Friday, 17 February 2012

New World Primates 7: Love Monkeys

It is a few days late, but it is appropriate that Valentine’s week should feature one of the most closely affectionate of the monkeys, the Red Titi Callicebus cupreus. Bristol currently has a pair, but people often walk past their enclosure because they are also among the most secretive of monkeys. Their preferred habitat is dense tangles of vines, edge forests, bamboo groves and similar habitats, where they can go about their lives undisturbed. Unlike many other species, they avoid other primates and do not move around in mixed associations, instead pursuing their lives in small family groups of a pair plus up to three offspring.

As with most larger primates, they specialise in fruits but will happily eat anything with food value, including insects and leaves.. They have not as far as I am aware been seen feeding on gum or sap, but almost anything else is on the menu – an escaped animal in the US was observed to eat acorns among other things, so nuts are probably also part of the wild diet. Unfortunately our female has diabetes, a common complaint in captive primates, and is probably due to being fed commercial fruit with a high sugar content compared to the fruits usually eaten by wild animals, especially mammals. These days the sugar content of the diet of all frugivorous mammals in captivity is carefully watched, but fruits similar to those eaten in the wild are quite hard to provide, so artificial diets are becoming increasingly common.

Secretive animals like titis do not make especially good exhibit animals, and as a result the captive population of tits is small. Of the numerous species, there are only two with even potentially self-sustaining captive populations, and the AZA in the US and EAZA in Europe have decided to focus on one each. In Europe the species is C.cupreus cupreus, a subspecies of the Coppery Titi, whereas in the US it is C. donacophilus, the White-eared Titi.

C.donacophilus with tails entwined
As with many South American primates, males are heavily involved in infant care. The infant transfers to the male for transport shortly after birth, and until it can move independently is only returned to its mother for feeding. Sometimes older juveniles will also help carry their siblings, but this has not been observed very often, unlike in callitrichids where it is standard behaviour. Young remain with their families until 2 or 3 years old, then disperse to find mates of their own. Once paired, male and female are extremely close, spending long periods of time in physical contact and appearing highly agitated if separated from each other. Communication is maintained in thick vegetation by a series of very complex vocalisations, whose meaning is not yet elucidated.

There have been very few studies of predation on wild titis, but birds of prey are likely to be the major enemy. Large snakes such as boas would certainly take them, but medium sized carnivores such as Tayra and Margay could also take them, especially at night when they are asleep in vine tangles or tree holes.
As with all forest animals, the biggest human threat to titis is deforestation. As long as the removal of trees is not too excessive however titis can cope with disturbed habitats quite well, as the dense vegetation of regenerating abandoned farmland suits them. Even so, at least one species, the Blonde Titi C. barbarabrownae is classed as Critically Endangered. Its wild population is estimated as perhaps as few as 250 animals, which makes it even rarer than the famous Lion Tamarins which live in the same Atlantic Rainforest of Brazil.

I mentioned that there were numerous species of titi earlier. As with many primates, it now appears they are far more diverse than was first thought, and where there were once believed to be only 4 or 5 species, the count today is probably nearer 20. As the different species occupy different forests, from rainforest with seasonal flooding to dry woodland edge in some species, there is an urgent need for studies into their ecology, which may be more variable than we think.

Next week, a dietary specialist, the White-faced Saki

(images from wikipedia)

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