2,801 research outputs found
Corticosterone Levels During Nest Departure of Juvenile American Kestrels
Many avian behavior patterns, such as breeding, migration and territoriality, are correlated with changes in hormone levels. Elevated levels of corticosterone, an adrenal steroid hormone, are associated with increased foraging and increased activity levels in birds. Young birds about to take their first flight may benefit from elevated plasma corticosterone levels that facilitate locomotor activity and foraging behavior while they are developing flight and hunting skills. I examined the relationship between corticosterone levels and the timing of nest departure in nestling American Kestrels (Falco sparverius). American Kestrels are cavity nesters and typically depart from the nest between 25-30 days of age, when they take their first flight. I collected blood from 21-25-day-old kestrels and monitored nest boxes to determine date of nest departure. Consistent with my prediction, as birds prepared to depart from the nest their plasma corticosterone levels increased significantly. The relationship between corticosterone levels and nest departure may be particularly important in those cavity nesters that must make a quick transition from inactivity to fullflight at the time of nest departure
Factors affecting breeding status of wading birds in the Everglades.
This goals of this research and monitoring effort are to document nesting effort
and roughly categorize success of nesting by wading birds in the central Everglades of
Florida, and to investigate the causes of nonbreeding in a high proportion of the adult
wading birds in the ecosystem The latter goal has focused on breeding of White Ibises
(Eudocimus albus) and has been approached through 1) understanding the nutritional,
behavioral, and hormonal aspects of normal breeding in a captive colony ofScarlet Ibises
(considered conspecific to White Ibises) in central Florida, and 2) comparing breeding and
nonbreeding wild White Ibises in the Everglades, in their physiology, nutritional state,
breeding phenology, contaminant load, and hormonal status. This report covers work on
this project between January and November, 2000. (81 page docoument
American Kestrel Reproduction: Evidence for the Selection Hypothesis and the Role of Dispersal
Many hypotheses attempt to explain why younger, less experienced birds have relatively low reproductive output. We evaluated reproductive patterns of marked American Kestrels Falco sparverius nesting in boxes in southwestern Idaho from 1992 to 2006 to test predictions of these hypotheses. Results were consistent with the selection (differential mortality) hypothesis and did not support the constraint, restraint or recruitment hypotheses. Most known-age Kestrels nested in their first year of life, and there was no apparent short-term or long-term reproductive advantage to delayed breeding. The number of years that Kestrels nested in study area boxes ranged from 1 to 6 years, with most Kestrels nesting in only 1 year. Reproductive rates were higher for birds with at least 1 year of nesting experience than for birds nesting in boxes for the first time. After 2 years of nesting, reproductive rates leveled off; there was no evidence for additional improvement or for senescence. Differences in reproductive output with experience/age were due to variation among and not within individuals. Individuals that nested in more than 1 year had similar reproductive rates in their first and second years. Poor producers either died or dispersed after 1 year of nesting in study area boxes. Successful females that nested early in the season and successful males that had been produced locally had the highest probability of returning to nest in a subsequent year
Local Recruitment and Natal Dispersal Distances of American Kestrels
Variation in recruitment patterns and dispersal behavior can have important consequences for population viability, genetic structure, and rates of evolutionary change. From 1992 to 2006 we studied a marked population of American Kestrels (Falco sparverius) nesting in boxes in southwestern Idaho to identify factors that affect local recruitment and natal dispersal distances. A low proportion (4%) of locally produced kestrels (n = 2180) returned to nest in study area boxes. Offspring of locally produced individuals were 3.1 times more likely to return than offspring of parents that did not hatch in study area boxes and, independent of a parent’s origin, males were 1.8 times more likely than females to return. Kestrels that hatched earlier in the breeding season and those that hatched immediately prior to a mild winter were more likely to return. Local natal dispersal distances were best explained by sex and parental origin but not by hatching dates. Fifty-four males moved an average of 5.3 km from their natal box to the location of their first breeding in the study area, and 27 females moved an average of 9.8 km. Offspring of locally produced parents dispersed shorter distances within the study area than offspring of other parents, and local natal dispersal distances of locally produced parents correlated with those of their same-sex offspring. Patterns of natal dispersal of American Kestrels in southwestern Idaho appear to be driven by a combination of parental dispersal tendencies and ecological factors. The population consists of a mix of immigrants and philopatric birds
Leadership Behaviors and Communication Satisfaction: Community Colleges in Micronesia
