Reptile behaviour (lecture 8)

Question 1

reptiles use many kinds of signaling

Answer 1

visual
auditory
olfactory

Question 2

visual

Answer 2

• medium range
• fast transmission rate
• does not travel around objects
• little night use
• fast fade out time
• easy locate sender
• varies from costly to manufacture and maintain signals(risk or predators)

ex. jacky dragons attract attention with tail flick; must be conspicuous against moving vegetation

dragons have UV vision
and change color

Question 3

auditory

Answer 3

• long range
• fast transmission rate
• travels around objects
• night use
• fast fade out time
• locate sender varies
• high cost to manufacture

ex. geckos vocalize

Question 4

olfactory

Answer 4

• short range
• slow transmission rate
• travels around objects
• night use
• slow fade out time
• locate sender is difficult
• low cost to manufacture

Question 5

most reptiles

Answer 5

solitary
have polygamous mating system
no parental care

Question 6

skinks, geckos, and snakes

Answer 6

have evolved some form of grouping and social behavior has evolved

• aggregation
• rudimentary parental care
• stable social groups

Question 7

Egernia

Answer 7

• genus of Australian skink
• shows the most complex forms of social behaviour
• a model system for understanding the evolution of social behavior
• stable pair bonds within and between seasons (social and genetic monogamy)
• groups consist of an adult pair and offspring

Question 8

social behavior and group structure

Answer 8

• facilitated by recognition of familiar and unfamiliar individuals and/or related and unrelated individuals
  ex. tree skinks appear to recognise related individuals

gidgee skinks and block role skinks are mainly able to distinguish familiar/unfamiliar individuals irrespective of relatedness

Question 9

sociality

Answer 9

expected to evolve when the benefits outweigh the costs

Question 10

cost

Answer 10

• increased visibility of predators

- increased competition for resources and increased disease and parasite transfer

Question 11

benefits

Answer 11

• increased protection from predators
• physiological benefits(reduced heat or water loss)
• parental care/protection

ex. Egernia
- increased vigilance in gidgee skinks and parental care in black rock skinks

Question 12

factors thought to promote sociality

Answer 12

ecological factors

life-history traits

Question 13

ecological factors promoting sociality

Answer 13

aggregation

limited resources

Question 14

aggregation

Answer 14

occurs when access to key resources (like shelter, food, and mate) is limited because they are clumped in space or time

Question 15

limited resources

Answer 15

can favor the evolution of territoriality and social groups

Question 16

life-history traits promoting sociality

Answer 16

long life span and long period until reproductive maturity may favor delayed offspring dispersal

Question 17

comparing social behavior within and between species

Answer 17

tree skinks differ in their social behavior depending on the habitat

• suggesting that habitat influence behavior
• almost all Egernia with stable social groups are rock dwelling, except for E. frerei(challenging habitat hypothesis)

Question 18

life history difficult to assess

Answer 18

-all examined species so far are long lived and have delayed juvenile dispersal