Question

Choose TWO of the specimens at this station to examine, sketch/diagram and label/describe. Be sure to label important features of the skull, describe their dentition/diet, habitat, note anyspecific adaptations to obtain food and/or to avoid predators, etc. (Consider the ecology, ie how is the species interacting with other species and the environment)

-Black and White Colobus skull

-Patas Money skull

-Vervet or Green Monkey skull

- Mandrill skull

-Baboon skull

Answer 1

Answer a)Black and White Colobus skull

The skull is prognathous, that is, the lower jaw projects beyond the upper. The orbits are relatively small and oval with narrow superciliary ridges. A postorbital bar forms a plate on the side of the skull separating the orbit from the temporal fossa. The nostrils are more or less lengthened by an extension of nasal skin, and the nose nearly touches the mouth.

The molar teeth have high pointed cusps, and the inside of the upper molars and the outside of the lower molars are slightly convexly buttressed. The enamel on the inside of the lower incisors is thick, and there is a lateral process on the lower second incisor.

Diet

Black colobus monkeys are herbivores and feed predominantly on seeds. Their robust, flat teeth allow them to chew tough seeds easily. This diet means that the species plays an important role as seed dispersers in the ecosystem. Black colobuses also eat large amounts of leaves, in particular, lianas, as well as flowers, buds and unripe fruits. Unlike most primates, Colobus monkeys have multi-chambered ruminant stomachs which allow them to easily digest these leaves. Younger leaves and seeds are preferred, as these are rich in nutrients and contain lower amounts of digestion-inhibiting compounds such as tannin. However, the black colobus monkey can withstand high levels of these poisonous compounds and can, therefore, eat food that is undigestable to other colobus monkeys. This means they can live in areas unoccupied by other species. Black colobus monkeys have also been observed eating soil, which may be to ensure that they have enough minerals such as sodium in their diet.

Habitat

The black colobus monkey is found in Equatorial Guinea, south-west Cameroon and central and north-western Gabon. Small populations may also occur in the north of the Republic of the Congo. The subspecies C.s.satanas is only found on Bioko Island, off the coast of Cameroon. The distribution of the black colobus has decreased dramatically - the species is now rare or absent in some areas of its range due to its habitat being destroyed for logging. Black colobuses are known to live at low densities, but there is currently no total population estimate for the species. One of the largest remaining populations of the species, consisting of 50,000-55,900 individuals, is found in Lope Reserve, Gabon. Other remaining large populations are found in the Foret des Abeilles in central Gabon and Douala-Edea Reserve in Cameroon.

The black colobus is an arboreal species that lives high in the canopy of the dense rainforest and occasionally coastal sand dune or wooded meadows. Black colobuses are unable to survive in the secondary forest that has re-grown after a major disturbance such as logging and therefore tend to avoid areas populated by humans. The black colobus cannot be bred in captivity due to the food and habitat it requires.

Their habitats include primary and secondary forests, riverine forests, and wooded grasslands; they are found more in higher-density logged forests than in other primary forests. Their ruminant-like digestive systems have enabled these leaf-eaters to occupy niches that are inaccessible to other primates.

Colobuses live in territorial groups of about nine individuals, based upon a single male with a number of females and their offspring. Newborn colobuses are completely white. Cases of allomothering are documented, which means members of the troop other than the infant's biological mother care for it.

Colobuses are important for seed dispersal through their sloppy eating habits, as well as through their digestive systems. They are prey for many forest predators and are threatened by hunting for the bushmeat trade, logging, and habitat destruction.

Answer b)Patas Money skull

HABITAT

The patas monkey avoids dense woodlands and lives in more open savanna and semi-deserts. The patas monkey has a remarkably high reproductive rate, perhaps as an evolutionary response to the high adult mortality rates associated with this strongly terrestrial lifestyle.

DIET

The patas monkey feeds on insects, gum, seeds, and tubers, a diet more characteristic of much smaller primates .

Alarm cells

Patas monkeys have several distinct alarm calls that warn members in the group of predators. Different alarm calls are given by different group members (i.e. adult females, adult males, juveniles, etc.) and certain alarm calls are distinctive of different types of predators. Unlike other primates, patas monkeys rarely take refuge from predators in trees. This is most likely the due to the relatively sparse tree cover in patas monkey habitats. While patas monkeys usually run on the ground away from predators, individuals have been observed to attack predators such as jackals and wildcats. This behavior has been observed in both males and females .