The major purpose of this study was to examine the satisfaction of Micronesian community college faculty with communication and their perception of their department chair\u27s leadership style. Specifically, this study examined (a) the relationship of communication satisfaction with leadership and demographic data; (b) the relationship between the Multifactor Leadership Questionnaire (MLQ) subset and the scales of the Communication Satisfaction Questionnaire (CSQ); (c) the difference between institutions in terms of satisfaction with communication or perception of leadership style; and (d) suggestions for improving communication. Significant relationship was found between the overall communication satisfaction with leadership quality and ethnicity. The data revealed that the scales of the Multifactor Leadership Questionnaire and the scales of the Communication Satisfaction Questionnaire were significantly correlated. The analysis of variance revealed differences in communication satisfaction between colleges. However, the perceptions of transformational leadership style were similar in all the colleges. Suggestions to improve communication were: the need for an open communication, to improve personal feedback, and to improve relationship with the supervisor
Seasonal Carotenoid Variation in American Kestrels
Carotenoids are micronutrient pigments produced by plants that may convey immunological benefits to consumers. Animals with high levels of carotenoid intake may have improved health and higher survival. American Kestrels (Falco sparverius) from broods hatched early in the breeding season are more likely to survive and return to the breeding population than birds hatched later in the season. We hypothesized that breeding adults and nestlings may be affected by seasonal patterns in primary productivity that lead to changes in prey quality and availability; therefore affecting carotenoid intake. We collected blood samples from American Kestrels breeding in nestboxes south of Boise, Idaho and measured carotenoid concentrations via spectrophotometry. Our results supported our hypothesis that there are seasonal patterns in carotenoid availability, but trends did not match our predictions. Adult birds did show seasonal declines in carotenoids, while nestlings showed seasonal increases. Further, adult carotenoid levels did not predict nestling levels and there was high annual variation in carotenoid concentrations. Circulating carotenoids may be affected by factors other than food intake (i.e., hormones) making trend difficult to interpret
Does Outdoor Recreation Decrease Stress? Investigating the Physiological Responses of Outdoor Recreation in Idaho
This poster was presented at the 2016 Idaho EPSCoR Annual Meeting, October 19-21, in Couer d\u27Alene Idaho
Commentary: The Past, Present, and Future of the Global Raptor Impact Network
Most raptor populations are declining and nearly a fifth are threatened with extinction; thus there is a need to increase collaboration to ensure efficient and effective research, management, and conservation. Here, we introduce the Global Raptor Impact Network (GRIN; www.globalraptors.org), a tool to enhance collaboration and conservation impact of the raptor research community. We provide an overview of the history and current state of GRIN, including plans for expansion. Predecessors to GRIN include The African Raptor DataBank, which was launched in 2012 to ascertain the conservation status of raptors across Africa; and the Global Raptor Information Network, which was launched in the late 1990s as a website to provide information regarding diurnal raptors and facilitate communication among researchers. GRIN expands the data collection and storage capabilities of the African Raptor DataBank to a global scale via mobile application. We have implemented data-sharing rules to ensure the safety of sensitive species, and users of the GRIN mobile app can designate their records as confidential. GRIN staff and partners are developing analyses of species\u27 population trends and geographic distributions to aid in conservation assessments. GRIN is also developing systematic reviews, detailed bibliographies, and online accounts that will summarize the state of knowledge for each raptor species. We hope that GRIN will benefit the entire raptor research community and aid in the collaboration necessary to help raptor populations thrive in the Anthropocene
Flushing Responses of Golden Eagles (\u3cem\u3eAquila chrysaetos\u3c/em\u3e) in Response to Recreation
Disturbance because of human activity, including recreation on wildlands, can affect bird behavior which in turn can reduce breeding success, an important consideration for species of management concern. We observed Golden Eagles (Aquila chysaetos) during the breeding season to determine whether the probability of flushing was affected by the type of recreationist, distance to encounter, eagle nest attendance, or date. We monitored eagles in 23 nesting territories from distant (600-1,200 m) observation points and recorded recreation activity within 1,200 m of eagles in the Owyhee Front of southwestern Idaho. In most (86%, n = 270) encounters, eagles did not flush in response to recreationists; however, whether an eagle flushed was affected by the type of recreationist and whether an eagle was at or away from the nest. Eagles were 60 times more likely to flush in response to recreationists that stopped a motor vehicle and transitioned to walking (11 of 17 passes) and 4.5 times more likely to flush in response to off-road vehicle (ORV) riders (17 of 121 passes) than during encounters with road vehicles (7 of 107 passes). Flushing was 12 times more likely for eagles away from nests (23 of 87 passes) than eagles at nests (13 of 183 passes). Eagles flushed at greater distances in response to recreationists that transitioned from motor vehicles to walking (lsmean = 620 m) than when responding to either ORV riders (lsmean = 525 m) or road vehicles (lsmean = 318 m). Flushing distances tended to decline throughout the breeding season to suggest seasonal changes in the costs and benefits of responding to disturbance. After flushing from nests, most eagles (77%) spentaway, but some (23%) spent \u3e90 mins away from nests. Limiting recreational activities within 650 m and 1,000 m of nest sites may decrease nest-site flushing events by 77% and 100%, respectively. Because eagles seem most sensitive to humans transitioning between motorized and non-motorized recreation, land managers may strike a balance between access needs of recreationists and buffering eagles from disturbance by using a mix of trail closures and no-stopping zones that prevent transitions from motorized to walking activities
- …