Geology topics

Douglas H. Johnson

Publications and source records attributed to Douglas H. Johnson.

At least 19 recordsLinked to original sources

USGS2025

The effects of management practices on grassland birds—Field Sparrow ( Spizella pusilla )

Keys to Field Sparrow ( Spizella pusilla ) management include providing shrub-dominated edge habitat adjacent to grasslands or grasslands with a shrub component (both of which must include dense grass and moderately high litter cover) and avoiding disturbances that eliminate woody vegetation. Field Sparrows have been reported to use habitats with 16–134 centimeters (cm) vegetation height, 20–145 cm visual obstruction reading, 17–90 percent grass cover, 2–45 percent forb cover, less than 63 percent shrub cover, 3–7 percent bare ground, 14–30 percent litter cover, and 1–7 cm litter depth.

Professional Paper↗

USGS2023

The effects of management practices on grassland birds—Loggerhead Shrike (Lanius ludovicianus)

The key to Loggerhead Shrike ( Lanius ludovicianus ) management is providing open grasslands with scattered trees and shrubs for foraging, nesting, and perching. Loggerhead Shrikes have been reported to use habitats with 20–266 centimeters (cm) vegetation height, greater than or equal to (≥) 10 percent grass cover, 3–48 percent forb cover, 2–25 percent shrub cover, 3–40 percent bare ground, and 11–67 percent litter cover.

Professional Paper↗

USGS2023

The effects of management practices on grassland birds—Bobolink ( Dolichonyx oryzivorus )

Keys to Bobolink ( Dolichonyx oryzivorus ) management are providing large areas of suitable habitat (for example, native or tame grasslands of moderate vegetative height and density, low shrub density, and moderate litter and forb cover), and protecting nesting habitat from disturbance during the breeding season. Bobolinks have been reported to use habitats with 10–166 centimeters (cm) average vegetation height, 6–75 cm visual obstruction reading, 17–65 percent grass cover, 3–50 percent forb cover, less than or equal to (≤) 22 percent shrub cover, ≤38 percent bare ground, 5–39 percent litter cover, and ≤9 cm litter depth.

Professional Paper↗

USGS2023

Marshbird response to herbicide control of cattail in northwestern Minnesota

Wetlands provide essential habitat for a wide variety of wildlife species. In the once wetland-rich Prairie Pothole Region and adjacent areas of central North America, many wetlands have been converted to agricultural production. Many remaining wetlands experience ecological change via the invasion and spread of non-native plant species, such as non-native narrowleaf ( Typha angustifolia ) and hybrid cattail ( Typha x glauca ), which spread aggressively and displace native vegetation, especially in large, impounded wetlands. Management of wetlands in these landscapes often includes broad-scale herbicide application intended to break up mats of cattail and restore areas to more wildlife-friendly conditions. Although restoration of wildlife habitat is a common goal of such management, marshbird response to invasive cattail control is poorly understood. To evaluate the effects of cattail management on wetland wildlife, we conducted standardized call-broadcast surveys for 5 species of marshbirds at 9 study sites that included survey locations associated with areas treated with herbicide and paired areas not treated with herbicide in wetland impoundments in northwestern Minnesota, USA, using a before-after, control-impact study design. We surveyed American bitterns ( Botaurus lentiginosus ), least bitterns ( Ixobrychus exilis ), pied-billed grebes ( Podilymbus podiceps ), soras ( Porzana carolina ), and Virginia rails ( Rallus limicola ) during the breeding season prior to herbicide application (late summer and early autumn of 2015) and during the 3 breeding seasons after herbicide application (2016–2018). We modeled species counts using a generalized linear mixed model with year-by-treatment interactions as fixed effects and site as a random effect. Before herbicide application, expected mean counts did not differ between treatment and control survey locations. Three years post-treatment, we detected significant increases in expected mean counts at treatment compared to control survey locations for soras ( t 193 = −3.373, P = 0.020) and Virginia rails ( t 193 = −3.167, P = 0.037), and point estimates for all species except least bittern were higher at treatment survey locations. Overall, our results suggest that these marshbird species responded positively to herbicide control of invasive cattail and that breeding marshbirds in these and similar wetland systems may experience positive population response over a period of at least 3 years following treatment.

