Patas Monkey (Erythrocebus patas) Fact Sheet: Behavior & Ecology

Activity Overview

• Most frequently observed stationary
• Not moving c. 40% of the time (Isbell et al. 1998a)

Daily Activity

• Diurnal, active during the day (Mittermeier et al. 2013)
  • 60% of time spent on the ground (Mittermeier et al. 2013)
• Travel and forage daily (Isbell 2013)
  • Mean daily travel distance 4.3-6.2 km (Nakagawa 1999)
  • Minimal travel may occur, eg. 500 m (Hall 1966)
  • Farthest distances in the mid-dry and wet season (Nakagawa 1999)
• Sleep alone in trees, except for mothers and their dependent offspring (Chism and Rowell 1988; Hall 1966)
  • Co-sleeping observed in West Africa with access to larger trees (Nakagawa 1992)
  • Rarely sleep in the same area on consecutive nights (Hall 1966; Isbell 2013)
  • Similar to rest positions (see below), commonly in the fork of trees or at branch intersections (Hall 1966)

Travel and Forage Pattern

• Set out c. 07:30 (Isbell 2013)
  • Rarely prior to 07:00 (Mittermeier et al. 2013)
• Rest mid to late afternoon (Hall 1966; Isbell 2013)
  • Reduced feeding during this period (Hall 1966)
  • In trees, recline or sit
    • Recline in branch fork with legs outstretched at about the same height as the head (Hall 1966)
      • Body bowed forward, hands resting near the feet (Hall 1966)
    • Sit on horizontal branches (Hall 1966)
      • Upright, legs dangling below the branch; like a bather on the edge of a swimming pool (Hall 1966)
      • Legs astride either side of the branch (Hall 1966)
      • Legs bent, with knees up under the chin (Hall 1966)
    • Lie flat along branch, body outstretched (Hall 1966)
• Resume feeding, foraging, and travel after rest period (Isbell 2013)
  • Females regularly initiate group movement (Hall 1966)
  • Fastest travel in late afternoon (Isbell 2013)
• Group splits up before sunset, typically; returning to sleeping trees (Mittermeier et al. 2013)
  • By 19:00, usually in trees to rest for the night (Mittermeier et al. 2013)

Drinking Pattern

• Drink daily, typically 2-4 times (Nakagawa 1999)
• Visit rivers, rock pools, waterholes, or puddles in the dry season (Mittermeier et al. 2013)

Home Range

• Largest home ranges for their body size of any primate (Isbell 2013)
• Reported range sizes
  • 5,200 ha (c. 20 mi² or 52 km²), group of 31 individuals in Uganda (Hall 1966; Mittermeier et al. 2013)
  • 2,850 ha (c. 11 mi² or 28.5 km²), one Kenyan group (Isbell 1998)
  • 266-440 ha (c. 1-1.7 mi² or 2.66-4.40 km²), one group in northern Cameroon (Nakagawa 1999; Nakagawa 2008)
  • 372-1,539 ha (c.1.4-5.9 mi² or 3.72-15.39 km²), introduced patas groups on mainland Puerto Rico (Gonzáles-Martínez 2004)
• All male groups have larger ranges (Mittermeier et al. 2013)

Overlap between Home Ranges

• Variable (Isbell 2013; Nakagawa 1999)

Overview

• Social animals, live in groups
• Males are socially peripheral, rarely receiving affiliative behavior from females within the group (Nakagawa 1992)

Group Structure

• Single-male, multi-female groups most of the year (Hall 1966; Isbell 2013)
  • Not a "harem" system, as in the hamadryas baboon (Mittermeier et al. 2013)
    • Extra-group males converge on groups during the breeding season (Carlson and Isbell 2001; Chism et al. 1984; Isbell 1998; Nakagawa 2008)
    • Up to 7 males associated with a single group in one mating season, one study (Carlson and Isbell 2001)
  • Females remain in natal group throughout life, typically (Isbell 2013)
  • Larger groups may have multiple males (Chism and Rogers 1997)
  • Resident male does not appear to have a reproductive advantage (Chism and Rogers 1997)

• All male groups, typically composed of dispersing males (Chism and Rogers 1997)
  • Composition fluctuates; may not be stable groups

Group Size

• Fluctuates widely over time (Isbell 2013; Isbell et al. 2009; Nakagawa et al. 2003)
  • Short term fluctuation due to seasonal births (Isbell 2013)
  • Local weather patterns, eg. drought, associated with group size (Nakagawa et al. 2003)

• Size range: 8-71 (Chism and Rogers 1997; Isbell 1998; Isbell et al. 1998b; Nakagawa 2008)
  • 15 typically (Mittermeier et al. 2013)
  • Introduced population in Puerto Rico follows a similar trend (Gonzáles-Martínez 2004)

