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Mary Ann Ottinger - One of the best experts on this subject based on the ideXlab platform.
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Absorption and biotransformation of polybrominated diphenyl ethers DE-71 and DE-79 in chicken (Gallus gallus), mallard (Anas platyrhynchos), American Kestrel (Falco sparverius) and black-crowned night-heron (Nycticorax nycticorax) eggs.
Chemosphere, 2010Co-Authors: Moira Mckernan, Jeff S. Hatfield, Robert C Hale, Barnett A. Rattner, Mary Ann OttingerAbstract:Abstract We recently reported that air cell administration of penta-brominated diphenyl ether (penta-BDE; DE-71) evokes biochemical and immunologic effects in chicken ( Gallus gallus ) embryos at very low doses, and impairs pipping (i.e., stage immediately prior to hatching) and hatching success at 1.8 μg g −1 egg (actual dose absorbed) in American Kestrels ( Falco sparverius ). In the present study, absorption of polybrominated diphenyl ether (PBDE) congeners was measured following air cell administration of a penta-BDE mixture (11.1 μg DE-71 g −1 egg) or an octa-brominated diphenyl ether mixture (octa-BDE; DE-79; 15.4 μg DE-79 g −1 egg). Uptake of PBDE congeners was measured at 24 h post-injection, midway through incubation, and at pipping in chicken, mallard ( Anas platyrhynchos ), and American Kestrel egg contents, and at the end of incubation in black-crowned night-heron ( Nycticorax nycticorax ) egg contents. Absorption of penta-BDE and octa-BDE from the air cell into egg contents occurred throughout incubation; at pipping, up to 29.6% of penta-BDE was absorbed, but only 1.40–6.48% of octa-BDE was absorbed. Higher brominated congeners appeared to be absorbed more slowly than lower brominated congeners, and uptake rate was inversely proportional to the log K ow of predominant BDE congeners. Six congeners or co-eluting pairs of congeners were detected in penta-BDE-treated eggs that were not found in the dosing solution suggesting debromination in the developing embryo, extraembryonic membranes, and possibly even in the air cell membrane. This study demonstrates the importance of determining the fraction of xenobiotic absorbed into the egg following air cell administration for estimation of the lowest-observed-effect level.
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the effects of polychlorinated biphenyls aroclor 1242 on thyroxine estradiol molt and plumage characteristics in the American Kestrel falco sparverius
Environmental Toxicology and Chemistry, 2002Co-Authors: Michael J Quinn, John B French, F Anne M Mcnabb, Mary Ann OttingerAbstract:The purpose of this experiment was to determine the effects of Aroclor 1242, a mixture of polychlorinated biphenyls (PCBs), on plumage characteristics and molt in the American Kestrel, Falco sparverius. Several characteristics of plumage, including color and molt schedule, are modulated by hormonal signals and hence may be modified by endocrine-active contaminants. If so, the functions of plumage (e.g., communication for mating or territorial defense) may be compromised by exposure to such compounds. Captive American Kestrels were fed Aroclor 1242 at 0, 6.0, and 60.0 ppm (n = 6 males and 6 females per treatment) mixed in their normal diet. Concentrations of plasma estradiol and thyroxine were measured weekly from the beginning of treatment. Measured plumage characteristics included width of the black subterminal band on the tail, color (a composite index of hue and saturation), reflectance from 230 to 800 nm, pattern of feather loss and regrowth on the tail and wing, and timing of onset and duration of molt. Aroclor 1242 depressed plasma thyroxine. Plasma estradiol levels remained low due to the phase of the breeding cycle. Treatments did not disrupt the measured plumage characteristics. This may be due to timing or dose of exposure or to genetic factors.
Julie A Heath - One of the best experts on this subject based on the ideXlab platform.
