these behaviors were replaced by regurgitation and food offering. The female was most often observed plastering and vocalizing. Behavioral differences between successful and unsuccessful pairs, possibly indicative of pair compatibility, included rates of approaching, billing, and biting. Numerous behaviors occurred more frequently during years that a chick hatched, including pseudoregurgitation, regurgitation, offering food items, and nest investigation. Males also spent more time in proximity to both the female and the nest during years that a chick hatched. Together, these results suggest that the amount of time pairs spend in proximity, the amount of time a male spends near the nest, and the frequency of certain behaviors may help evaluate compatibility and the likelihood of successful reproduction for pairs of great hornbills.

Parent-offspring behavior of Jambu fruit doves (Ptilinopus jambu).

Fruit doves (Ptilinopus) constitute a genus of small to medium-sized, brightly colored arboreal birds, whose diets consist entirely of fruit. Little is known about the behavior of fruit doves because most species inhabit dense forests and are difficult to observe in the wild. This study describes the parental behavior of Jambu fruit dove pairs (Ptilinopus jambu) in a captive breeding program at the Saint Louis Zoo. Continuous video recordings were made of three pairs which raised a total of eight squabs over 2 years; daily rates of parental and squab behaviors were quantified. Overall, females were present at the nest, brooded their squabs, pecked, and attempted feedings more often than males. Parents also cared for their squabs at different times throughout the day. Males fed and brooded squabs during the middle of the day, while females fed throughout the day and brooded in the morning, evening, and overnight. Feeding rates were lower than those described for seed-eating doves (Columbinae), with hours between consecutive feedings, and squabs rarely begged before feeding events. Most squab behaviors involved initiating or terminating brooding and self-preening. These behaviors increased as squabs approached fledging, and coincided with a shift from full to partial brooding, and a decrease in parental allopreening. Older squabs also initiated feeding less frequently. Together, these data provide the first description of parental behavior in a Ptilinopus fruit dove. The results of this study may help improve captive breeding efforts, which are likely to become increasingly important for future conservation and reintroduction programs.

Kinematic activity of gray wolf (Canis lupus) sperm in different extenders, added before or after centrifugation

We evaluated two approaches to improving in vitro wolf sperm survival. Both approaches aimed to reduce the exposure of sperm to prostatic fluid resulting from electroejaculation: (1) use of extender formulations recently developed for the domestic dog (the most closely related domestic species); and (2) dilution of ejaculate shortly after semen collection. Three commercial extenders were compared with the TRIS-based extender we had previously used. We also compared the effects on motility of adding extender immediately after collection to our previous protocol in which extender was added after centrifugation. Both subjective and objective (computer-assisted semen analysis program) kinematic measurements were made. Relatively minor differences were noted (and not in total or progressive motility) between the centrifugation protocols. Two of the commercial extenders resulted in significant improvement in motility over the TRIS-based extender and one of the other commercial extenders at 8 hours after collection (mean ± SEM; total motility was 68.3 ± 4.0% and 70.0 ± 4.0% compared with 53.3 ± 4.0% and 55.0 ± 4.0%, respectively; progressive motility 58.6 ± 5.4% and 57.1 ± 5.4% compared with 32.8 ± 5.4% and 39.3 ± 5.4%; P < 0.05). We inferred that components in two of the commercial dog extenders might provide more protection for wolf sperm, prolonging their motility.

Nutrition and Behavior of Fennec Foxes (Vulpes zerda)

Fennec foxes make popular pets because of their small size, minimal odor, and highly social behaviors. They are kept in zoos for conservation and educational programs. The exotic animal practitioner is most likely to be presented with fennec foxes that are overweight because of inappropriate diets or excessive feeding. Clients attempting to hand-rear fennec foxes need advice about formula selection, amounts to feed, protocols for keeping pups warm, and weaning. This article provides information on social behavior, reproduction, and parental behavior, nutrition, and hand-rearing.