Possible Uses for Animal Tracking and Sensor Data
Ragnar Stølsmark and Erlend Tøssebro
Institute of Electrical Engineering and Computer Science, University of Stavanger, Stavanger, Norway
Keywords: Animal Tracking, Sensors.
Abstract: What other uses are there for animal tracking? We argue that the location data can be made more useful by
analyzing it to determine the future position of animals and optimize farming. Other sensors such as
temperature and RFID could be added to increase benefit for both farmers and scientists. Adding more
sensors is not trivial and major challenges include energy consumption, cost, size and establishing a market.
However these obstacles can be dealt with and the possibility of having mobile sensor platforms available to
the public is intriguing.
1 INTRODUCTION
The invention of the GPS technology has
revolutionized animal tracking. Animal tracking
used to be reserved for scientists tracking radio
tagged animals with big antennas. Now, with
inventions such as Telespor (Thorstensen et al.,
2004), farmers are tracking their animals and are
able to easily locate them over the internet. This is of
course a big improvement over the way it used to be,
when the farmer could spend weeks walking in
difficult terrain trying to retrieve his animals.
Large scale animal tracking generates vast
amounts of data. A sheep flock can consist of
several hundred animals that have their position
logged multiple times each day for approximately
three months. It is our opinion that using this data
only to establish the location of animals is a terrible
waste. Just by performing some simple analysis it
could be possible to improve farming and create
models of animal movement.
Adding different sensors to the animal is
certainly possible if a modular platform such as
Libelium’s Waspmote is used. This will open up a
range of new possibilities such as accurate local
weather forecasting and predator detection. However
it has far greater challenges and is therefore also
more difficult to achieve than simply adding an
analysis layer on top of the animal location data.
This article is focused on sheep and sheep
farming, since that is what we have previous
experience from. We feel however that many of the
observations are true also for other types of animals
such as cows, goats and horses.
This paper is structured as follows: Section 2
covers related work. In section 3 different uses for
animal location data is described, including farming
optimization and location extrapolation. Section 4
shows examples of what can be achieved by adding
different types of sensors. The fifth section discusses
difficulties concerned with adding more sensors.
Section 6 concludes the paper.
2 RELATED WORK
The electronic shepherd research project
(Thorstensen et al., 2004) culminated in the
commercial Telespor product, which is the
technology that Norwegian sheep farmers use to
track their sheep. It has become quite popular and is
also being used for cows. The technology is based
on obtaining the position of the sheep via GPS and
transmitting it via GSM to a central server. The
farmer can then view the position of his sheep on a
web site. This technology in itself already generates
location data and can therefore be used for those
things we suggest in the next section. It is not
modular and therefore will need to be modified in
order to support additional sensors.
In the survey on wireless sensor networks by
(Akyildiz et al., 2002), they list a lot of the possible
sensors that can be used in a wireless sensor
network. These include temperature, humidity,
movement, pressure and noise among others. This
244
Stølsmark R. and Tøssebro E..
Possible Uses for Animal Tracking and Sensor Data.
DOI: 10.5220/0004315402440249
In Proceedings of the 2nd International Conference on Sensor Networks (SENSORNETS-2013), pages 244-249
ISBN: 978-989-8565-45-7
Copyright
c
2013 SCITEPRESS (Science and Technology Publications, Lda.)
survey, although a bit old, is also a good
introduction into many of the typical wireless sensor
network problems such as energy consumption, cost
and size issues.
Animal movement analysis is studied by (Jonsen
et al., 2003) in an article concerned with how the
data from GPS tracking can be used to create animal
movement models. It uses state-space modeling to
model animals’ interaction with the environment
while also dealing with measurement error. This
method could be used if one would try to make a
movement model for sheep based on the data from
Telespor. State-space modeling for creating animal
movement models has also been studied by
(Patterson et al., 2008).
Finkenzeller and Müller has written a good
introduction (Finkenzeller and Müller, 2010) into
near-field communication (NFC) and RFID which is
recommended for those interested in these emerging
technologies.
There is a strong tradition for farming
optimization. An example is the paper by (Mulder et
al., 2006) which tries to optimize cattle breeding by
testing out different breeding strategies and
determine which strategy leads to the highest milk
yield. In the article by (Zervas, 1998) he argues that
there is a need for a collective optimizing strategy to
best utilize the Greek pastures. A perfect mix of
sheep and goats should be used to maximize the
potential of the grazing areas.