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reproductive failure of a human tolerant species the American Kestrel is associated with stress and human disturbance
Journal of Applied Ecology, 2013Co-Authors: Erin H Strasser, Julie A HeathAbstract:Summary 1. The rapid increase of human activity in wild and developed areas presents novel challenges for wildlife. Some species may use human-dominated landscapes because of favourable resources (e.g. high prey availability along roadsides); however, use of these areas may increase exposure to anthropogenic stressors, such as human disturbance or noise, which can negatively affect reproduction or survival. In this case, human-dominated landscapes may act as an ecological trap. 2. We evaluated whether American Kestrel Falco sparverius reproductive failure was associated with human disturbance (traffic conditions and land development) or other common predictors of reproductive outcome, such as habitat and clutch initiation date. Also, we examined relationships among human disturbance, corticosterone (CORT) concentrations and nest abandonment to explore potential mechanisms for stress-induced reproductive failure. 3. Twenty-six (36%) of 73 Kestrel nesting attempts failed and 88% of failures occurred during incubation. Kestrels nesting in higher disturbance areas were 99 times more likely to fail than Kestrels nesting in lower disturbance areas. Habitat and clutch initiation date did not explain reproductive outcome. 4. Females in higher disturbance areas had higher CORT and were more likely to abandon nests than females in lower disturbance areas. There was no relationship between male CORT and disturbance or abandonment. Females spent more time incubating than males and may have had more exposure to anthropogenic stressors. Specifically, traffic noise may affect a cavity-nesting bird’s perception of the outside environment by masking auditory cues. In response, incubating birds may perceive a greater predation risk, increase vigilance behaviour, decrease parental care, or both. 5. Synthesis and applications. Proximity to large, busy roads and developed areas negatively affected Kestrel reproduction by causing increased stress hormones that promoted nest abandonment. These results demonstrate that species presence in a human-dominated landscape does not necessarily indicate a tolerance for anthropogenic stressors. Managers should carefully consider or discourage projects that juxtapose favourable habitat conditions with areas of high human activity to decrease risk of ecological traps. Noise mitigation, while locally effective, may not protect widespread populations from the pervasive threat of traffic noise. Innovative engineering that decreases anthropogenic noise at its source is necessary.
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challenges in creating an American Kestrel body condition index based on size adjusted mass
Journal of Raptor Research, 2011Co-Authors: Julie A Heath, Lina Bardo, Erin H Strasser, Mark A Foster, David M BirdAbstract:Abstract Size-adjusted mass is a common body condition index (BCI) used to indicate nonstructural energy reserves (fat and protein). BCIs are calculated from ratios of mass divided by a morphometric(s) or residuals of a regression between mass and a morphometric(s). The morphometrics used in BCIs must accurately represent structural size to reliably index energy reserves and, ideally, BCIs should be validated with comparisons to true fat and protein reserves. Many studies of American Kestrels (Falco sparverius) have included BCIs in ecological analyses; unfortunately, few studies have reported how well morphometrics represented structural size or provided validation of BCIs relative to independent measures of energy reserves. We evaluated relationships between several morphometrics and mass to better understand which morphometrics may best represent structural size for two Kestrel populations: captive birds at McGill University in Montreal, Canada, and free-living Kestrels in southwestern Idaho, U.S.A. We...
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effects of developmental conditions on nestling American Kestrel falco sparverius corticosterone concentrations
General and Comparative Endocrinology, 2011Co-Authors: Erin H Strasser, Julie A HeathAbstract:How n estling birds respond to stressful situations may constitute an important survival co mponent that has lasting developmental effects on the hypothalamic pituitary adrenal (HPA) axis. As birds are exposed to increasing amounts of potential anthropogenic stressors through land use change, understanding how these factors contribute to HPA development is important. We examined whether conditions experienced during the nestling stage affected free-living American Kestrel (Falco sparverius) HPA activity prior to fledging. Kestrels experienced varying levels of human disturbance around their nest and we classified this environmental exposure as high or low environmental human disturbance based on traffic patterns and land use. We then exposed some broods from high and low disturbance areas to a standardized disturbance protocol. Prior to fledging we collected blood samples from 25day-old nestlings immediately after capture and 15 min post-capture. Corticosterone (CORT) did not vary with environmental human disturbance levels, disturbance protocol treatment, or with an interaction between environmental human disturbance and disturbance protocol treatment suggesting that nestling Kestrels may not perceive external conditions related to human disturbance as stressful or Kestrels may acclimate to disturbance. We also compared the relative effects of environmental human disturbance outside the nest cavity, conditions within the nest cavity (brood size), and individual condition (nestling fat scores) on baseline and stress-induced CORT. Baseline CORT did not vary with human disturbance level, brood size or fat score. F at scores best explained stress-induced CORT with nestlings in better condition displaying elevated CORT. These results suggest that individual variation is more likely to explain HPA development compared to nest conditions or the external environment. This study demonstrates the importance of considering the effects of developmental conditions on the stress response at several scales.
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American Kestrel reproduction: evidence for the selection hypothesis and the role of dispersal
Ibis, 2009Co-Authors: Karen Steenhof, Julie A HeathAbstract:Many hypotheses attempt to explain why younger, less experienced birds have a 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 levelled 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.
