John K Hodges

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Adult male elephants periodically show the phenomenon of musth, a condition associated with increased aggressiveness, restlessness, significant weight reduction and markedly elevated androgen levels. It has been suggested that musth-related behaviours are costly and that therefore musth may represent a form of physiological stress. In order to provide data(More)
A radiometabolism study is described to provide the first comparative data on the time course, route, and characteristics of excreted [3H]cortisol metabolites in three nonhuman primates: the common marmoset (Callithrix jacchus), the long-tailed macaque (Macacafascicularis), and the chimpanzee (Pan troglodytes). A low dose (40-100 microCi) of 3H-labeled(More)
The aims of the present study were (i) to provide basic comparative data on the time course, route, and characteristics of excreted [14C]testosterone (T) metabolites in three nonhuman primates: the common marmoset (Callithrix jacchus), the long-tailed macaque (Macaca fascicularis) and the chimpanzee (Pan troglodytes) and (ii) to use this information to help(More)
The extent to which catharrine primate males are able to discern the fertile phase during the female ovarian cycle under natural conditions is still debated. In a recent study, we showed that wild male long-tailed macaques are able to detect the fertile phase, but the cues males used to assess female reproductive status remained unclear. In the present(More)
The role of sexual displays in mating strategies and their reliability in indicating the time of ovulation has given rise to multiple explanations in nonhuman primates. In order to discriminate among hypotheses, socio-sexual behaviors were recorded in a semifree ranging group of Tonkean macaques (Macaca tonkeana), together with sexual skin swelling volumes(More)
The aims of the present study were to (i) determine the relative abundance of the 5alpha-reduced progestins 5alpha-pregnane-3-ol-20-one (5alpha-P-3OH) and 5alpha-dihydroprogesterone (5alpha-DHP) and progesterone (P4) in African elephant feces and to establish improved fecal progestin assays for monitoring ovarian function; and (ii) describe longitudinal(More)
Estrone conjugates (E1C), pregnanediol glucuronide (PdG), and estriol (E3) in urine, and immunoreactive E1C, E3, pregnanediol (Pd), and progesterone (P4) in feces were determined along with records of perineal sex skin swelling throughout 7 nonconception cycles and 3 full-term pregnancies of 4 adult female bonobos (Pan paniscus). A typical preovulatory(More)
Ovarian cycles in catarrhine primates are uniquely characterized by prolonged periods of sexual activity in which the timings of ovulation and copulation do not necessarily correspond. According to current hypotheses of primate social evolution, extended sexuality in multi-male groups might represent part of a female strategy to confuse paternity in order(More)
Measurement of immunoreactive progesterone, pregnanediol and oestradiol in faeces collected throughout ovarian cycles in three species of callitrichid primates is reported. Faecal hormone concentrations were compared with plasma progesterone profiles during PGF2 alpha-controlled (n = 7) and natural (n = 8) cycles in Callithrix jacchus and Saguinus(More)
Musth in male African elephants, Loxodonta africana, is associated with increased aggressive behavior, continuous discharge of urine, copious secretions from the swollen temporal glands, and elevated androgen levels. During musth, bulls actively seek out and are preferred by estrous females although sexual activity is not restricted to the musth condition.(More)