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Behavioral influence of adult orangutans on their offspring

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THE BEHAVIORAL INFLUENCE OF ADULT
ORANGUTANS ON THEIR OFFSPRING
Tasnim Ghanim
900162878
ORANGUTANS
• Orangutans are a species known to be solitary and asocial, in which males and
females do not live together.
• This kind of behavior may have a certain influence on juvenile Orangutans, and the
kind of behaviors they acquire from that.
Hypothesis:
The offspring of a pair of Orangutans will present
behaviors that mirror those of the mother, since the
mother is the only parent to provide any parental care
THE STUDY
• Due to the solitary of the female orangutan,
and to be able to observe the behaviors, the
study was done on a juvenile and both of
her parents in their zoo enclosure.
PREVIOUS STUDIES
• When male and female orangutan are
held in captivity, they tend to be more
social (Edwards & Snowdon, 1980).
• Orangutans held captive are usually less
focused on mating attempts, while in the
wild males and females only meet to mate
(Edwards and Snowdon, 1980).
TESTING THE
HYPOTHESIS
• To test their hypothesis, the authors classified between
parentally influenced behaviors the juvenile Orangutan, Bella,
performed, and the play behaviors (McUmber, 2016).
• They also noted whether these behaviors performed in the
presence of a single parent, both parents, or alone, and they
were recorded by the number of occurrences (McUmber,
2016).
RESULTS
• The results showed that offspring’s
behavior was more affected by the
presence of the mother than the father
(McUmber, 2016).
• This raises the question of how
different the juvenile would turn out to
be if the environment was different.
RESEARCH
QUESTIONS
Based on the food sharing hypotheses, will
the juvenile Orangutans be able to
recognize for food items that are
nutritionally beneficial for them on their
own, or will they depend on their mothers?
Will Orangutans be able to acquire
knowledge regarding nest building while in
captivity, and apply it in the wild?
ST
1
QUESTION: FOOD SHARING
•A study performed by Jaeggi, Noordwijk and Schaik (2008) tested
multiple
predictions
of
the
food
sharing
nutritional
and
informational hypothesis.
•Their predictions according to the informational hypothesis have
been supported, in which young inexperienced offspring were
capable of requesting more food and with more variation with
younger offspring, and as they grew older, the offspring has more
knowledge about the nutritional benefits of the food items (Jaeggi,
2008).
CONT. FOOD SHARING
•The predictions per the nutritional hypothesis state that during
the weaning period of juveniles, the rates of food transfer will
be at highest, and that the offspring will solicit food items that
are more nutritional as they cannot obtain them by themselves
(Jaeggi, 2008).
1.
According to the informational hypothesis of food sharing,
the juvenile Orangutans were able to recognize the food
items that were beneficial to them.
2.
This was not the case according to the nutritional
hypothesis.
ND
2
QUESTION: NEST BUILDING
The captive Orangutans face a delay in acquisition
of forest skills, and one of these skills is the nesting
skill, in which some ex-captives were eager nestbuilders, and were competent, and others didn’t try
(Rijksen, 1978).
This can be due to the fact that there is a
genetic component that leads to the
behavior of nest-building, so individuals will
build nests without guidance (Casteren,
2012).
CONT. NEST BUILDING
Although they face a delay, the ex-captive Orangutans
were able to acquire the nest-building skills just as wild
Orangutans, by learning easier skills and more difficult
skills later on (Russon, 2007)
Some Orangutans gain knowledge
Others who didn’t try nest
regarding how to build nests when
building in captivity, will
they are in captivity, and this may
eventually learn how to nest-
be a result of a genetic factor.
build and master the skill.
REFERENCES
Casteren, A. Van, et al. “Nest-Building Orangutans Demonstrate Engineering Know-How to Produce Safe, Comfortable Beds.” Proceedings of the National Academy
of Sciences, vol. 109, no. 18, 2012, pp. 6873–6877., doi:10.1073/pnas.1200902109.
Edwards, Sara D., and Charles T. Snowdon. "Social Behavior of Captive, Group-Living Orangutans". International Journal of Primatology, vol 1, no. 1, 1980, pp. 3962. Springer Nature, doi:10.1007/bf02692257.
Jaeggi, Adrian V., et al. “Begging for Information: Mother–Offspring Food Sharing among Wild Bornean Orangutans.” American Journal of Primatology, vol. 70, no. 6,
2008, pp. 533–541., doi:10.1002/ajp.20525.
McUmber, Raechel, et al. “Parental Influences on the Behavior of a Juvenile Bornean Orangutan (Pongo pygmaeus).” The Review: A Journal of Undergraduate
Student Research, vol. 17, no. 8, 2016.
Rijksen, Herman Dirk. “A Field Study on Sumatran Orang Utans (Pongo Pygmaeus Abelii Lesson 1827): Ecology, Behaviour and Conservation.” Proefschrift
Wageningen, 1978.
Russon, Anne E., et al. “Orangutan Leaf-Carrying for Nest-Building: Toward Unraveling Cultural Processes.” Animal Cognition, vol. 10, no. 2, 2006, pp. 189–202.,
doi:10.1007/s10071-006-0058-z./