Animal Tracking
Key aspects in making the transmitters
Checking the animal's health and fitting a transmitter prior to release (click to enlarge)
Transmitters designed to cope with cold and/or wet conditions
A penguin fitted with a transmitter (click to enlarge)
The transmitters need to be very sensitive to pass on all the information possible about the animal's condition eg whether it is still breathing. Obviously designing a unit which covers a large range is more useful to many researchers whose animal subjects may travel vast distances. One aspect which has had a lot of attention is making the units waterproof, as earlier versions were not always able to keep out water. In making units which can't be too big or may need to run for a long time there is also a requirement for a lower power output and Sirtrack puts its attention to this also. Some units are made with a stealth mode, where the unit is only transmitting at certain set time periods. Some researchers may need to track large numbers of their subjects so the receivers are made with a wide range of frequencies. They can monitor up to 200 channels and the users can reconfigure the receivers in the field if necessary.
Designing a transmitter
Often Sirtrack is designing a transmitter for a customer on the other side of the world. Once the customers have provided their specifications the staff consult books to find out in depth the habits of the animal and the terrain and weather of its territory.
Staff also need to think about how long the transmitters need to run plus the size and weight of the animal. Sirtrack has made transmitters for over 500 species. These have included transmitters for tiny animals such as 10g bats, giant weta and frogs. The smallest transmitter is .9 g and runs for thirty days. The largest equipment was designed for elephants and required a 3.5m collar.
The designer tries to keep to 20% of the weight of the animal. They use different types of collar materials. For example synthetic collars are used for kangaroos as these animals damage leather collars with their sharp claws.
When designing a collar they need to work out how to attach it depending on whether it's for a bird, a snake or a mammal. Some collars need to be especially designed so that eventually they will fall off the animal and be retrieved later.
Colour is important too as it can help a researcher identify which animal they are watching when there is a crowd. In one instance the colour of the collar made a fatal difference to the project. The white collars had been designed for Judas goats , enabling them to wear a transmitter to allow hunters to follow the herd. Unfortunately these particular goats were white as well and ended up being shot by the hunters, who could not distinguish the collars at a distance.
