We work on animals in zoos and domestic animals owned by ourselves and various associates. Careful observations of spontaneous behaviors are performed in order to formulate hypotheses on rhinarium function.
Dogs are notorious for their digging disposition and capacity. The rhinarium is used in various ways before and during digging for underground prey. Such observations of spontaneous behaviors are important for designing meaningful experiments.
Dogs are the main experimental animals because they have prominent rhinaria and are accessible and social. All of our animals love to come to the laboratory where they meet friendly people, make new experiences, get treats for doing simple tasks, and quite often can play with other dogs during the breaks. Even more exciting is field work where we study how the animals use their rhinaria under semi-natural conditions.
This infrared thermograph shows a dog having correctly chosen the warm penal from a distance of about 1 m and pushing it backwards in order to get access to a food reward.
We perform functional magnetic resonance imaging (fMRI) on alert dogs in collaboration with Ádám Miklósis group in Budapest, Ungern. We hope to see activity in the brain when we stimulate the rhinarium. The method is also use on humans and the dogs are awarded for their collaboration. MRI works without damaging radiation.
We use thermal imaging for determining rhinarium temperature in various species and under various conditions. The method detects heat radiating from surfaces and allows for measurements with minimal interference with the animals. Rhinarium temperatures in dangerous animals can be determined from safe distances.
Thermal image of an alert cat, including a temperature scale. The rhinarium is the coldest surface in the scene.
Rhinaria occur only in mammals and in all major mammalian groups, even in marsupials and monotremes (egg-laying mammals). This suggests that the rhinarium has evolved at the base of the mammalian branch and may originally have a function related to the mammalian way of reproduction and development. We investigate therefore also newborn mammals and perform longitudinal studies to follow their development.
Temperature-sensitive cells have receptor proteins forming membrane ion channels. Different types of these channels open and close at different temperatures, such that a wide range of temperatures can be signaled to the brain. However, dogs can tolerate and sense much lower skin temperatures, almost down to the freezing point, than is possible with the known channels. Other cold-tolerant mammals seem to have the same ability. We work on this vexing problem in collaboration with Makoto Tominagas group in Okazaki, Japan.
Rhinarium tissue structure is analyzed by light and electron microscopy. Collaborating zoos, farmers and veterinarians inform us if an animal has to be relieved from painful terminal illness or fatal injury. This network gives us access to more tissue samples than we can process, without harming any animal for our research.
In animals with true, wet rhinaria, the outer surfaces of skin cells are richly folded on the nanometer scale. These folds develop in parallel with the keratinization of the cells. Such folding is absent in normal skin cells.
Evolution and ecology
We study a wide variety of mammals in order to understand how the rhinarium has evolved. As all sensory organs, the rhinarium filters vital information from the external world, thereby securing the survival of the animal in its environment in competition with other animals. However, in many cases it is unknown what type of information the animals obtain from their rhinaria.
A kinkajou (Potos flavus), a relative to the raccoon in the family of Procyonidae, peeks from its home at Ystad Zoo. The prominent rhinarium is wet and cold if the animal is awake and alert, and dry and warm in resting kinkajous. The same is true in dogs, but not in deer and cattle.
Dogs assist humans in countless ways. They search, guard, hunt, rescue, track, warn, and do hard physical work. They can even diagnose certain diseases, alert for upcoming epileptic seizures and guide the blind, much better than any technical device. In addition to being great company. Humans benefit from the keen senses, excellent social abilities and strong physique of dogs. By refining our understanding of the senses and physiology of dogs we can suggest improvements for both sides in this partnership.
Our studies help to select the breeds and individuals most suitable for certain tasks, we can guide humans to better understand and assist the dogs, and we can identify special needs the animals may have when solving particular problems or while being exposed to specific conditions.
Facilities and equipment
At the Department of Biology we have access to a wide variety of facilities, equipment and methods. So far, we have used the following resources. The list will grow as our work proceeds.