here - Joshua M. Linder

Acoustic Monitoring:
Transforming Primate Conservation Strategies in African Tropical Forest Protected Areas
JOSHUA M. LINDER1, CHRISTOS ASTARAS2, PETER WREGE3, and DAVID W. MACDONALD2.
1Department
of Sociology and Anthropology, James Madison University (linderjm@jmu.edu), 2WildCRU, University of Oxford, 3Cornell Lab of Ornithology, Cornell University
Partners and Funding:
GUN HUNTING INTENSITY
& TEMPORAL PATTERNS
THE PROBLEM
Hunting of wild animals to supply a growing commercial
trade in bushmeat is leading to declines of wildlife in many
African tropical forest protected areas. Anti-poaching
patrols have been largely unable to curtail illegal hunting
due, in part, to an inability to properly evaluate the patrol’s
impact on hunting and wildlife abundance and to adjust
patrol activity based on changing hunting patterns.
Annual/seasonal
gun hunting
patterns
Year 2: 2,050 gunshots recorded
0.55 shots/day/sensor
Year 1: 1,954 gunshots recorded
0.49 shots/day/sensor
Xmas/New Years
OUR OBJECTIVE
Daily gun hunting activity
Develop, test, and provide training for an evidence-based, decision-support
system to help design and assess the efficacy of anti-poaching patrols using
a novel application of passive acoustic monitoring techniques to quantify
spatial and temporal patterns of gun hunting activity.
Weekly gun hunting patterns
>65% of gun hunting
occurs at night
WHAT WE DID & WHERE WE DID IT
1
3
2
4
Market day
GUN HUNTING OFFTAKE
Concurrent hunter surveys
(weekly offtakes; 30 hunters from 3 villages)
Deployed 12 autonomous recording units (ARUs) in the tropical forest of
Cameroon’s Korup National Park (1,260 km2) for 2 years (June 2013 – May 2015)
 1,954 gunshots
recorded in Year 1
Total detection
area = 54 km2
 Extrapolated to 2,146
annual gunshots
(adjusted for days per month
the sensors did not operate)
 Hunter success rate = 75%
 Primates = ~14% of gun
hunting offtake
This is an ARU. It has a
gunshot detection radius
of 1.2 km and a detection
area of 4.5 km2.
 Gun hunting accounts for
77% of the total annual
offtake
Therefore…
 Each ARU continuously records sounds
(24 hrs/day; 365 days/yr) at a 4 kHz
sampling rate, capable of capturing
gunshots and animal vocalizations.
 Acoustic data, in the form of .wav files, are
stored directly to SD flash memory cards in
the ARU, which are changed when
batteries are replaced every 3 months.
 185,353 hrs of sound data
were collected
Gunshots
Red colobus calls
 Quantified spatio-temporal
patterns of gun hunting by
locating sound signatures of
gunshots in sound files
 Scanned sound files and tagged
candidate gunshots using an
automatic detector in RavenPro®
software; experts and hunters
manually screened potential
gunshots to exclude similar
sounds
 Determined detection range of
ARUs from an analysis of
controlled gunshots from known
distances to the ARU
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
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1,609 animals shot annually in 54 km2 study area
30 animals shot / km2
>37,000 animals shot annually in all of Korup NP
>5,000 primates killed annually
WHY THIS MATTERS
 Acoustic monitoring provides unprecedented level of detail on spatial
and temporal patterns of gun hunting, which can be used to:
 design, evaluate, and adapt anti-poaching patrols
 By using acoustic monitoring to establish a baseline for gun hunting
activity, protected area managers can then assess how different antipoaching patrol strategies influence spatio-temporal gun hunting
patterns.
 We are currently testing the efficacy of different antipoaching patrol strategies in Korup NP.
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