Female Dominance Hierarchy

• Variable across populations; weak hierarchies in some (Isbell et al. 1998b; Nakagawa 2008)
  • Agonistic behaviors, similar to vervets, reported (Isbell et al. 1998b; Nakagawa 2008)
  • Some wild and managed care groups form nearly a linear dominance hierarchy (Loy et al. 1993)

Non-territorial, though intolerant of other groups (Isbell 2013)

Affiliative Behaviors (from Hall 1966 unless otherwise noted)

• Allogroom, both genders and all ages groom other group members (Nakagawa 1992)
  • Commonly observed, similar to that of baboons
    • Peak activity in morning, though observed throughout the day's resting period
    • Approaching, followed by close sitting is often an invitation for grooming
  • Males rarely groom or receive grooming
    • Groom c. 96% less frequently than females
    • Receive < 10% of all grooming observations
  • Infants groomed by nearly all adult females
• Co-sleep
• "Kiss"; observed in wild and individuals in managed care
  • One individual approaches another, stretching the head forward so that its mouth touches that of the other
  • Sometimes precedes grooming

Play (from Hall 1966 unless otherwise noted)

• Infants (aged 3 to 12 months) and juveniles
  • Frequently play for long periods, up to 30 minutes; no parallel in other terrestrial monkey
    • Prevalent during morning (up to 10:00)
    • Often in groups of 6 or more juveniles
  • Bounce, chase, and wrestle; on the ground most often
    • Bounce alone or as an invitation to chase
      • Up and down, in the same spot; hopping quickly from hands to feet and back, continually; limbs held straight
      • Often with apparent high-speed enthusiasm
      • Alone; may run, full speed toward a bush, throwing the body sideways before making contact with the hands and feet; catapulting off and galloping away
    • Full speed sprints over open ground
    • Spar and wrestle; opponents stand on hind legs and face one another
      • Grapple with hands around shoulders and arms
      • Slap with hands
      • Mouth held open
      • Mock-biting
  • Few observations of playing with or manipulating non-food objects
• Adult females occasionally play with juveniles or their infants

Aggression (from Hall 1966 unless otherwise noted)

• Rare, only 49 episodes observed during the course of one 627 hours observational study
  • Aggression by one most often met by the rapid retreat of another
    • Followed by counter-threat on occasion
    • Chase distances typically < 50 m
  • Physical contact uncommon
    • c. 20% of aggressive interactions; brief biting without inflicting visible wounds
• Little or no vocalization during aggression
• Associated most commonly with 3 social situations
  • Rough play by a juvenile or young adult with an infant; mother directs threat-attack
  • Feeding areas with dense, clustered foods or those with a sought-after food resource (e.g. mushrooms)
  • Reproductive interest and/or copulation
    • Male may threaten others that come near a female of interest
    • Group members (adult females and some young adults) harass the adult male during copulation attempts; including open-mouthed threats, lunges, and hitting or touching the male's face (Carlson and Isbell 2001; Hall 1966)
• Threat displays
  • Yawn; known as a threat-yawn, displays large canine teeth
  • Stare; fully facing opponent with a directed prolonged gaze, mouth held open with head slightly lowered
  • Slap; strike out with a hand toward another
    • One or two quick movements, most often
  • Striding quickly toward another
• Fighting brief
  • Bite, typically a brief nip
  • "Surprise" attack; individual pounces on the back of another and delivers a quick bite
  • Grapple
• Male group leaders rarely initiate attacks on group members

Vocalization

Patas Monkey audio clips provided by the Cornell Lab of Ornithology Macaulay Library.

• Calls often quiet, especially compared to baboons (Hall 1966; Isbell personal communication; Mittermeier et al. 2013)
  • Frequent vocalizations, audible to humans only at close proximity (Isbell personal communication)
  • Limited vocal repertoire
• Alarm calls, given by adults and immatures (Isbell 2013)
  • Audible to c. 100 m (Hall 1966)
  • Predator specific alarm calls (Enstam and Isbell 2002)
  • Adult females and immatures (from Enstam and Isbell 2002; Isbell 2013 unless otherwise noted)
    • Chirp or nyow
      • High-pitched staccato; similar to "leopard alarm" given by female vervets
      • Indicates presence of olive baboons, domestic dogs, lions, or leopards (Isbell personal communication)
    • Chutter
      • Often softer than a chirp
      • Indicates presence of smaller mammalian predators, such as black-backed jackals and domestic dogs
      • Softer version of this call may also indicate the presence of snakes (Enstam and Isbell 2002)
    • Cough
      • Softest call
      • Indicates presence of black-backed jackals or African wild cats
      • May evoke active defense; eg. chase or hit at a predator (Enstam and Isbell 2002)
  • Adult males (Isbell 2013)
    • Calls acoustically distinct from that of females and immatures (Enstam and Isbell 2002)
    • Bark-grunt, a deep, two-note alarm call (Enstam and Isbell 2002)
      • Equivalent meaning as females' chirp; also given when extra-group males are detected (Enstam and Isbell 2002)
• Other Intra-group calls
  • Soft sounds, often difficult for human observers to hear (Isbell 2013)
  • Moo calls given by all members of a group
    • By infants when separated from their mothers
    • By females when approaching other mothers or in encounters with another group
    • By all age/sex classes when the rest-periods are over and the group begins to move
  • Squeal
    • By immatures under threat of another group member
  • Chutter or gecker, and less frequently scream
    • By immatures and females during agonistic interactions

