Primate Interactions: Polyspecific Associations

Definition• Dispersing individuals

• Groups of two or more species

• Permanent or moderate association

Distribution

• Rare among prosimians, apes

• New and Old World Monkeys- common

Considerations….

• Is it random?

• Is it mutually beneficial?

• Does it only benefit one party but not the other (neutral = commensalism)?

• Does it benefit one party and influence the other party negatively? (Parasitism)

Benefits

• Foraging– Avoid previously used areas– Increased insect capture rate– Share knowledge of food sources

• Predation– Detection faster, earlier– Avoidance (larger groups)

model

Allen’s galago

Needle clawed galago

potto

Demidoff’s galago

Lorises

Examples

• Dispersing anecdotes

• Guenons (Africa)

• New World Primates- Manu, Peru (see Ch 8- Terborgh reading in coursepak).

Cebus and Saimiri

Capuchin (Cebus)

Squirrel monkey (Saimiri)

Type of Association

• Positive for Squirrel monkey, slightly negative for Capuchin

• Moderate association, seasonal

To understand benefits...• Who leads?

• What happens when species is alone?

• How is contact initiated?

Leadership

• Not necessarily who is in front– Large group size (squirrel

monkeys)– Circumstances (type of activit

or food (Table 8.1 in article, See graph next page)

Graph from Table 8.1 (article) - values are percents of both Cebus categories

When Squirrel monkeys travel with Capuchin

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INSECT FRUITTRAVEL

TRAVEL FAST

Category (Table 8.1)

Squirrel monkey lead

Capuchine lead

Leadership?

• Capuchins more influential regarding group movements

• But Squirrel monkeys more actively try to maintain relationship with groups.

What happens when alone?

• Squirrel monkeys change behavior significantly more than capuchines when alone.– Travel further, faster– Seemed to actively seek other capuchin

groups – Influence each other’s travel when together

(graph next page).

Travel data (Table 8.2)

Travel rates (meter/hour)

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Squirrel monkeyalone

Both speciestogether

Capuchin alone

Who initiates contact?

• Squirrel monkeys seem to actively seek out Capuchin groups.

• Capuchin don’t make any vocal sounds when squirrel monkeys come and go.

• Squirrel monkeys are with capuchins more than capuchins with squirrel monkeys (see table 8.3).

Seasonal- Table 8.3 reworked

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Squirrelmonkeyalone

Capuchinalone

Squirrelmonkeywith at

least oneCapuchin

sps

Squirrelmonkey

with both

Late Dry/Early Wet(Aug-Nov)

Rainy (Jan-Feb)

Late rain (Mar-Apr)

No Fruit (May-Jun)

Benefits-Predation

•Capuchins have excellent predator detection skills (vocal, Vigilance)•Squirrel monkeys are more intensive foragers, don’t pay attention as much (also smaller in size).

• Group size might benefit both.

Benefits- Foraging

• FRUIT– Squirrel monkeys learn where fruit trees are

(but don’t leave?)– Exploit fruit/nuts of Scheelea

• Insect feeding– Improve insect flushing (not really…)

Summary• Squirrel monkeys benefit…

– Predator warning– Access to Scheelea nuts– Learn fruit source location (esp.when scarce)

• Capuchin– Negative- increased travel– Lose fruit perhaps– Possible selfish herd

Tamarins

• Saddle-backed

• Emperor

General comments

• Permanent associations

• Territorial

• Emperor Tamarins dominant to saddle-backed

• Not always coordinated but keep in contact with each other vocally.

Leadership (table 8.4)

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Saddle back lead Emperor lead

Vertical cling-leap

General notes

• Both may travel more when alone.

• Predation- not clear benefits because separated when feeding often.

• Foraging- not clear (overlap)

Territorial disputes

Distance traveled (m) to next food tree

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Successful Unsuccessful

Outcome of dispute between groups

Territorial benefits?

• Larger groups can actively displace smaller ones from resources.

“don’t mess with me!”

Colobus and GuenonsColobus

Red (left)Black and white

(right)

CercopithecusRed-tailed (left)

Blue monkey (mid)Mangabey (right)

Patterns of association

Kibale forest

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Red-tailed Blue

Kakamanga Forest

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Red-tailed Blue

Uganda Kenya

Forest differences??

• Less overlap in diet between species

• Less likely to use the other for information

• Lower predation?

• Presence of other species (mangabeys, baboons, red colobus)

• Lower density of animals

• More overlap in diet, use each other for information

• More predation?• Lower density of

animals

Kibale Kakamanga

Benefits and costs

• Possible predator detection at Kakamanga (larger groups at Kibale)

• Red-tails gain knowledge of food sources from blue monkeys at Kakamanga.

• BUT red-tails do get chased.

• Both species travel further when in association.