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J. Bart

Publications and source records attributed to J. Bart.

11 recordsLinked to original sources
USGS2005

The Program for Regional and International Shorebird Monitoring (PRISM)

This report describes the "Program for Regional and International Shorebird Monitoring" (PRISM). PRISM is being implemented by a Canada-United States Shorebird Monitoring and Assessment Committee formed in 2001 by the Canadian Shorebird Working Group and the U.S. Shorebird Council. PRISM provides a single blueprint for implementing the shorebird conservation plans recently completed in Canada and the United States. The goals of PRISM are to (1) estimate the size of breeding population of 74 shorebird taxa in North America; (2) describe the distribution, abundance, and habitat relationships for each of these taxa; (3) monitor trends in shorebird population size; (4) monitor shorebird numbers at stopover locations, and; (5) assist local managers in meeting their shorebird conservation goals. PRISM has four main components: arctic and boreal breeding surveys, temperate breeding surveys, temperate non-breeding surveys, and neotropical surveys. Progress on, and action items for, each major component are described. The more important major tasks for immediate action are carrying out the northern surveys, conducting regional analyses to design the program of migration counts, and evaluating aerial photographic surveys for migration and winter counts.

General Technical Report↗
USGS2005

High priority needs for range-wide monitoring of North American landbirds

This document is an extension of work done for the Partners in Flight North American Landbird Conservation Plan (Rich et al. 2004). The Continental Plan reviewed conservation status of the 448 native landbird species that regularly breed in the United States and Canada. Two groups of species were identified as having high conservation importance: the PIF Watch List, made up of species for which there is conservation concern, and Stewardship Spices that are particularly characteristic of regional avifaunas. In addition, continental scale monitoring needs were identified for all species. Here we extend the monitoring needs aspect of the Plan, providing additional detail and suggesting the best means of filling the gaps in broad-scale, long-term trend monitoring. This analysis and report was compiled by the Partners in Flight (PIF) Science Committee as a contribution to current work by the North American Bird Conservation Initiative to assess the status of bird population monitoring in North America and to make recommendations for improvements.

Partners in Flight Technical Series↗
USGS2004

Goals and strategies for estimating trends in landbird abundance

Reliable estimates of trends in population size are critical to effective management of landbirds. We propose a standard for considering that landbird populations are adequately monitored: 80% power to detect a 50% decline occuning within 20 years, using a 2-tailed test and a significance level of 0.10, and incorporating effects of potential bias. Our standard also requires that at least two-thirds of the target region be covered by the monitoring program. We recommend that the standard be achieved for species' entire ranges or for any area one-third the size of the temperate portions of Canada and the United States, whichever is smaller. We applied our approach to North American Breeding Bird Survey (BBS) data. At present, potential annual bias for the BBS is estimated at ??0.008. Further, the BBS achieves the monitoring standard for only about 42% of landbirds for which the BBS is considered the most effective monitoring approach. Achieving the proposed monitoring target for ???80% of these species would require increasing the number of BBS - or similar survey - routes by several-fold, a goal that probably is impractical. We suggest several methods for reducing potential bias and argue that if our methods are implemented, potential bias would fall to ??0.003. The required number of BBS or similar routes would then be 5,106, about 40% more than in the current BBS program. Most of the needed increases are in 15 states or provinces. Developing a comprehensive land-bird monitoring program will require increased support for coordination of the BBS (currently 2 people) and new programs for species that are poorly covered at present. Our results provide a quantitative goal for long-term land-bird monitoring and identify the sample sizes needed, within each state and province, to achieve the monitoring goal for most of the roughly 300 landbird species that are well suited to monitoring with the BBS and similar surveys.

