Wild Israel: Mongooses walking by

Wild Israel Mongooses w

By DIANA BARSHAW
For years I saw gray, slinky animals walk by, sometimes alone or sometimes in a group of one adult, which I assumed was the mother, and several young. For all those years I didn't know what species of mammal I was observing. It was only last year when I studied a Mammals of Israel poster that I realized I had been watching what for me is almost a mystical animal; the heroic, viper-killing mongoose made famous by Rudyard Kipling in his story "Rikki-Tikki-Tavi." Mammals in the order Carnivora are divided into two suborders, the dog-like (Caniformia) and the cat-like (Feliformia). Mongooses (nemiot in Hebrew) are part of the Feliformia and most are in the family Herpestidae, including the Egyptian mongoose (Herpestes ichneumon) which is the only species of mongoose present here. This species lives in non-desert habitats in most of Africa, southern Spain and east throughout Israel and Egypt. Rina Ben-Ya'acov working with Dr. Yoram Yom-Tov of Tel Aviv University studied the behavior of Egyptian mongooses for several years. Her study concentrated on two family groups living in the area of Kibbutz Ma'agan Michael. By watching them consistently and by feeding the animals at the beginning of the study, she managed to acclimate them to her presence. In this way Ben-Ya'acov was able to recognize individuals and observe intimate details of their interactions. She found that mongoose families live in territories with boundaries marked by family dunghills. The families were made up of several females, one male and their offspring. The females in these groups cooperated in caring for the cubs. Ben-Ya'acov watched them nursing not only their own cubs but also the cubs of other females in the group. She also saw the females feed prey to older cubs that were not their own, and that all the females and sometimes even the male helped to lead the cubs when they were old enough to prowl through their territory. Another study on the social behavior of Egyptian mongooses living in Spain did not show the same family structure. Its authors never found females living together - the mongooses were mostly recorded alone except during the spring when cubs were with their mothers. The authors speculate that Egyptian mongooses have a flexible social structure: Dependable food supplies allow the mongooses to be more social than when food is harder to find. Ben-Ya'acov examined the fecal remains of the mongoose families she studied and found that they ate a variety of prey including insects, snails, birds, amphibians and reptiles. Of course, mongooses are famous for preying on snakes, in particular venomous snakes. I found a report that states that when the Ministry of Agriculture poisoned jackals in 1964, the mongoose population was also severely reduced. This led to an increase in the number of viper bites. When the mongoose population recovered the incidence of viper bites decreased. (However, until I can get a copy of the paper which describes how these results were obtained this information remains uncertain.) It is startling and intimidating how false information can proliferate. For example, if you search the Internet for information about mongoose immunity to snake venom, you will find many reports stating that contrary to what everyone thinks, mongooses are not immune from venom. On the Wikipedia page for Egyptian mongooses it states, "Contrary to popular opinion, they are not immune to snake venom [6]." As you can see, this statement has a citation. However the citation is not primary literature. It is another site much like Wikipedia, and around and around the false information goes. Contrary to the Web sites, Egyptian mongooses do have a remarkable resistance to venom. In 1977 Michael Ovadia and his supervisor Prof. Elazar Kochva showed that mongooses are resistant to snake venoms that affect the nervous system, and in 1996 Avner Bdolah and his colleagues showed mongooses to be resistant to another type of snake venom that affects the circulatory system. More recently a group of scientists led by Orna Ashera in the lab of Prof. Sara Fuchs of the Weizmann Institute published a series of papers that show how the Egyptian mongoose resists the nervous-system venoms. These snake venoms work by competing with acetylcholine, a neuro transmitter. What that means is the toxin takes the place of the proper chemical which the body uses to communicate between nerves and muscle. When the nerves can't communicate with the muscle, the organism becomes paralyzed and usually dies of suffocation. In the mongoose there are mutations in the system that cause the toxin to lose this competition with acetylcholine. This makes these mongooses at least 10 times as resistant to this snake venom than an animal without these changes. So with all the solid evidence that shows mongooses are indeed protected from snake venom, from where does the false rumor originate? I think I know the answer. In "Rikki-Tikki-Tavi" Kipling said about mongoose immunity, "That is not true. The victory [of the mongoose over the snake] is only a matter of quickness of eye and quickness of foot." If you see a mongoose walking by think how lucky we are that they eat the snakes that might bite us. The writer has a PhD in animal behavior and ecology.