u por many people, the term JL or "endangered species" tradition- ally has conjured up images of bald eagles, grizzly bears, whales, and other charismatic species. To be sure, these mag- L L E T I nificent creatures do need help U.S. DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE SERVICE iu many paHs of their ranges, MAY/JUNE 1997 VOL. XXII NO. 3 and protecting their habitat benefits other species at the same time. But as knowledge of ecology and the importance of biodiversity has grown, so has our understanding of the vital roles played by invertebrates, plants, and a host of other lesser- known species. One far-sighted aspect of the Endangered Species Act is that it offers protection to virtually all plant and animal taxa that are in danger of extinction, without regard to their esthetic appeal or utility to people. This edition of the Endangered Species Bulletin provides some examples of lesser-known species, the importance of which might not always be obvious. -ji » I _ i« s I5 U.S. Fish & Wildlife Service a WASHINGTON D.C. OFFICE Washington, B.C. 20240 John Rogers, Acting Director E. La Verne Smith, Chief, Division of Endangered Species (703)358-2171 Jamie Rappaport Clark, Assistant Director for Ecological Senices Ren Lohoefener, Deputy Chief Division of Endangered Species (703)358-2171 Lesli Gray, Acting Chief. Branch of Information Management (703)358-2171 Jay Slaclc, Chief Branch of Conservation and Classification (703)358-2105 Richard Hannan, Chief Branch of Recovery & Consultation (703)358-2106 REGION ONE Eastside Federal Complex, 911 N.E.I 1th Ave, Portland OR 97232 California. Haivaii. Idaho. Nevada. Oregon. Michael J. Spear, Regional Director (503)231-6118 Washington. American Samoa. Commomvealth http://WWW. r 1. fws. gov of the Northern Mariana Islands. Guam and the Pacific Trust Territories REGION TWO P.O. Box 1306. Albuquerque, NM 87103 Arizona, New Mexico. Oklahoma, and Texas Nancy Kaufman, Regional Director (505)248-6282 http://sturgeon.irml.r2.fws.gov REGION THREE Federal Bldg., Ft. Snelling, Twin Cities MN 55111 Illinois. Indiana. Iowa. Michigan. William Hartwig, Regional Director (612)725-3500 Minnesota. Missouri, Ohio, and Wisconsin http://www.fws.gov/~r3pao/r3home.html REGION FOUR 1875 Century Blvd., Suite 200, Atlanta, GA 30345 Alabama. Arkansas. Louisiana. Georgia. Kentucky. Noreen Clough, Regional Director (404)679-4000 Mississippi, North Carolina. South Carolina. Florida, http://www.fws.gov/~r4eao Tennessee. Puerto Rico, and the U.S. Virgi?i Islands REGION FIVE 300 Westgate Center Drive. Hadley, MA 01035 Connecticut. Delaware. District of Columbia, Ronald E. Lambertson, Regional Director (413)253-8659 Maine. Mar^'land, Massachusetts. New Hampshire, http://www.fws.gov/~r5fws New fersey. New York. Pennsylvania. Rhode Island. Vermont, Virginia, and West Virginia REGION SIX P.O. Box 25486, Denver Federal Center, Denver CO 80225 Colorado. Kansas. Montana. Nebraska. North Ralph O. Morgenweck, Regional Director (303)236-792^^ Dakota. South Dakota. Utah, and Wyoming http://www.r6.fws.gov/www/fw^^ REGION SEVEN 1011 E. Tudor Rd., Anchorage, AK 99503 Alaska Dave Allen, Regional Director (907)786-3542 http://www.fws.gov/~r7hpirm IN THIS ISSUE 4 A "Living Fossil' in California U L L E T I N Telephone: (703)358-2390 Contributors Fax: (703)358-1735 Bradley Goettle 6 Life in a Stone Pool Internet: Gary Norquist [email protected] Richard Biggins Return of the Riversnails http://wivu'.fws.gov/~r9endspp/endspp.html Steven A. Ahlstedt 8 Diane Pupek Editor Martha Balis-Larsen 10 Navy Michael Bender Tim Sutterfield Protects Mike Bender Island Associate Editor Earl Possardt Monarch Jennifer Greiner Linda Andreasen Buddy Jensen Editorial Assistance Art Director Martha Balis-Larsen David Yeargin Scott Krueger 12 Big-Eared Bat Bounces Back 14 Seeking an Accord with Rattlesnakes 18 Freshwater Fauna Posters On the Cover With its shield-like shell, dorsally-fused eyes, and twin tail filaments, the vernal pool tadpole shrimp is a fascinating if not widely known creature. It swims the vernal pools (opposite page) of central California. Photo by Larry Serpa ne Endangered Species Bulletin welcomes manuscripts on a ivide range of topics related to endangered species. We areparticidarly interested in news about recovery, habitat conserva- Departments tion plans, and cooperative ventures. Please contact the Editor before preparing a manuscript. We cannot guarantee publication. 16 Spotlight on Hatcheries: The Fish and Wildlife Sen.ice distributes the Bulletin primarily to Federal and State agencies, Dexter National Fish Hatchery and and official contacts of the Endangered Species Program. It also is reprinted by the University Technology Center o/Michigan as part of its own publication, the Endangered Species UPDA TE. To subscribe, write Jhc Endangered Species UPDATE, School of Natural Resources, University of Michigan, Ann 'Arbor, MI 48109-1115: or call 313/763-3243. 