Minnesota↗

USGS2023

Application of habitat association models across regions: Useful explanatory power retained in wetland bird case study

Species often exhibit regionally specific habitat associations, so habitat association models developed in one region might not be accurate or even appropriate for other regions. Three programs to survey wetland-breeding birds covering (respectively) Great Lakes coastal wetlands, inland Great Lakes wetlands, and the Prairie Pothole Region offer an opportunity to test whether regionally specific models of habitat use by wetland-obligate breeding birds are transferrable across regions. We first developed independent, regional population density models for four species of wetland-obligate birds: Pied-billed Grebe ( Podilymbus podiceps ), Virginia Rail ( Rallus limicola ), Sora ( Porzana carolina ), and American Bittern ( Botaurus lentiginosus ). We then used adjusted pseudo- R 2 values to compare the amount of variation explained by each model when applied to data collected in each of the three regions. Although certain habitat characteristics, such as emergent vegetation and wetland area, were consistently important across regions, models for each species differed by region—both in variables selected for inclusion and often in the directionality of relationships for common variables—indicating that habitat associations for these species are regionally specific. When we applied a model developed in one region to data collected in another region, we found that explanatory power was reduced in most (71%) models. Therefore, we suggest that ecological analyses should emphasize regionally specific habitat association models whenever possible. Nonetheless, models created from inland Great Lakes wetland data had higher median explanatory power when applied to other regions, and the amount of explanatory power lost by other transferred models was relatively small. Thus, while regionally specific habitat association models are preferable, in the absence of reliable regional data, habitat association models developed in one region may be applied to another region, but the results need to be cautiously interpreted. Additionally, we found that median explanatory power was higher when local-scale habitat characteristics were included in the models, indicating that regionally specific models should ideally be based on a combination of local- and landscape-scale habitat characteristics. Conservation practitioners can leverage such regionally specific models and associated monitoring data to help prioritize areas for management activities that contribute to regional conservation efforts.

Illinois, Indiana, Michigan, Minnesota, New York, ↗

USGS2023

The effects of management practices on grassland birds—Dickcissel ( Spiza americana )

Keys to Dickcissel ( Spiza americana ) management include providing dense, moderate-to-tall vegetation, particularly with a well-developed forb component, and moderately deep litter. Dickcissels have been reported to use grassland habitats with 4–166 centimeters (cm) average vegetation height, 6–85 cm visual obstruction reading, 11–68 percent grass cover, 1–86 percent forb cover, less than or equal to (≤) 10 percent shrub cover, less than (<) 27 percent bare ground cover, <30 percent litter cover, and ≤ 6 cm litter depth.

Professional Paper↗

USGS2023

The effects of management practices on grassland birds—Clay-colored Sparrow ( Spizella pallida )

Keys to Clay-colored Sparrow ( Spizella pallida ) management include providing grasslands with a shrub or forb component or shrub-dominated edge habitat, which includes dense grass and moderately high litter cover, and avoiding disturbances that completely eliminate woody vegetation. Clay-colored Sparrows have been reported to use habitats with 20–186 centimeters (cm) average vegetation height, 3–50 cm visual obstruction reading, 15–74 percent grass cover, 5–23 percent forb cover, less than 30 percent shrub cover, 1–20 percent bare ground, 10–63 percent litter cover, and less than or equal to 5 cm litter depth.

Professional Paper↗

USGS2023

Converting CRP grasslands to cropland, grazing land, or hayland: Effects on breeding bird abundances in the northern Great Plains of the United States

Recent declines of grassland bird populations in North America are linked to habitat loss and fragmentation associated with agricultural practices. One tool used to conserve soil, water and wildlife habitat on agricultural fields is the U.S. Department of Agriculture’s Conservation Reserve Program (CRP), the largest agricultural conservation program in the United States. Managers and conservationists recognize CRP as an important component of conserving grassland birds in the central portion of the United States. However, recent widespread expiration of CRP contracts could negatively influence grassland bird populations. Few studies have evaluated how former CRP-enrolled fields may function as grassland bird habitat. In this paper, we analyzed data from a long-term (1990–2017) study aimed at comparing grassland bird abundance (24 species) between idled CRP grasslands and fields where the CRP contracts expired. Some of these fields where contracts expired were maintained as pasture or hayland, and others were converted back to cropland. Estimated abundances of most species were considerably higher in idled CRP than in fields with expired CRP contracts. Post-CRP land use also appeared to affect most bird abundances, with lower abundance in grazed grasslands and haylands relative to idled CRP, but higher abundance than cropland. The responses of obligate and facultative grassland specialists to post-CRP management varied among species, with some being negative and some being positive depending on post-CRP land use, which is unsurprising given the variable habitat requirements of grassland birds. Our results have implications for wildlife managers who must design conservation strategies around the land use decisions of private landowners. Our results support the idea of maintaining a mosaic of undisturbed CRP grasslands and post-CRP grasslands that are hayed or grazed, which should guarantee some undisturbed nesting cover in the landscape for some bird species and some disturbed grasslands that may have long-term benefits for other species.

