PRIMATE ECOLOGY

Geographic range:≤40 N & S latitude

I. PRIMATE HABITAT TYPES

A. FOREST CLASSIFICATION

Most primates inhabit forestsThey can be categorized by:

1. AGE/STRUCTURE Primary

Undisturbed Muriquis

Secondary Regenerating, successional Santa Rosa

Recently disturbed Fires, anthropogenic activities Some species adapted Even urban Langurs, macaques (crop

raiders), marmosets (tree plantations)

Edge Some callitrichines

2. TYPEClimate/latitude

Temperature/rain e.g. tropical, temperate, dry

Species composition e.g. Dipterocarp forests of SE Asia

Altitude e.g. lowland, montane, cloud

B. PRIMATE BIOMES

Tropical rainforest

Evergreen forest

Semi-evergreen to dry

Temperate forestsome macaques and colobines

Riparian forest

Swamp forestAllen’s swamp monkey, orangs

Mangrove forest

Savanna/woodland

Baboons

Scrub forest Acacia scrub

Grassland

II. ECOLOGICAL NICHE

Niche requirementsNiche partitioning

A. REQUIREMENTS / ENVIRONMENTAL FACTORS

Need enough resources and the space to contain them

Some species have more specific requirements than others and are more vulnerable, e.g. pitheciines

Others are more adaptable Howlers, langurs, macaques

B. NICHE PARTITIONING

Text: e.g. Makoku, Gabon 5 lorids 10 monkeys 1 ape

Size Substrates

Diet Howlers vs spiders –

plant categories 3 sympatric bamboo

lemurs - plant parts Foraging habits – squirrel vs

capuchins (Polyspecific associations)

Level Timing – nocturnal species

III. ABIOTIC AND BIOTIC FACTORS THAT AFFECT PRIMATES

A. ABIOTIC FACTORS

1. Space 2. Sleeping sites3. Climate4. Water & Minerals

1. SPACE

Tied to Group/population size (biotic factor) Other sympatric species

Home ranges related to available space/resources and group size

2. Sleeping sites

I. Trees (biotic but space) Height Particular architecture/species Insect repellent properties Examples: howlers and vervets

II. Holes/tangles for galagos, callitrichines

III. Cliffs – savanna, Hamadryas, and gelada baboons

3. Climate Rainfall, humidity, solar energy, wind Within- and between-year variability Food availability

Home range use/travel Energy available for activity

Seasonal fluctuations in activity Rain/heat may impede activity Hibernating species

Parasite load

4. Water and minerals Water – plants and animals Soil

Plants Consumption - geophagy

Trace minerals Aid to digestion –

interfere with tannins Clay – kaolin – binding

agent Salt licks Gums for calcium (biotic)

Colobus eating charcoal

B. BIOTIC FACTORS

1. Food species2. Other animals/organisms

1. Food Abiotic factors affect food availability at all levels

FOOD CHAIN: plants →1°consumers→2 °consumers Intra- and inter-year climatic fluctuations (millipede

boom, Lonchocarpus, Chicle fruit) Biotic factors

Competition – plant and animal foods Group members Conspecifics Other species

Primates – similar niche requirements Other spp – e.g. leaf cutter ants

2. ANIMALS/ORGANISMS

A. MatesB. Group membersC. CompetitorsD. Polyspecific associationsE. PredatorsF. Pathogens

a. MATES

Availability Numbers and distribution

Competition Within- and between-group 1-male groups –

High variation in reproductive success

b. MEMBERS OF SOCIAL GROUP

Competition for all resources

Support network Within-group and

between-group competition/ aggression

Dominance hierarchy

c. COMPETITORS Within-group: All resources Conspecifics: While compete due to identical niche

requirements, maintain at least core area Congeners: Close niche requirements but often

allopatric Other primates: Similar niche requirements Other species (e.g. my monkeys)

Coatis, guans, parrots, leaf cutter ants… in tree

d. POLYSPECIFIC ASSOCIATIONS

Primate↔primate, primate↔bird (use cues)

Benefits Foraging success Predation

Increase vigilance Dilution effect

Costs Competition – Text e.g.’s decreased foraging efficiency Increase apparency and risk of predation

