Geology topics

Jane E. Fallon

Publications and source records attributed to Jane E. Fallon.

3 recordsLinked to original sources

USGS2013

The North American Breeding Bird Survey 1966–2011: Summary analysis and species accounts

The North American Breeding Bird Survey is a roadside, count-based survey conducted by volunteer observers. Begun in 1966, it now is a primary source of information on spatial and temporal patterns of population change for North American birds. We analyze population change for states, provinces, Bird Conservation Regions, and the entire survey within the contiguous United States and southern Canada for 426 species using a hierarchical log-linear model that controls for observer effects in counting. We also map relative abundance and population change for each species using a spatial smoothing of data at the scale of survey routes. We present results in accounts that describe major breeding habitats, migratory status, conservation status, and population trends for each species at several geographic scales. We also present composite results for groups of species categorized by habitats and migratory status. The survey varies greatly among species in percentage of species' range covered and precision of results, but consistent patterns of decline occur among eastern forest, grassland, and aridland obligate birds while generalist bird species are increasing.

North American Fauna↗

USGS2012

Using multi-species occupancy models in structured decision making on managed lands

Land managers must balance the needs of a variety of species when manipulating habitats. Structured decision making provides a systematic means of defining choices and choosing among alternative management options; implementation of a structured decision requires quantitative approaches to predicting consequences of management on the relevant species. Multi-species occupancy models provide a convenient framework for making structured decisions when the management objective is focused on a collection of species. These models use replicate survey data that are often collected on managed lands. Occupancy can be modeled for each species as a function of habitat and other environmental features, and Bayesian methods allow for estimation and prediction of collective responses of groups of species to alternative scenarios of habitat management. We provide an example of this approach using data from breeding bird surveys conducted in 2008 at the Patuxent Research Refuge in Laurel, Maryland, evaluating the effects of eliminating meadow and wetland habitats on scrub-successional and woodland-breeding bird species using summed total occupancy of species as an objective function. Removal of meadows and wetlands decreased value of an objective function based on scrub-successional species by 23.3% (95% CI: 20.3–26.5), but caused only a 2% (0.5, 3.5) increase in value of an objective function based on woodland species, documenting differential effects of elimination of meadows and wetlands on these groups of breeding birds. This approach provides a useful quantitative tool for managers interested in structured decision making.

Maryl↗

USGS2003

Use of North American Breeding Bird Survey data to estimate population change for bird conservation regions

Conservation planning requires information at a variety of geographic scales, and it is often unclear whether surveys designed for other purposes will provide appropriate information for management at various scales. We evaluated the use of the North American Breeding Bird Survey (BBS) to meet information needs for conservation planning in Bird Conservation Regions (BCRs). The BBS originally was developed to provide regional estimates for states, provinces, physiographic regions, and larger areas. Many analyses have used physiographic regions within states/provinces as strata. We evaluated potential consequences of using BCRs instead of the BBS physiographic regions, testing for spatial differences in sample intensity within states and provinces. We reclassified the BBS survey routes to BCRs and conducted route regression trend (interval-specific population change) analyses for a variety of regions and time intervals. Our results were similar to those based on traditional BBS regions and suggest minimal consequences of the reclassification for the BBS sample. We summarized population change within BCRs and assessed the efficiency of the BBS in estimating population change for 421 species surveyed. As would be expected from an omnibus survey, many species appeared to be poorly monitored by the BBS, with 42% of species encountered at <1 bird per route from the survey, and 28% of trend estimates too imprecise to detect a 3% per year change over 35 years. Our results indicated that the quality of the survey for estimation of population change varied among BCRs. Population trends of species were heterogeneous over space and time, varying among BCRs for 76% of species and over time for 39% of species. Regional heterogeneity also existed in trends of species groups from the BBS. While 49% of all species in the survey had increasing populations, grassland breeding birds showed consistent declines, with only 18% of species having positive trend estimates. Bird Conservation Regions appear to provide reasonable strata for summary of BBS data.

Journal of Wildlife Management↗