California Fish and Wildlife Journal最新文献

{"title":"Tricolored blackbird survey methods","authors":"D. Airola, Edward C. Beedy, Susan Sanders, Joseph Medley","doi":"10.51492/cfwj.110.6","DOIUrl":"https://doi.org/10.51492/cfwj.110.6","url":null,"abstract":"Surveys for the tricolored blackbird (Agelaius tricolor), a California-listed threatened species, are needed to provide essential information about its status and distribution to support conservation efforts. Surveying for the species, however, poses challenges because of its colonial nesting habits, large flock sizes, and frequent interannual movements among colony sites. We present standardized approaches for tricolored blackbird surveys to accommodate a variety of goals, including determining potential for occurrence, detecting colonies, estimating population numbers, and assessing nesting success. Pre-survey research should assess overlap with the species’ geographic range and include database searches for recent and historical occurrences. Site surveys should assess availability of sufficient suitable foraging habitat (grasslands, irrigated pasture, shallow wetlands, agricultural fields) within 5 km of potential nesting habitat and nearby drinking water. Confirming presence or absence of nesting at a historical colony site, or at an area within the range of the tricolored blackbird that provides suitable nesting and foraging habitat, requires at least three surveys conducted about three weeks apart during the breeding season, generally April, May, and June in most of the species’ range. Colonies can be located by searching for foraging flocks and following them to colonies and by checking for nesting activity at suitable nesting substrates, especially those used in the past. Surveyors can estimate numbers from counts of foraging flocks departing and arriving at colonies, average density and area occupied by the nesting colony, and post-nesting density transects. Colony nesting success (i.e., whether a colony successfully fledged some young), is easily determined and is often the only feasible metric to attain on reproduction. Determining reproductive success (the average number of young fledged per occupied nest) may be feasible under ideal and intensive surveys but is impractical at many colonies due to accessibility limitations.","PeriodicalId":29697,"journal":{"name":"California Fish and Wildlife Journal","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141377039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isabelline coloration: a heretofore unrecognized chromatic aberration in bighorn sheep","authors":"V. Bleich","doi":"10.51492/cfwj.110.8","DOIUrl":"https://doi.org/10.51492/cfwj.110.8","url":null,"abstract":"Coloration is among the characteristics noted first by observers, and color has a strong influence on how animals are perceived. Abnormal coloration has been reported in a variety of taxa, but less frequently among mammals than other classes of vertebrates. Chromatic disorders occurring among Mammalia include albinism, leucism, piebaldism, melanism, xanthism, erythrism, and isabellinism, but only leucism, melanism, and piebaldism have been confirmed in bighorn sheep (Ovis canadensis); ‘albinism’ has been reported in that taxon, but in the absence confirmatory evidence. Bighorn sheep possessing white, or extremely light-colored pelage, have been described in the literature as albinistic, leucistic, or simply as ‘white’. Isabellinism is a genetic anomaly that manifests as sandy- or cream-colored pelage that appears washed-out and otherwise would be dark in color. Some reports of albinistic, leucistic, or ‘white’ bighorn sheep, however, likely represent animals that were of isabelline coloration. This is the first paper to ascribe this unusual color morph to bighorn sheep, and I (1) provide photographs, references, and other evidence of what appears to be isabellinism in that species; (2) explain why those observing ‘white’ bighorn sheep likely have failed to recognize isabelline coloration; (3) discuss the evolutionary consequences of that anomalous condition in terms of fitness and future adaptation; (4) emphasize the role of what may appear to be meaningless observations in terms of their potential ramifications for understanding or explaining phenomena that heretofore have not been fully explored; and (5) encourage readers to recognize that natural history observations have potentially important implications for the interpretation of adaptation and natural selection, and can provide new insight into prior conclusions or future applications.","PeriodicalId":29697,"journal":{"name":"California