home> giantpanda> Witness how the Scientists are doing Kin Discrimination in Giant Pandas!

Background

 

In the bear population, a female can mate with one or several males. Usually, the female will mate with the most dominant male but not always and not exclusively.  After the cubs are born, they spend an average of 2-3 years with their mother and then they leave to establish their own territory. The daughters often establish a territory close or within their mother's territory while the male offspring disperse and establishes a territory further away from his mother and any female sibling that might be living close to his mother. In this way, during the mating season, related males have less of a chance encountering their kin (their female relatives) which in effect prevents inbreeding. The father, who has mated with the female mother, will recognize the female he has mated with and so will recognize the cubs that she is raising as potential offspring of his. In this manner, the male will have less of a tendency to kill those cubs. Killing cubs, in the animal kingdom, is a way for a male to stop the female from nursing. The process of nursing usually prevents female mammals from ovulating. A male that kills another's male's cubs stops the nursing process and therefore causes the female to enter another estrous, and will allow the male to copulate with that female and sire his own offspring. In the case of the Pandas, infanticide, the killing of cubs, have been observed in the wild at least once. And as in the other bear species, such as the black and brown bears it is a behavior that must be taken into consideration. Female infanticide also exists. There are evidence that the more dominant the female, the better success she has in raising and protecting her offspring. We are not sure of all the reasons female bears kill another female's offspring, but some of the reasons might be that when a female shows her strength, other bears fear her and stay away from her cubs. Another reason might be the limited supply of resources, such as good territory for food and water supply and the exposure to males. Female infanticide has not been observed in Pandas as of yet. Daughters who establish territories close to their mothers benefit both themselves and their mother. Being familiar and related to their "next door neighbor" they can share resources, "worry less" over infanticide and experience less stress during encounters and maybe, as shown in brown bears, experience cub adoption by their relative in case they are unable to raise their own offspring (observed in captive Pandas under artificial conditions with non-related females).

In the case of the Giant Pandas, very little is known about their behavior in the wild.  These days, China Research and Conservation Center for the Giant Panda in Wolong Nature Reserve, Sichuan Province, China, is in the process of a reintroduction program to examine the steps that are needed in order to begin the reintroduction of the captive born and wild caught Pandas back into the wild. Because of the limited number of habitat available for Pandas and the small number of Pandas that live in each reserve, it is important to know if related Pandas can recognize each other and if released in the same reserve, will avoid inbreeding. In the wild, other bear populations prevent inbreeding through dispersal and avoidance. In the Panda Population the mechanism for inbreeding- prevention is unknown.

The study that I conducted is only the first part of a longer and more complex study that I will continue in the future. At this stage, I wanted to examine the ability of the Pandas to recognize each other through body odor and urine (and at a future time through "scent marks") and in the event recognition occurs, whether the bears choose their kin's smell or try to avoid it.

I designed an experiment to examine this behavior. I used methods that were designed by Dr. Ron Swaisgood from the Center for Reproduction of Endangered Species, Zoological Society of San Diego, San Diego, California.

The first step was to identify related individuals that have not been housed next to each other. This task is important and somewhat difficult in the breeding center since all the pandas are moved around between the enclosures once a month and each individual leaves their Body Odor, urine scent and Anogenital Gland Secretion, AGS, (a waxy substance produced by a gland near the anus opening that is used by the Pandas to mark their territory). Therefore, most individuals are familiar with each other's smell to some extent. In addition, I had to make sure that the individuals that I choose to participate in the study have not been housed in adjacent enclosure in the past 30 days. This will ensure, at least in a way, that the individuals have not been in contact for some time.

Mr. Wei RongPing, the center's Director of Research is the one individual who has all knowledge regarding the familiar (genetic) relationship between the bears as well their housing arrangement. After receiving all the information from Mr. Wei, I decided to concentrate on the 11 month old cubs and their mothers and 2 sub-adults (4 years old) and their mothers. The cubs were separated from their mothers at the age of 5 and 6 months and were not exposed to the smells of any of the other Pandas or the smell of their mother since the separation.

It is important to alternate between tests and not to test the same animal on consecutive days. There must be at least 48 hours between testing of the same animal.   It is also important to have some animals begin with urine testing and some with Body Odor, so the differences in responses can be compared.

All tests should be documented in a written form as well as with a video camera.  This way more than one person can observe the tests and the responses and results can be discussed.

It is important to understand that working with animals can be unpredictable and may take longer than you expect. Animals cannot and should not be forced to participate in an experiment and I am a strong believer in giving the animal a choice, whether to stay in the room and respond to the stimuli that I presented to it, or leave the room and into the yard and ignore the stimulus. I don't believe in locking the animal in a closed room and wait until it decides to respond. It is important to note that different scientists do things in different ways and according to their own philosophy.



METHODOLOGY