Clifford J. Jolly

Species, Subspecies, and Baboon Systematics

The baboons of the genus Papio [excluding the gelada (Theropithecus) and (pace Delson, 1975), the mandrills, and drills (Mandrillus)] comprise a cluster of para-patric populations spread across most of the Ethiopian faunal zone. The present paper uses baboon diversity to explore some aspects of species definition and diagnosis, without attempting a comprehensive revision of the group or an exhaustive exploration of the species concept. The baboons are well suited to this purpose, because the various phenotypically distinct “forms” (which I call subspecies) have some but not all of the attributes commonly used to define one or another variant of the species concept. Another advantage is their quasi-continuous distribution, mostly undivided by extrinsic barriers that would avoid the problem of delineating natural units yet including some populations that are geographically isolated but not phenetically distinct, which illustrate the problems of definition raised by extrinsic isolation.

Growth, development, and sexual dimorphism in vervet monkeys (Cercopithecus aethiops) at four sites in Kenya

Body weight and ten body segment measurements were collected from 367 wild-trapped vervet monkeys (Cercopithecus aethiops) in central and southern Kenya. The animals represent between 70 and 95% of the animals in each of 30 troops at four geographical locations separated by 80 to 380 km. The capture sites differed in altitude, mean annual rainfall and temperature. Two questions are addressed: (1) what are the differences in male and female growth patterns, and (2) what is the relationship between size, climate, and availability of food? Each animal was assigned to an age class based on dental examination. Means for all variables do not diverge for males and females from birth to age class 4 (15-18 months). After this, male and female growth rates diverge. This sexual dimorphism in growth pattern may reflect timing of entry into the reproductive community. A nested analysis of variance (ANOVA) was employed to compare sites, groups within sites and individuals within groups. Statistically significant differences between sites in body weight and body segment measurements are found for adult females. Except for tail length, these differences do not follow Bergmanns or Allens Rules correlating size differences and temperature, but rather may reflect proximity to cultivated areas or tourist lodges with greater access to human food.

Sexual transmission of SIVagm in wild grivet monkeys

This study reports the prevalence of simian immunodeficiency virus and the relationship of serostatus to age and sex among a wild population of Ethiopian grivet monkeys (Cercopithecus aethiops aethiops). Seropositivity paralleled patterns of sexual activity, being nearly universal in females of reproductive age, and absent in all males except those that were fully adult. One female seroconverted between two capture seasons at an age consistent with first breeding. Our findings support a predominantly sexual mode of transmission among SIVagm infected grivets.

Conservation Implications of Hybridization in African Cercopithecine Monkeys

Numerous field reports of hybrid monkeys and documented cases of persistent hybrid zones suggest that natural hybridization is common among African cercopithecines. Both theoretical considerations and a review of cases lead us to conclude that parapatric hybridization among closely related allotaxa is a widespread, usually natural process whose incidence may be modified by human influence. Sympatric hybridization, between species ecologically distinct enough to have overlapping ranges, is rarer, and in monkeys tends to occur in settings where natural or anthropogenic habitat edges restrict migration and hence access to unrelated conspecific mates. Although sympatric hybridization occurs in the absence of human disturbance, and may even have been a creative force in cercopithecine evolution, anthropogenic habitat fragmentation may increase its incidence. Hybridization with a more abundant form may increase the level of threat faced by a species whose numbers and range have been severely restricted, either naturally or artificially.

Mitochondrial evidence for the hybrid origin of the kipunji, Rungwecebus kipunji (Primates: Papionini)

Common baboons (Papio), gelada baboons (Theropithecus) and baboon-mangabeys (Lophocebus) are closely related African papionin monkeys. In 2005, the species Lophocebus kipunji was described from relict montane and submontane forests in Tanzania, based upon a single specimen and observations of living animals. Its initial assignment to Lophocebus was based on its overall morphology, but subsequent genetic studies suggesting that it was sister taxon to common baboons (Papio) led to its generic separation, as Rungwecebus. As a mangabey-like sister-taxon to Papio, Rungwecebus could be interpreted either as an arboreal derivative from a more terrestrial, baboon-like ancestor, or as a survivor of a mangabey-like common ancestor of the Lophocebus-Papio-Theropithecus clade. Here, we present a new, strongly-supported, mitochondrial DNA (mtDNA) phylogeny that includes Papio baboons from populations geographically close to the kipunji. Rather than supporting sister-taxon status, the new phylogeny not only situates the kipunjis mtDNA among Papio haplotypes, it clearly assigns it to a mitochondrial clade including geographically adjacent yellow baboons (Papio cynocephalus). This relationship suggests either that the kipunji is descended from a yellow baboon, and has converged on a mangabey-like morphology, or, much more likely, that it originated by hybridization between Papio cf.cynocephalus females and Lophocebus sp. males, about 0.65 Ma. We believe this to be the first case among mammals in which a natural occurrence of inter-generic hybridization can be shown to have resulted in a new, distinct, long-surviving taxon. More such cases can be anticipated as molecular evidence accumulates.

CSF monoamines, age and impulsivity in wild grivet monkeys (Cercopithecus aethiops aethiops).

