Treesearch

We provide recommendations on the best practices for mist netting for the purposes of monitoring population parameters such as abundance and demography. Studies should be carefully thought out before nets are set up, to ensure that sampling design and estimated sample size will allow study objectives to be met. Station location, number of nets, type of nets, net placement, and schedule of operation should be determined by the goals of the particular project, and we provide guidelines for typical mist-net studies. In the absence of study-specifi c requirements for novel protocols, commonly...

We evaluated data from 22 mist-net capture stations operated over 5 to 13 years in northern California and southern Oregon, to help develop sampling designs for monitoring using mist nets. In summer, 2.6% of individuals were recaptured at other stations within 1 km of the original banding station, and in fall, 1.4% were recaptured nearby. We recommend that stations be established 1?5 km apart to promote independent sampling. Percent of young birds in the total captured was similar among stations, both in summer and fall, indicating that large numbers of stations might not be necessary to...

Several authors have recently discussed the problems with using index methods to estimate trends in population size. Some have expressed the view that index methods should virtually never be used. Others have responded by defending index methods and questioning whether better alternatives exist. We suggest that index methods are often a costeffective component of valid wildlife monitoring but that double-sampling or another procedure that corrects for bias or establishes bounds on bias is essential. The common assertion that index methods require constant detection rates for trend estimatio...

Mist nets are an important tool for population monitoring, here defi ned as assessment of species composition, relative abundance, population size, and demography. We review the strengths and limitations of mist netting for monitoring purposes, based on papers in this volume and other literature. Advantages of using mist nets over aural or visual count methods include ease of standardized sampling, low observer bias, ability to detect species that are often missed using other count methods, and opportunity to examine birds in the hand (providing information on condition, age, sex, and...

While two cyprinid fishes introduced from nearby drainages have become widespread and abundant in the Eel River of northwestern California, a third nonindigenous cyprinid has remained largely confined to <25 km of one major tributary (the Van Duzen River) for at least 15 years. The downstream limit of this species, speckled dace, does not appear to correspond with any thresholds or steep gradients in abiotic conditions, but it lies near the upstream limits of three other fishes: coastrange sculpin, prickly sculpin, and nonindigenous Sacramento pikeminnow. We conducted a laboratory stream...

The scale at which habitat variables are measured affects the accuracy of resource selection functions in predicting animal use of sites. We used logistic regression models for a wide-ranging species, the marbled murrelet, (Brachyramphus marmoratus) in a large region in California to address how much changing the spatial or temporal scale of variables changes accuracy in predicting sites occupied by murrelets (sites believed to be used for nesting). This seabird forages in the ocean and nests inland in large, old trees. Classification accuracy of independent plots, assessed at 4 spatial...

Four independent studies of conifer growth between 1880 and 2002 in upper elevation forests of the central Sierra Nevada, California, U.S.A., showed correlated multidecadal and century-long responses associated with climate. Using tree-ring and ecological plot analysis, we studied annual branch growth of krummholz Pinus albicaulis; invasion by P. albicaulis and Pinus monticola into formerly persistent snowfields; dates of vertical branch emergence in krummholz P. albicaulis; and invasion by Pinus contorta into subalpine meadows. Mean annual branch growth at six treeline sites increased...

Mountain regions are uniquely sensitive to changes in climate, and are especially vulnerable to climate effects acting on many biotic systems and the physical settings. Because mountain regions serve as sources of needed natural resources (e.g.,water, forests) and as foundations for desired human activities (e.g., tourism, places to live),changes in mountain systems cascade into issues of regional and national concern. Mountains also comprise highly sensitive systems that may act as "canaries in the coal mine" to provide early signals of significant climate-driven.

I represent a nascent effort in western North America that is committed to improving integration of climate-related research and its societal implications. We go under the name of CIRMOUNT, that is, Consortium for Integrated Climate-Related Research in Western North American Mountains. In a sense, CIRMOUNT is a North American answer (in the affirmative) to Thomas Schaaf’s (UNESCO/MAB) question of whether the global mountain change community represented at Entlebuch wants to continue the Mountain Research Initiative, MRI-UNESCO Mountain Biosphere Reserve (MBR) commitment. The answer is a...

Flames from the Old Fire sweep through lands north of San Bernardino during late fall of 2003. Like many Southern California fires, the Old Fire consumed susceptible forests at the urban-wildland interface and spread to nearby city neighborhoods. By incorporating weather models into fire perimeter projections, scientist Francis Fujioka is improving fire modeling as a tool for managing wildfire and protecting life and property.