A practical approach to evaluation of fertility in the female gorilla

Abstract

Measurements of urinary estrogen, pregnanediol-3-glucuronide, and bioactive luteinizing hormone indexed by creatinine on a daily basis in female gorillas reflect ovarian function. The use of small urine samples obviates the need for capture, restraint, or isolation and provides the basis for a nonstressful evaluation of reproductive status or fertility. Initial attempts at artificial insemination have thus far been unsuccessful when the fertile period was predicted by urinary estrogen and pregnanediol-3-glucuronide evaluations. The cause of these failures cannot be attributed to any one factor, but hormone profiles suggest that insemination preceded ovulation by more than one week in both cases. The prolongation of the follicular phase in conjunction with both inseminations when compared to all follicular phase intervals in the same individual (30 and 32 vs 21.8 2 2.4 (mean * SE; n = 10) days, respectively) may indicate a delay of ovulation as a result of the physical manipulation of the female.

Sexual behavior and hormonal estrus cycles in captive aged lowland gorillas (gorilla gorilla)

“…Cycle lengths based on sexual behavior were as regular as those determined by hormonal data. For both Babs and the aged Alpha, cycle lengths based on hormonal data were consistent with previous reports for female gorillas under 35 [Nadler, 1980;Lasley et al, 1982].…”

“…Yet, with few exceptions, most work on reproductive aging in primates has focused on macaques [e.g., Graham et al, 1979;Small, 1984;Walker, 1995;Johnson & Kapsalis, 1998;Pavelka & Fedigan, 1999;Shideler et al, 2001]. Numerous cross-sectional reproductive hormonal studies based on one or two menstrual cycles in female apes have been conducted, but none of these included aged (Z35 years old) gorillas as their subjects [e.g., Nadler, 1975Nadler, , 1980Graham, 1979;Lasley et al, 1982;Mitchell et al, 1982;Dahl et al, 1987;Bellem et al, 1995;Takahata et al, 1995;Jurke et al, 2001a;Miyamoto et al, 2001].…”

Sexual and Hormonal Cycles in Geriatric Gorilla gorilla gorilla

“…Surprisingly, primatologists have investigated ape species markedly less well, though long lifespans, large body sizes, slow life history traits, and close taxonomic ties with humans may make them more suitable paradigms for research on reproductive aging in humans. Researchers have conducted numerous cross-sectional reproductive hormonal studies, but they are often based only on 1 or 2 menstrual cycles of nonaged female apes (Bellem et al, 1995;Czekala et al, 1991;Dahl et al, 1987;Graham, 1979;Jurke et al, 2001a,b;Lasley et al, 1982;Mitchell et al, 1982;Miyamoto et al, 2001;Nadler, 1975Nadler, , 1980Vervaecke et al, 1999). Available data from aged chimpanzees and bonobos regarding cycling at advanced ages have not yielded consistent results; some geriatric individuals cycle regularly, while others cease cycling in the years before death (Goodall, 1986;Graham, 1979;Jurke et al, 2000;Nishida et al, 2003).…”

Birth of a Western Lowland gorilla (Gorilla gorilla gorilla) following in vitro fertilization and embryo transfer

“…Analysis of urinary hormones for monitoring ovarian function in gorillas is an established procedure [Mitchell et al, 1982;Lasley et al, 1982] and was used in the present study as evidence that the menstrual cycles of 31 to 41 days were ovulatory. The PdG and E 1 G profiles for the pre-IVF cycles were consistent with previous studies, indicating peaks in the mid-luteal and mid-cycle phases, respectively [Mitchell et al, 1985;Bellem et al, 1995].…”