Common Warthog (Phacochoerus africanus) Fact Sheet: Behavior & Ecology

Daily activity

• Diurnal (active in daylight) (Somers 1997)
  • Feed most of the day; 60-70% of daytime activity (Somers 1997)
    • Peaks in early morning and late afternoon (Clough and Hassam 1970; Somers 1997)
    • Females appear to feed for longer periods of time than males (Clough and Hassam 1970; Somers 1997)
  • Rest in bushes or burrows to avoid mid-day heat or rainy weather (Clough and Hassam 1970; Somers 1997)
    • May wallow in mud when temperatures are high (Somers 1997)
• Nighttime activity
  • Remain in burrows at night; c. sunset to sunrise (Clough and Hassam 1970; Cumming 1975; Somers 1997)
    • Burrows/holes provide shelter from nighttime cold or rain, daytime heat, and predators (Cumming 2013)
      • Shelter in aardvark burrows or erosion-gulley holes, uncommonly in caves (see Cumming 1975 for descriptions)
    • Characteristics of preferred burrows: short, wide entrances; in areas close to water with lower burrow density (White and Cameron 2009)
      • No apparent burrow preference by females during birthing season, analysis excluded internal burrow features (White and Cameron 2009)
    • Change sleeping burrows frequently (Cumming 2013)
  • Active at night rarely (de Jong and Butynski 2014)
    • Few instances reported in areas where harassed in daytime by humans or other predators
    • Possibly occurs in regions with soaring daytime temperatures

No seasonal migration (Cumming 2013)

Ranges overlap (from Cumming 2013)

• No apparent fixed boundaries
  

Range Size (from Cumming 2013)

• Varies by locality
  • 0.24-6.0 km² (0.1-2.3 mi²)

Facultatively social (from White et al. 2010 unless otherwise noted)

• Live alone or in small groups
  • Degree of association varies by population and by season
    • Groups fragment in regions with a distinct dry season
    • Solitary adult females are common
• Males are primarily solitary
  • Associations with females are temporary
  • Join groups more often during the mating season
• Females live alone or in groups known as "sounders" (Smith 2011)
  • Matriarchal groups of one or more breeding females and their offspring (White 2010)
  • Offspring emigrate to surrounding areas; males are more likely to disperse than females (White 2010)

Group composition (from White et al. 2010 unless otherwise noted)

• Sounders (adult female groups)
  • Solitary adult female with her infant, juvenile, and/or yearling offspring
  • Multiple adult females without young
  • Multiple adult females with their infant, juvenile, and/or yearling offspring
• Bachelor group
  • Adult male with other adult or yearling male(s)
  • 2-4 animals typically (Cumming 2013)
• Yearling groups
  • Associations of all-female, all-male, or males and females
  • Most are mixed-gender

Sounder size

• Range: 2-8 individuals
  • Numbers fluctuate seasonally (White 2010)
  • Related sows may join to form larger groups; 12-18 individuals (Cumming 2013)
• Factors limiting size
  • Dimensions of sleeping burrow (Cumming 2013)

Typically non-territorial

• Do not patrol territories (from Cumming 2013 unless otherwise noted)
  • Do not defend territories, core areas or sleeping holes (when not in use)
• Scent mark range boundaries
  • Mark edges of home-ranges
    • Deposit urine and secretions from glands located on the face (see Olfaction/scent marking, below)

Aggression (from Cumming 1975 unless otherwise noted)

• Spar
  • Head used to hit and push opponent
  • Broad snout used to push; rapidly disengage and strike back at one's opponent
    • Warts cushion blows to the head
  • Tusks are not used as weapons
• Chase group members
• Often to gain position or access to water resources

Affiliative behaviors

• Allomothering
  • Mothers share nursing duty, "allo-suckling" (Child et al. 1968; Plesner-Jensen et al. 1999)
    • c. 50% of observed groups allo-suckle offspring, one study (Plesner-Jensen et al. 1999)
    • Benefits unclear (Plesner-Jensen et al. 1999)
• Greetings not highly ritualized (from Cumming 1975)
  • Nuzzle
    • Sniff and touch noses, mouths, and pre-orbital areas of the face
  • Rub against one another
  • Rest chin on another's back
• Allogrooming (from Cumming 1975)
  • Mouth used to groom one another
    • Hair drawn through the lips or incisors; similar to the movements made to pluck grass
  • Lasts up to 10-15 minutes

Play

• Young spar (from Estes 1993)
• To practice fighting skills

Vocalization (from Cumming 1975)

• Seldom vocalize in the wild
• Grunt during courtship, in greeting, or alarm
  • "Chant de coeur" - loud, rhythmic, grunt heard during courtship
    • Male call, audible to 80 m or more
    • Described as similar to an idling motor
    • Mouth held slightly open; lower jaw moves rhythmically with emitted grunts
  • Greeting call - explosive grunts, given when an individual runs up to another in its group
  • Location call - brief series of grunts, similar to the "chant de coeur"
    • Lactating female call, given when separated from her young
  • Alarm grunt - short, low grunt; usually precedes flight
• Squeal & squeak to display submission, discomfort, or pain
• Growl
  • Warning snort - high-intensity, low-pitched "Woooooomph"
    • Sound as a forceful expulsion of air