3 USES FOR ANIMAL
LOCATION DATA
An animal tracking system delivers a set of time
stamped locations for each animal. This makes it
possible to see the last known location of the animal
and also create a trace of the animal’s movement
from the beginning of the tracking. But with some
further analysis of the data, it is possible to increase
the utility of such a system.
3.1 Location Extrapolation
Animals’ movements are seldom completely random
as they are conscious beings with certain needs.
Examples of such needs are the need to sleep, eat
and drink. This leads to patterns in their movement
that can be used to extrapolate their current or future
position based on the location data and a movement
model. In its simplest form this location
extrapolation can simply be to assume constant
velocity and calculate a future location using the last
known speed and direction.
Using knowledge of animal behavior it is
possible to obtain far better predictions. Many
animals sleep at night. Therefore their position at
dawn will be close to where they ended up the
previous evening. This can be used both in location
extrapolation, by implementing a no movement at
night rule, but also in duty cycling. Since the
animals do not move at night, the tracking device
can be switched off during this time and rather have
more updates during the day.
To predict the future location of the animal
weeks in advance, knowledge of animal behavior
and tracking data from previous years becomes
important. Their relative importance compared to
last measured location and direction should increase
the further into the future one tries to predict. Sheep
can be used as a good example of how animal
behavior can be used in far future prediction. Sheep
prefer to eat the more nutritious early spring grass.
To get to this grass, the sheep moves higher and
higher up into the mountains as the summer
progresses. This can be used to predict the altitude
the sheep will most likely be at in a few weeks.
Knowing the altitude it is possible to rule out areas
that are either too high or too low. For such a system
to work each animal type should have its own
behavior model. Including previous year’s location
data to adjust the behavior model on an individual
level would probably also be important. Animals are
individuals and some prefer to stay with the flock
while others are lone wolfs and do not come down
from the mountains until the winter sets in.
To create a behavioral model it will be important
to have one set of location data to use while
developing it and another set of data to verify the
validity of the model. It will also be important to test
the accuracy of the predictions on an animal species
basis. Some species have more regularity in their
movement than others and can therefore be predicted
further into the future. If it is even possible to give
any meaningful predictions more than a few days in
advance is an open question that requires further
investigation.
3.2 Farming Optimization
Farmers have a strong tradition for optimizing the
farms annual output. In case of sheep farms their
output is measured in the amount of meat they
produce. An example of such an optimization is the
strategic breeding that has led to sheep that produce
more meat and also meat of a more desirable quality
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245
in terms of fat percentage. We argue that the
location data can be used to optimize farming in
several ways.
Location data combined with knowledge of an
animal’s weight before and after the grazing season
should be analyzed to establish the best grazing area.
If one area over time sets itself apart from the rest,
by providing a larger weight gain among the animals
that have grazed there, measures should be taken to
optimize the time the animals spend in that area.
This optimization can be achieved in at least three
ways. The animals can be released as close as
possible to this area. This will lead to more animals
discovering the good pastures and therefore graze
there. Selective breeding is also an efficient way of
controlling where the animals go to graze, since
small animals learn from their mothers where to go.
Therefore the grazing pattern of the animals should
be taken into consideration as one of the parameters
when deciding which animals should be allowed to
breed. The grazing area can also be affected by the
farmer by making it more desirable for the animals.
This can be done by easing access via improved
trails or by putting the salt stone in that area. The
salt stone is a block of salt that the farmer place in
the grazing area so that the animals have access to
salt. The animals will go to lick the salt stone quite
often. Therefore it is quite a popular spot for the
animals and it makes sense to put it in the best
grazing area.
When the grazing season ends it is time to collect
the animals. Already this is greatly simplified by
using an animal tracking system, but we think that
there is still room for improvement. It should be
possible for an animal tracking system to
automatically find the shortest possible path to
retrieve the animals. This is not as trivial as it might
sound. To get a good solution it would have to take
into account many factors: The start and end
location, the presence and quality of trails in the
area, the future position of the animals at the time of
collection and the benefit of leading a smaller flock.
There could probably be other factors as well. It
would certainly be beneficial to the farmer to get a
suggested path as the areas can be large and difficult
to walk across and therefore choosing the wrong
path can lead to many hours of extra work.