Fish and Wildlife Journal","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141379797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rescuing and monitoring White Sturgeon during drought on the Tuolumne River","authors":"Christopher Diviney, Alisa Dahl","doi":"10.51492/cfwj.110.10","DOIUrl":"https://doi.org/10.51492/cfwj.110.10","url":null,"abstract":"","PeriodicalId":29697,"journal":{"name":"California Fish and Wildlife Journal","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141380618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Short-term movement patterns of the Pacific sleeper shark off California","authors":"Michael S. Wang, S. Aalbers, C. Sepulveda","doi":"10.51492/cfwj.110.9","DOIUrl":"https://doi.org/10.51492/cfwj.110.9","url":null,"abstract":"This study evaluated the movement patterns of four Pacific sleeper sharks (Somniosus pacificus) outfitted with satellite-based tags off the California coast, a region for which there is no reported tracking data. Pacific sleeper sharks (1.5–2.1 m) attained maximum individual depths ranging from 603–1,323 m, with an overall average depth of 424 ± 84 m. Depth distribution was relatively similar between day and night, remaining well below the thermocline throughout periods at liberty. A 180-cm individual tagged off central California exhibited a deeper but more consistent depth distribution throughout the day (µ = 528 ± 28 m) and night (µ = 545 ± 26 m), whereas a 221-cm shark tagged off southern California occurred deeper during the day (µ = 392 ± 43 m) than at night (µ = 352 ± 62 m) with continuous vertical oscillations between 300 and 500 m. Ambient water temperatures at depth ranged from 3.3–11.0°C, with a collective average temperature of 7.3°C. Despite extensive and continuous vertical movements, horizontal displacement was minimal over the 30-d tracks (µ = 1.7 km/d). Although the data presented here are temporally and spatially limited, findings support previous reports of consistent vertical oscillations within other regions in the Pacific. Insights into the movements and habitat use of this vulnerable elasmobranch provides a better understanding of the species within a previously undocumented portion of its range.","PeriodicalId":29697,"journal":{"name":"California Fish and Wildlife Journal","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141378545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trends in pinniped interactions with commercial passenger fisheries vessels in California","authors":"Zachary A. Schakner, Daniel Studt, Elizabeth A. Hellmers, Maren L. Levine","doi":"10.51492/cfwj.110.7","DOIUrl":"https://doi.org/10.51492/cfwj.110.7","url":null,"abstract":"The resurgence of pinniped populations along the West Coast of the United States, a consequence of the Marine Mammal Protection Act, has resulted in unintended ecological and socio-economic repercussions. The conflict between pinniped and fisheries in California, a persistent management challenge for decades, primarily manifests as depredation (the removal or damage of hooked fish) from Commercial Passenger Fishing Vessels (CPFVs). Depredation not only results in stolen fish but also in lost fishing opportunities due to the presence of pinnipeds deterring target fish species or necessitating vessel relocation. Using logbook data from 1994 to 2021, we explored spatiotemporal trends in pinniped depredation of CPFVs in California. Our model, which evaluates the factors predicting the number of fish depredated, revealed a distinct concentration of pinniped depredation in Southern California, with increasing rates of depredation during summer and spring. Over our time series, depredation is decreasing, as our model found a seven percent decrease in the number of fish depredated each calendar year. Correspondingly, changepoint and trend analysis revealed two key trend reversals in 1999 and 2014, exemplified by a rapid peak and ensuing drop in overall depredation. Overall, our study suggests that depredation is shaped by an interplay of environmental factors, the population dynamics of pinnipeds, and the patterns of fishing activities within the California current ecosystem.","PeriodicalId":29697,"journal":{"name":"California Fish and Wildlife Journal","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141381566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial relationships and mesoscale habitat variance in co-occurring populations of Church’s sideband and Trinity bristle snail in the Greater Trinity Basin, northern California","authors":"Robert