Capuchins/squirrel monkeys, other e.g.’s? Guenons, guenons-swamp monkeys, guenon/colobus,

tamarins, Goeldi’s/tamarins, lemurs

e. PREDATORS

Strong influence, especially small primates

Terrestrial/arboreal Aerial Can affect access to

resources, e.g. water in dry season

f. PATHOGENS Density dependent diseases/parasites

Insects Hosts - botflies Vector borne illnesses -

malaria Human pathogens - TB Health of population and

resistance to disease contingent on abiotic and biotic factors

Climate Habitat/forest level

Fecal pathogens higher in understory

IV. HOME/DAY RANGE

Geographic range: genus vs. species

Home range Core Area Day Range Size/length tied to diet, resources,

body size, competitors… Howlers vs capuchins vs spiders

V. DEGREE OF TERRITORIALITYTerritorial pairs: gibbons, indrisFemale philopatryResource-defense polygyny

Defends area/food to attract females Male philopatric – chimps Capuchins

Spacing mechanisms Non-territorial – high degree of overlap

between groups but often defend core area

VI. ACTIVITY BUDGETS

How do animals spend their time amongst the various activities

FEED, REST, MOVE, SOCIAL Differences between and within species

Species-specific patterns Intraspecific variability

Seasonal Age, sex, reproductive condition, individual

differences

VII. DIET

A. DIETARY CATEGORIES

HERBIVORY Frugivory Folivory Gumnivory Gramnivory Nectivory

FAUNIVORY Animal matter Tarsiers

OMNIVORY Small-bodied primates –

frugivore-insectivores Larger-bodied primates –

frugivore-folivores

B. DIETARY ADAPTATIONS

Phylogenetic constraints Taxonomic group-level adaptations

Resource acquisition / processing /digestion

e.g. morphological and physiological adaptations Marmosets’ modified clawlike nails

& peg-like incisors/canines Aye-ayes’ middle fingers Colobines’ digestive/ detoxification

abilities Population - nature of resources Cultural adaptations

Macaques opening coconuts and washing food, chimps cracking nuts & dipping/fishing

C. NATURE OF RESOURCES

Density, abundance, distribution, availability Affects home & day range size, social

organization & within-group relations, degree of territoriality & between-group relations

Distribution in time and space Patchy – in space and time – e.g. fruit Random – e.g. leaves of species that are

edible Uniform – e.g. grass

Defensibility Correlated with abundance and

distribution in time and space

1. Where resources are

defensible:

Female cooperation Formation of matrilines Between-group competition e.g. macaques, baboons, patas, langurs Also within-group competition for resources

Results in differential reproductive success

2. Where resources are indefensible:

Females unrelated & not cooperating

Forage on own Solitary foragers, e.g.

nocturnal prosimians Ripe fruit specialists, e.g.

chimps, spiders

VIII. LIFE HISTORY CHARACTERISTICS

Important conservation considerations

Species-specific characteristics Physical characteristics, e.g. size Life stages, e.g timing, duration… r- vs K-selected species

classic examples within order Primates

Related to phylogeny and environmental pressures, e.g. galagos

A. BODY SIZE Larger animals

Need more space/resources

Grow slower Leave fewer offspring Easier to hunt by

humans Smaller animals

More predators Can recover more

quickly

B. LIFE STAGES :

What are stages? Length of stages

C. REPRODUCTIVE PARAMETERS :

Litter size Gestation length Interbirth interval Generation length Along with lifespan →mean # offspring / lifetime

IX. DEMOGRAPHY:

Study of populations in terms of size, structure, change over time….

Size of group and numbers of individuals in each of the age-sex categories important conservation concerns

May indicate health of population(s) over time

X. CONSERVATION:

Problems: Habitat destruction Human overpopulation

Agriculture Logging – arboricides

Mixed stands and arboreal corridors important Fuel/mineral exploitation

PROBLEMS cont’d Less necessary economic

interests Minerals/gems

War Destruction of habitat

Fighting Herbicides Hunger Migrations, e.g. into forest,

former reserves…

Brazil, result of mining

PROBLEMS cont’d

Hunting Food for indigenous

people Bush meat Stupid stuff Pests

“Empty forest syndrome” Lose seed dispersers

PROBLEMS cont’d

Animal Trade Biomedical Folk remedies Zoos Pets