Science Spotlight: California Fish and Game, Volume 104-1 Now Available July 31, 2018 The latest issue of the scientific journal California Fish and Game is now available online (for free!). Volume 104, Number 1 features a gorgeous photo of a black-tailed jackrabbit in sunlit profile taken by renowned photographer David Jesse McChesney. The latest issue of the scientific journal California Fish and Game is now available online (for free!). Volume 104, Number 1 features a gorgeous photo of a black-tailed jackrabbit in sunlit profile taken by renowned photographer David Jesse McChesney. The back cover image, also by McChesney, features two cottontails at play. We are fortunate to be allowed the use of these amazing images to promote the content of the latest issue. Individual papers in this issue include: Reproductive aspects of Sphyraena ensis (Perciformes: Sphyraenidae) inhabiting the coast of San Blas Nayarit, southeast Gulf of California (PDF). The Mexican barracuda is the subject of a study that gathers baseline data for this important fishery resource. Although the species constitutes one of the main economic pursuits along the coast of Nayari, Mexico, little is known about its reproductive biology. A one-year study of specimens caught via commercial fishing revealed that females outnumber males (1:1.87 male:female). They also grow larger—a reproductive strategy that allows them to produce more eggs. By comparing the size of the liver and reproductive organs of the specimens, relative to their overall size, researchers were able to determine that both sexes are at their reproductive peak from April to June. The study results suggest that a fishery closure during this peak reproductive time can provide long-term population benefits for the species. Comparison of rabbit abundance survey techniques in arid habitats (PDF). An important component of any species management plan is population data, which is why it is important to know which survey methods are most effective and cost-efficient. Cypher et. al assesses four methods for counting rabbits and hares in arid climates: 1) visual encounter surveys (walking slowly and counting every animal observed); 2) spotlight surveys (driving slowly at night while shining spotlights out each side of the vehicle); 3) aerial surveys (using a low-flying helicopter to flush and count animals along transect routes); and 4) track stations (putting bait in clearings that have been raked smooth, then counting tracks). The results provide interesting observations to consider based upon the individual researcher’s budget, the habitat being studied, and staff time and availability. Field method for estimating the weight of tule elk from chest circumference (PDF). Studying larger animals provides an entirely different set of challenges. CDFW biologists frequently capture tule elk for the purpose of relocating them, gathering data and/or providing veterinary care. Administering a proper dose of sedatives and reversal agents is critical for the safety of the animal as well as its human handlers. Since the dosage is based upon weight, the challenge is figuring out how to accurately estimate the weight of an animal that is the size of a full-grown cow. Langner and Casady address this issue by determining a field method for estimating the weight of tule elk. The researchers captured and weighed more than 50 elk over a four-year period, measuring the chest circumference of each animal. The data were analyzed and resulted in a conversion chart that aids researchers in more accurately estimating weights of tule elk in the field. The latest issue also contains a review of Butch Weckerly’s book, Population ecology of Roosevelt elk: conservation and management in Redwood National and State Parks and a reprint of a scientific paper originally published in 1947 entitled, “Ecology of a cottontail rabbit (Sylvilagus audubonii) population in Central California." California Fish and Game is CDFW’s official scientific journal devoted to the conservation and understanding of the state’s plants and animals. This issue (either in hi-res or low-res) can be found in its entirety online. CDFW Photos. Categories: California Fish and Game Journal Tagged: california fish and gamescientific journalcfgblack-tailed jackrabbitscience Related Articles Science Spotlight: New Issue of Fish and Game Scientific Journal Now Available California Fish and Game, Volume 104, Issue 2, is now available online! California Fish and Game is CDFW's official, quarterly, scientific journal devoted to the conservation and understanding of the flora and fauna of California and surrounding areas, and the eastern Pacific Ocean. California Fish and Game, Volume 103, Issue 3 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” analyzes and presents observation data for this species from a variety of published and unpublished sources dating from 1889 to 2016. State Fisheries Biologists Continue Efforts to Eradicate Deadly Fish Bacteria Eight months after a bacterial outbreak in CDFW fish hatcheries led to the massive depletion of stocks, state fisheries biologists are still working hard on recovery efforts and a plan to stock California’s waters for anglers in 2021 and beyond. Science Spotlight: “Upcycling” Christmas Trees to Create Fish Habitat Christmas can be the gift that keeps giving -- to anglers and fish alike. In the north state, CDFW fish habitat technicians oversee the collection of discarded Christmas trees, which will be used to build underwater habitat structures for local waterways. Long after they’ve brightened holiday homes, these trees will provide shelter for juvenile warmwater fish species -- and ultimately will create better fishing opportunities for anglers. The Value of California’s Market Squid Arriving on the heels of the farm to fork movement, the COVID-19 pandemic has disrupted supply chains and altered product demand, which has inspired businesses to restructure and Californians to pay particular attention to where their food comes from. Many understand that almonds, artichokes or lettuce are grown in their own backyard, mostly in the Central or Salinas Valleys. But when residents are asked about wild-caught food sources coming from the ocean, tuna, salmon or perhaps rockfish might immediately come to mind. While those are indeed popular fisheries, the largest of California’s commercial fisheries actually target invertebrates, not fish! CDFW and Oregon State University Researchers Estimate the Population Size of Fishers in Northern California and Southern Oregon Scientists with the California Department of Fish and Wildlife (CDFW) and Oregon State University recently published the results of a population study on fishers (Pekania pennanti) in northern California and southern Oregon. Led by CDFW Wildlife Statistician Dr. Brett Furnas and three coauthors, CDFW Senior Environmental Scientist Richard Callas, CDFW Research Analyst Russ Landers and Dr. Sean Matthews of Oregon State University, the study produced the first-ever robust estimates of density and size of the fisher population in northern California. Comments are closed.