REGIONAL NEWS & RECOVERY UPDATES.
Vernal Pool Fairy Shrimp (Branchinecta lynchi) Vernal pool invertebrate surveys funded by the U.S. Fish and Wildlife Service's (FWS) Oregon State Office have revealed the presence of this threatened crustacean within several pools in the Agate Desert near Medford, Oregon. One of four vernal pool invertebrates listed in 1994, this animal has a relatively wide distribution in California vernal pools. Prior to this discovery, its northernmost known location was south of Mount Shasta, California, 80 miles (128 kilometers) south of the Agate Desert area. Vernal pools in the Agate Desert area have been recognized as a rare and imminently threatened natural community type. The FWS is cooperating with a number of Federal, State, county, city, and private stakeholders in an effort to develop a vernal pool conservation plan for the Agate Desert area.
Lahontan National Fish Hatchery Complex Fisheries began operation of the new fish lock at the Marble Bluff Fish Facility in Nevada during the second week in April. Although the modification to the facility is not complete, the lock can be operated manually. The lock enables the passage of at least five times the former number of fish during one set and the fish are never lifted out of the water. Therefore, both capacity and the condition of the fish that are captured have greatly improved. Over 100,000 cui-ui (Chasmistes cujus), an endangered fish, have been assisted up-stream of Marble Bluff Dam to spawning habitat in the lower Truckee River.
There were 4 to 5 weeks remaining in the migration season as this edition of the Bulletin was being prepared, so another large migration season is anticipated. This year will not provide a full test of the potential for the new fish lock because the impacts caused by a flood of 1997 have not yet been resolved. By 1999, the facility's capacity will be tested under optimum design conditions.
Salton Sea Susan Saul, acting Chief of Public Affairs for FWS Region 1, assisted staff at the Salton Sea National Wildlife Refuge (NWR), California, in hosting a media tour to Mullet Island, site of the recent death of 6,000 double-crested cormorant (Phalacrocorax auritus) chicks, on May 6. Newcastle disease is the suspected cause of the cormorant deaths. News media interest in the fish and wildlife die-offs at Salton Sea remains strong. Although this species is not endangered, the endangered brown pelican (Pelecanus occidentalis) is also found at the Salton Sea.
Reported by LaRee Brosseau of the FWS Portland Regional Office.
Whooping Crane (Grus americana) The well-known whooping crane flock that migrates between the U.S. and Canada is growing four percent annually and is expected to exceed 200 by the fall of 1999.
Another 98 whooping cranes are now in captivity, mostly in the three breeding centers at the Patuxent Wildlife Research Center in Laurel, Maryland; the International Crane Foundation in Baraboo, Wisconsin; and the Calgary Zoo in Canada. With captive production growing enough to support to support reintroduction efforts, removal of the second egg from nests (to promote double-clutching) in Canada was discontinued in 1997 after nearly 30 years. This winter, one set of twin chicks arrived at Aransas NWR, the first twins that have arrived since 1964. Twinning in the Aransas/Wood Buffalo flock has averaged 14 percent of the young.
Beginning in 1993, whooping cranes raised in captivity have been soft-released in the Kissimmee (Kissim -ee) Prairie region of central Florida. Although bobcats took many of the birds shortly after release and continue to be a major predator, changes in release location and methods have led to 70 percent survival of released birds. The Florida whooping cranes are just reaching breeding age, with four pairs exhibiting nesting behavior. No egg production has been seen yet. Currently 70 whooping cranes are in Florida.
The recovery plan calls for three separate breeding flocks totaling 90 pairs before this endangered species can be reclassified as threatened. Studies are now under way to pick the best location for another migratory population. Proposed sites include the Interlakes area of Manitoba and either the Marsh Island Refuge in Louisiana or Chassahowitzka NWR in Florida. This selection should be made sometime this summer, with proposed reintroduction efforts starting after the year 2000.
Northern Aplomado Falcon (Falco femoralis septentrionalis) The historic range of the northern aplomado falcon in the United States includes southeastern Arizona, southern New Mexico, and southwest Texas. Common in the United States in the early 1900's, the aplomado falcon disappeared from most of its range by 1940; the last verified nesting of native aplomado falcons occurred in New Mexico in 1952. The FWS listed the northern aplomado falcon as endangered in 1986, and the Arizona Game and Fish Department listed it under State law in 1988.