Olfaction/Scent Marking

• Males mark more frequently than females (Radke and Niemitz 1989)
  • Frequency increases during rutting and mating periods (Cumming 2013; Radke and Niemitz 1989)
• Forms of marking
  • Rub regions of the face on tree trunks, stumps, and other solid objects (Estes et al. 1982; Radke and Niemitz 1989)
    • Preorbital glands (damp patch in front of the eye) and tusk glands (flange of the upper lip beside the tusk) deposit pheromones (Cumming 2013; Estes et al. 1982)
  • Urinate
    • Females urinate to mark edges of home ranges (Radke and Niemitz 1989)
    • Estrus females urinate frequently (Estes 1990)
    • Behaviors unique to males
      • Spray urine, and possibly secretions from the preputial gland, over the urine of females (Radke and Niemitz 1989)
      • Urinate in wallows (Estes 1990)
  • No evidence for use of dung piles to mark

Trot and run

• Quadrupedal
• Tail and mane held erect; back rigid (Cumming 2013)
• Quick, springy stride (Meijaard et al. 2011)
  • Burst of speed up to 55 km/hr (34 mi/hr) (Estes 1993)
  • Over short distances, capable of evading a man on horseback or a lion (Melliss 1991, Howell 1944)

Symbiotic relationships

• Aardvark (Orycteropus afer)
  • Aardvark holes used as shelter against predators, temperature extremes, and humidity (Meijaard et al. 2011)
    • In the wild, warthogs do not dig their own burrows; rely solely on those constructed by other animals (White and Cameron 2009)
    • Individuals in managed care reported to dig burrows (Cumming 1975)
• Dung scavengers
  • Invertebrates use warthog feces to breed and feed (Carpaneto et al. 2010)
    • Tunneling scarab beetles such as yellow-shouldered dung beetle (Liatongus militaris) and Gazelle scarab (Digitonthophagus gazella) are commonly associated with ungulate feces
      • Chambers are dug under warthog droppings; dung capsules are excavated and brought inside the nest to feed offspring (larvae) (Cambefort and Hanski 1991; Carpaneto et al. 2010)
• Mutualistic interactions
  • Oxpeckers (Buphagus spp.) and Southern Ground-Hornbill (Bucorvus leadbeateri) glean tick from warthogs and other ungulates (Coetzee 2010; Plantan et al. 2013)
    • Warthogs appear to solicit and to yield to grooming; gently drop to the ground when being cleaned (Breitwisch 1992; Coetzee 2010)
    • Relationship not fully mutualistic; oxpeckers often wound-feed from hosts (Grobler and Charsley 1978; Nunn et al. 2011; Plantan et al. 2013; Weeks 2000)
    • Controlled study suggests oxpeckers minimally reduce adult tick load and prolong healing time of wounds (Weeks 2000)
  • Banded mongoose (Mungos mungo) groom warthogs to remove ticks (Meijaard et al. 2011; Sazima 2010)
• Parasitic interactions
  • Tsetse fly host (Child et al. 1968)
    • Tsetse flies act as a vector and transmitter of cattle trypanosomiasis
    • Warthogs killed in large numbers in an effort to eradicate the fly and prevent the spread of disease

Predators

• Principal predators
  • African lion (Panthera leo) and leopard (Panthera pardus) (Cumming 1975)
    • Lions dig out burrows or lie in wait to ambush warthogs as they exit their holes each morning (Cumming 2013; Estes 1990)
    • At times in Sengwa, lion prides have specialized in hunting warthogs (Cumming 2013)
• Other mammals prey on adults, juveniles, and infants
  • Spotted hyena (Crocuta crocuta), cheetah (Acinonyx jubatus), and African wild dog (Lycaon pictus) (Cumming 1975)
• Anti-predator behaviors(from Cumming 1975 unless otherwise noted)
  • Vocalize and actively defend
    • Grunt, squeal, growl, and woomph (Estes 1990)
    • Sweep tusks laterally in defense (White and Cameron 2009)
  • Hide or retreat, to seek shelter
    • Lay low in thick cover
    • Withdraw into burrows (Estes 1990)
      • Adults back into holes (Estes 1990; Estes 1993)
      • Tusks used in defence against a pursuing predators (Estes 1990; Estes 1993)
  • Flee; typically, not moving great distances (White 2010)
    • Lack endurance and speed to outrun many predators (White 2010)

Males spar during the yearly rut, pushing and striking one another on the head. The object is to destabilize one's opponent; tusks are not used as weapons in such battles.

Image credit: © Derek Keats from Flickr. Some rights reserved.

Oxpeckers (pictured above) and banded mongoose feed on ticks attached to warthogs. Interactions such as these are complex. Warthogs may benefit by receiving help in reducing parasites, but may also be harmed by the birds which can inflict new wounds and prolong healing time of older sores.

Image credit: © Peter Steward from Flickr. Some rights reserved.

Breitwisch (1992)
Cambefort and Hanski (1991)
Carpaneto et al. (2010)
Child et al. (1968)
Clough and Hassam (1970)
Coetzee (2010)
Cumming (1975)
Cumming (2013)
de Jong and Butynski (2014)
Estes (1990)
Estes (1993)
Estes et al. (1982)
Grobler and Charsley (1978)
Meijaard et al. (2011)
Nunn et al. (2011)
Plantan et al. (2013)
Plesner-Jensen et al. (1999)
Radke and Niemitz (1989)
Smith (2011)
Sazima (2010)
Somers (1997)
Weeks (2000)
White (2010)
White and Cameron (2009)
White et al. (2010)