Geology Reports⌕ Search

Geology topics

Douglas H. Johnson

Publications and source records attributed to Douglas H. Johnson.

At least 37 records · Page 2Linked to original sources
USGS2020

The effects of management practices on grassland birds—Chestnut-collared Longspur ( Calcarius ornatus )

Keys to Chestnut-collared Longspur ( Calcarius ornatus ) management are providing and maintaining native pastures with fairly short overall vegetation and sparse litter accumulation but with areas of taller and denser vegetation and accumulated litter for nesting, and tailoring grazing intensity to local conditions. Chestnut-collared Longspurs have been reported to use habitats with 10–77 centimeters (cm) average vegetation height, 1–50 cm visual obstruction reading, 15–67 percent grass cover, 5–16 percent forb cover, less than (<) 6 percent shrub cover, 1–44 percent bare ground, 6–63 percent litter cover, and <7 cm litter depth.

Professional Paper↗
USGS2020

The effects of management practices on grassland birds—Lark Bunting ( Calamospiza melanocorys )

Keys to Lark Bunting ( Calamospiza melanocorys ) management include providing short vegetation with protective nest cover and tailoring grazing systems to the type of grassland. Lark Buntings have been reported to use habitats with 6–72 centimeter (cm) average vegetation height, 2–11 cm visual obstruction reading, 13–71 percent grass cover, less than or equal to (≤) 48 percent forb cover, ≤17 percent shrub cover, 10–57 percent bare ground cover, 25 percent litter cover, and ≤2 cm litter depth.

Professional Paper↗
USGS2020

The effects of management practices on grassland birds—Sprague’s Pipit ( Anthus spragueii )

Keys to Sprague’s Pipit ( Anthus spragueii ) management include providing suitable grassland habitat, especially native prairie, with intermediate vegetation height and low visual obstruction, and controlling succession therein. Sprague’s Pipits have been reported to use habitats with no more than 49 centimeters (cm) average vegetation height, 4–14 cm visual obstruction reading, 15–53 percent grass cover, less than (<) 21 percent forb cover, <18 percent shrub cover, <44 percent bare ground, 10–63 percent litter cover, and less than or equal to 11 cm litter depth.

Professional Paper↗
USGS2020

The effects of management practices on grassland birds—Horned Lark ( Eremophila alpestris )

The key to Horned Lark ( Eremophila alpestris ) management is maintaining areas with short, sparse vegetation by burning, mowing, or grazing. Horned Larks have been reported to use habitats with less than or equal to (≤) 70 centimeters (cm) average vegetation height, 3–26 cm visual obstruction reading, 15–67 percent grass cover, 3–70 percent forb cover, ≤21 percent shrub cover, 1–44 percent bare ground, ≤63 percent litter cover, and ≤9 cm litter depth.

Professional Paper↗
USGS2019

The effects of management practices on grassland birds—Thick-billed Longspur (Rhynchophanes mccownii)

The key to Thick-billed Longspur ( Rhynchophanes mccownii ) management is providing short, sparsely vegetated native grasslands of adequate size. Mixed-grass prairies can be made suitable for breeding Thick-billed Longspurs by implementing moderate-to-heavy or season-long grazing. Thick-billed Longspurs have been reported to use habitats with 5–42 centimeters (cm) average vegetation height, 3–7 cm visual obstruction reading, 15–67 percent grass cover, less than (<) 8 percent forb cover, <7 percent shrub cover, 2–60 percent bare ground, 10–63 percent litter cover, and <5 cm litter depth.