Aplomado falcons are predators of small birds in grasslands and savannahs. Their decline in the U.S. is largely attributed to habitat deterioration due to brush encroachment in grasslands, possibly exacerbated by overgrazing. Pesticide use associated with expanding agricultural development in the southwest also aggravated the aplomado falcon decline in the late 1940's and early 1950's. A recent study by the FWS Arizona Ecological Services Field Office focused on the recovery plan's goal to monitor and evaluate contamination in aplomado falcon potential prey items and made recommendations as to the most suitable areas in Arizona for reintroduction.
Meadowlarks (Stumella spp.), mourning doves (Zenaida macroura), lizards (Cnemidophorua spp.), and grasshoppers (Caelifera sp.) were collected in 1992 as representative samples of the aplomado falcon's prey base. DDE was the only organochlorine compound detected, and concentrations were below those known to adversely affect reproduction even in the most sensitive avian species. No differences in contaminant levels were found among the five areas sampled. Therefore, aplomado falcons theoretically could be reintroduced into any of the five study areas.
Flat-Tailed horned Lizard (Phryosoma mcallii) The western edge of the Sonoran Desert in southeastern California, southwestern Arizona, and adjoining portions of Baja California and Sonora, Mexico is one of the hottest and driest parts of North America. Annual precipitation is often less than 10 centimeters (4 inches) and summer temperatures frequently soar to 43 degrees Centigrade (110 degrees Fahrenheit) or more in this baked landscape of sandy plains, scattered dunes, and sparse, simple vegetation communities dominated by creosote (Larrea divaricata), white bursage (Ambrosia dumosa), and galleta grass (Hilaria rigida). This harsh environment is home to the flat-tailed horned lizard, a small reptile with a flattened body and tail and relatively long spines on its head. It manages to survive in the desert by escaping the heat of day in shallow burrows it digs or that are dug by other lizards or small animals by feeding on harvester ants.
In 1994, memoranda of understanding signed by a number of Federal agencies called for developing and implementing conservation strategies for species heading for listing. Key habitats of the flat-tailed horned lizard remain primarily on Federal lands or lands managed by California Department of Parks and Recreation. Recognizing that conservation of this lizard could possibly be implemented through appropriate management of State and Federal lands, the Bureau of Land Management's California Desert District organized a working group of Federal and State biologists and land managers in late 1994 to begin development of a conservation strategy. After many long and sometimes contentious workgroup sessions, meetings with user groups and conservationists, and with input from a group of herpetologists, a conservation agreement was signed in the summer of 1997. Signatory agencies included FWS Regions 1 and 2, Bureau of Land Management in Arizona and California, Bureau of Reclamation, Marine Corps Air Station-Yuma, El Centro Naval Air Facility, Arizona Game and Fish Department, and California Department of Parks and Recreation. Based on the obligation of these agencies to implement the conservation strategy, and conservation actions carried out since the species was proposed for listing, the proposal to list the flat-tailed horned lizard was withdrawn on July 15, 1997.
The conservation strategy establishes four management areas in California and one in Arizona, totaling nearly one-half million acres. Management of the areas is designed to ensure long-term viable populations of horned lizards. A research area is also established in California.
Reported by Larry A. Dunkeson of the FWS Albuquerque Regional Office.
Gulf Sturgeon (Acipenser oxyrinchus desotoi) Biologists have located additional spawning sites for this threatened fish. Eggs were found in six locations within the Choctawhatchee River system in Florida and Alabama. Previously, only two spawning sites were known, both in the Suwannee River in Florida. Dewayne Fox of the North Carolina Cooperative Fish and Wildlife Research Unit collected 30 adult gulf sturgeon in Choctawhatchee Bay before their upstream migration into fresh water. Male and female fish, weighing from 50 to 170 pounds, were sexed and equipped with internal or external radio and sonic tags. Egg samplers were deployed in areas that tagged fish frequent. Habitats at all spawning sites consisted of rivers with limestone bluffs or outcroppings of hard substrates. This information will be valuable in locating other sites.
Reported by Lorna Patrick of the FWS Panama City, Florida, Field Office.
|Printer friendly Cite/link Email Feedback|
|Publication:||Endangered Species Bulletin|
|Date:||Jul 1, 1998|
|Previous Article:||Lower Rio Grande Valley National Wildlife Refuge.|
|Next Article:||LISTING ACTIONS.|