why are most primates diurnal
shift from solitary to grou protection (social skills)
activity shift due to environmental factors (day length/weather) affecing food availability
diurnal vs nocturnal
nocturnal= active at night (most lemurs); thought to be ancestral condition
diurnal= active in day (most primates)
cathemeral?
both active in day and night (lemurs)
-> also known as metaturnality
taxa examples of cathemerality
common brown lemur (E. fulvus fulvus) shift between nocturnal + diurnal states depending on food availability
mongoose lemur (goes from nocturnal to diurnal throughout year seasonallly)
gregarious
group size= spending time in a social group (common)
solitary primates
rare; usually with other individuals for mating/infanct dependency
what is the ‘degree of cohesiveness’
whether group members remain together on a routine basis
activity budget
how primates delegate time to essential activtieis:
- reproductive
- survival
- sociality
split between:
- energy minimizers
- energy maximizers
energy minimizers: diet?
usually folivorous + within a territory/habitat
more time devotd to resting
less energy devoted to travelling
rely on leaves as harder to digest
energy maximizers; diet?
usually fruit/high-value food (meat)
more time devoted to travelling/searching for food patches
disperesed territory
what is diet influenced by
seasonal fluctations in availibty of preffered food
types of primate diets
insectivirous
faunivoroes
frugivorous
folivorous
types of primate habitats
semi-terrestial (arboreal + ground travelling)
arboreal
pros + cons of arboreality
more at risk of injury from falling
but safer from predators
pros + cons of semi-terriestiality
more at risk to predators in low visibility
mixed travelling= different food accessisble
day range vs home range
day range= travel within a day
hoem range= area where a primate lives
explain territoriality
territorial primates; defend an entire resources area from other species/consepectivis whereas non territorial primates tend to have their home ranges overlap
territorality—> isnt fixed (small and larger home ranges; i.e. a tree in a forest)
qualities unique to primates: body
- oppossoble big toe/prehensile hands
- flat nails on hands and feet
- locomotion in hind-limb dominants
qualities unique to primates” smell
- unspecialized olfactory sense reducded in idurnal primates (more focus on visual)
exeption: lemurs
qualities unique to primates: vision
- stereoscopic + binocular vision for 3D/depth
2. colour vision
stereoscopic vision
the ability to see things in three dimensions (3-D).
Stereoscopic vision is what allows for true depth perception.
binocular vision
seeing with two eyes that have an overlapping field of view.
This is essential to stereoscopic vision
qualities unique to primates: birth
females= smallet litters, larger gestations
extended juvenile period in children
qualities unique to primates: brain
larger brain to body ratio (neocortex ratio; white matter to grey matter)
primate dentition
2 insisors
1 canine
3 premolars
(two sets) 3 molars
body size ratio distribution according to diets?
insectivores < frugivorous< folivorous
why do small primates tend to eat more high energy foods?
smaller body size= higher metabolism= means more energy is lost therefore relative higher energy requirements
what must a primate diet do
- satisfy energy requirements
- provide specific nutrients
- minimize exposure to dangerous toxins
what is food important for
- basal metabolism
- active metabolism
- growth rate
- reproductive effeort (+ other energy rquirements)
folivorous primate adaptations and benefits
- larger body size/exended digestive tract
- more food in a given area (hence less energy expenditure/travel)= small home range
- ability to digest toxic leaves (special stomacts or cellulose enzymes)
examples of folivorous primates
mountain gorillas
colobines (b+ w colobus monkey)
cercopithecines (red howler monkey)
what is a primate?
a generalized order of mammal
specialized in ‘non specialization’ (flexible and behavioural plasticity)
trends of arboreality?/primate
pendadactlity (5 digits) flat nails tatcile sensive pads prehensility/grasping tendency towards erectness generalized denitition reduction of olfaction clavicle
mircosematic
‘small smellers; reliance on vision
macrosemantic
‘large smllers’; reliance on smell
types of locomotions
vertical climbing upright sitting bipedalism brachiation knuckle walking
clavicle
colalr bone; allows for flexible shoulder joints
primatology?
bridges anthropology and zoology
human evolution studies…
- reconstruction via fossils
- ethnic diversity
- living primates as evolutionary models
rhinarium
furless skin surface surrounding the external openings of the nostrils in many mammals. ( in strepsirhines)
dry nose animals
haplorhines; have no rhinarium