The Kangaroo Rat - A Keystone Species
What is a Keystone Species? It is a species that plays a critical role in maintaining the structure of an ecological community and whose impact on the community is greater than would be expected based on its relative abundance or total biomass. source
The native Kangaroo Rat, a keystone species, was described today by Dr. Francis Villablanca, Associate Professor of Biology at Cal Poly in San Luis Obispo, spoke at the Morro Bay Natural History Museum.
The Kangaroo Rat(Dipodomys heermanni)is found throughout California and the local subspecies commonly called the Morro Kangaroo Rat (Dipodomys heermanni morroensis), is on the endangered species list and hasn't been seen in decades. It was native to the Los Osos area.
Several other subspecies are also endangered. They are very amazing and interesting both in their abilties and in their impact on the ecosystem. They are solitary, build tunnels in sandy areas, and have the ability to jump up and while in the air use their tail to turn their body so they are moving in a completely different direction. This technique makes them very difficult for raptors to capture them, especially since their hearing is very acute. If they hear a raptor overhead, they leap up change direction, and keep this up moving in a very unpredictable way as they change direction with each leap.
The Kangeroo Rat is considered a keystone species because when their numbers decrease or increase all kinds of other species (who are dependent on them) decrease or increase too.
A long term study of Kangeroo Rats in Arizona show how dramatic are the effects of this rodent. A fence was built some twenty years ago to prevent the kangeroo rat from crossing the barrier. The desert shrub land became grassland as the tunneling and seed gathering of the kangaroo rat was prevented. Six species of mice increased in the arid grassland, and seed-eating bird populations that need bare places for foraging were reduced.
They are also the primary prey of the also endangered Kit Fox(Vulpes macrotis).
Read more about Keystone Studies in Arizona
More about Morro Bay Kangaroo Rat
Monday, March 15, 2010
A Keystone Species
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What a beautiful and amazing animal. The way they move, they sound almost like little furry helicopters. Would like to see video of this.
ReplyDeleteOne video Not as good at showing the jumping or leaping action as shown in the presentation but still...
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