Biology - Macaques Flashcards
Genus and species of the two most common research macaques.
Macaca mulatta and Macaca fascicularis
Describe threatened status and diversity of rhesus macaques.
Among the least threatened and most biologically diverse.
How much do rhesus macaques weight? How long do they live for?
Females: 4.4 - 10.9 kg, Males: 5.5 - 12 kg
Live for approx. 29 years
What are the common names of M. fascicularis? What are phenotypic characteristics of males and females?
Cynomolgus monkey, long-tailed or crab-eating macaque . Females have a beard, males have cheek whiskers.
How much do cyno macaques weigh? How long do they live?
Females: 2.5-5.7 kg, Males: 4.7 - 8.3 kg.
Live up to 37 years old.
What is the dental formula of macaques? How many teeth do they have?
2 (I2, C1, PM2, M3). 32 teeth
What is the purpose of cheek pouches? Where are they found?
Storage of food. Originate in midbuccal area extend towards neck.
When are macaques active? Are they terrestrial or arboreal? Where do they sleep? Can they swim?
Diurnal. Both terrestrial and arboreal. Sleep in trees in the wild. Excellent swimmers.
How are M. mulatta typically divided?
Based on Indian or Chinese origin.
What is the diploid chromosome number of macaques?
42
What macaque species is a CITES status I?
M. silenus, the lion-tailed macaque
What is unique about the environmental habitat of macaques relative to other NHPs?
Inhabit the widest environmental and geographical habitat.
Where do cynos live relative to rhesus macaques? What temperatures do they prefer?
Cynos more subtropical climates, in costal, mangrove, swamp, and riverine forests. Cynos less tolerant to cold than M. mulatta or M. fuscata.
Describe the social structure of macaques in the wild. How do cynos differ from rhesus?
Live in male-dominated, multimale-multifemale groups ranging from 10 - 50 members (Average 32 in rhesus and 20 in cynos). Rhesus females adhere to strict hierarchical class system with dominant male changing groups every few years. Cynos have less stringent hierarchical dominance ranking and groups are often led by a number of high ranking males.
What is the most common threat behavior in macaques? What will submissive animals do? How is tension among adults following an act of aggression manifested? How is reconciliation shown?
Wide-open mouth with staring eyes. Submissive animals with scream and bare teeth, or perform a silent bare-tooth display. Tension manifests as an increase in self-grooming, shaking, and scratching. Reconciliation shown by subservient member staring into the eyes and touching the genitals of the dominant member.
When is the breeding season in rhesus macaques? What is the gestation period and when do births typically occur? What is the interbirth interval?
5 month breeding season from mid-September to mid-February in northern hemisphere. Gestation 164 days. Births in spring and summer. 360 day interbirth interval.
What is the length of the menstrual cycle? What is the mean estrous period?
28 days, with 9.2 day estrous period.
When do rhesus macaques reach sexual maturity?
Females: 4.5 years
Males: 6.5 years
What is the birth weight of rhesus macaques? Where are the testes in newborn males, and how does this change with time?
475-500 grams. Tetes in scrotum at birth, then ascent into the inguinal region and do not descend until 3-4 years of age.
When does sex skin develop in females? When is reddening maximum? What changes do males show?
Develops at 2-3 years. Maximal at time of ovulation. Males may show reddening of the skin of their fac and hindquarters during breeding season.
When do cynomolgus macaques mate and give birth?
Lack strong seasonality and capable of mating and birthing throughout the year. Birth peak during late summer and early autumn.
What is the gestation period, menstrual cycle length, mean estrus length, and interbirth interval in cynomolgus macaques?
163.5 days. 28 days menstrual cycle with 11 day estrus length. 390 day interbirth interval.
When does sexual maturity occur in cynomolgus macaques?
Females: 3.5 years
Males: 5.5 years
What is the average weight of newborn cynomolgus macaques? How does their appearance change after birth?
362-400 grams. Born black and transition to gray in first few months.
Do cynomolgus macaques have sex skin?
Yes, but it is less prominent