3.3 Other Applications
The location data collected from the sheep can also
be used in non-farming related purposes. An
example is automated collection of trails and paths.
The sheep follows paths through the landscape and
these can be mapped by a simple algorithm. The
hypothesis is that the more the trail is used by the
sheep, the better the trail. There are two reasons for
this. First, the sheep is an animal that prefers
comfort and will therefore choose the best trails
from A to B. Secondly; the sheep creates their own
trails through use alone. Therefore the more use the
larger and better the trail. These trails should
therefore be ranked based on their use and could
then be presented to the public who wants to plan a
hiking trip.
4 OTHER SENSORS
It is possible to attach sensors to an animal that can
be used in combination with the location data to
provide interesting information for the farmer as
well as others. This section covers different sensor
types and the benefit of adding them.
4.1 Temperature Sensor
The use of a temperature sensor can be divided into
two categories depending on the sensors placement.
The sensor could be placed as an external sensor that
measures the ambient temperature. It is also possible
to attach an internal sensor that monitors the
animal’s body temperature.
The external sensor is interesting as a tool in
weather forecasting. The data collection is
synchronized and performed multiple times in many
locations. This gives a unique possibility to create
accurate local weather models about how the
temperature changes with the terrain. This kind of
data collection would be almost impossible to
achieve any other way. It is easy to get synchronized
temperature readings from stationary weather
stations and a scientist walking with a thermometer
can add mobility. However, having 500 scientists
walking around for 3 months, doing regular
synchronized temperature readings, is impossible.
The animals could easily have other weather related
sensors attached as well. Examples include a
barometer to measure atmospheric pressure and a
moisture meter to detect rain.
An internal body temperature sensor could be a
useful feature for farmers. A lot of animals die each
year from diseases. By monitoring the animal’s body
temperature it could be possible to detect fever. The
farmer could then take the appropriate action. This
could mean seeing the animal to administer
treatment or retrieving it back to the farm for
observation. It could also be used to improve animal
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death detection. This can be achieved today by
movement detectors, but they have a longer
detection time. They require the animal to remain
stationary for 24 hours. The long detection time is
unavoidable since it needs to distinguish between
sleeping and dead animals. A temperature sensor can
alert the farmer the moment the internal temperature
of the animal drop below normal values. This could
save animals lives in a situation where they have
been attacked by predators. If some dies, the farmer
would be alerted much quicker. He can then tend to
those that are wounded.
4.2 Gas Sensors
A gas sensor can measure the concentration of
different gases in the air. Since some animals
wander around in forests, it could be possible to
attach a gas sensor to detect forest fires. Early
detection is essential to minimize the damage caused
by such fires. Therefore it would be very useful to
protect the most fire prone forests by having animals
walk around as mobile fire detectors. During a forest
fire a nearby gas sensor would detect a sharp
increase in carbon monoxide (CO) and carbon
dioxide (CO
2
) levels. This alone could be sufficient
as a detection device. Combining it with an increase
in temperature measured by a temperature sensor
would further enhance the possible forest fire
detection rate. Such a combination should be of the
type where a fire is detected if the sum of gas
concentration and temperature increase is higher
than some defined threshold. This would make it
possible to detect situations where there is a lot of
smoke, and therefore a high CO concentration, but
not yet a great increase in temperature. The
temperature sensor can help in detecting fires when
the wind is blowing the smoke away from the
animal. An animal-based forest fire detection system
would have to go through rigorous testing before
being deployed. These tests would have to include
the particular animal that the system is intended for.
Without animal-specific tests it is impossible to tell
how close the animal would go to a nearby fire. If
the animals generally run away before the sensors
can detect fires the system is of very little use as it
could only detect fires that the animal could not
escape from.
4.3 Microphone
A microphone can be used to listen for, and
recognize, special noises in the environment. The
question is what such a system should listen for.
Since animals wander around in the forest or
mountains an obvious choice is other animals or
humans. The microphone could for instance try to
detect the presence of predators such as wolves or
foxes. This could be useful for public statistics. If an
area has too many predators, maybe a choice has to
be made between killing some of the predators or
ban farmers from letting their animals graze in those
areas. Birds are another thing that could be detected
by a microphone. Since they often make very
characteristic noises that are loud enough to be
carried some distance, they are the perfect match for
microphone-based detection. The information about
the presence of birds in an area can be interesting for
researchers as well as bird watchers. Also if it is a
predator bird such as an eagle, it could be interesting
for the farmer as well.
