A great deal of research has been carried out on the ability of animals to find their way around, but most of the accumulated information has come from studies on laboratory rats and under laboratory conditions. The research system that has been built in the Zoological Garden will enable Yael Weisberg, an MSc student at the Sagol School, under the supervision of Dr Yossi Yovel, to study the navigation strategy of wild rats under natural conditions.  Which senses do they use? How far from their nests do they usually travel? What is the greatest distance from their nest that they might travel? The research assumption is that the rats' navigation strategy enables them to move freely in their surroundings, with no need to orient by passing through constant landmarks and with the ability to take shortcuts between every two locations in the field. The basic research system was built by Orit Dashevsky, a PhD student under the supervision of Dr Yossi Yovel.  Orit caught young rats in the Zoological Garden, habituated them, enabled them to breed and created a small active and breeding colony. Yael is working with the rat colony that Orit has established and continues to construct and develop it: a system of open cages –   spacious and comfortable wooden boxes – that allow the rats to go in and out as they please. The rat cages are monitored 24/7 by cameras and by a microphone that detects the ultrasonic frequencies that the rats use to communicate with each other. The research system was built in an isolated corner of the Zoological Garden, in a big yard that provides the rats with a variety of safe areas – from sun, rain, and people. The rats can move freely in the yard, investigate it and choose where to go and when to return to their nest. The young rats that are born in the colony are habituated to the researchers' hands and are accustomed to wearing a backpack. In the future, the backpack will include a GPS to enable tracking the rats in the yard. When new rats are introduced into the research system, they are prevented from leaving their nest box until they feel "at home" in it, a process that takes about a week. The researcher then opens up a little hole in the box roof and the rats can start to go out and in at will. Yael's research is still in its early stages. From preliminary trials it seems that the rats like to explore their environment during the night, return to their nest box at dawn, and spend the day sleeping. During the first stage of the research the rats will be able to freely explore their yard and data on their exploration habits will be collected. At a later stage the rats will be moved to a novel location, outside their territory, where they will be released and will have to find their way back home. The rats will be equipped with a GPS, enabling the researchers to learn about their navigation strategy. The uniqueness of the current study lies in that the researcher knows the full history of all the rats. In other studies in which navigation strategy has been investigated in nature, the researchers did not know for certain where the animals had been previously, and therefore had to take into consideration that the rats may have had certain prior knowledge of their environment. Thanks to the current study we will soon be able to learn about the rats' first encounter with their nearby environment, their travel habits, and their navigation strategy. 

Rat research system, Photos: Yael Weisberg

Left up: a “home” box – a  view of the inside. A hole in the roof enables the rats to go out and in from the box as they please; Right up: The research system, which hosts the “home” boxes of the rat and the tracking equipment; Left down: a rat learns to carry a backpack; Right down: The yard in which the rats can freely wander,  Photos: Yael Weisberg