M. Sullivan","doi":"10.51492/cfwj.109.13","DOIUrl":"https://doi.org/10.51492/cfwj.109.13","url":null,"abstract":"In resource management, the kind and extent of ecological co-occurrence between closely related species frequently requires assessment of the spatial relationship among taxa. In my study, analysis of inter-species pair-wise distances revealed no syntopic overlap between Church’s sideband (Monadenia churchi) and Trinity bristle snails (M. setosa). No pair of samples had the same geographic coordinates and no parapatric boundary in environmental covariates was evident between species. This “microsympatric” spatial relationship resembled a metapopulation structure with no high degree of overlap, as co-occurrence was rare and small in geographic scope. Fifteen forest cover-types and 82 soil-types were identified between species. The most common forest-type for M. churchi was Sierra Mixed Conifer (39.9%) and Douglas fir (28.9%). In M. setosa the most common forest-types were the same but in much different percentages (78.8% and 14.8%, respectively). Sixty-one and 39 soil-types were associated with samples of M. churchi and M. setosa, respectively. The Hohmann-Neuns family complex was the most common (22.5%) soil-type for M. churchi and the Holland Deep-Hugo family complex was the most (50.6%) dominant for M. setosa. There were significant differences between species in all environmental attributes and in values of monthly temperature and precipitation, which reflected variance in the mesoclimatic regime seasonally. Principal Components Analysis (PCA) accounted for 57.8% of the dispersion contained in environmental variables on the first 3-eigenvectors. Evapotranspiration and Summer and Winter Temperatures loaded positively while Summer and Winter Precipitation and Elevation loaded negatively along PC I (26.2%). Given significant inter-species differences in ecological occupancy, it seems plausible that microsympatry is based in part on both mesoscale habitat variance and subtle differences in mesoclimate defined by seasonal variation in temperature and precipitation. The hypothesis that M. setosa is adapted to cool habitats and M. churchi to warmer more arid environs in microsympatry was substantiated at a macroscale level.","PeriodicalId":29697,"journal":{"name":"California Fish and Wildlife Journal","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139254376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Book Review – George Meléndez Wright: The Fight for Wildlife and Wilderness in the National Parks","authors":"V. Bleich","doi":"10.51492/cfwj.109.15","DOIUrl":"https://doi.org/10.51492/cfwj.109.15","url":null,"abstract":"","PeriodicalId":29697,"journal":{"name":"California Fish and Wildlife Journal","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139252741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Central Valley anadromous salmonid habitat suitability criteria","authors":"Mark Gard","doi":"10.51492/cfwj.109.12","DOIUrl":"https://doi.org/10.51492/cfwj.109.12","url":null,"abstract":"Habitat suitability criteria (HSC) are a key information source used in designing habitat restoration projects. Many site-specific HSC have been developed in the Central Valley of California for various life stages of anadromous salmonids. Substantial differences between the HSC can be due to watershed characteristics and the methods used to develop the HSC. Spawning HSC generally have optimum depths of 0.3–1 m, optimum velocities of 0.3–1 m/s, and substrate sizes ranging from 25–100 mm. Optimum conditions for fry are generally shallow (less than 0.5 m) and slow (less than 0.1 m/s) with woody cover. Juvenile salmonids use deeper (0.5–1 m) and faster (up to 0.4 m/s) conditions than fry but are similar to fry in their preference for woody cover. HSC developed by the U.S. Fish and Wildlife Service on the Yuba River are recommended for evaluating habitat restoration projects on larger rivers, while HSC developed on Clear Creek are recommended for evaluating habitat restoration projects on smaller Central Valley streams. A key limitation of existing HSC is that they were only developed for in-channel conditions; fishery benefits of floodplain restoration projects are best quantified using total wetted area. Optimal HSC values are most useful in the initial design of habitat restoration projects, while flow-habitat relationships for existing versus proposed conditions can be useful in identifying needed design refinements, such as adding large woody debris.","PeriodicalId":29697,"journal":{"name":"California Fish and Wildlife Journal","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139252009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of