Geology topics

Jacquelyn M. Gehrt

Publications and source records attributed to Jacquelyn M. Gehrt.

3 recordsLinked to original sources

USGS2023

Lesser Prairie-chicken incubation behavior and nest success most influenced by nest vegetation structure

Incubation breaks are necessary for any nesting bird but can increase the mortality risk of the nest or attending parent. How intrinsic and extrinsic variables affect nest attentiveness—the proportion of time a female is on nest during incubation— and subsequent survival of the nest remains unclear for uniparental species. We related female nest attentiveness to nest survival and tested the effects of intrinsic and extrinsic variables on nest attentiveness by female Lesser Prairie-chickens ( Tympanuchus pallidicinctus ) using GPS locations of 87 females at 109 nest sites in 3 study areas in Kansas during 2013–2015. Daily nest survival increased by 39% when nest attentiveness increased from 21% to 98%. Female Lesser Prairie-chickens were 18% less attentive as body mass increased from 600 to 920 g. Daily precipitation and temperature, controlled for days into the incubation period, had interactive effects on nest attentiveness with nest attentiveness lowest on cool, wet days and increasing as temperature increased, regardless of precipitation (41% attentiveness at 16°C and 79 mm of precipitation to 90% attentiveness at 37°C and 41 mm of precipitation). Nest attentiveness increased by 11% as the quantity of grass at the nest site increased from 5% to 78% when visual obstruction was at 1 and 2 decimeters (dm) and increased 9% as the quantity of grass at the nest site increased from 5% to 83% when visual obstruction was at its maximum (3 dm). Our findings reveal the critical importance of nest attentiveness and incubation behavior, not only in relation to demography, but within the context of changing environmental conditions. As warmer temperatures and extreme precipitation events become more common and change the growth rates of vegetation, species like the Lesser Prairie-chicken that are ground-nesting, rely on vegetation cover, and exhibit uniparental care could experience negative demographic consequences.

Kansas↗

USGS2022

Role of landscape features in resource selection by female Greater Prairie-chickens within a constrained environment

Greater Prairie-chickens ( Tympanuchus cupido ) historically occupied 20 states within the contiguous United States; however, due to habitat degradation and loss, they are currently found in 11 states, only four of which have a stable population. Kansas supports a relatively large abundance of Greater Prairie-chickens, where the Flint Hills ecoregion historically supported the largest population density of all ecoregions. In the past decade, the Flint Hills population has declined by 75 % to an estimated 8,334 individuals in 2021 from 34,180 individuals in 2015 due to landscape changes and intensification of grassland management practices. The Fort Riley Military Reservation in the northwest portion of the Flint Hills ecoregion is one of a few areas within the ecoregion that does not implement grazing or vast annual burning. The Greater Prairie-chicken population within Fort Riley has remained relatively stable over the past 25 years despite being constrained by surrounding landscape features and development. We analyzed multiple scales of resource selection by 46 female Greater Prairie-chickens during March-April 2019–2021 on Fort Riley to investigate why this population is doing relatively well compared to populations in surrounding areas. We tested landscape feature, vegetation, and burn mosaic variables to evaluate which variables had the greatest influence on resource selection. Landscape features had the greatest influence on resource selection. Females avoided trees within Fort Riley for both breeding season use and nest-site selection at a greater margin than any other study in Kansas. Additionally, fourth-order selection was not evident within this study system, contrary to studies within surrounding areas. Our findings join a growing body of literature that suggests containment of woody encroachment as a high priority for managers to maintain or expand prairie grouse habitat in many different environments. This containment is especially critical on Fort Riley because of its constrained environment, and further woody encroachment could lead to loss of habitat that is inescapable by the Greater Prairie-chicken population on Fort Riley. Spatially-explicit evaluations of habitat availability are increasingly important as more areas within the Greater Prairie-chicken range become constrained by urbanization, agricultural expansion, and intensive management practices.

Kansas↗

USGS2020

Looking at the bigger picture: How abundance of nesting and brooding habitat influences lek-site selection by Lesser Prairie-Chickens

Lesser Prairie-Chicken ( Tympanuchus pallidicinctus ) populations have declined throughout most of their distribution since the mid-1980s. These declines are largely attributed to loss of habitat through the conversion and expansion of cropland, construction of oil wells and other anthropogenic features on the landscape, and grazing intensification. Changes in habitat availability and quality are seemingly having a disproportionate effect on the reproductive habitat of Lesser Prairie-Chickens, as some populations continue to decline. Nest and brood survival are crucial to population growth of Lesser Prairie-Chickens, with adequate reproductive habitat vital to population persistence. To better understand the influence of reproductive habitat availability on populations, we quantified the composition of reproductive habitat in lek landscapes across the northern extent of the Lesser Prairie-Chicken range. We measured vegetation at six study sites in Kansas and Colorado from 2013–2016. We sought to quantify available nest and brooding habitat adjacent to leks, investigate the relationship between reproductive habitat availability and lek attendance by males at several spatial scales, and examine vegetation characteristics that influence lek attendance. Within 5 km of a lek, 25% (2546/10,320 points) and 26% (2682/10,320 points) of random locations provided nesting and brooding habitat, respectively. Changes to reproductive habitat at both scales affected male attendance at leks. Visual obstruction of vegetation was the main predictor of male lek attendance at both spatial scales and limited the amount of reproductive habitat in lek landscapes. Accordingly, management should increase visual obstruction throughout the Lesser Prairie-Chicken range to increase reproductive success and improve populations to facilitate achieving the conservation goal set by the Western Association of Fish and Wildlife Agencies of a 10 y average Lesser Prairie-Chicken population of 67,000 birds.

Colorado, Kansas↗