Primates - part I
We can very conveniently divide the primates into two groups (suborders).
Strepsirrhini and Haplorrhini
Generally, we could say that the Strepsirrhini include the more primitive forms such as lemurs, galagos and lorises.
Best distinguishing character is probably a comb made of front incisors that is used for grooming.
Haplorrhini (with some exceptions) include what most people think about when they think of monkeys and apes.
All primates have certain characteristics that they share (we usually don't delve this deeply into characteristics like this, but this group includes us!)
Table 12-1 - discuss.
Primate ancestors can be tracked back about 56 million years (fossils), though other techniques seem to indicate the origin can be tracked back further.
Seven familes in the Strepsirrhini:
Five “lemur” families, galagos, and lorises. Some of these we'll only cover briefly.
The lemur families underwent tremendous radiation in Madagascar.
Family Cheirogaleidae - mouse/dwarf lemurs.
Generally small arboreal lemurs that eat pretty much anything.
May hibernate during colder seasons.
Generally solitary, but will nest together.
Population densities can get fairly high (up to 700 individuals/km2)
Family Lemuridae - “true” lemurs.
Includes some better known species such as the ring-tailed lemur.
Ring tailed lemurs:
Live in female dominant groups, but males compete with each other for females (may use something your text calls “stink fights”)
(Female doesn't always choose winner). Lemuridae may be terrestrial, semi-arboreal, or arboreal.
A group of lemurs known as bamboo lemurs (two genera, three species) live only in small areas of bamboo found in rainforests.
Present an interesting example of resource partitioning (eat different parts or ages of the bamboo).
(Some can tolerate large amounts of cyanide that the bamboo puts into new shoots).
Family Lepilemuridae
“Sportive” lemurs.
Eight species of nocturnal leaf eaters.
Like rabbits, will eat their feces since their food is of such poor quality.
Family Indriidae
Woolly lemurs, sifakas, and the indri.
Indri's are the largest living lemurs.
Live in monogamous pairs and may move around in small family groups when young are there.
Has loud vocalizations to help maintain boundaries.
Others live in larger groups and are not monogamous (sifaki's).
Females are again dominant (seems normal in lemur species).
Generally diurnal except for the avahi (also monogamous).
Family Daubentoniidae
Aye-aye - found only in Madagascar.
Nocturnal, mostly insectivorous.
Forage by tapping wood, listening for insects, and if found using a very long third digit to extract insects (can also use teeth to tear up wood).
May cover large distances on the ground, but seem to spend most of their time in trees. Family Lorisidae
Africa and southeast Asia.
Nocturnal omnivores.
Seem to have unusually slow metabolism.
Family Galagidae
Galagos - occur in Africa. Also known as bushbabies.
Eat almost anything, including tree resin.
Apparently this is an adaptation to survive the dry season.
Are well known for leaping large distances.
Have numerous vocalizations that help in communication.