Fecal progesterone and estrogen metabolite monitoring for cyclicity and pregnancy in southern tamandua (Tamandua tetradactyla).

Reproductive management of the southern tamandua (Tamandua tetradactyla) should include timed introductions for breeding to minimize aggression and pregnancy monitoring. Since serial blood sampling could cause unnecessary stress, and urinary progesterone metabolites are found in very low concentrations, this study sought to validate progesterone and estradiol enzyme immunoassays for measuring fecal progesterone metabolite (FPM) and fecal estrogen metabolite (FEM) concentrations in two females. Peaks in FEM concentrations coincided with breeding and conception, were 5-6 times higher than baseline concentrations, and were followed by clear luteal phases distinguished by FPM concentrations 5-6 times higher than baseline concentrations. FPM concentrations during the first 30-53 days of gestation overlapped with luteal phase concentrations, thereafter increasing to 8-25 times higher than baseline concentrations. FEM concentrations during the first 41-44 days of gestation remained near basal values for one female, whereas concentrations were 1.8 times higher than baseline for the second. FEM concentrations became elevated for the former by 44 days of gestation and increased further for the latter after 53 days, ultimately averaging four times higher than baseline for both females. The biphasic increase in FPM and FEM concentrations, follicular and luteal phase durations (follicular: 7 ± 1 days, luteal: 25 ± 1 days), total cycle length (41 ± 1 days), and gestation (161-165 days) documented in this study were consistent with previous reports from serum and urine analyses. Monitoring FPM and FEM is a reliable noninvasive method for tracking reproductive cycles and pregnancy in southern tamandua that overcomes the challenges associated with serum or urinary hormone analysis.

Seasonal Changes in Fecal Glucocorticoid Metabolite Concentrations in Bison (Bison bison) Living with or without Wolves (Canis lupus).

The threat of predation can cause increased adrenal secretion of glucocorticoids that, if sustained, can result in chronic stress that might predispose animals to disease, reduced growth, or poor fertility. Fecal glucocorticoid metabolite (FGM) concentrations were measured between September 2011 and July 2012 in two Montana bison (Bison bison) herds, one herd living with and the other without wolves (Canis lupus) in their habitat. The relevance of FGM concentrations (as measured by the corticosterone enzyme immunoassay) and a confirmation of an acute adrenal response was demonstrated by transient increases (P<0.001) in FGM concentrations in bison herded through a chute system and following a wolf encounter. The FGM concentrations were higher in the herd with wolves than the herd without wolves overall (P=0.045), but the monthly differences between the herds were inconsistent (magnitude=0.3-3.5 µg/g; P=0.011 month×herd). The herd with wolves had higher FGM in April, June, July, September, and November, but the herd without wolves had higher FGM in January, February, and May. Seasonal changes in FGM concentrations (P<0.001) were measured across the year in both herds (magnitude=10.8 and 6.9 µg/g, respectively), exceeding any differences between herds potentially attributable to wolf presence. Concentrations of FGM were highest in April-July and were lowest in January-February. Evidence of a chronic stress response was not found, and increased disease susceptibility in the bison living with wolves seems unlikely.

NOVEL PREGNANCY DIAGNOSIS AND ALTRENOGEST SUPPLEMENTATION LEAD TO SUCCESSFUL PREGNANCY IN A BLACK-FOOTED CAT (FELIS NIGRIPES).

This is the first time fecal prostaglandin F2α metabolite (PGFM) analysis and altrenogest were used to determine and maintain a pregnancy in a zoo-housed black-footed cat (BFC; Felis nigripes). The established pair had not produced offspring during the year since their arrival at Birmingham Zoo. Fecal samples were collected daily and analyzed by enzyme immunoassay for progestagen, estrogen metabolite, and PGFM concentrations. After a 4-mo separation, the pair was reintroduced, and breeding was reinitiated. Two pregnancies were suggested by sustained, elevated progestagen concentrations (mean >3 × baseline) but were confirmed by elevated PGFM concentrations (mean 4-25 × baseline) beginning about 1 mo after presumed or observed breeding. The first pregnancy was lost after ∼51 days, and altrenogest was administered (0.088 mg/kg/day) in order to help sustain the second pregnancy, which went to term, but the kitten did not survive. Ultrasonographic and radiographic evaluations of pregnancy were utilized during the second pregnancy to provide information on litter size.

Characterization of the behavior and reproductive endocrinology of giant river otters (Pteronura brasiliensis) in managed care.

