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Geomatics, surveying
& measurement
technical
20 PositionIT – Aug/Sep 2018
The use of drones in conservation
by Dr Debbie Jewitt, Ezemvelo KZN Wildlife and Luke Wijnberg, 3DroneMapping
Drones, or unmanned aerial vehicles (UAVs), are rapidly changing the face of the conservation industry.
They have the potential to revolutionise conservation and spatial ecology. At the core of conservation is the
monitoring of species populations and their habitats.
Traditional approaches to
collecting species populations and
habitats data may be resource
intensive, potentially inaccurate,
difficult to validate and may pose a
significant threat to human safety
due to the presence of dangerous
animals or environments [1]. In fact,
the leading cause of wildlife workers'
deaths in the US (66%) is due to
manned aircraft crashes. The slow,
low-level, manned flights required
to collect biological data may lead to
aerodynamic stalls, power-line collisions
or crashes due to downdrafts [2].
UAVs provide an opportunity to obtain
accurate data and high-resolution
images in a better, faster, cheaper
and safer manner [3, 4]. The use of
drones in the conservation sector is
not limited to only monitoring species
and their habitats. Drones can be used
for management purposes, technical
services, eco-tourism marketing,
law enforcement, anti-poaching
and search-and-rescue efforts. We
discuss a few of the potential drone
applications and challenges faced in
the conservation sector.
Drone use in conservation
Species monitoring and
habitat mapping
There is a growing body of literature
on the use of drones for monitoring
species and their habitats. Drones
have been used successfully, amongst
others, to monitor a wide range of
species from birds and reptiles [5]
to elephants [6] and marine species
such as turtles, whales, dolphins and
dugongs [7]. Mapping habitat allows an
assessment of habitat extent, condition
and suitability [8, 9]. Similarly,
modelling the spatial and temporal
abundance of species provides
insights into vegetation dynamics
and ecosystem processes or disease
transmission and persistence [10, 11].
Drones are proving extremely
beneficial in places where humans
cannot easily or safely reach, or where
we are unable to perform functions
in a timely and efficient manner.
For example, Cape vultures (Gyps
coprotheres) are cliff nesting species.
Traditionally, ecologists survey the
nesting vultures from the bottom of
a cliff at an oblique angle. The birds
nest on ledges or potholes in the
cliff face, making it difficult to detect
all the nesting birds. Drones can fly
parallel to the cliff face, making it
much easier to detect and photograph
the nesting birds. Recent surveys have
suggested an increase from 36 to
77 nests detected at a colony and a
population increase from 120 to over
200 individuals (pers. comm. Andy
Ruffle and Mike Neethling, Oribi Vulture
Viewing Hide). Similarly, surveys
of crocodiles have indicated a 26%
increase in the number of crocodiles
detected and yielded superior size
class determinations [12]. These
results unfortunately do not indicate a
real increase in the numbers of these
threatened species, it is simply an
improved technology yielding better
results. This poses challenges to
accurately comparing historical survey
data with data acquired with the new
drone technology. Data will need to be
collected by both methods for a couple
of years in order to develop statistical
correlations between the datasets to
apply it to historical data for trend
analyses.
The advancement of machine learning
algorithms and artificial intelligence
will enhance the ability to collect and
analyse the data. Chirayath and Earle
developed fluid lensing, an algorithm
that allows a drone to “see” through
waves, effectively opening up the
shallow marine environment and
reefs for drone surveys [13]. Object
identification and counting will in future
facilitate game counts, but significant
photographic databases are required
for correct object identification.
Consider, for example, animal species
that may be sexually dimorphic, occur
Fig. 1: Counting crocodiles. (Credit: P. Hanbury)
PositionIT – Aug/Sep 2018 21
technical
GEOMATICS, SURVEYING & MEASUREMENT
in different habitats, or may adopt
different poses such as standing,
sitting or lying down. The computer
programme needs to be taught that
all these variations are still indeed the
same kind of animal.
