Sex Role Socialization and Perception of Opportunity Structure: Impact on Educational and Occupational Decisions of Black Females

A study of why Black females remain over-represented In traditional female oriented occupations

Conspecific brood parasitism in the tropics: an experimental investigation of host responses in common moorhens and American purple gallinules

Species occupying a broad latitudinal range may show greater phenotypic plasticity in behavior than species with smaller ranges or more specific habitat requirements. This study investigates for the first time the occurrence of conspecific brood parasitism (CBP) in sympatric tropical populations of the common moorhen (Gallinula chloropus pauxilla Bangs) and the American purple gallinule (Porphyrula martinica L.). CBP occurred in at least 20% (N = 76) of common moorhen nests on the Rio Chagres in Panama. Half (N = 20) of the parasitic eggs were accepted, but 10 were destroyed or ejected from host nests. Introductions of experimental eggs into nests revealed hosts were more likely to accept parasitism later in the host's laying period and during incubation, consistent with expectation of an adaptive response. CBP was not detected in a small sympatric population of American purple gallinules. Members of this population did not eject experimental eggs, suggesting a lack of experience with costly CBP. Contrasting ecological factors help explain why these two species of rail (Family Rallidae) differ in regard to CBP. Purple gallinule territories were sparse, owing to the distribution of preferred habitat. Moorhens flocked outside of the breeding season. They nested more synchronously, at higher densities, and primarily in ephemeral floating vegetation. Further, moorhens suffered a rate of nest loss nearly double that of American purple gallinules, and this increased over the course of the breeding season. Moorhen clutches were larger on average, and more variable in size than those of purple gallinules. Reproductive effort and rate (seasonality) constitute important life history differences between these species that may constrain the evolution of reproductive tactics. Comparing these sympatric populations, and others differing in life-history traits and ecological constraints, highlights the role of risk management in the evolution of CBP

Loblolly pine provenance testing in Tennessee

Six loblolly pine (Pinus taeda L.) provenance test plantations distributed across Tennessee (ages 19 to 26 years from planting) were evaluated on an individual tree basis for total height, dbh, volume and basal area. In addition, wood specific gravity and percentage composition of cortical monoterpenes were evaluated at the Ames Plantation in west Tennessee and the Highland Rim Forestry Field Station near Tullahoma. Significant differences among provenances were found at Ames Plantation, the Highland Rim Forestry Field Station, the Counce plantation in west Tennessee and the Stephen\u27s Switch plantation in the lower elevations of the Cumberland Mountains. At the Stephen\u27s Switch plantation, trees from southeast Tennessee, north Alabama and the North Carolina Piedmont and Coastal Plain produced significantly more volume and basal area on a per hectare basis than trees from the Georgia Piedmont or the South Carolina Coastal Plain. At Ames Plantation, trees from Tishomingo, MS (upper- Coastal Plain), Accomac, VA (eastern shore), Johnston, SC (Piedmont), Chilesburg, VA (Piedmont) and Crossett, AR (upper-Coastal Plain) consistently produced the most volume per hectare, basal area per hectare and tonnes of wood per hectare. Intermediate production was attained by trees from Griffin, GA and Cullman, AL, both of the upper- Coastal Plain region. Low production was associated with provenances that originated near Georgetown, SC (Coastal Plain) and in Gulf Coastal Plain localities. Trees in the Counce plantation varied significantly only in diameter and volume per tree. Trees from the South Carolina Coastal Plain, south Alabama and the North Carolina Coastal Plain were largest in diameter and volume, while those from the Georgia Piedmont, Maryland Coastal Plain and northeast Mississippi were smallest. No significant differences among provenances for unextracted and extracted specific gravity, or extractives were evident at either Ames Plantation or the Highland Rim. However, extractives were produced at the Highland Rim in significantly greater amounts than at Ames. With one exception, a general pattern of decreasing specific gravity from the Atlantic Coastal Plain (.475 to .471), inland into the Piedmont region (.466 to .463) was indicated. Considerable variation was found in cortical monoterpene composition; beta-pinene, myrcene, limonene, and beta-phellandrene showed bimodality, while the alpha-pinene data had normal distribution. Combined data from the Ames and Highland Rim plantations revealed that 12 of 16 possible phenotypes occurred when each tree was classified as being high or low for each of the 4 monoterpenes showing bimodality. High amounts of limonene and beta-phellandrene occurred in greater percentages in trees of western origins, while high amounts of myrcene were frequently found in eastern trees. Distribution of beta-pinene was patchy and no trend was identified. A trend of increasing percent alpha-pinene content in a southwest to northeast pattern was indicated. It was recommended that trees best suited to west Tennessee growing conditions included those from Virginia, the Carolina Piedmonts and north Mississippi. Loblolly pine plantations on the Highland Rim should consist of trees from Virginia and the Carolina Piedmonts. Trees from southeast Tennessee, north Alabama and the North Carolina Piedmont were recommended for planting in the lower elevations of the Cumberland Mountains. Trees planted at the Friendship Forest (ridge and valley) and Norris (ridge and valley) did not indicate statistically significant differences among provenances. Future measurements of these provenance tests were not recommended

Seasonal home range dynamics and sex di�erences in habitat use in a threatened, coastal marsh bird

