Gibbons Flashcards
Do gibbons ever go to the ground?
No
What do they drink?
Water trapped in plants
How do they move?
By brachiation, the only true brachiating primates.
What do they eat to sustain their high energy lifestyle?
Ripe fruits
Gibbons never travel along the same routes. True or false?
False: they have v. defined routes across their home territories, e.g. they always poop in the same gaps
Lar/white-handed gibbons are dichromatic, and this is based on sex. True or false?
False, both sexes can be either colour
How many members does the average group of gibbons have?
2-6, generally a mating pair and offspring
What time of the day do gibbons eat?
Early morning
Do gibbons socially groom?
Yes
What are sub-adults?
Offspring that are older than juveniles.
Are sub-adults fully integrated into the group?
No they stay on the periphery and will eventually disperse
Gibbons are completely safe running about in the canopy. True or false?
False: fatalities are common
As well as fruit, what will gibbons eat?
Flowers as they have a high nectar (sugar) content.
Gibbons are small-bodied. What advantage does this give them?
They can exploit terminal branches.
Who do they compete with for food?
Fruit bats and giant squirrels
Gibbons will not eat invertebrates. True or false?
False; they will manipulate epiphytes to find them
Gibbons make nests. True or false?
False; they sleep separately in the canopy so as not to attract predators
When do gibbons go to bed?
A few hours before dark
Gibbons can individually distinguish each other’s calls. True or false?
True
Extra-pair copulations are common in both members of the pair. True or false?
True; both the male and female are banging the neighbours
Which sex has a particularly impressive vocal call?
The female, called the ‘Female Great Call’
What is the male’s reply to the Female Great Call?
The Male Coda
What is the traditional view of this calling?
Advertising the strength of their pair bond, plus territorial defence
What is Volker’s view?
Calling is a mate-testing mechanism, female is advertising her quality (or his lack of)
It has been found that gibbons do not stay in the same groups for their whole life. True or false?
True
Gibbons are peaceful and rarely aggressive. Why?
Because they are all banging each other there is a lot of paternity confusion. Therefore there are high degrees of relatedness, both known and unknown. Gibbons live in big polyamorous hippy groups where its all love
Gibbons were traditionally thought to be territorial. Why would this be?
Because territoriality preserves monogamy.
Where has recent(ish) research on gibbons been conducted? Who was it by?
The Khao Yai rainforest in Thailand
Sommer and Reichard, 2000
Sommer and Reichard, 2000;
Khao Yai has disproved what 3 assumptions about gibbons?
- They live in nuclear families
- They maintain lifelong, monogamous relationships
- They are territorial
Sommer and Reichard, 2000;
How has research at Khao Yai shown territoriality to be false?
The home ranges of different groups overlap
Sommer and Reichard, 2000;
How has research at Khao Yai shown nuclear grouping/lifelong monogamy to be false?
Not a single individual stayed with the same partner throughout life, many were serial monogamists or became polyandrous/polygynous.
Do maturing individuals set up new home ranges?
No, they ‘squeeze’ into neighbouring groups
Sommer and Reichard, 2000
How does calling show mate testing?
The female will sing her great call to advertise herself, testing the male to sing his coda and signal that she is already taken
Therefore what can female calling be perceived to be?
An indicator trait, with call intensity demonstrating quality
Sommer and Reichard, 2000
What percentage of groups at Khao Yai displayed non-monogamous grouping?
~25% (polyandry and polygynandry)
What did work by Sommer and Reichard (2000) show?
Short dispersal distances + EPCs = patchwork families = high degree of relatedness = low aggression and infanticide