4.4 NFC or RFID
NFC and RFID are similar technologies since they
both work over distances under a few meters and
they only require one of the communicating parties
to have power. Either of them can be used in an
animal tracking network as proximity sensors. In the
sheep tracking example it could be used to ensure
that the lambs are still with their mother. It could
also be used to check how frequently a particular
spot is visited without continuous GPS tracking. In
sheep farming this could be used to evaluate a salt
stone placement. By placing a NFC or RFID reader
next to the salt stone, the chip-equipped sheep could
be counted. If few sheep use the salt stone, it can be
moved to a new location. Similar applications are
sure to exist in other types of animal monitoring as
well. Animal proximity can also be used to trigger
some event. In cattle farming it is already used to
control that each cow gets the right amount food and
do not steal food reserved for others. It could also
trigger cameras so that it would be possible for the
farmer to see images of their animals while they are
grazing. This could be used to determine their
current size which is an important economic factor
as the income of the farmer is dependent on the total
weight of the animals that are sold at the end of the
season.
5 DISCUSSION
As have been documented in the previous chapter
there are a lot of sensing tasks that can be performed
by animals equipped with modular sensor boards.
However there are four main obstacles: energy
PossibleUsesforAnimalTrackingandSensorData
247
consumption, size, cost and establishing a
marketplace.
Energy consumption is a major obstacle,
especially if multiple sensors are added. Some
sensing tasks also require the sensor device to be
switched on all the time. This is not compatible with
scenarios where animals are without supervision for
several months. Having to change the battery on all
the animals mid-season will in most cases be
unacceptable. There are two solutions to this issue.
The easiest is to fit a bigger battery. This solution is
limited in two ways. The first is size. Big batteries
are bulky and heavy. Forcing the animals to carry
these for months on end could be considered as
animal cruelty. The second problem is price as high
capacity batteries are quite costly. The other solution
is energy harvesting. As this study (Nadimi et al.,
2011) shows, an animal, such as a sheep, generate a
lot of energy while grazing. This could be used to
power the sensors. This technology is relatively new
and therefore it should be expected to become better,
cheaper and smaller over the next years. This will
most likely make energy harvesting a better solution
than using big batteries.
A similar problem to energy consumption is the
issue of size. If too many sensors are put on an
animal it is not possible for it to comfortably carry
the equipment. The size limit is of course animal-
specific. A big cow can carry more than a small
goat.
Cost is also a big factor. The cost of adding
another sensor cannot exceed the perceived benefit
of adding that sensor to the party responsible for
paying for it. Adding a temperature sensor to
measure the weather is not important to most
farmers. Therefore the cost of adding a new sensor
must be paid by those interested in using the data
produced by that sensor. This would involve the
weather service paying the farmer to be allowed to
put temperature sensors on his animals. This leads to
the last problem, the establishment of a common
marketplace where farmers with free sensor capacity
can offer that capacity to customers willing to pay
the extra cost of adding more sensors. A web-based
marketplace where customers can browse based on
area and sensor type would seem like a good option
for this kind of service. It should also be possible to
discover already existing sensor deployments to
allow new customers access to those data, for a
price.
6 CONCLUSIONS
Animal tracking is already being used by both
farmers and researchers to locate animals. By
applying some logic, it is possible to add value to the
location data. Location extrapolation to predict
future locations and optimized farming is just a
couple of examples. Since this can be done with the
equipment being used today, this is merely a
question of implementing the logic into the systems.
Adding more sensors could also be beneficial.
The best candidates are those that can work well
with discrete measurements, since they require less
energy. Temperature sensors and RFID stands out as
sensors that could be quite easily added and are very
useful both to farmers and scientists. Generally
adding more sensors are more complicated than
doing more reasoning on the location data.
Challenges such as energy consumption, cost and
size are all serious concerns. The biggest challenge
however is to establish a market for such a solution.
To be successful it needs to be easy for farmers to
offer sensor capacity to customers and for customers
to find available sensors in an area. On top of all this
it needs to be affordable. It is hard to tell if such a
service is economically viable, as that depends on
the application of the sensor data, but it would
definitely be interesting to see it developed.
Something so radically different could easily spawn
new inventions only made possible by effortless
access to mobile sensor data.
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