Propagation of giant river otters (GRO) in zoos is inconsistent: some pairs never reproduce while others are prolific in producing young but can be hindered by low cub survival. Developing effective breeding programs requires understanding normal reproductive parameters and behavior. Fecal samples were collected for 6-16 months from five breeding pairs, two individual females, and one female pair at seven zoos, and analyzed for fecal progesterone, estrogen, testosterone, and glucocorticoid (FGM) metabolites via enzyme immunoassay. Enclosure characteristics and management routines were recorded at six facilities where behavior was assessed over 1 week. Median fecal progestogens during pregnancy and pseudopregnancy were ∼2.5-3.8× greater than basal concentrations. Gestation lasted 66.5 ± 3.5 days (62-70 days); pseudopregnancies lasted 58 ± 11.6 days (41-69 days). Elevated progestogens indicate ovulation but cannot distinguish pregnancy from pseudopregnancy. Periodically sustained, elevated progestogens observed in two females housed without a male indicated spontaneous ovulation. Elevations in fecal estrogens were not associated with estrus, and seasonality in male testosterone was not observed. Wavering scream and contact call vocalizations among reproductively successful males and females, respectively, suggested the importance of social communication. Most facilities housing successful pairs had larger enclosures with more water than land area, vegetation, and limited public exposure. Baseline FGM were negatively correlated with enclosure size and percentage of water area (p < 0.05), and lower baseline FGM were associated with reproductive success (p < 0.05). These results suggest that housing GRO in spacious enclosures with open water and some insulation from disturbance might promote appropriate behavior, lower FGM, and reproduction.

Estrogenicity of captive southern white rhinoceros diets and their association with fertility.

The captive southern white rhinoceros (SWR) population is not currently self-sustaining, primarily due to poor or absent reproduction of captive-born (F1+) females. In this study, we investigate the role of dietary phytoestrogens in this reproductive phenomenon by characterizing activation of SWR estrogen receptors (ESRs) 1 and 2 by diet items from nine North American institutions and comparing female SWR fertility to total diet estrogenicity. Of the diet items tested, alfalfa hay and soy and alfalfa-based commercial pellets were found to be the most potent activators of SWR ESRs. In contrast, most grass hays tested were not estrogenic. The estrogenicity of total diets varied across the institutions surveyed and the degree of diet estrogenicity was positively associated with the percentage of the total diet comprised by pellets. Comparisons of fertility records of the institutions surveyed showed no significant relationship between diet estrogenicity and fertility for female SWR conceived or born in the wild (F0). However, for F1+ females, there was a significant negative relationship between institutional diet estrogenicity and fertility. Taken together, these data suggest that developmental exposure to phytoestrogens may be the cause of poor fertility in captive-born female SWR. Whether the low fertility of the current population of captive-born female SWR is permanent or can be reversed by removing phytoestrogens from the diet remains unclear. However, our findings suggest that in order for the SWR population to become self-sustaining, the development and feeding of low phytoestrogen diets should be strongly considered.

Differences in fecal androgen patterns of breeding and nonbreeding kori bustards (Ardeotis kori).

To better understand breeding conditions to promote reproduction in captive kori bustards, fundamental endocrine studies measuring fecal androgen metabolites in male and female kori bustards were conducted. Feces collected weekly from males and females were analyzed for testosterone using enzyme-linked immunoassay. Results from adult males (n = 5), adult females (n = 10), immature males (n = 10), and immature females (n = 10) revealed seasonally elevated testosterone concentrations in fertile, but not nonfertile adult males and females (P > 0.05). Adult females that were not maintained in a breeding group, or that did not produce eggs, did not demonstrate increases in testosterone compared to egg laying counterparts. In males, but not females, seasonal testosterone increases were accompanied by weight gain. Peaks in male fecal androgen metabolites ranged from 10- to 22-fold higher than nonbreeding season (181.5 ± 19.1 vs. 17.0 ± 0.94 ng/g; P < 0.05). Mean breeding season values for adult males were 83.6 ± 6.1 ng/g vs. nonbreeding season values of 12.3 ± 0.73 ng/g (P < 0.05). In females, average breeding season testosterone concentrations were approximately 4-fold higher than nonbreeding season (55.9 ± 6.0 vs. 14.5 ± 1.8 ng/g), with peaks 10- to 30-fold higher. Results show that noninvasive fecal androgen metabolite analysis can provide a means of predicting fertility potential of male and female kori bustards and might be utilized to assess effects of modifying captive environments to promote reproduction in this species.