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body condition and the adrenal stress response in captive American Kestrel juveniles
Physiological and Biochemical Zoology, 1998Co-Authors: Julie A Heath, Alfred M DuftyAbstract:ABSTRACT We examined the adrenal response to handling stress of birds in different body conditions. In order to affect the birds' body condition, young (73‐d old) female American Kestrels (Falco sparverius) were maintained for 6 wk on one of three diets: a control diet (fed ad lib.) and two calorically restricted diets. To invoke a stress response, we removed birds from their cages and took repeated blood samples over the course of an hour. All birds responded to handling stress with an increase in plasma corticosterone, but control birds (in good body condition) showed a more rapid increase to maximum corticoste‐rone levels, followed by a decrease. Both groups of food‐restricted birds had a slower rate of increase to maximum corticosterone levels and then maintained high corticosterone levels through 60 min. These results suggest that birds in good physical condition respond more quickly to stressors and adapt physiologically to stressful situations more rapidly than do birds in poor physical condition. ...
David M Bird - One of the best experts on this subject based on the ideXlab platform.
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challenges in creating an American Kestrel body condition index based on size adjusted mass
Journal of Raptor Research, 2011Co-Authors: Julie A Heath, Lina Bardo, Erin H Strasser, Mark A Foster, David M BirdAbstract:Abstract Size-adjusted mass is a common body condition index (BCI) used to indicate nonstructural energy reserves (fat and protein). BCIs are calculated from ratios of mass divided by a morphometric(s) or residuals of a regression between mass and a morphometric(s). The morphometrics used in BCIs must accurately represent structural size to reliably index energy reserves and, ideally, BCIs should be validated with comparisons to true fat and protein reserves. Many studies of American Kestrels (Falco sparverius) have included BCIs in ecological analyses; unfortunately, few studies have reported how well morphometrics represented structural size or provided validation of BCIs relative to independent measures of energy reserves. We evaluated relationships between several morphometrics and mass to better understand which morphometrics may best represent structural size for two Kestrel populations: captive birds at McGill University in Montreal, Canada, and free-living Kestrels in southwestern Idaho, U.S.A. We...
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The Use of Captive American Kestrels (Falco sparverius) as Wildlife Models: A Review
Journal of Raptor Research, 2009Co-Authors: Lina Bardo, David M BirdAbstract:Abstract The American Kestrel (Falco sparverius) is a common North American falcon. As a result of a number of characteristics, including small size, annual reproduction, ability to be housed in large numbers, and ease of breeding in captivity, these falcons have been used as wildlife models for over four decades. Kestrels are best known for their use in the demonstration that 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT), and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) caused eggshell thinning and reproductive failure in birds, and their use in the amelioration of captive propagation programs for the Peregrine Falcon (F. peregrinus). Since that time, Kestrels have continued to play a prominent role in wildlife research, particularly in the field of toxicology, where they remain the only raptor species to be bred in sufficient numbers in captivity for statistically significant research. Kestrels have also been used for studies of avian biology, physiology, nutrition, and behavior. In recent y...
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plasma corticosterone in American Kestrel siblings effects of age hatching order and hatching asynchrony
Hormones and Behavior, 2003Co-Authors: Oliver P Love, David M Bird, Laird J ShuttAbstract:Although it is well documented that hatching asynchrony in birds can lead to competitive and developmental hierarchies, potentially greatly affecting growth and survival of nestlings, hatching asynchrony may also precipitate modulations in neuroendocrine development or function. Here we examine sibling variation in adrenocortical function in postnatally developing, asynchronously hatching American Kestrels (Falco sparverius) by measurements of baseline and stress-induced levels of corticosterone at ages 10, 16, 22, and 28 days posthatching. There was a significant effect of hatching order on both baseline and stress-induced corticosterone levels during development and these effects grew stronger through development. First-hatched chicks exhibited higher baseline levels than later-hatched chicks throughout development and higher stress-induced levels during the latter half of development. Furthermore, there was significant hatching span (difference in days between first- and last-hatched chicks) × hatching order interaction on both baseline and stress-induced corticosterone levels during development. Hatching span was also positively correlated with both measures of corticosterone and body mass in first-hatched chicks, but was negatively correlated with these factors through most of the development in last-hatched chicks. It is known that hatching asynchrony creates mass and size hierarchies within Kestrel broods and we suggest that hierarchies in adrenocortical function among siblings may be one physiological mechanism by which these competitive hierarchies are maintained.
