Female Western Lowland Gorilla Research Articles

Dimensions of the Foot Muscles in the Lowland Gorilla

We dissected the hindlimb of a female western lowland gorilla and determined the muscle dimensions (mass, fascicle length, and physiological cross-sectional area: PCSA). Comparisons of the muscle parameters of the measured gorilla with corresponding reported human data demonstrated that the triceps surae muscles were larger and had more capacity to generate force than the other muscle groups in both species, but this tendency was more prominent in the human, probably as an adaptation to strong toe-off during bipedal walking. On the other hand, PCSAs of the extrinsic pedal digital flexors and digiti minimi muscles were larger in the western lowland gorilla, suggesting that the foot, particularly the fifth toe, has a relatively high grasping capability in the lowland gorilla.

Lumbar Diskectomy In A Human-Habituated Western Lowand Gorilla

The case of lumbar laminectomy in an adult female western lowland gorilla with herniated lumbar disk is presented. The gorilla had developed progressive lower extremity weakness, which progressed to the inability to walk. MRI showed a herniated disk at the L1-L2 level. Surgical laminectomy resulted in complete resolution of symptoms. Prompt diagnosis and treatment, with cooperation between veterinarians, neurosurgeons and anesthesiologists was required in this case to result in a favourable outcome. The differences in the human and gorilla spine are presented

Proximity patterns of female western lowland gorillas (Gorilla gorilla gorilla) during the six months after parturition.

Studies of wild mountain gorillas have demonstrated strong preferences among new mothers for the silverback. Protection against infanticide has been theorized to be the primary cause for this attraction. We examined social partner preferences in captive western lowland mothers during the 6 mo after parturition and found that juveniles and females were the primary members of the new mothers' social network. Mothers spent significantly more time in close proximity with both of these subgroups than with the silverback. Proximity patterns changed over time: new mothers spent more time near females in the month after parturition than in the month prior to parturition, and spatial proximity increased again in months 2-6 postparturition. These findings differ from those reported for wild mountain gorillas, which may reflect the lack of infanticide risk in captivity. Given current hypotheses that infanticide may be a limited in western lowland gorillas, the social partner preferences observed here may be indicative of patterns in wild populations.

Reproductive intervals in captive female western lowland gorillas with a comparison to wild mountain gorillas.

A wide disparity between parturition and the resumption of sexual behavior in two captive female western lowland gorillas prompted an investigation of interbirth intervals (IBIs) in captive western lowland gorillas that had reared their infants. To determine reproductive intervals, a questionnaire was sent to 30 institutions (19 in North America and 11 in Europe) that maintained captive females who had previously reared or were currently rearing their offspring. Information compiled relates to the length of reproductive intervals, including lactational anestrus, estrous behavior to conception and from parturition to conception, and IBIs. These data are compared with studies published on wild mountain gorillas. The median IBI for 16 mothers still rearing infants when their next conception occurred was 4 years (range 2.33-6.42 years, N = 16). Twenty-one percent of the 52 mothers in this study are no longer reproducing. The mean time without reproduction since separation from their last offspring was 5.43 years. This study indicates that the length of IBIs, lactational anestrus, and intervals from parturition, separation, and estrous behavior to conception compare closely with findings for wild populations. Incompatibility between partners may be a factor limiting further reproduction in some captive mothers in this study.

Female Primate Sexual Behavior and Conception: Are There Really Sperm to Spare? [and Comments and Reply

Female Primate Sexual Behavior and Conception: Are There Really Sperm to Spare? [and Comments and Reply