Fecal corticosterone concentrations and reproductive success in captive female southern white rhinoceros.

Prolonged or frequent secretion of adrenal glucocorticoids in response to aversive stimuli can negatively impact reproduction. Because female southern white rhinoceros (Ceratotherium simum simum) reproduce poorly in captivity, we compared fecal corticosterone metabolite concentrations among parous, nulliparous, and adolescent females and examined social and physical aspects of the captive environment that might be related to differences in corticosterone metabolite concentrations. Aggression, dominance, sexual and play interactions, social group size and composition, enclosure size, and other housing characteristics were assessed though behavioral observations and review of historical and institution records. Concentrations of metabolized corticosterone in fecal samples were analyzed by enzyme immunoassay. The proportion of nulliparous females did not differ (p>0.05) between subordinate and dominant animals, and subordinates did not have a higher mean fecal corticosterone concentration than dominants (p>0.05). Of the behaviors examined, only the frequency of sexual play behaviors differed (p<0.05) between dominants and subordinates. Average corticosterone concentrations differed (p<0.05) across housing institutions but were not consistently elevated (p>0.05) for females housed in most of the environmental conditions assessed. Housing with a female companion known from adolescence, however, tended to be associated (p=0.06) with a lower mean corticosterone concentration than that when housing with a female companion introduced during adulthood or no female companion. Wild-caught females had a higher (p<0.05) average corticosterone concentration than captive-born females. Average corticosterone concentration did not differ (p>0.05) between acyclic and cycling, or nulliparous and parous females.

Preliminary evaluation of deslorelin, a GnRH agonist for contraception of the captive variable flying fox Pteropus hypomelanus.

BACKGROUND: This study was conducted to study the effects of a gonadotropin-releasing hormone (GnRH) agonist, deslorelin, on luteinizing hormone (LH), testosterone (males), semen characteristics and pregnancy in the variable flying fox Pteropus hypomelanus. STUDY DESIGN: Male (n = 3) and female (n = 5) bats received a 4.7-mg implant and were housed with untreated bats (eight females and three males, respectively). Plasma was collected twice monthly and analyzed for hormone concentrations, and semen was collected from untreated and treated males 1 month preimplantation, 3 months postimplantation and 4 months postimplantation. RESULTS: Administration of a GnRH challenge 1 month postimplantation showed an attenuated response in treated (n = 4), but not in untreated (n = 4), male and female bats. Plasma LH was lower in treated versus untreated males (p = .04), but not in females. Testosterone was lower in treated versus untreated males (p < .001). Spermic ejaculates were obtained from treated males, although no untreated females became pregnant during the 8-month study. One treated female became pregnant 6 months after implantation. CONCLUSION: Deslorelin is a useful and reversible contraceptive for P. hypomelanus.

Social and spatial relationships in captive southern white rhinoceros (Ceratotherium simum simum).

Although critical to the conservation of white rhinoceros, captive breeding has proven challenging because of the poor and irregular reproductive health of many captive rhinos, and social interactions may play a significant role. This research investigated the social and spatial relationships of two captive groups of southern white rhinoceros (Ceratotherium simum simum) by examining the frequency of companion changes, the number of space maintenance vocalizations made per hour by each reproductively mature female, and dominant/subordinate interactions. The observed captive rhinos did not change their companionships during the study. They exhibited space maintenance vocalizations and display greater than once per hour, particularly when feeding. Females housed with four calves on 0.033 km(2) exhibited space maintenance vocalizations more frequently (X+/-SE = 6.19+/-0.199/hr) than females housed with one calf and more space (0.06 km(2), X+/-SE = 0.55+/-0.182/hr) and females housed without calves and more space (0.65 km(2), X+/-SE = 1.90+/-0.086/hr). Wider separation of food piles and of females with young calves is suggested to reduce the interpreted spatial stress. The presence of a large number of rhinos in restricted captive space resulted in the formation of herds with dominance hierarchies that were enforced during competition for food and shade. The most subordinate rhino in each of the herds exhibited unusual behaviors such as dung-kicking and nonestrus urine squirting, and neither has ever reproduced. Suppression of subordinate rhinos might lead to social stress that could negatively impact reproductive success. Zoo Biol 26:487-502, 2007. (c) 2007 Wiley-Liss, Inc.