the short-term effects of hurricane richard on the diet, behaviour, and sub-grouping patterns of...

The Short-Term Effects of Hurricane Richard on the Diet, Behaviour, and

Sub-Grouping Patterns of Spider Monkeys (Ateles geoffroyi) at Runaway

Creek Nature Reserve, Belize

Jane Champion1, Kayla Hartwell1, Mary Pavelka1, and Hugh Notman1 & 2

1University of Calgary and 2Athabasca University, Alberta, Canada

Hurricane Richard

• October 25, 2010• Category 2 hurricane • Winds up to 155 kph• Runaway Creek

Nature Reserve directly in path

• $80 million (US) damage

Belize Weather Center

Runaway Creek Nature ReserveBelize Protected Areas

RCNR

Hurricane Richard damage at RCNR

Damage assessment:– 42.8% major damage– 27.6% minor damage– 29.6% no observable damage

Hurricane Iris

• Monkey River, Belize

• October 8, 2001

• Category 4 hurricane

• Top winds 230 kph

www.NOAA.com

Hurricane Iris

• 100% forest defoliation• No fruit available for 18 months• Diet switched to total folivory• Increase in time spent inactive • Decrease in social behaviour

ResultsDramatic reduction in population density, group size, and

fruit availability/consumption

Objective of this Presentation

Document short-term effects of Hurricane Richard on Runaway Creek Nature

Reserve spider monkey population, diet, activity, and subgroup size and stability.

Predictions1. Population losses

2. A change in diet, which will reflect changes in food availability

– Lower fruit consumption– Increase consumption of leaves and fallback foods

3. A change in activity budgets – More time dedicated to traveling– Less time spent in social activities

4. Reduced sub-group size

Methods• 10 minute focal samples on adults and subadults

• Instantaneous subgroup scans every 30 minutes

• Subgroup composition changes recorded via ad libitum sampling

• 4 months pre- and 3 months post-hurricane data used

– 35 field days during each period (70 days total)

Adult Subadult Juvenile InfantMale 5 2 5 3Female 13 2 6 1

Total individuals: 37

• All individuals accounted for in 3 months post-hurricane

• 3 births between December 2010 and January 2011

Results: Population Changes

Group composition as of January 2011

Results: Diet

• Taken from all instantaneous subgroup scan samples• Paired t-tests• Less ripe fruit (p<0.001)• More flowers (p=0.015), leaves (p<0.001), and unripe fruit (p<0.001)

0

0.1

0.2

0.3

0.4

0.5

0.6

Flowers Ripe Fruit Unripe Fruit Leaves

Pre-hurricane

Post-hurricane

*

* *

*

Mea

n pr

opor

tion

of fe

edin

g ac

tivity

Results: Activity

• Taken from all instantaneous subgroup scan samples• Paired t-tests• More time feeding (p=0.001), and in social activities (p=0.023)

*

*M

ean

prop

ortio

n of

acti

vitie

s

Results: Subgroup Size

• Taken from all focal and scan samples• Paired t-tests• Average subgroup per day decreased (p=0.026)

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5Pre-Hurricane

Post-Hurricane

*

Mea

n nu

mbe

r of i

ndiv

idua

ls p

er s

ubgr

oup

per d

ay

Results: Subgroup Stability

• Collected ad libitum during subgroup follows• Paired t-tests• Both fissions (p=0.005) and fusions (p=0.014) per hour decreased

**

Mea

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eque

ncy

of fi

ssio

ns/f

usio

ns p

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on h

ours

Summary of short term-effects of the hurricane

1. No population losses2. Evidence of dietary flexibility3. Minor changes to activity budget 4. Evidence of grouping flexibility toward

smaller, more stable subgroups

Implications and directions for research

• Spider monkeys more resilient to major habitat disturbance than expected, at least in the short-term.

• Support some of the findings reported for Hurricanes Emily and Wilma (Rebecchini et al)

• Future research is required to examine forest regeneration in more detail and the long-term effects of these changes to spider monkeys and other primate species

Acknowledgements

• Project supervisors: Mary Pavelka and Hugh Notman

• Co-author: Kayla Hartwell• Field support: Stevan Reneau and Gilroy Welch• Statistical support: Dr. Tak Fung• Natural Sciences and Engineering Research

Council of Canada, National Geographic Society, The University of Calgary