Brain monoaminergic activity has been associated with behaviors, such as impulsive risk-taking, that tend to peak during adolescence in humans and nonhuman primates. This study was designed to assess natural variation in monoamine neurotransmitter metabolism in relation to age and behavioral impulsivity in grivet monkeys (Cercopithecus aethiops aethiops) living in their native habitat and subject to natural ecological pressures. Cisternal cerebrospinal fluid, collected from 22 animals living in the Awash National Park, Ethiopia, was assayed for the major metabolites of serotonin (5-hydroxyindoleacetic acid, 5-HIAA), dopamine (homovanillic acid, HVA) and norepinephrine (3-methoxy-4-hydroxyphenylglycol, MHPG). Concentrations of HVA declined significantly from one year of age to older adulthood. Further, a significant curvilinear relationship was identified between age and the 5-HIAA/HVA ratio, with the trough coinciding with the period of adolescence. Finally, behavioral impulsivity, as measured by re-entering baited traps a second time after the animal had already been captured and sampled for CSF, was related to lower levels of MHPG. The results suggest that normal variation in central monoaminergic activity may have functional consequences in wild populations.

Kinda baboons (Papio kindae) and grayfoot chacma baboons (P. ursinus griseipes) hybridize in the Kafue river valley, Zambia

The ranges of small kinda (Papio kindae) and much larger grayfooted chacma (P. ursinus griseipes) baboons adjoin in the Kafue National Park, Zambia. In a visual survey of baboons at 48 sites in the Kafue River drainage we found that, contrary to previous reports, groups at the species interface near the town of Ngoma are phenotypically diverse and presumably formed by multigenerational hybridization. Mitochondrial and/or Y‐chromosome genetic markers from fecal samples (N=164) collected at 29 sites support this conclusion. Groups with phenotypic signs of a history of hybridization also had taxon‐specific mitochondria and Y‐haplotypes from both parental species. Although the distribution of mitochondrial haplotypes largely mirrored that of external phenotypes, a significant proportion of male specimens from grayfoot as well as hybrid groups carried kinda Y‐chromosomes, and kinda Y‐chromosomes were involved in all observed cases of mitochondrial/Y‐chromosome discordance. These observations are consistent with, though they do not prove, a population history in which the range of chacmas and the hybrid zone have advanced at the expense of the kinda range. They also suggest that, unexpectedly, kinda male×chacma female matings are much more common than the reciprocal cross in the ancestry of hybrids. We suggest that distinctive male kinda behavior and the “juvenile” appearance of kinda baboons of both sexes, perhaps combined with obstetric difficulties of a small kinda female carrying the large offspring of a chacma male, may account for this bias. Am. J. Primatol. 73:291–303, 2011.

Migration of male hamadryas baboons into anubis groups in the Awash National Park, Ethiopia

Among “savanna” baboons, males are the dispersing sex, and females are philopatric. Despite clear evidence for migration of adult males at Erer-Gota, Ethiopia (Abegglen, 1984), it is generally believed that a different pattern-dispersal only by female transfer-is found in hamadryas baboons,Papio hamadryas hamadryas (Pusey and Packer, 1987; Pusey, 1988; Stammbach, 1987). Since the late 1960s, there have been isolated observations of hamadryas males migrating into anubis groups in the Awash National Park, Ethiopia (Nagel, 1973; Kawai and Sugawara, 1976; Sugawara, 1982). Since 1983, we have observed 11 individually identified adult hamadryas immigrants in four anubis groups above the Awash Falls and have trapped and tagged 9 of them. One subadult male was also captured and marked. Repeated visits to the study site allow us to document long-term residence of these “cross-migrant” males in their host groups. The longest-resident male has been in the same group for 5 years or more; a conservative estimate of the average length of residence is 3 years. We estimate that 25 hamadryas males have moved into this ozne over the last 15 years. Although larger than the hamadryas males captured in 1973, all but one of our cross-migrants appear phenotypically hamadryas. By comparing, the ages of our cross-migrants with Abegglens account of the typical hamadryas male life-history, we have found that the adult hamadryas males seem to immigrate at ages consistent with having left their

SIVagm incidence over two decades in a natural population of Ethiopian grivet monkeys (Cercopithecus aethiops aethiops)

Abstract: The incidence of SIVagm seropositivity in a natural population of Ethiopian grivet monkeys (Cercopithecus aethiops aethiops) is investigated using plasma samples collected in 1973, and shown to be similar to that reported from the same population in 1990–91. Results tend to support our previous conclusions: endemic SIVagm has little or no impact on the survival of wild grivet monkeys, and the virus is transmitted almost always by sexual contact, occasionally by trauma, and rarely if ever maternally. Small differences between 1973 and 1990–93 suggest that the stress of drought years may raise the incidence of traumatic transmission, and temporarily depress transmission by sexual activity, in this population.

Vertebrate faunas from the Awash Group, Middle Awash Valley, Afar, Ethiopia

ABSTRACT We present a preliminary report on vertebrate faunas from the Middle Awash Valley in the Afar Depression, from the newly described Adu-Asa, Sagantole, Matabaietu, and Wehaietu Formations. These units, together with the well-known hominid-bearing Hadar Formation and the Chorora Formation, comprise the Awash Group, which is over one kilometer thick, spans the late Neogene, and contains vertebrate fossils throughout. Significantly, periods are represented—the late Miocene to early Pliocene and Middle to late Pleistocene—that are poorly or incompletely known elsewhere in East Africa. At least 24 mammalian families and 170 species are represented in the Awash Group. In the newly described stratigraphic units, faunal change is documented for a number of mammalian groups. This is especially true for Proboscidea, specifically anancine gom-photheres (Gomphotheriidae: Anancinae) and elephants (Elephantidae: Stegotetra-belodontinae and Elephantinae), the Artiodactyla, particularly suids (Suidae), bovids (Bo...