Professional Paper↗
USGS2019

The relative importance of wetland area versus habitat heterogeneity for promoting species richness and abundance of wetland birds in the Prairie Pothole Region, USA

Recent work has suggested that a tradeoff exists between habitat area and habitat heterogeneity, with a moderate amount of heterogeneity supporting greatest species richness. Support for this unimodal relationship has been mixed and has differed among habitats and taxa. We examined the relationship between habitat heterogeneity and species richness after accounting for habitat area in glacially formed wetlands in the Prairie Pothole Region in the United States at both local and landscape scales. We tested for area–habitat heterogeneity tradeoffs in wetland bird species richness, the richness of groups of similar species, and in species’ abundances. We then identified the habitat relationships for individual species and the relative importance of wetland area vs. habitat heterogeneity and other wetland characteristics. We found that habitat area was the primary driver of species richness and abundance. Additional variation in richness and abundance could be explained by habitat heterogeneity or other wetland and landscape characteristics. Overall avian species richness responded unimodally to habitat heterogeneity, suggesting an area–heterogeneity tradeoff. Group richness and abundance metrics showed either unimodal or linear relationships with habitat heterogeneity. Habitat heterogeneity indices at local and landscape scales were important for some, but not all, species and avian groups. Both abundance of individual species and species richness of most avian groups were higher on publicly owned wetlands than on privately owned wetlands, on restored wetlands than natural wetlands, and on permanent wetlands than on wetlands of other classes. However, we found that all wetlands examined, regardless of ownership, restoration status, and wetland class, supported wetland-obligate birds. Thus, protection of all wetland types contributes to species conservation. Our results support conventional wisdom that protection of large wetlands is a priority but also indicate that maintaining habitat heterogeneity will enhance biodiversity and support higher populations of individual species.

North Dakota, South Dakota↗
USGS2019

The effects of management practices on grassland birds—Northern Harrier ( Circus hudsonius )

The key to Northern Harrier ( Circus hudsonius ) management is providing tall, dense vegetation in extensive mesic or xeric grasslands or in wetlands. Northern Harriers have been reported to use habitats with 15–106 centimeter (cm) average vegetation height, 28–75 cm visual obstruction reading, 24–53 percent grass cover, 18–25 percent forb cover, less than or equal to 2 percent shrub cover, 3–5 percent bare ground, 23–30 percent litter cover, and 2–6 cm litter depth.

Professional Paper↗
USGS2019

The effects of management practices on grassland birds—Mountain Plover ( Charadrius montanus )

The key to Mountain Plover ( Charadrius montanus ) management is maintaining sparsely vegetated grasslands. Grasslands can be made suitable for breeding Mountain Plovers by preserving large prairie dog ( Cynomys species) towns, conducting prescribed burns, or implementing heavy grazing in some situations. Mountain Plovers have been reported to use habitats with 2–38 centimeters average vegetation height, 14–87 percent grass cover, 2–14 percent forb cover, 4–55 percent shrub cover, 9–72 percent bare ground, 2 percent litter cover, and 4–6 cm litter depth.

Professional Paper↗
USGS2019

The effects of management practices on grassland birds—Upland Sandpiper ( Bartramia longicauda )

The key to Upland Sandpiper ( Bartramia longicauda ) management is providing grasslands of various heights with few shrubs. In general, Upland Sandpipers forage within short vegetation and nest and rear broods within taller vegetation. Upland Sandpipers have been reported to use habitats with less than (<) 93 centimeters (cm) vegetation height, 5–75 cm visual obstruction reading, greater than or equal to 33 percent grass cover, less than or equal to (≤) 50 percent forb cover, ≤13 percent shrub cover, 3–12 percent bare ground, 11–30 percent litter cover, and <13 cm litter depth.

Professional Paper↗
USGS2019

The effects of management practices on grassland birds—Long-billed Curlew ( Numenius americanus )

Keys to Long-billed Curlew ( Numenius americanus ) management include providing large, open, level to gently rolling grasslands with short vegetation, and tailoring grazing regimes to local conditions. Long-billed Curlews have been reported to use habitats with 3–75 centimeters (cm) average vegetation height, less than or equal to 27 cm visual obstruction reading, 20–71 percent grass cover, 4–50 percent forb cover, 2–12 percent shrub cover, 7–40 percent bare ground, and less than 3 cm litter depth.

