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

1
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
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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
3
Runaway Creek Nature Reserve
Belize Protected Areas
RCNR
4
Hurricane Richard damage at RCNR

• Damage assessment
• 42.8 major damage
• 27.6 minor damage
• 29.6 no observable damage

5
Hurricane Iris

• Monkey River, Belize
• October 8, 2001
• Category 4 hurricane
• Top winds 230 kph

www.NOAA.com
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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

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Results
Dramatic reduction in population density, group
size, and fruit availability/consumption
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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.
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Predictions

• 1. 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

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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)

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Results Population Changes
Group composition as of January 2011
Adult Subadult Juvenile Infant
Male 5 2 5 3
Female 13 2 6 1
Total individuals 37 Total individuals 37 Total individuals 37 Total individuals 37 Total individuals 37

• All individuals accounted for in 3 months
  post-hurricane
• 3 births between December 2010 and January 2011

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Results Diet



Mean proportion of feeding activity

• Taken from all instantaneous subgroup scan
  samples
• Paired t-tests
• Less ripe fruit (plt0.001)
• More flowers (p0.015), leaves (plt0.001), and
  unripe fruit (plt0.001)

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Results Activity


Mean proportion of activities

• Taken from all instantaneous subgroup scan
  samples
• Paired t-tests
• More time feeding (p0.001), and in social
  activities (p0.023)

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Results Subgroup Size

Mean number of individuals per subgroup per day

• Taken from all focal and scan samples
• Paired t-tests
• Average subgroup per day decreased (p0.026)

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Results Subgroup Stability


Mean frequency of fissions/fusions per
observation hours

• Collected ad libitum during subgroup follows
• Paired t-tests
• Both fissions (p0.005) and fusions (p0.014) per
  hour decreased

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Summary of short term-effects of the hurricane

1. No population losses
2. Evidence of dietary flexibility
3. Minor changes to activity budget
4. Evidence of grouping flexibility toward smaller,
   more stable subgroups

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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

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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