RESUMEN
In multi-female multi-male group-living species, both sexes can copulate with diverse partners. According to the priority of access model, high-ranking males have higher access to females during their fertile phases than the lower-ranking competitors. However, when females' ovarian cycles are synchronized, dominant males are unable to monopolize all females, which gives a chance to lower ranking males to sporadically copulate and increase their likelihood to fertilize a female. Therefore, subordinate males perhaps show physiological characteristics allowing them to contend with the advantage that the dominant males already have. It was investigated if sperm counts, weight of the seminal coagulum, and testosterone levels showed any differences according to their social rank in male stump-tailed macaques. Testosterone levels increased linearly in relation to social rank (Pâ¯=â¯0.004). No evidence was found that in the first ejaculation dominant rank was positively related to sperm counts and weight of the seminal coagulum. In the second ejaculation a positive correlation between dominant rank and sperm counts and weight of the seminal coagulum was found (Pâ¯<â¯0.001). By the third ejaculation there was a negative correlation between sperm counts and dominant rank (Pâ¯<â¯0.001), but no variability in the weight of the seminal coagulum. The results showed that high-rank is related to better physiological conditions to sustain multiple ejaculations, thanks to having higher testosterone levels.
Asunto(s)
Macaca/fisiología , Semen/fisiología , Predominio Social , Espermatozoides/fisiología , Testosterona/sangre , Animales , Macaca/sangre , MasculinoRESUMEN
Macaca mulatta on Cayo Santiago (CS) were examined with intravenous glucose tolerance tests (IV-GTT) for evidence of abnormalities in glucose clearance and insulin secretion. About 10% of the 98 monkeys had impaired glucose clearance associated with impaired insulin secretion. Another 6% had either fasting or secretory hyperinsulinemia with slightly increased rates of glucose clearance, and 20% had low insulin secretion, but no significant changes in glucose clearance. Results were compared to those obtained with CS-derived monkeys tested at Sabana Seca (SS). Glucose clearance per amount of insulin secreted was 40% more effective among CS macaques than among those at SS. There were no differences in weight between impaired and control macaques on CS. Effects of genetics, physical activity, and food consumption can be studied among these macaques and results related to similar metabolic abnormalities in prediabetic and diabetic human beings.
Asunto(s)
Glucemia/metabolismo , Diabetes Mellitus Experimental/sangre , Insulina/sangre , Macaca mulatta/sangre , Macaca/sangre , Medio Social , Academias e Institutos , Animales , Diabetes Mellitus Experimental/genética , Prueba de Tolerancia a la Glucosa/veterinaria , Puerto Rico , Factores de RiesgoRESUMEN
The relationship between serum total cholesterol (STC) and social dominance rank was investigated in adult (greater than or equal to 5 year old) males of a single, naturally-formed free-ranging troop of rhesus monkeys (Macaca mulatta) on Cayo Santiago, Puerto Rico. Dominance rank, age and body weight were not correlated with STC, nor was rank correlated with age or body weight. The mean (+/- 1 SD) STC was 154.0 +/- 27.0 mg/dl. Seven of the 34 males sampled had STC levels (189.1 +/- 4.3 mg/dl) greater than 1 SD above the mean for all males. These monkeys did not differ significantly in age or body weight from each other or the remaining males in the study, but 5 of the 7 monkeys with high STC were high-ranking in the group and 7 of 8 monkeys with STC (115.6 +/- 5.8 mg/dl) 1 SD or more below the mean for all males were low-ranking. The difference was significant (p less than .05, Fisher's Exact Test).
Asunto(s)
Colesterol/sangre , Macaca mulatta/sangre , Macaca/sangre , Predominio Social , Animales , Conducta Animal , Masculino , Estrés Fisiológico/fisiopatologíaRESUMEN
La relación entre el colesterol sérico total (STC) y el rango social de dominio se investigó en machos adultos (>- 5 años) de una sola tropa formada en un ambiente fibre y natural de monos rhesus (Macaca mulatta) en Cayo Santiago, Puerto Rico. El rango de dominio, la edad y el peso corporal no se correlacionaron con STC, ni se correlacionó con la edad ni peso corporal. La media (ñ 1 SD) fue de 154.0 ñ 27.0 mg/dl. Siete de los 34 machos del muestreo tenían niveles de STC (189.1 ñ 4.3 mg/dl) mayores de 1 SD sobre la mediana para todos los machos. Estos monos no se diferenciaron significativamente en edad ni peso corporal entre ellos ni de los otros machos del estudio, pero cinco de los siete monos con STC alto eran machas de alto rango en el grupo y siete de ocho monos con STC (115.6 ñ 5.8 mg/dl) 1 SD o más por debajo de la media para todos los machos eran de bajo rango. La diferencia fue significativa (p<.05, "Fisher's Exact Test")