A comprehensive understanding of spatiotemporal ecology is needed to develop con- servation strategies for declining species. The king rail (Rallus elegans) is a secretive marsh bird whose range historically extended across the eastern United States. Inland migratory populations have been greatly reduced with most remaining populations inhabiting the coastal margins. Our objectives were to determine the migratory status of breeding king rails on the mid-Atlantic coast and to characterize home range size, seasonal patterns of movement, and habitat use. Using radiotelemetry, we tracked individual king rails among seasons, and established that at least a segment of this breeding population is resident. Mean (±SE) home range size was 19.8 ± 5.0 ha (95% kernel density) or 2.5 ± 0.9 (50% kernel density). We detected seasonal variation and sex differences in home range size and habitat use. In the nonbreeding season, resi- dent male home ranges coincided essentially with their breeding territories. Overwintering males were more likely than females to be found in natural emergent marsh with a greater area of open water. Females tended to have larger home ranges than males during the nonbreeding season. We report for the first time the use of wooded natural marsh by overwintering females. Brood-rearing king rails led their young considerable distances away from their nests (average maximum distance: ~600 ± 200 m) and used both wooded natural and impounded marsh. King rails moved between natural marsh and managed impoundments during all life stages, but the proximity of these habitat types particularly benefitted brood-rearing parents seeking foraging areas with shallower water in proximity to cover. Our results demonstrate the importance of interspersion of habitat types to support resident breeders. Summer draining of impounded wetlands that are seasonally flooded for wintering waterfowl allows regrowth of vegetation and provides additional habitat at a critical time for wading birds

Interclutch variability in egg characteristics in two species of rail: Is maternal identity encoded in eggshell patterns?

© 2022 Johnson, McRae. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Maternal signatures are present in the eggs of some birds, but quantifying interclutch variability within populations remains challenging. Maternal assignment of eggs with distinctive appearances could be used to non-invasively identify renesting females, including hens returning among years, as well as to identify cases of conspecific brood parasitism. We explored whether King Rail (Rallus elegans) eggs with shared maternity could be matched based on eggshell pattern. We used NaturePatternMatch (NPM) software to match egg images taken in the field in conjunction with spatial and temporal data on nests. Since we had only a small number of marked breeders, we analyzed similar clutch images from a study of Eurasian Common Moorhens (Gallinula chloropus chloropus) with color-banded breeders for which parentage at many nests had been verified genetically to validate the method. We ran 66 King Rail clutches (n = 338 eggs) and 58 Common Moorhen clutches (n = 364 eggs) through NPM. We performed non-metric multidimensional scaling and permutational analysis of variance using the best egg match output from NPM. We also explored whether eggs could be grouped by clutch using a combination of egg dimensions and pattern data derived from NPM using linear discriminant analyses. We then scrutinized specific matches returned by NPM for King Rail eggs to determine whether multiple matches between the same clutches might reveal maternity among nests and inform our understanding of female laying behavior. To do this, we ran separate NPM analyses for clutches photographed over several years from two spatially distant parts of the site. With these narrower datasets, we were able to identify four instances where hens likely returned to breed among years, four likely cases of conspecific brood parasitism, and a within-season re-nesting attempt. Thus, the matching output was helpful in identifying congruent egg patterns among clutches when used in conjunction with spatial and temporal data, revealing previously unrecognized site fidelity, within-season movements, and reproductive interference by breeding females. Egg pattern data in combination with nest mapping can be used to inform our understanding of female reproductive effort, success, and longevity in King Rails. These methods may also be applied to other secretive birds and species of conservation concern.ECU ALS PLOS Institutional Account Progra

Seasonal home range dynamics and sex differences in habitat use in a threatened, coastal marsh bird

A comprehensive understanding of spatiotemporal ecology is needed to develop conservation strategies for declining species. The king rail (Rallus elegans) is a secretive marsh bird whose range historically extended across the eastern United States. Inland migratory populations have been greatly reduced with most remaining populations inhabiting the coastal margins. Our objectives were to determine the migratory status of breeding king rails on the mid-Atlantic coast and to characterize home range size, seasonal patterns of movement, and habitat use. Using radiotelemetry, we tracked individual king rails among seasons, and established that at least a segment of this breeding population is resident. Mean (±SE) home range size was 19.8 ± 5.0 ha (95% kernel density) or 2.5 ± 0.9 (50% kernel density). We detected seasonal variation and sex differences in home range size and habitat use. In the nonbreeding season, resident male home ranges coincided essentially with their breeding territories. Overwintering males were more likely than females to be found in natural emergent marsh with a greater area of open water. Females tended to have larger home ranges than males during the nonbreeding season. We report for the first time the use of wooded natural marsh by overwintering females. Brood-rearing king rails led their young considerable distances away from their nests (average maximum distance: ~600 ± 200 m) and used both wooded natural and impounded marsh. King rails moved between natural marsh and managed impoundments during all life stages, but the proximity of these habitat types particularly benefitted brood-rearing parents seeking foraging areas with shallower water in proximity to cover. Our results demonstrate the importance of interspersion of habitat types to support resident breeders. Summer draining of impounded wetlands that are seasonally flooded for wintering waterfowl allows regrowth of vegetation and provides additional habitat at a critical time for wading birds.ECU Open Access Publishing Support Fun

Reach- and catchment-scale determinants of the distribution of freshwater mussels (Bivalvia: Unionidae) in south-eastern Michigan, U.S.A.

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73643/1/j.1365-2426.2003.01165.x.pd