habitat suitability criteria for macroinvertebrate community metrics for use in habitat restoration projects","authors":"Mark Gard","doi":"10.51492/cfwj.109.14","DOIUrl":"https://doi.org/10.51492/cfwj.109.14","url":null,"abstract":"Community-based macroinvertebrate habitat suitability criteria are needed for two reasons: (1) community-based criteria, such as with macroinvertebrates, are a better measure of ecosystem health than single-species habitat suitability criteria (HSC); and (2) if food rather than physical habitat is the limiting factor for juvenile salmonids, it is better to evaluate habitat restoration projects based on macroinvertebrate habitat than juvenile habitat. The goal of this study was to generate habitat suitability criteria for macroinvertebrates in the Sacramento River. Habitat suitability criteria were derived for three macroinvertebrate community metrics. One of the metrics (biomass of baetids, chironomids and hydropsychids) was selected to represent food supply for juvenile salmonids, while the other two metrics (total biomass and diversity) were selected as measures of ecosystem health. Baetidae, Chironomidae and Hydropsychidae were chosen because they are the dominant taxa present in stomach contents samples of Sacramento River juvenile Chinook Salmon Oncorhynchus tschawytscha. Habitat suitability criteria were developed using data from 75 macroinvertebrate samples stratified by season, mesohabitat type, depth, velocity, and substrate. The criteria for depth, velocity and substrate were developed taking into account several potential confounding variables, and using a polynomial regression for depth and velocity, and analysis of variance for substrate (a categorical variable). The criteria showed no effect of substrate on baetid/chironomid/hydropsychid biomass or diversity. Criteria for total biomass showed a higher suitability for larger cobbles, versus other substrates, for total biomass. The optimum depths for baetid/chironomid/hydropsychid biomass, total biomass and diversity were, respectively, 0.82–0.85 m, 0.61–0.67 m and 1.16–1.19 m. The optimum velocities for baetid/chironomid/hydropsychid biomass, total biomass and diversity were, respectively, 0.73–0.79 m/sec, 0.61–0.67 m/sec, and 0.61–0.73 m/s. Suggestions for development of future macroinvertebrate HSC include: (1) stratifying sampling by depth, velocity and substrate; (2) measuring the amount of organic matter in samples for use as an additional potential confounding factor; and (3) sampling a large area (0.84 m2) with a sampler with a rubber foam lining on the bottom of the sampler.","PeriodicalId":29697,"journal":{"name":"California Fish and Wildlife Journal","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139253641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Utilizing the time-to-event framework to estimate elk abundance over a large spatial scale in the Klamath Mountains of California","authors":"Sara Moriarty-Graves, Erin Zulliger, Tom Batter, Christine Found-Jackson","doi":"10.51492/cfwj.109.10","DOIUrl":"https://doi.org/10.51492/cfwj.109.10","url":null,"abstract":"In northern California, Roosevelt (Cervus canadensis roosevelti) and Rocky Mountain (C. c. nelsoni) elk occupy a wide variety of habitats over a large extent, including the Marble Mountains Elk Management Unit (MM EMU). Dense forest canopy and steep, mountainous terrain present significant challenges for monitoring elk populations using traditional aerial and ground-based methods. These constraints have resulted in inadequate spatial and temporal research and monitoring. To address the need for comprehensive and reliable elk abundance estimates, we implemented a landscape-level camera trap study within the MM EMU. We deployed 180 cameras and applied a time-to-event model to estimate elk abundance. This method uses the movement rate, area in front of each camera, and leverages the latency time to detection for a given species. Analysis yielded an estimate of 1,415 (95% CI: 1,044–1,919) elk across the management unit. Here, we present the use of a recently developed method to non-invasively estimate the abundance of unmarked elk at the landscape-level in northern California. Implementation of this method can provide reliable information to aid management decisions for the continued recreational, ecological, and economic benefits of elk and wildlife in general.","PeriodicalId":29697,"journal":{"name":"California Fish and Wildlife Journal","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139253979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}