Facial Expressions

• "Grimace & Gecker" (Loy et al. 1993)
  • Bare teeth, followed by a gecker vocalization

Habit  (Mittermeier et al. 2013)

• Quadrupedal: walk, lope, and run on four legs
• Digitigrade: walk on toes

Gaits and Forms of Locomotion

• Walk (from Isbell et al. 1998a unless otherwise noted)
• Slowest gait, most frequently observed form of locomotion
• Only one foot off the ground at any given time
• Tail held curved downward, away from the body (Hall 1966)
• Commonly feed, forage, and walk simultaneously
• Lope (from Isbell et al. 1998a unless otherwise noted)
• Intermediate speed, appearance of a rocking motion
• Front and hind feet alternating suspension off the ground
  • Greyhound-like in their stride (Hall 1966)
• Run (from Isbell et al. 1998a unless otherwise noted)
• Least commonly observed form of terrestrial locomotion
• Fastest of all primates, to c. 55 km/hr (34 mi/hr) (Hall 1966)
• All feet suspended off the ground simultaneously at some point in the stride
• Tail held higher (Hall 1966)
• Climb (from Hall 1966 unless otherwise noted)
• Scale large, vertical trees with arms and legs spread (frog-like), inching up slowly
  • Head held up on ascent and descent
• Using all limbs to move within trees or bushes (Isbell et al. 1998a)
  • Only young observed swinging by a branch, by the arms alone
• Move along thin branches in tree tops
• Pounce
• To capture grasshoppers or lizards (Hall 1966)
• Leap or jump (from Hall 1966 unless otherwise noted)
• Vertically, to catch flying insects (Hall 1966; Isbell et al. 1998a)
• Across gaps in tree branches, nearly 6 m
• Jump to the ground from heights of a few feet (c.1 m)
  • Young somersault from small bushes, landing on all fours

Ants and thorn trees  (Isbell 2013; Isbell et al. 2013)

• Crematogaster ants live in the swollen thorns of the whistling thorn tree (Acacia drepanolobium), defending it from attack by herbivores
• The ants and gum from the tree provide a large component of the patas diet
• Patas eat gum and ants until the biting ant horde becomes too painful and the monkey moves on

Predators

• Behavioral responses to predators dependent on nature of the threat
  • Vocalize to announce the nature of predatory threats, adults and immatures (see Vocalization) (Isbell 2013)
  • When encountering signs of a predator on the ground, patas do not typically seek refuge in trees; an unusual response for a primate (Enstam and Isbell 2002; Isbell 2013; Isbell et al. 2009)
    • When presented with the call of a mammalian predator, no instances of patas seeking shelter in trees were observed (Enstam and Isbell 2002)
  • When in trees and presented with the call of a mammalian predator, patas generally do a visual scan from their arboreal location, one study (Enstam and Isbell 2002)
    • May descend the tree and run away
  • Fight or flight responses dependant on the type of predatory threat (Isbell 2013)
    • Flee from olive baboon, African wild dog, and domestic dog
    • Chase black-backed jackal and African wild cat
    • Collectively mob leopards
    • Encircle snakes, standing bipedally and staring

Temminck's red colobus (Pcocolobus badius temminckii)

• Travel and play together in interspecific groups, Saloum Delta National Park (Isbell 2013)

Grooming is an affiliative behavior.

All genders and ages participate, though males only occasionally engage in this activity. Infants are frequently the recipients of grooming and receive the attentions of nearly all group females.

Image credit: © transpixt from Flickr. The image has been cropped to focus attention on the specified behavior. Some rights reserved.

Carlson and Isbell (2001)

Chism and Rogers (1997)

Chism and Rowell (1988)

Chism et al. (1984)

Enstam and Isbell (2002)

Gonzáles-Martínez (2004)

Hall (1966)

Hall et al. (1965)

Isbell (1998)

Isbell (2013)

Isbell et al. (1998a,b)

Isbell et al. (2009)

Isbell et al. (2013)

Loy et al. (1993)

Mittermeier et al. (2013)

Nakagawa (1992)

Nakagawa (1999)

Nakagawa (2008)

Nakagawa et al. (2003)