Minnesota, Montana, North Dakota, South Dakota↗

USGS2022

The effects of management practices on grassland birds—Burrowing Owl ( Athene cunicularia hypugaea )

Keys to Burrowing Owl ( Athene cunicularia hypugaea ) management include providing areas of short, sparse vegetation and maintaining populations of prey species and of burrowing mammals to ensure availability of burrows as nest sites. In particular, the conservation of black-tailed prairie dog ( Cynomys ludovicianus ) and Richardson’s ground squirrel ( Urocitellus richardsonii ) colonies is vital to the preservation of Burrowing Owls on the Great Plains. Burrowing Owls have been reported to use habitats with less than 31 centimeters (cm) average vegetation height, 5–12 cm visual obstruction reading, 12–36 percent grass cover, 29–45 percent forb cover, 1–11 percent shrub cover, 11–58 percent bare ground, and 6–27 percent litter cover.

Professional Paper↗

USGS2021

The effects of management practices on grassland birds—Short-eared Owl (Asio flammeus)

The key to Short-eared Owl ( Asio flammeus ) management is providing large grasslands and wetlands, particularly those that can support high densities of voles ( Microtus species). Short-eared Owls have been reported to use habitats with 30–90 centimeters (cm) average vegetation height, 7–47 cm visual obstruction reading, 31–85 percent grass cover, 8–26 percent forb cover, less than 18 percent shrub cover, 43 percent litter cover, and 1–2 cm litter depth.

Professional Paper↗

USGS2021

The effects of management practices on grassland birds—Grasshopper Sparrow ( Ammodramus savannarum )

The key to Grasshopper Sparrow ( Ammodramus savannarum ) management is providing large areas of contiguous grassland of intermediate height with moderately deep litter and low shrub density. Grasshopper Sparrows have been reported to use habitats with 8–166 centimeters (cm) average vegetation height, 4–80 cm visual obstruction reading, 12–95 percent grass cover, 4–40 percent forb cover, less than 35 percent shrub cover, less than or equal to (≤) 38 percent bare ground, 5–61 percent litter cover, and ≤9 cm litter depth.

Professional Paper↗

USGS2021

Demographic and potential biological removal models identify raptor species sensitive to current and future wind energy

A central challenge in applied ecology is understanding the effect of anthropogenic fatalities on wildlife populations and predicting which populations may be particularly vulnerable and in greatest need of management attention. We used 3 approaches to investigate potential effects of fatalities from collisions with wind turbines on 14 raptor species for both current (106 GW) and anticipated future (241 GW) levels of installed wind energy capacity in the United States. Our goals were to identify species at relatively high vs low risk of experiencing population declines from turbine collisions and to also compare results generated from these approaches. Two of the approaches used a calculated turbine-caused mortality rate to decrement population growth, where population trends were derived either from the North American Breeding Bird Survey or a matrix model parameterized from literature-derived demographic values. The third approach was potential biological removal, which estimates the number of fatalities that allow a population to reach and maintain its optimal sustainable population set by management concerns. Different results among the methods reveal substantial gaps in knowledge and uncertainty in both demographic parameters and species-specific estimates of fatalities from wind turbines. Our results suggest that, of the 14 species studied, those with relatively higher potential of population-level impacts from wind turbine collisions included barn owl, ferruginous hawk, golden eagle, American kestrel, and red-tailed hawk. Burrowing owl, Cooper’s hawk, great horned owl, northern harrier, turkey vulture, and osprey had a relatively lower potential for population impacts, and results were not easily interpretable for merlin, prairie falcon, and Swainson’s hawk. Projections of current levels of fatalities to future wind energy scenarios at 241 GW of installed capacity suggest some species could experience population declines because of turbine collisions. Populations of those species may benefit from research to identify tools to prevent or reduce raptor collisions with wind turbines.

