Gibbons

Question 1

Do gibbons ever go to the ground?

Answer 1

No

Question 2

What do they drink?

Answer 2

Water trapped in plants

Question 3

How do they move?

Answer 3

By brachiation, the only true brachiating primates.

Question 4

What do they eat to sustain their high energy lifestyle?

Answer 4

Ripe fruits

Question 5

Gibbons never travel along the same routes. True or false?

Answer 5

False: they have v. defined routes across their home territories, e.g. they always poop in the same gaps

Question 6

Lar/white-handed gibbons are dichromatic, and this is based on sex. True or false?

Answer 6

False, both sexes can be either colour

Question 7

How many members does the average group of gibbons have?

Answer 7

2-6, generally a mating pair and offspring

Question 8

What time of the day do gibbons eat?

Answer 8

Early morning

Question 9

Do gibbons socially groom?

Answer 9

Yes

Question 10

What are sub-adults?

Answer 10

Offspring that are older than juveniles.

Question 11

Are sub-adults fully integrated into the group?

Answer 11

No they stay on the periphery and will eventually disperse

Question 12

Gibbons are completely safe running about in the canopy. True or false?

Answer 12

False: fatalities are common

Question 13

As well as fruit, what will gibbons eat?

Answer 13

Flowers as they have a high nectar (sugar) content.

Question 14

Gibbons are small-bodied. What advantage does this give them?

Answer 14

They can exploit terminal branches.

Question 15

Who do they compete with for food?

Answer 15

Fruit bats and giant squirrels

Question 16

Gibbons will not eat invertebrates. True or false?

Answer 16

False; they will manipulate epiphytes to find them

Question 17

Gibbons make nests. True or false?

Answer 17

False; they sleep separately in the canopy so as not to attract predators

Question 18

When do gibbons go to bed?

Answer 18

A few hours before dark

Question 19

Gibbons can individually distinguish each other’s calls. True or false?

Answer 19

True

Question 20

Extra-pair copulations are common in both members of the pair. True or false?

Answer 20

True; both the male and female are banging the neighbours

Question 21

Which sex has a particularly impressive vocal call?

Answer 21

The female, called the ‘Female Great Call’

Question 22

What is the male’s reply to the Female Great Call?

Answer 22

The Male Coda

Question 23

What is the traditional view of this calling?

Answer 23

Advertising the strength of their pair bond, plus territorial defence

Question 24

What is Volker’s view?

Answer 24

Calling is a mate-testing mechanism, female is advertising her quality (or his lack of)

Question 25

It has been found that gibbons do not stay in the same groups for their whole life. True or false?

Answer 25

True

Question 26

Gibbons are peaceful and rarely aggressive. Why?

Answer 26

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

Question 27

Gibbons were traditionally thought to be territorial. Why would this be?

Answer 27

Because territoriality preserves monogamy.

Question 28

Where has recent(ish) research on gibbons been conducted? Who was it by?

Answer 28

The Khao Yai rainforest in Thailand

Sommer and Reichard, 2000

Question 29

Sommer and Reichard, 2000;

Khao Yai has disproved what 3 assumptions about gibbons?

Answer 29

1. They live in nuclear families
2. They maintain lifelong, monogamous relationships
3. They are territorial

Question 30

Sommer and Reichard, 2000;

How has research at Khao Yai shown territoriality to be false?

Answer 30

The home ranges of different groups overlap

Question 31

Sommer and Reichard, 2000;

How has research at Khao Yai shown nuclear grouping/lifelong monogamy to be false?

Answer 31

Not a single individual stayed with the same partner throughout life, many were serial monogamists or became polyandrous/polygynous.

Question 32

Do maturing individuals set up new home ranges?

Answer 32

No, they ‘squeeze’ into neighbouring groups

Question 33

Sommer and Reichard, 2000

How does calling show mate testing?

Answer 33

The female will sing her great call to advertise herself, testing the male to sing his coda and signal that she is already taken

Question 34

Therefore what can female calling be perceived to be?

Answer 34

An indicator trait, with call intensity demonstrating quality

Question 35

Sommer and Reichard, 2000

What percentage of groups at Khao Yai displayed non-monogamous grouping?

Answer 35

~25% (polyandry and polygynandry)

Question 36

What did work by Sommer and Reichard (2000) show?

Answer 36

Short dispersal distances + EPCs = patchwork families = high degree of relatedness = low aggression and infanticide