Primates
February 4
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Key features of primates
- Grasping hands and feet
- Collarbone (clavicle)
- Radius and ulna
- Forward facing eyes and stereoscopic vision
- Body size: double the size -> 8x heavier
- Smaller animals have greater heat loss than larger animals
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Primate Activity Patterns
- Nocturnal: active at night
- Diurnal: active during the day
- Crepuscular: active at dawn and dusk
- Cathemeral: active any time of day or night
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Primate Diet
- Variety of fruits, insects, flowers, and leaves [eat only leaves require special gut adaptations]
- Larger primates typically eat more leaves while smaller primates eat more insects
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Primate Habitats
- Tropical rainforests, dry forests, deserts, and savannas; primary vs. secondary forests; ecological Niche; forest microhabitats: emergent layer, canopy, understory
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Primate Evolutionary Ecology
- Bottom-up processes - plants altering their form to help/deter a primate
- Top-down processes - pushed by predators
- Other processes- seed dispersal and pollination; predation pressures on primates; plant defensive adaptations: physical/chemical (like caffeine or giant hogweed, opium in poppies, cocaine in the coca plant)
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Primate Ranging Patterns
- Daily path length - distance travelled in a day
- Daily range - area the animal ventured into during a day
- Home range - all the day ranges over the year; core area; territory
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Primate Conservation:
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Habitat disturbance: logging, agriculture; forest fragmentation
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Hunting pressures [subsistence (sustainable) vs economic (unsustainable)]
Ex. Behaviour and Anthropology: must find solution by working together with locals
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Primate Sociality
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Complex social lives, including: deception; female mate choice (quite subtle); homosexuality (observed in hundreds of species); kin recognition; warfare; friendship
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Primate Social Grooming: about hygiene(卫生), but also forming and reconciling social bonds
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Primate Dominance Hierarchies: social order sustained by: aggression; affiliation; other behaviour patterns
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Primate Social Organization
- Residence group composition
- Mating systems: who mates with whom
- Foraging coherence: who eats with whom
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Philopatry type
- Female philopatry - males leave at sexual maturity
- Male philopatry - females leave at sexual maturity
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==Advantages of groups==: improved predator protection; improved access to food; resource defense; increased access to potential mates
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==Disadvantages of groups==: increased predator encounters; more mouths to feed; increased travel/foraging costs; disease transmission
- Disease Transmission: gorillas and chimpanzees afflicted by same diseases as humans, like Ebola or COVID-19
Suborder: Strepsirhines
A suborder of primates that includes the lemuriform primates, which consist of the lemurs of Madagascar, galagos (“bushbabies”) and pottos from Africa, and the lorises from India and southeast Asia.
Characteristics
- Dental toothcomb (牙梳) - comprising a group of front teeth arranged in a manner that facilitates grooming
- Moist rhinarium(鼻) - furless skin surface surrounding the external openings of the nostrils
- Tapetum lucidum - a layer of tissue in the eye of many vertebrates
- Postorbital barea - a bony arched structure that connects the frontal bone of the skull to the zygomatic arch, which runs laterally around the eye socket.
- Unfused mandibular(下颌骨) and frontal symphases - line of junction where the two lateral halves of the mandible typically fuse at an early period of life
Two Superfamilies
- Lemuroidea - lived on Madagascar and Comoro Islands; arboreal quadrupeds and leapers; some are partially terrestrial; many small-bodied species are nocturnal; female dominance; varied diet
- Lemurs only exist in Madagascar (马达加斯加特有的狐猴)
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- Lorisoidea - found throughout sub-Saharan Africa and Southeast Asia; lorises and galagos; arboreal quadrupeds; nocturnal, varied diet
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Suborder: Haplorhine
The “dry-nosed” primates, is a suborder of primates containing the tarsiers and the simians (Simiiformes or anthropoids), as sister of the Strepsirrhini (“moist-nosed”)
Characteristics
- Dry nose
- Retinal fovea - responsible for sharp central vision (also called foveal vision)
- Postorbital closure - separating the orbit from the temporal region
- Fused mandibular and frontal symphases (compared to Tarsiers)
Three infraorders: Tarsiiformes, Platyrrhini, and Catarrhini
Tarsiiformes
- One genus (Tarsius); found in Southeast Asia (e.g., Philippines); small body size (80-130g); relatively large eyes (larger than brain), with fused lower leg bones; entirely faunivorous
Platyrrhines (Neotropical Monkeys)
- Central and South America; body mass: 110g – 11.4kg; Cebidae, Atelidae, and Callitrichidae; prehensile tail in a few species; most are entirely arboreal
Catarrhini (Old World Monkeys and Apes)
- Africa, Asia, and Southeast Asia; body mass: 1kg – 75kg; Cercopithecidae, Hylobatidae, and Hominidae; variety of diets, social organizations, and adaptations
