Open main menu
Home
Random
Recent changes
Special pages
Community portal
Preferences
About Wikipedia
Disclaimers
Incubator escapee wiki
Search
User menu
Talk
Dark mode
Contributions
Create account
Log in
Editing
Squirrel monkey
(section)
Warning:
You are not logged in. Your IP address will be publicly visible if you make any edits. If you
log in
or
create an account
, your edits will be attributed to your username, along with other benefits.
Anti-spam check. Do
not
fill this in!
=== Reproduction === Squirrel monkey mating is subject to seasonal influences. Squirrel monkeys reach sexual maturity at ages of 2β2.5 years for females and age 3.5β4 years for males. Females give birth to young during the rainy season, after a 150- to 170-day gestation. Only the mothers care for the young. ''Saimiri oerstedti'' are weaned by 4 months of age, while ''S. boliviensis'' are not fully weaned until 18 months old. Squirrel monkeys live to about 15 years old in the wild, and over 20 years in captivity. [[Menopause]] in females probably occurs in the mid-teens.<ref name="MLWalker1">{{cite journal|vauthors=Walker ML, Anderson DC, Herndon JG, Walker LC|year=2009|title=Ovarian aging in squirrel monkeys (Saimiri sciureus)|journal=Reproduction|volume=138|issue=4|pages=793β799|doi=10.1530/REP-08-0449|pmid=19656956|pmc=7723027|doi-access=free}}</ref> Studies show that ''Saimiri collinsi'' time the weaning of their young with the period of time when there will be maximum fruit availability in the environment. This reduces the energetic struggles that newly weaned juveniles will face when transitioning from a milk diet where they are dependent on their mother for food to a more diverse diet where they have to forage for food.<ref>{{Cite journal|last1=Stone|first1=Anita I.|last2=Ruivo|first2=Luana V. P.|date=2020|title=Synchronization of weaning time with peak fruit availability in squirrel monkeys (Saimiri collinsi) living in Amazonian Brazil|journal=American Journal of Primatology|language=en|volume=82|issue=7|pages=e23139|doi=10.1002/ajp.23139|pmid=32333419|issn=1098-2345|doi-access=}}</ref> There is evidence that squirrel monkeys show sexual dimorphism during the breeding season. In the months leading up to breeding and in the months of breeding, sexually mature adult males have been recorded to increase in size by significant amounts relative to females. These size changes are caused by seasonal fluctuations in androgen hormones synthesized in the hypothalamus, pituitary, adrenal and gonadal axes. The fluctuations include increases in the concentrations of [[testosterone]], [[androstenedione]], and [[dehydroepiandrosterone]] levels in sexually mature males during the breeding season, peaking in January. Following the breeding season, these androgen concentrations drop.<ref name=":3">{{Cite journal|last1=Wiebe|first1=R. Herbert|last2=Williams|first2=Lawrence E.|last3=Abee|first3=Christian R.|last4=Yeoman|first4=Richard R.|last5=Diamond|first5=Edward J.|date=1988|title=Seasonal changes in serum dehydroepiandrosterone, androstenedione, and testosterone levels in the squirrel monkey (Saimiri boliviensis boliviensis)|url=https://onlinelibrary.wiley.com/doi/abs/10.1002/ajp.1350140309|journal=American Journal of Primatology|language=en|volume=14|issue=3|pages=285β291|doi=10.1002/ajp.1350140309|pmid=31973444|s2cid=83608106|issn=1098-2345}}</ref> The evolutionary reasoning for these size changes in sexually mature males is suggested to be both intra-sexual selections among males and also female choice selection, as the larger males are more likely to be preferred by females and partake in more copulations. There is not clear evidence yet as to why females choose larger males, but a leading hypothesis is that the larger males are more likely to have better vigilance for their young.<ref>{{Cite journal|last=Boinski|first=S.|date=1987|title=Mating Patterns in Squirrel Monkeys (Saimiri oerstedi): Implications for Seasonal Sexual Dimorphism|url=https://www.jstor.org/stable/4600051|journal=Behavioral Ecology and Sociobiology|volume=21|issue=1|pages=13β21|doi=10.1007/BF00324430|jstor=4600051|bibcode=1987BEcoS..21...13B |s2cid=23241941|issn=0340-5443}}</ref>
Edit summary
(Briefly describe your changes)
By publishing changes, you agree to the
Terms of Use
, and you irrevocably agree to release your contribution under the
CC BY-SA 4.0 License
and the
GFDL
. You agree that a hyperlink or URL is sufficient attribution under the Creative Commons license.
Cancel
Editing help
(opens in new window)