Infant survival is significantly impacted by dam- and management-related factors in zoo-managed Eulemur populations

Due to their potential impact on population growth, many studies have investigated factors affecting infant survival in mammal populations under human care. Here we used more than 30 years of Association of Zoos and Aquariums (AZA) studbook data and contraception data from the AZA Reproductive Management Center, along with logistic regression models, to investigate which factors affect infant survival in four Eulemur species managed as Species Survival Plans® in AZA. Across species, infant survival to 1 month ranged from 65% to 78%. Previous experience producing surviving offspring was positively correlated to infant survival in collared (Eulemur collaris), crowned (Eulemur coronatus), and mongoose (Eulemur mongoz) lemurs. Both dam age and previous use of contraception were negatively correlated to infant survival for collared lemurs, though our results suggest the latter may be confounded with other factors. Blue-eyed black lemurs (Eulemur flavifrons) were affected by birth location, suggesting differences in husbandry that may affect infant survival. These results can be used to assist in reproductive planning or to anticipate the likelihood of breeding success. Population managers may also be able to focus their reproductive planning on younger dams or those with previous experience to predict successful births. Future studies should seek to determine what aspects of previous dam success are most important to infant survival, investigate sire-related factors, and examine factors related to cause of death in infants that may lead to differential survival. Our hope is to present a framework that may be useful for investigating infant survival in other mammal species' breeding programs.

Women's experiences of infertility after the Holocaust

Nuremburg trial evidence demonstrated that Nazis sought methods of mass sterilization of Jewish women. Immediately upon arrival at the concentration camps, over 98% of women stopped menstruating. There has been minimal investigation as to the cause(s) of amenorrhea, beyond malnutrition and trauma. The major objectives of this article are to 1) provide an alternate hypothesis to explain women's amenorrhea, i.e., surreptitious administration of exogenous hormones to women; 2) detail survivors' reproductive histories so as to demonstrate long-term sequellae, especially pregnancy losses; 3) provide women's subjective narratives of the short- and long-term experience of reproductive losses; 4) link women's amenorrhea, subsequent primary and secondary infertility and the evidence for the hypothesized causal mechanism, i.e., the administration of sex steroids which might have led to both immediate and long-term reproductive impacts. We conducted telephone interviews from 2018 to 2021 with Holocaust survivors internationally in 4 languages. We collected 93 testimonies from female Holocaust survivors (average age 92.5) or offspring who could provide complete reproductive histories for survivors. The interviews focused on reproductive histories, including amenorrhea beginning in 1942-45, subsequent attempts to conceive, numbers of pregnancies, miscarriages and stillbirths. Ninety-eight percent of women interviewed were unable to conceive or carry to term their desired number of children. Of 197 confirmed pregnancies, at least 48 (24.4%) ended in miscarriages, 13 (6.6%) in stillbirths and 136 (69.0%) in live births. The true number of pregnancy losses is likely much higher. Only 15/93 (16.1%) of women were able to carry more than two babies to term, despite most wanting more children desperately. Amenorrhea among Jewish women arriving at concentration camps was too uniform and sudden to be effected only by trauma and/or malnutrition. Survivors' narratives and historical evidence suggest the role of exogenous hormones, administered without women's knowledge to induce amenorrhea as well as subsequent primary and secondary infertility.

Melengestrol acetate contraceptive implant use in colobus monkeys (Colobus guereza): Patterns through time and differences in reproductive potential and live births

Melengestrol acetate (MGA) implants are progestin-based reversible contraceptives used to manage fertility in zoo populations. Although it is recommended that MGA implants should be replaced every 2 years, the duration of efficacy has not been systematically evaluated in most species. Anecdotal reports for Old World monkeys indicate that reproduction may be suppressed longer if the implant is not removed. This study uses Guereza colobus monkey (Colobus guereza) as a model Old World monkey species to examine the effects of MGA implants on reproductive potential. In particular, we investigate whether the probability of reproducing (pR) and rates of stillbirth differ among (1) non-implanted females, (2) females who have had MGA implants removed, and (3) females whose implants were left in past expiration. We found no significant difference in pR between non-implanted and implant-removed groups, but when implants were left in past expiration, the pR was significantly lower than in other groups. Both parity and age significantly impacted pR for the non-implanted group (i.e., younger females and those who were parous increased pR), but neither were significant factors for the implant-removed group. Stillbirth rates were significantly higher post-contraception as compared with pre-contraception. These results support similar analyses in other taxa that show a shorter time to reversal after MGA contraception when implants are removed, making this a good contraceptive option for females likely to receive a breeding recommendation, especially when a more predictable time to reversal is important.