20 Regional News and Recovery Updates Printed ivith t vgetable-based ink on recycled and recyclable paper. If you do not keep 22 Rulemaking Actions back issues, please recycle the paper, pass them along to an interested person, or a donate them to a local school or library. by Bradley Goettle A "Living Fossil" in California How many "living fossils" can you name? A living fossil is basically an organism living today that appears identical to specimens in the fossil record. The most famous example is probably the coelacanth, a primi- tive fish known only from fossils until a live individual was recov- ered by a deep- \ sea trawler in 1938, virtually un- changed from its | fossil ancestors of approximately 70 million years ago. The tadpole shrimp is a present- day example. A freshwater crustacean "living fossil," it' derives its name from looking somewhat like a frog or toad tadpole at first glance. The general body characteristics of shallow depressions underiain by soil tadpole shrimp have remained the same types that restrict the downward for millions of years. They include a percolation of water. In California, shield-like carapace (shell), a dorsally- ephemeral pools are typically referred Illustration fused pair of eyes, a segmented abdo- to as vernal (spring) pools because the by J. W. men, paired tail filaments, and paired pools are filled and wet during the Martin ventral appendages called phyllopods winter and spring rainy season, and are ("leaf plus feet"), which beat in a dry the rest of the year. wavelike motion from front to back. Vernal pools, considered highly- They act as propulsion for the animal unique freshwater ecosystems, are and effectively funnel microscopic food typically dry seven to eight months out Vernal pool tadpole shrimp particles up to its mouth. The vernal of the year. They provide habitat for may reach an inch and a pool tadpole shrimp (Lepidurus invertebrate animals such as crusta- half in length, are typically packardi) is the only species in the ceans, flatworms, snails, and insects, as olive or grey colored, and genus Lepidurus found in the vernal or swim or scoot along muddy well as such vertebrates as amphibians, or rocky bottom sediments. springtime pools of California's Central birds, and even mammals. Vernal pools This coloration is Valley and the San Francisco Bay area. are important breeding sites for frogs sometimes mottled and Vernal pools are ephemeral wetlands, and salamanders, as well as feeding and provides good camouflage, typically clustered into pool "com- resting sites for migrating waterfowl. helping them blend in with plexes," which form in areas where a Vernal pool tadpole shrimp (like the aquatic plants or when they Mediterranean climate (a moderate related "fairy shrimp" species) only live burrow into the muddy bottom sediments. climate with distinct and regular wet in these ephemeral freshwater habitats, and dry seasonality) combines with an environment with few aquatic ENDANGERED SPECIES BULLETIN MAY/JUNE 1997 VOLUME XXII NO, 3 4 predators, especially fish. Tadpole of the demand for essentially flat lands shrimp and fairy shrimp are not found in near metropolitan areas for develop- marine, estuarine, or riverine systems, and ment. Vernal pools also are subject to ^hey become easy prey if a connection such threats as invasions of aggressive develops between the vernal pool and non-native plant species, gravel mining, more permanent waters containing fish. fertilizer and pesticide contamination, A key adaptation to this alternately overgrazing, off-road vehicle use, and wet and dry environment is the female contaminated stormwater runoff. tadpole shrimp's ability to produce One way to give these remarkably thousands of drought-resistant cysts well-adapted and virtually defenseless (encapsulated eggs) during her lifespan, animals a chance to survive another some of which hatch out during the million years is through the Habitat same wet season. However, for reasons Conservation Plan (HCP) approach. An that remain unclear, a large portion of HCP can be designed for a project or a the cysts produced in any given wet region, such as an entire watershed or a season will hatch only after the pool county, and generally can help accom- dries and subsequently refills, possibly modate the resource needs and eco- several years later. These cysts can nomic needs of all interests, including remain dormant and viable while the project proponents, regulatory Photo by J. L. King embedded in vernal pool soil sediments agencies, and, of course, the wildlife. for up to 10 years while waiting to Efforts already underway to help hatch. Reaching sexual maturity in as protect vernal pool tadpole shrimp and The vernal pool tadpole shrimp is a species found little as three weeks allows the tadpole their habitat include conservation only in California. The shrimp to hatch, mature, and produce easements with landowners, consulta- shrimp ranges in the Central cysts quickly after the pools refill, using tions with Federal agencies to avoid or Valley from the Redding ^to their advantage a short-lived environ- reduce effects on threatened or endan- area (Shasta County) in the 'iient to which few predator species gered species, and research on the north to around Visalia have adapted.