Effect of Predator Type, Season, Brood Size, and West Nile Virus Infection on the Nest Defense Behavior of Male and Female Eastern Bluebirds (Sialia Sialis)

Parent birds may benefit by defending nests from potential predators if such behavior increases the likelihood that their young will survive. However, such behavior may also be costly, with some risk of injury or even death. Thus, because birds seek to maximize life-time reproductive success rather than current reproductive success, parents must assess the danger posed by a potential nest predator and then choose appropriate responses (Radford and Blakey 2000

The Archaeology and Remote Sensing of Santa Elena’s Four Millennia of Occupation

In this study, we present the results of a comprehensive, landscape-scale remote sensing project at Santa Elena on Parris Island, South Carolina. Substantial occupation at the site extends for over 4000 years and has resulted in a complex array of features dating to different time periods. In addition, there is a 40-year history of archaeological research at the site that includes a large-scale systematic shovel test survey, large block excavations, and scattered test units. Also, modern use of the site included significant alterations to the subsurface deposits. Our goals for this present work are threefold: (1) to explicitly present a logical approach to examine sites with long-term occupations; (2) to examine changes in land use at Santa Elena and its implications for human occupation of this persistent place; and (3) to use the remote sensing program and past archaeological research to make substantive suggestions regarding future research, conservation, and management of the site. Our research provides important insight into the distribution of cultural features at this National Historic Landmark. While the majority of archaeological research at the site has focused on the Spanish period, our work suggests a complex and vast array of archaeological features that can provide insight into over 4000 years of history in the region. At a gross level, we have identified possible Late Archaic structures, Woodland houses and features, Late Prehistoric and early Historic council houses, and a suite of features related to the Spanish occupation which builds on our previous research at the site. In addition to documenting possible cultural features at the site, our work illustrates the value of multiple remote sensing techniques used in conjunction with close-interval shovel test data

Brooding and Provisioning of Nestlings by Male and Female White-eyed Vireos (Vireo griseus)

Most species of songbirds exhibit biparental care, but, for many taxa and species, little is known about the relative contributions of males and females in brooding and provisioning nestlings. Additional studies of the contributions of males and females in brooding and feeding nestlings are needed to better understand the respective roles of males and females as well as the factors that might contribute to interspecific variation in those roles. We examined the roles of adult male and female White-eyed Vireos (Vireo griseus) in brooding and provisioning nestlings in east-central Kentucky during the 1996 breeding season. Nests were located by monitoring adult behavior and checking likely nest sites. Once eggs hatched, nests were video-recorded to monitor the behavior of adults. Subsequent review of videos revealed that both male and female White-eyed Vireos brooded young and that males provisioned nestlings at higher rates than females. In contrast to males in many other species of songbirds, male White-eyed Vireos assisted in brooding young and provisioned nestlings at higher rates than their mates. One possible explanation for this is that low rates of extra-pair paternity might increase male confidence of their paternity status. Parental care provided by male White-eyed Vireos may also limit energy expenditure by their mates and increase the likelihood of females re-nesting if nests are predated or initiating second nesting attempts if initial attempts are successful

Vocalizations of the White-Breasted Nuthatch

Volume: 95Start Page: 440End Page: 45

Avian Reproduction: Anatomy & the Bird Egg

This site contains lecture notes regarding avian reproduction from Dr. Gary Ritchison's Ornithology course at Eastern Kentucky University. The lecture notes are interspersed with some especially nice images and diagrams pertaining to reproductive organs, egg production, copulation and fertilization, egg composition, egg color, and egg laying habits of birds

Effect of Variation in Nestling Hunger Levels on the Begging Behaviour of Nestlings and the Provisioning Behaviour of Adult American Kestrels

Little is known about how variation in nestling begging intensity influences the behaviour of adult raptors and how responses of adult males and females to such variation might differ. Our objective was to manipulate the begging intensity of nestling American Kestrels (Falco sparverius) and examine the responses of adults. We studied 12 pairs of American Kestrels nesting in nest boxes from 1 March to 1 July 2014 at the Blue Grass Army Depot, Madison County, Kentucky. Nest boxes were modified with a separate compartment for a camcorder to record nestling behaviour, and a second camcorder was placed outside the nests to monitor adult behaviour. To manipulate nestling hunger levels, 12 to 26-day-old nestlings in six nests were deprived of food for 24 h and those in the other six nests were fed until satiated. At each nest, we alternated control (no treatment) and treatment (fed or food deprived) days over a 4 day period to minimise the possible effect of nestling age on adult and nestling behaviour. Nestling begging intensity differed among treatments, with nestlings in food-deprived nests begging with greater intensity after food deprivation and those in fed-treatment nests begging with less intensity after being fed. Adult male and female American Kestrels provisioned nestlings at similar rates, with both sexes feeding nestlings at higher rates after food deprivation and at lower rates after fed treatments. Thus, the begging behaviour of nestling American Kestrels varied with hunger level, and adult American Kestrels responded by adjusting provisioning rates. Although the response of adults to nestling begging suggests that natural selection might favour \u27dishonest\u27 begging to obtain more food, the potential costs of \u27dishonest\u27 begging, such as attracting predators, reduced immunocompetence, and loss of indirect fitness benefits if such begging negatively impacts siblings and parents, may outweigh any possible benefit

Intra- and intersexual functions of singing by male blue Grosbeaks: The role of within-Song Variation

Songs of individual male Blue Grosbeaks (Passerina caerulea) typically begin with the same combination of elements, but the sequence and number of elements in the latter portion of songs vary. We examined the possible functions of within-song variation in Blue Grosbeaks at the Blue Grass Army Depot near Richmond, Kentucky, USA from 15 April to 31 July 2007. We examined singing rates and song characteristics of second-year (SY; n = 6) and after-second-year (ASY; n = 14) males, and conducted playback experiments (n = 15) to identify the possible function of variation in song length. Male Blue Grosbeaks sang at highest rates prior to pairing, maintained relatively high singing rates during the post-pairing/pre-nesting and nest-building/egg-laying stages, and sang at lower rates during the incubation, nestling, and fledgling stages.These results suggest high singing rates are important in attracting mates and establishing territories, and lower singing rates may result from trade-offs associated with parental care. Males used longer songs during aggressive encounters with conspecifics and responded more aggressively to playback of longer songs. This suggests songs containing more elements signal increased aggression. Within-song variation may be an important way to vary song meaning for male Blue Grosbeaks, and perhaps other males in species with a single song type but repertoires of several different song elements. © 2009 by the Wilson Ornithological Society