Ecosphere↗

USGS2021

The effects of management practices on grassland birds—Lark Sparrow (Chondestes grammacus)

Keys to Lark Sparrow ( Chondestes grammacus ) management include providing open grasslands with sparse-to-moderate herbaceous and litter cover and a woody component and allowing occasional burning or moderate grazing. Lark Sparrows have been reported to use habitats with 10–63 centimeters (cm) average vegetation height, 10–54 percent grass cover, 9–25 percent forb cover, 4–18 percent shrub cover, 16–38 percent bare ground, 12–45 percent litter cover, and less than or equal to 1 cm litter depth.

Professional Paper↗

USGS2020

The effects of management practices on grassland birds—Nelson’s Sparrow ( Ammospiza nelsoni nelsoni )

The key to Nelson’s Sparrow ( Ammospiza nelsoni nelsoni ) management is providing dense grasses or emergent vegetation near damp areas or freshwater wetlands. Nelson’s Sparrows have been reported to use habitats with 20–122 centimeters (cm) average vegetation height, 41 cm visual obstruction reading, 40–58 percent grass cover, 24 percent forb cover, 5 percent shrub cover, 13 percent bare ground, and 2–7 cm litter depth.

Professional Paper↗

USGS2020

The effects of management practices on grassland birds—Lesser Prairie-Chicken ( Tympanuchus pallidicinctus )

The key to Lesser Prairie-Chicken ( Tympanuchus pallidicinctus ) management is maintaining expansive sand shinnery oak ( Quercus havardii ) or sand sagebrush ( Artemisia filifolia ) grasslands. Within these grasslands, areas should contain short herbaceous cover for lek sites (that is, an area where male prairie-chickens gather to engage in courtship displays to attract mates); shrubs or tall residual grasses for nesting; and areas with about 25 percent canopy cover of shrubs, forbs, or grasses 25–30 centimeters (cm) tall for brood rearing. Historically, the Lesser Prairie-Chicken was considered a gamebird that was hunted throughout its range. In response to low population levels and considerations related to listing the species as State or Federally threatened, recreational hunting seasons currently are closed throughout the species’ range. This account does not address harvest or its effects on populations but instead focuses on the effects of habitat management. Lesser Prairie-Chickens have been reported to use habitats with less than or equal to (≤) 600 cm average vegetation height (including shrubs), ≤70 cm visual obstruction reading, 4–78 percent grass cover, ≤30 percent forb cover, ≤66 percent shrub cover, 3–61 percent bare ground, 2–58 percent litter cover, and ≤3 cm litter depth.

Professional Paper↗

USGS2020

The effects of management practices on grassland birds—Sedge Wren ( Cistothorus stellaris )

Keys to Sedge Wren ( Cistothorus stellaris ) management include providing tall, dense grasslands with moderate forb coverage and minimizing disturbances during the breeding season. Sedge Wrens have been reported to use habitats with 30–166 centimeters (cm) average vegetation height, 8–80 cm visual obstruction reading, 15–75 percent grass cover, 3–78 percent forb cover, less than or equal to (≤) 15 percent shrub cover, less than (<) 35 percent bare ground, 10–30 percent litter cover, and ≤6 cm litter depth.

Professional Paper↗

USGS2020

The effects of management practices on grassland birds—LeConte’s Sparrow ( Ammospiza leconteii )

Keys to LeConte’s Sparrow ( Ammospiza leconteii ) management include controlling succession and providing uplands and lowlands with tall, thick herbaceous vegetation and thick litter. LeConte’s Sparrows have been reported to use habitats with 30–90 centimeters (cm) average vegetation height, 19–41 cm visual obstruction reading, 35–43 percent grass cover, 16–27 percent forb cover, less than (<) 18 percent shrub cover, <4 percent bare ground, 39–45 percent litter cover, and 2–6 cm litter depth.

Professional Paper↗

USGS2020

The effects of management practices on grassland birds—Baird’s Sparrow ( Centronyx bairdii )

Keys to Baird’s Sparrow ( Centronyx bairdii ) management are providing native or tame grasslands with moderately deep litter, controlling excessive grazing, and curtailing shrub encroachment. Baird’s Sparrows have been reported to use habitats with less than or equal to (≤) 101 centimeters (cm) average vegetation height, 3–46 cm visual obstruction reading (VOR), 15–71 percent grass cover, 5–25 percent forb cover, ≤50 percent shrub cover, less than (<) 44 percent bare ground, 10–63 percent litter cover, and ≤21 cm litter depth.

Professional Paper↗