Recent accomplishments of CDFW's scientific community
The latest issue of California Fish and Game, 103-3, makes a significant contribution to the body of research related to longfin smelt in California. A paper titled, “Historic and contemporary distribution of Longfin Smelt (Spirinchus thaleichthys) along the California coast (PDF)” analyzes and presents observation data for this species from a variety of published and unpublished sources dating from 1889 to 2016. This anadromous fish, which is listed as threatened under the California Endangered Species Act, has been documented in a diverse range of habitats, including coastal lagoons, bays, estuaries, sloughs, tidal freshwater streams and nearshore habitats. In addition to providing a comprehensive look at the existing information available for longfin smelt along the California coast, this paper identifies additional information needed to improve management and enhance recovery of the species within the state.
In “Distribution and derivation of dabbling duck harvests in the Pacific Flyway (PDF),” the authors look at abundance, banding and harvest data from throughout the Pacific Flyway and other important source areas in the Central Flyway to estimate the distribution and derivation of Pacific Flyway dabbling duck harvests during 1966−2013. The Pacific Flyway has long been considered an important wintering area for dabbling ducks. Better knowledge of the origins of these birds could assist in both harvest and habitat management.
The authors of “Distribution of Amargosa River pupfish (Cyprinodon nevadensis amargosae) in Death Valley National Park, CA (PDF)” endured harsh environmental conditions to document the occurrence of Amargosa River pupfish along the lower Amargosa River drainage where the species has not been previously documented. The downstream-most location of Amargosa pupfish captured in this study extends the previously recorded geographic range approximately 49 river km. The findings not only determine the distribution of Amargosa River pupfish within Death Valley National Park, but will help identify suitable locations at which to establish long-term monitoring sites.
California Fish and Game has published high-quality, peer-reviewed science for the past 103 years, making important contributions to the understanding and conservation of California’s wildlife.
Cover photo courtesy of Gerald and Buff Corsi © California Academy of Sciences.
The California Department of Fish and Wildlife (CDFW) has completed its annual waterfowl breeding population survey.
Mallards, gadwall and cinnamon teal comprised 54 percent of the ducks observed, down 30 percent from last year. The number of mallards decreased from 263,774 to 198,392 (a decrease of 25 percent) and total ducks decreased from 417,791 to 396,529 (a decrease of five percent).
The most notable decrease occurred in the Sacramento Valley area, where mallards were estimated at a record low of 31,000 (73 percent below the long-term average).
Given the abundant precipitation, one might expect the numbers to be higher. In some parts of the state, it did indeed increase available habitat (uplands and ponds). But in many areas, last winter’s heavy rains largely resulted in deep, fast-flowing water, which is not ideal for dabbling ducks. Other reasons for low duck observations could include winter flooding of nesting habitat that normally remains dry, the late-season flooding of the rice fields in the Sacramento Valley and the conversion of rice fields and pastures to tree crops.
CDFW biologists and warden pilots have conducted this annual survey using fixed-wing aircraft since 1948. This year’s survey was conducted from April 3 through May 4 in the Central Valley, and May 9-10 in northeastern California. The population estimates are for the surveyed areas only, which include the majority of the suitable duck nesting habitat in the state. Surveyed areas include wetland and agricultural areas in northeastern California, throughout the Central Valley, the Suisun Marsh and some coastal valleys.
The full Breeding Population Survey Report can be found at www.wildlife.ca.gov/conservation/birds/waterfowl.
The majority of California’s wintering duck population originates from breeding areas surveyed by the U.S. Fish and Wildlife Service (USFWS) in Alaska and Canada. Those survey results should be available in early August. CDFW survey information, along with similar data from other Pacific Flyway states, is used by the USFWS and the Pacific Flyway Council when setting hunting regulations for the Pacific Flyway states, including California.
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