Professional Paper↗
USGS2019

The effects of management practices on grassland birds—Marbled Godwit ( Limosa fedoa )

Keys to Marbled Godwit ( Limosa fedoa ) management include providing large expanses of short, sparsely to moderately vegetated landscapes that include native grasslands and wetland complexes. Optimal wetland complexes should contain a diversity of wetland classes and sizes, such as ephemeral, temporary, seasonal, semipermanent, permanent, and alkali wetlands, as well as intermittent streams. Marbled Godwits use wetlands of various salinities. The species has been reported to use habitats with less than or equal to 70 centimeters (cm) average vegetation height, 4–23 cm visual obstruction reading, and 1–9 cm litter depth.

Professional Paper↗
USGS2019

The effects of management practices on grassland birds—Willet ( Tringa semipalmata inornata )

Keys to Willet ( Tringa semipalmata inornata ) management include providing large expanses of native grasslands and wetland complexes. Wetland complexes should contain a diversity of wetland sizes and classes, such as ephemeral, temporary, seasonal, semipermanent, and permanent wetlands, as well as intermittent streams. Willets use wetlands of various salinities. Willets require short, sparse upland grasslands for nesting and foraging and wetland complexes for foraging. Broods use taller, denser grass cover than do nesting adults. Willets have been reported to use habitats with less than or equal to 70 centimeters (cm) average vegetation height, 4–23 cm visual obstruction reading, 15 percent bare ground, 38 percent litter cover, and 1–9 cm litter depth.

Professional Paper↗
USGS2019

The effects of management practices on grassland birds—Wilson’s Phalarope ( Phalaropus tricolor )

The key to Wilson’s Phalarope ( Phalaropus tricolor) management is providing wetland complexes containing suitable wetland characteristics (that is, open water, emergent vegetation, and open shoreline) and upland habitat (native grassland or tame hayland) throughout the breeding season. Wilson’s Phalaropes have been reported to use habitats with 15–32 centimeters (cm) average vegetation height, 8–18 cm visual obstruction reading, 45–53 percent grass cover, 19–22 percent forb cover, and less than 3 cm litter depth.

Professional Paper↗
USGS2019

The effects of management practices on grassland birds—Rates of Brown-headed Cowbird (Molothrus ater) parasitism in nests of North American grassland birds

The Brown-headed Cowbird ( Molothrus ater ) is an obligate brood parasite that relies entirely on host species to incubate its eggs and rear its young. The Brown-headed Cowbird is a host generalist; eggs of the cowbird have been found in nests of more than 220 species of North American birds. Although cowbirds are not considered a serious threat to their primary avian hosts, cowbird brood parasitism has been recognized as a potential threat to the survival of threatened and endangered species and has been implicated in the declines of other bird species through reduced reproductive output. In this chapter, we summarized the rates of cowbird brood parasitism for 40 grassland bird species. The reported rates of brood parasitism by Brown-headed Cowbirds varied considerably among and within grassland host species, and the factors that influence parasitism rates were described. Defenses possessed by cowbird hosts in grasslands include aggressively defending their nests against female cowbirds, egg rejection, desertion of parasitized nests, and burying cowbird eggs in the nest lining.

Professional Paper↗
USGS2018

Extending the habitat concept to the airspace

Habitat is one of the most familiar and fundamental concepts in the fields of ecology, animal behavior, and wildlife conservation and management. Humans interact with habitats through their senses and experiences and education to such a degree that their perceptions of habitat have become second nature. For this reason, it may be difficult at first to accept the airspace as habitat, an area that is invisible, untouchable, highly dynamic, and its occupants difficult to see. Nonetheless, the habitat concept, by definition and in practice, applies readily to the airspace. Some ecological and behavioral processes including habitat selection, foraging, and reproduction are operational in the airspace, while others, particularly those mediated by resource limitation such as territoriality, are likely uncommon if present at all. The behaviors of flying animals increasingly expose them to anthropogenic hazards as development of the airspace accelerates. This exacerbates the need to identify approaches for managing these human–wildlife conflicts in aerial habitats, especially where human safety or at-risk populations are concerned. The habitat concept has proven useful in shaping environmental law and policy to help mitigate these conflicts. It remains to be seen whether current law can bend to include a more expansive concept of habitat that includes the airspace.

Book chapter↗