uplands within hundreds of feet of the vernal pool. Eggs are laid in the vernal pool, then the juveniles leave the pool two or three months later, not to return until the following spring to breed. Therefore, the upland areas surrounding a vernal pool are critical for the survival of these species. In California and New York state, the endangered tiger salamander (Ambystoma tigrinum) is dependent on vernal pools to breed as described above. A few other obligate vernal pool species are the marbled salamander (Ambystoma opacum), Jefferson's salamander (Ambystoma jeffersonianum), the blue-spotted salamander (Ambystoma laterale) and the spotted salamander (Ambystoma maculatum). Some other species, notably Anostraca, fairy shrimp and their relatives, lay eggs capable of entering a state of cryptobiosis. They hatch when rains replenish the water of the pool, and no stage of the animals' life cycle leaves the pool, except when eggs are accidentally transported by animal phoresis, wind, or rarely, by flood. Such animal populations may be very old indeed, when the conditions for seasonal vernal waters are stable enough. As an extreme example, Branchipodopsis relictus on the main island of the Socotra archipelago, which is exceedingly remote for what it is, a continental fragment of Gondwana, is believed to have been isolated since the Miocene. Branchipodopsis relictus is correspondingly isolated genetically as well as geographically. Vernal pools can serve as a temporary habitat for migrating birds, especially in California. The rich invertebrate population in these pools provide food for ducks, herons, egrets, plovers and many other species. See also California native plants Gilgai Playa Pond Riparian zone Swamp Wetland References External links Sacramento Splash - Vernal Pools of Mather Field Massachusetts Division of Fisheries and Wildlife - To Certify Vernal Pools California Vernal Pools - A collection of information and resources Vernal Pool Association Jepson Prairie Reserve Ontario Vernal Pool Association Bodies of water Wetlands