WALLACE RESOURCE LIBRARY
Module 02 – Ecological Survey
Techniques
D04 – Camera trapping to assess large
mammal populations in Amazonia
Why survey mammal populations?
• Understand population dynamics
- e.g. calculating the carrying capacity of the
environment for different mammals
• Determine impacts of extreme events
- e.g. extreme high water levels of during flooded season
• Check sustainability of hunting
- confirm hunting quotas are leaving sufficient animals
for stable populations
Line transects
• Used for counting numbers of
conspicuous animals
• Observers walk along transect
• Distance at which animals of
interest are seen are measured
• Software estimates population
densities
Camera traps
• Digital cameras triggered remotely by motion and
heat
• Placed along trails where mammals are easily
photographed
• Capture images of shy and elusive animals, and
crepuscular and nocturnal animals
Survey methodology
• Cameras placed in pairs on
trails of the Pacaya Samiria
Nature Reserve, Peru, for 3
months
• Cover an area of
approximately 50km2
• Checked weekly to collect
images/change batteries
• Counts calculated per 1000
camera trap days
Research questions
1. Based on the camera trap images, how did the sizes
of the red brocket deer and ocelot populations
change between 2009 and 2011?
2. How might any changes in red brocket deer and
ocelot numbers be related to the extreme high
water levels of 2009?
SummarySummary
Conclusions
Conclusions
• Captured images of red brocket deer fell
significantly between 2009 and 2011
• Captured images of ocelot increased
significantly between 2009 and 2011
• The high water levels may explain the
population size changes
• reducing food availability and
increasing competition and
predation for the deer
• increasing prey density for the
ocelot