Grassland bird use of Conservation Reserve Program fields in the Great Plains

Douglas H. Johnson

USGS · 93813

Grassland bird use of Conservation Reserve Program fields in the Great Plains

Abstract

An enormous area in the Great Plains is currently enrolled in the Conservation Reserve Program (CRP): 19.5 million acres (nearly 8 million ha) in Montana, North Dakota, South Dakota, Wyoming, Nebraska, Colorado, Kansas, Oklahoma, and Texas. This change in land use from cropland to grassland since 1985 has markedly influenced grassland bird populations. Many, but certainly not all, grassland species do well in CRP fields. The responses by birds to the program differ not only by species but also by region, year, the vegetation composition in a field, and whether or not a field has been hayed or grazed. The large scale and extent of the program has allowed researchers to address important conservation questions, such as the effect of the size of habitat patch and the influence of landscape features on bird use. However, most studies on nongame bird use of CRP in or near the Great Plains have been short-lived; 83% lasted only 1-3 years. Further, attention to the topic seems to have waned in recent years; the number of active studies peaked in the early 1990s and dramatically declined after 1995. Because breeding-bird use of CRP fields varies dramatically in response both to vegetational succession and to climatic variation, long-term studies are important. What was learned about CRP in its early stages may no longer be applicable. Finally, although the CRP provisions of the Farm Bill have been beneficial to many grassland birds, it is critical that gains in grassland habitat produced by the program not be off set by losses of native prairie.

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Wildlife Society Technical Review Report

Source-reported bounding extent: 25.84° to 49° latitude; -116.05° to -93.51° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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BibTeX RIS

Douglas H. Johnson. 2005. Grassland bird use of Conservation Reserve Program fields in the Great Plains. https://pubs.usgs.gov/publication/93813

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USGS2008

Sources and implications of lead ammunition and fishing tackle on natural resources

A technical review of lead sources that originate from hunting, shooting sports, and fishing activities was undertaken by the American Fisheries Society and The Wildlife Society. The report addresses (1) sources of lead that originate from hunting, shooting sports, and fishing activities, (2) the hazard and risk that lead from these activities pose to natural resources, and (3) the management implications for fish and wildlife professionals and policy makers.

Wildlife Society Technical Review↗

USGS1993

Acidic Depositions: Effects on Wildlife and Habitats

The phenomenon of 'acid rain' is not new; it was recognized in the mid-1800s in industrialized Europe. In the 1960s a synthesis of information about acidification began in Europe, along with predictions of ecological effects. In the U.S. studies of acidification began in the 1920s. By the late 1970s research efforts in the U.S. and Canada were better coordinated and in 1980 a 10-year research program was undertaken through the National Acid Precipitation Assessment Plan (NAPAP) to determine the causes and consequences of acidic depositions. Much of the bedrock in the northeastern U.S. and Canada contains total alkalinity of <200 ?eq 1-1, thus, it lacks acid-neutralizing capacity. In the U.S. about 5% of the land area and in Canada about 43 % of the land area is sensitive to acidic depositions. Further, these areas receive >20 kg/ha/yr of wet sulphate depositions and are vulnerable to acidifying processes. Acidic depositions contribute directly to acidifying processes of soil and soil water. Soils must have sufficient acid-neutralizing capacity or acidity of soil will increase. Natural soil-forming processes that lead to acidification can be accelerated by acidic depositions. Long-term effects of acidification are predicted, which will reduce soil productivity mainly through reduced availability of nutrients and mobilization of toxic metals. Severe effects may lead to major alteration of soil chemistry, soil biota, and even loss of vegetation. Several species of earthworms and several other taxa of soil-inhabiting invertebrates, which are important food of many vertebrate wildlife species, are affected by low pH in soil. Loss of canopy in declining sugar maples results in loss of insects fed on by certain neotropical migrant bird species. No definitive studies categorically link atmospheric acidic depositions with direct or indirect effects on wild mammals. Researchers have concentrated on vegetative and aquatic effects. Circumstantial evidence suggests that effects are probable for certain species of aquatic-dependent mammals (water shrew, mink, and otter) and that these species are at risk from the loss of foods or contamination of these foods by metals, especially methylmercury. Continued acidification of terrestrial habitats, to the extent that earthworm populations are broadly reduced, might expose some fossorial mammalian species to risk because of decline in their major prey species. Acidic deposition affects primarily aquatic habitats of avian species by disrupting food webs (ecological effects) and increasing amounts of available heavy metals (mercury, aluminum, cadmium) in prey of avian species (toxicological effects). The ecological effects of acidifying wetlands are to reduce acid-intolerant prey (invertebrates) and to change prey quality from high-calcium bearing prey to low-calcium bearing prey. The toxicological effects are to increase contamination by heavy metals, especially methylated mercury, in foods of breeding waterbirds. The combination of these 2 types of effects results in potentially lower survival of adults and reduced production, growth, or survival of young of many bird species. Effects of acidification on herpteofauna and their habitats are mainly reproductive failure of susceptible species and reduced or metal-contaminated foods for both amphibians and reptiles.