Lecture 11

Question 1

Describe meerkat groups.

Answer 1

Consists of 3-30 individuals

Matriarch that mothers 75% of group.

Question 2

In Meerkat groups there are 2-15 adult helpers that…?

Answer 2

help in guarding, carrying, feeding.

Question 3

Describe meerkat foraging characteristics?

Answer 3

Forage for 5-8 hrs. in the open.
May dig up to 20cm below ground.
While digging, unable to detect predators.

Question 4

What was the study done by Cluttonbrock?

Answer 4

Selfish sentinels in cooperative mammals.

Question 5

Describe Cluttonbrock’s study.

Answer 5

Meerkats alternate guard duty.
Raised guard present 50% foraging time.
Guards announce presence with repeated calls.

Question 6

Foraging animals are less __________ when a guard is present.

Answer 6

vigilant

Question 7

In 2000 hrs. of observation no guards were killed by predators. Why?

Answer 7

Guards remained close to burrow.

Question 8

Describe the observations in the Ranchland.

Answer 8

Raised guard 12% foraging time
Ind. spent 1.5% of foraging time on raised guard.
Guarding at ground level = to park

Question 9

Describe the observations at Kalahari Park?

Answer 9

Raised guard 56% of time.

Ind. spent 10% foraging time on raised guard.

Question 10

In meerkat groups ________ __________ spent more individual time in raised guard than individuals in larger groups.

Answer 10

solitary individuals

Question 11

T/F: The amount of time a guard was present within the small group was significantly more.

Answer 11

false, less

Question 12

What was observed about predation rates between the park and ranchland?

Answer 12

Predation rates on small groups in the park and ranchland increased equally with decreased group size.

Question 13

Dominant females in meerkat groups do what?

Answer 13

Contributed less to raised guarding than any other group member (including immigrants)

Question 14

How much time did unrelated immigrants spend in raised guard?

Answer 14

Spent and equal amount of time on raised guard as other individuals in the group.

Question 15

What are some characteristics abt babysitters in meerkat groups?

Answer 15

Sitters stay with newborns for first 3 weeks in 24 hr. shifts.
Sitters lose 1-2% of body weight.

Question 16

A study was done where meerkats were fed with hard boiled eggs. What were the findings?

Answer 16

Increased guarding time 30%
Long guarding bouts
3X likely to be raised guards
More likely to guard before forage.

Question 17

What did Munn study in 1986?

Answer 17

Observed large flocks of mixed species birds in Peru rain forest.

Question 18

What were the roles of the birds Munn studied?

Answer 18

Some were food finders and others were alarm callers.

Question 19

What was true about the large mixed species flocks?

Answer 19

Appear to offer increased fitness in terms of improved vigilance and food discovery.

Question 20

Within flocks there is a division of labor; what is it?

Answer 20

Alarm callers are the antshrike and tanager who give alarm calls majority and first to sound them. Other birds forage.

Question 21

What do the sentinels do in these mixed species flocks?

Answer 21

Rely on insect flushing of other species within flock
They gather under foraging bird and collect insects
Never grabbed food frm foraging species.

Question 22

What do sentinels do that is especially bitchy?

Answer 22

They freaking alarm call so foraging bird will fly away and they can take food. Or pursue the same flying insect.

Question 23

Munn played recordings of true/false alarm calls. What was his hypothesis?

Answer 23

If calls are deceptive then false alarms should elicit the same response as true.

Question 24

What did Munn find when he classified 106 alarm calls as true or false?

Answer 24

True calls were given when hawk model or if other flock species alarmed and froze for several minutes.
False calls were followed by sentinels flying into open to chase insects, or if no hawk was within 20m of calling bird.

Question 25

False calls were given _______ percent of the time by sentinels.

Answer 25

50%

Question 26

In Munn’s experiment, how do flock members react to true or false alarm calls.

Answer 26

They respond consistently to both true and false alarm calls, but not to control rattle call.

Question 27

Tanagers sounded alarms less when foraging…?

Answer 27

alone than when another bird was involved.

Question 28

When did the rate of responding increase?

Answer 28

When either sentinel species was feeding its young.

Question 29

Sentinel species give a significant amount of _______ ______.

Answer 29

false alarms.

Question 30

How can herding animals reduce their risk of predation?

Answer 30

Herding with diluting partners.

Question 31

In herding group selection, larger bodied species may have a better what?

Answer 31

Have a naturally better vantage point.

Question 32

Giraffes may provide an added benefit of what?

Answer 32

Increased vigilance and improved detection abilities for predators.

Question 33

In the presence of predators, what do giraffes do?

Answer 33

Engage in a staring posture when in the presence of predators.

Question 34

Mixed species herds will benefit from the ________ ________.

Answer 34

dilution effect

Question 35

What areas to giraffes avoid?

Answer 35

woody areas, prefer savanna habitats.

Question 36

In giraffe-zebra herds…?

Answer 36

Presence of giraffes lowered the average time zebras were vigilant by 65%.

Question 37

T/F: Zebra spent 50% less time when herding with wildebeest than with giraffes.

Answer 37

False, switch giraffes and wildebeest.

Question 38

When do zebras focus scan?

Answer 38

When herding alone they’re used proportionally more than general scans.

Question 39

What scans do zebras use when herding with giraffe?

Answer 39

Used general scans more than focus scans.