Management applications
Drones may facilitate the management
of Protected Areas. For example,
drones can be used to monitor alien
plant invasions, check fence lines
and infrastructure, and map water
sources etc. Burn scar mapping is
another essential application because
fire is an important management tool
and managers need to determine
the extent and intensity of burns
applied in a reserve. Fire removes
moribund vegetation and limits bush
encroachment. It can be used as
a tool to move herbivores around
the Protected Area. Another very
successful application has been the
assessment of erosion control features
and monitoring active erosion along
river courses. Drones therefore
provide an indication of the success of
management interventions.
Search and rescue
Remote, mountainous areas are
attractive to hikers but often these
areas can be dangerous and climatic
conditions can change rapidly,
resulting in some hikers getting lost
or injured. Finding these hikers may
be resource intensive and flying
manned aircrafts at high altitudes in
areas of steep topography is risky.
Manned aircraft are exposed to huge
risks when deployed for search and
rescue operations at high altitude.
Due to low air density, wind shear
and other factors, these flights need
to be undertaken by experienced
pilots and have resulted in loss of life
or damage to equipment. Search-
and-rescue flights need to be done
with groundspeed as low as possible
to scan the area for people. The
cost of manned flights is another
consideration as crew, fuel and
insurance need to be accounted for.
A recent search-and-rescue operation
in the Drakensberg cost almost
R77-million. The SAPS helicopter
crashed at high altitude, putting the
lives of experienced and specialised
staff and a tracking dog at risk (Pers.
comm. Stephen Richert, Ezemvelo KZN
Wildlife).
In light of this, the authors
investigated the use of drones to
complement existing search-and-
rescue efforts in the Drakensberg.
Fixed-wing and multirotor aircraft
where used in simulation exercises to
detect personal effects and clothing.
Multirotors ranging from the DJI Mavic,
Phantom 4 and the Matrice 600 were
used in the assessment and all of
the aircraft could successfully detect
the placed items when flown along a
designated hiking trail. The smaller
multirotors were more portable and
could be carried into the search area,
providing improved visuals on cliff
ledges, overhangs and ravines. The
optical zoom on the DJI Matrice 600
provided greater up-close inspection
capability with its 30x optical zoom.
The fixed-wing Believer aircraft
proved extremely useful, providing
high-resolution mosaicked imagery
that could be systematically searched.
The preliminary trials were not without
their challenges, however. The cold
temperatures at high altitude limited
battery operation (typical battery
operating specifications range from
0°C to 40°C). The temperature
limitations on the batteries could be
overcome by ensuring the batteries
were warmed before use, with active
flights keeping the batteries warm.
Similarly, the cold temperatures
combined with cloudy conditions
Fig. 2: A fence line contrast between a Protected Area (top) and an overgrazed farm
(bottom). This provides insights into the effects of stocking rates on vegetation.
(Credit: L. Wijnberg)
Fig. 3: Mapping a river bed with contour lines to assess erosion along the river course.
(Credit: L. Wijnberg)
22 PositionIT – Aug/Sep 2018
technical GEOMATICS, SURVEYING & MEASUREMENT
resulted in icing of instruments and
control surfaces. This was previously
unheard of and not considered as a
flight risk. It was therefore essential to
keep a close watch on the instruments
at all times.
Challenges
Flights
Whilst drones are generally safe
and easy to fly, without due care
and planning they are prone to
failure. One of the most common
mistakes is to fly the drone without
having read the manuals or setting
the appropriate parameters on the
applications associated with the drone,
e.g. calibrating the home position and
return-to-home heights. The same
goes for not adhering to the operating
specifications for various components
such as operating the batteries in
extreme cold or heat. These can
interfere with flight operations and
sensors, leading to mission failures.
Mitigation measures can be planned
by adjusting the time of flights,
shortening flight times or the like.
Wind is another factor often not
adequately taken into consideration.
Flying into the wind can shorten flight
times, meaning the battery life may
not be sufficient to return to the
designated landing areas. Winds aloft
need to be taken into consideration
since the ridges and valleys offer a
false sense of security as they often
shelter the pilot from winds that the
aircraft may be experiencing 400 ft
above.
An increase in altitude dramatically
reduces air density. An aircraft’s
handling characteristics such as
endurance, turn diameter and stall
speed all need to be considered when
planning sorties.
Maintaining separation from manned
aircraft is crucial for all operations.