Journal of Wildlife Management↗
USGS2003

Impacts of the Brown Tree Snake: Patterns of Decline and Species Persistence in Guam's Avifauna

Predation by brown tree snakes ( Boiga irregularis ) devastated the avifauna of Guam in the Mariana Islands during the last half of the twentieth century, causing the extirpation or serious reduction of most of the island's 25 resident bird species. Past studies have provided qualitative descriptions of the decline of native forest birds but have not considered all species or presented quantitative analyses. We analyzed two sets of survey data gathered in northern Guam between 1976 and 1998 and reviewed unpublished sources to provide a comprehensive account of the impact of brown tree snakes on the island's birds. Our results indicate that 22 species, including 17 of 18 native species, were severely affected by snakes. Twelve species were likely extirpated as breeding residents on the main island, 8 others experienced declines of ≥90% throughout the island or at least in the north, and 2 were kept at reduced population levels during all or much of the study. Declines of ≥90% occurred rapidly, averaging just 8.9 years along three roadside survey routes combined and 1.6 years at a 100-ha forested study site. Declines in northern Guam were also relatively synchronous and occurred from about 1976 to 1986 for most species. The most important factor predisposing a species to coexistence with brown tree snakes was its ability to nest and roost at locations where snakes were uncommon. Large clutch size and large body size were also related to longer persistence times, although large body size appeared to delay, but not prevent, extirpation. Our results draw attention to the enormous detrimental impact that brown tree snakes are likely to have upon invading new areas. Increased containment efforts on Guam are needed to prevent further colonizations, but a variety of additional management efforts would also benefit the island's remaining bird populations.

Guam↗
USGS1999

Evaluation of mist-net sampling as an index to productivity in Kirtland's Warblers

Many applied and theoretical investigations require information on how productivity varies in time and space (Temple and Wiens 1989. DeSante 1995). Examples include studies of habitat quality, population trends, life-history tactics, and metapopulation dynamics. From a demographic perspective, productivity is the number of young counted at a given time of year, produced per adult (e.g. Caswell 1989). Various measures have been used to estimate productivity. One of the most attractive is mist netting during the summer after young have left the nest, but ideally before they have left the study area. Several programs use this approach, including the Constant Effort Sites Scheme of the British Trust for Ornithology (Baillie et al. 1986, Bibby et al. 1992) and the Monitoring Avian Productivity and Survivorship (MAPS) program (DeSante et al. 1993) in North America. Hatching-year (HY) and after-hatching-year (AHY) birds are widely believed to have different susceptibilities to netting (DeSante et al. 1995, Peach et al. 1996), so the ratio of HY's to AHY's obtained from netting is not used as an estimate of productivity. Instead, investigators hope that the relative susceptibility to capture is about the same among the samples being compared so that the age ratios in mistnet samples provide a reliable index to productivity (DeSante 1995, DeSante et al. 1995).

The Auk↗
USGS1995

Reliability of the Breeding Bird Survey: Effects of restricting surveys to roads

Breeding Bird Surveys (BBS), which are widely used to monitor trends in avian populations (e.g. Robbins et al. 1989, Sauer and Droege 1993), are conducted along roads but are used to infer changes in regionwide populations. Such inferences may be inaccurate if trends in habitat along roads differ from regionwide trends. For example, if forest cover regionwide remained constant but forest cover along roads declined (due for example to development), then BBS data for species found primarily in the forest might show declines despite regional populations being stable. We investigated this issue by measuring change in forest cover in western (i.e. unglaciated) Ohio (Fig. 1). Change in forest cover between 1963 and 1988 was determined for: (a) the complete study area; (b) areas 0 to 140 m from a road (inner roadside strip); and (c) areas 141 to 280 m from a road (outer roadside strip).

The Auk↗
USGS1992

Annual survival rates of adult and immature eastern population tundra swans

Tundra swans ( Cygnus columbianus) of the eastern population were neckbanded in Maryland, North Carolina, and Alaska from 1966 through 1990. These swans were resighted and recaptured during autumn, winter, and spring, 1966-1990. Although the original motivation for this study involved swan movements, we wanted to use the resulting data to test hypotheses about sources of variation in swan survival rates. Recaptures of legbanded and neckbanded swans permitted us to estimate neckband loss rates, which were found to vary with age and sex of swans, and number of years since initial application. Estimates of annual neckband retention rate ranged from about 0.50 for adult male swans ≥ 2 years after initial neckbanding to > 0.96 for immature swans and adult females the first year following neckbanding. This variation in neckband loss rates prevented the simple correction of survival estimates to account for such loss. Consequently, we developed a series of multinomial models parameterized with survival, sighting, and neckband retention probabilities for use with the recapture and resighting data.

Alaska, Maryland, North Carolina↗