Creating spatial references as to the
intended route of aircraft and their
current positions allows all operators
to know where everyone is in the sky
and how to keep out of each other’s
way. Progress is underway to develop
aircraft tracking systems for both
manned and unmanned aircraft and is
currently in testing. This is expected to
significantly reduce the risk of possible
mid-air collisions while allowing pilots
to focus on the task at hand.
Animal disturbance
The use of drones to monitor
animals may create undesirable and
unforeseen impacts on wildlife [14].
Even if there is no visual response
from the animals there may still be
physiological stress responses such as
elevated heart beats, as observed in
studies conducted on Black bears in
North America [15]. Different species,
life histories, environments, historical
context, type of UAV (shape, volume
and colour) and method of operation,
will all influence animal disturbance
responses [14]. Empirical evidence
needs to be collected across a wide
range of species and habitats. Best
practice guidelines suggest minimising
audio and visual disturbance to
animals, choosing a launch site
away from animals and avoiding a
threatening flight approach or sporadic
flight movements.
Bird of prey interactions with drones
are well known in the industry and
indeed birds of prey are being trained
to remove drones from areas where
flight is illegal, unsafe or infringing
privacy rights. Breeding and territorial
birds are more likely to attack drones.
Some examples in the region include
fish eagles, kites and even pied crows.
Legislation
Drone flights are regulated by the
South African Civil Aviation Authority
(SACAA) and there are numerous
restrictions in place as to where and
how flights can be conducted. It is
a lengthy and expensive process to
become legally compliant. However,
there are additional pieces of
legislation that prohibit or regulate
flights in other areas. The National
Fig. 4: A simulated body made from clothing that was used in the search and rescue trial.
(Credit: L. Wijnberg.)
Fig. 5: The Drakensberg Mountains where search and rescue trials were conducted using
drones. (Credit: D. Jewitt)
PositionIT – Aug/Sep 2018 23
technical
GEOMATICS, SURVEYING & MEASUREMENT
Environmental Management: Protected
Areas Act (Act 57 of 2003) and
provincial ordinances regulate all
flights (manned and unmanned) over
Protected Areas. Flights may not be
lower than 2500 ft above the highest
point without prior written permission
from the management authority.
Conclusions
Drones are revolutionising workflows
in many industries. There are
multiple applications of drones in the
conservation sector. However, the
current legislation and drone limitations
(e.g. battery life, payload) make them
well suited to monitoring smaller areas.
Depending on the scale of application,
manned flights or satellites would be
more appropriate tools to use. This is
not to say that drones have no role or
are taking over manned aircraft uses
in conservation, but may supplement
or enhance the currently capabilities
and deliverables. Improving technology
and accessibility in all these forms of
Fig. 6: A search and rescue trial conducted using drones. (Credit: D. Jewitt)
African geospatial survey and solution
provider Geosense have upgraded their
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addition of a Leica Pegasus: Two Ultimate
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The portable mapping system enables
the rapid and simultaneous collection of
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and high-density point cloud data
from a moving vehicle. With no trafc
management required, the risk to staff is
signicantly reduced, allowing surveys to
be completed in less time and at a fraction
of the cost of utilising traditional methods.
The P2U sensor is the latest, upgraded
variant of the Pegasus range and features
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a new web sharing platform, enhancing
the usability of the Pegasus system in
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The captured 3D geospatial data has
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Coupled with extensive survey experience
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“In conjunction with our aerial survey
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The captured data can be processed
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For more information please get in touch
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remote sensing are providing a range
of tools to aid conservation initiatives.
Acknowledgements
The following people are thanked for
their input into the drone programme
for conservation: Norbert Plate,
Gerd Oliver, Frik Lemmer, Sonja
Krueger, Wayne Evans, Stephen
Richert, Elesta Hadebe, Andy Ruffle,
Mike Neethling, Cátharine Hanekom,
Phillip Hanbury, Chris Williams,
Scott Hill and Gary Mortimer.
References
The references are available with the
online version of this article at
https://wp.me/p5dDng-156Y.
Contact Dr Debbie Jewitt,
Ezemvelo KZN Wildlife,
debbie.jewitt@kznwildlife.com