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copulatory behaviour and paternity in the American Kestrel the adaptive significance of frequent copulations
Animal Behaviour, 1998Co-Authors: Morris Villarroel, David M Bird, U KuhnleinAbstract:The adaptive significance of repeated withinpair copulations is not well understood. We analysed the copulatory behaviour of 16 pairs of solitary-nesting American Kestrels, Falco sparverius, in southern Quebec (Canada), and the achieved reproductive success (paternity) of 21 Kestrel families determined by DNA fingerprinting, in terms of four hypotheses. (1) The paternity assurance hypothesis, which suggests that males copulate frequently to avoid being cuckolded, was rejected because there were few extrapair copulation attempts (<1% of all copulations observed), withinpair copulations were not timed during the fertile period and mate attendance did not increase as the fertile period approached. (2) The immediate material benefits hypothesis, which suggests that females trade copulations for food, was refuted because copulations most often occurred without food transfers, especially outside the fertile period. (3) The female mate guarding of males hypothesis, which suggests that females distract their mates from other mating opportunities by copulating frequently, was rejected because extrapair copulation attempts were infrequent, male and female solicitation frequencies were similar and females did not differ in the timing or frequency of solicitations. (4) The mate assessment hypothesis, which suggests that assessment of mate quality is mediated via copulation, most closely predicted the behaviour observed since withinpair copulations were frequent outside the fertile period and at pair formation, males and females solicited similar numbers of copulations and pairs did not differ significantly in solicitation or copulation frequency. In line with this hypothesis we found that only one brood was extrapair, probably the result of mate replacement. © 1998 The Association for the Study of Animal Behaviour
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sexually dimorphic eggs nestling growth and sibling competition in American Kestrels falco sparverius
Functional Ecology, 1997Co-Authors: David J Anderson, J Reeve, David M BirdAbstract:1. American Kestrel (Falco sparverius) nestlings are sexually dimorphic, with daughters larger than sons. The larger daughters have an advantage during sibling competition for food in excess of their higher per capita food requirements, and we predicted that parents would reduce this competitive disparity by differentially enhancing the growth of sons, specifically by laying them in larger eggs. 2. In a captive breeding population, eggs producing sons were significantly larger than eggs producing daughters; laying order effects were controlled. 3. The influence of sibling egg size ratios on post-natal size relationships persisted through the nesting period, providing parents with a tool to manipulate size-related phenomena in their offspring.
Moira Mckernan - One of the best experts on this subject based on the ideXlab platform.
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Absorption and biotransformation of polybrominated diphenyl ethers DE-71 and DE-79 in chicken (Gallus gallus), mallard (Anas platyrhynchos), American Kestrel (Falco sparverius) and black-crowned night-heron (Nycticorax nycticorax) eggs.
Chemosphere, 2010Co-Authors: Moira Mckernan, Jeff S. Hatfield, Robert C Hale, Barnett A. Rattner, Mary Ann OttingerAbstract:Abstract We recently reported that air cell administration of penta-brominated diphenyl ether (penta-BDE; DE-71) evokes biochemical and immunologic effects in chicken ( Gallus gallus ) embryos at very low doses, and impairs pipping (i.e., stage immediately prior to hatching) and hatching success at 1.8 μg g −1 egg (actual dose absorbed) in American Kestrels ( Falco sparverius ). In the present study, absorption of polybrominated diphenyl ether (PBDE) congeners was measured following air cell administration of a penta-BDE mixture (11.1 μg DE-71 g −1 egg) or an octa-brominated diphenyl ether mixture (octa-BDE; DE-79; 15.4 μg DE-79 g −1 egg). Uptake of PBDE congeners was measured at 24 h post-injection, midway through incubation, and at pipping in chicken, mallard ( Anas platyrhynchos ), and American Kestrel egg contents, and at the end of incubation in black-crowned night-heron ( Nycticorax nycticorax ) egg contents. Absorption of penta-BDE and octa-BDE from the air cell into egg contents occurred throughout incubation; at pipping, up to 29.6% of penta-BDE was absorbed, but only 1.40–6.48% of octa-BDE was absorbed. Higher brominated congeners appeared to be absorbed more slowly than lower brominated congeners, and uptake rate was inversely proportional to the log K ow of predominant BDE congeners. Six congeners or co-eluting pairs of congeners were detected in penta-BDE-treated eggs that were not found in the dosing solution suggesting debromination in the developing embryo, extraembryonic membranes, and possibly even in the air cell membrane. This study demonstrates the importance of determining the fraction of xenobiotic absorbed into the egg following air cell administration for estimation of the lowest-observed-effect level.
Christopher J. W. Mcclure - One of the best experts on this subject based on the ideXlab platform.
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evaluating citizen science outreach a case study with the peregrine fund s American Kestrel partnership
PLOS ONE, 2021Co-Authors: Sarah E. Schulwitz, Greg C Hill, Vanessa Fry, Christopher J. W. McclureAbstract:Citizen science programs can be powerful drivers of knowledge and scientific understanding and, in recent decades, they have become increasingly popular. Conducting successful research with the aid of citizen scientists often rests on the efficacy of a program's outreach strategies. Program evaluation is increasingly recognized as a critical practice for citizen science practitioners to ensure that all efforts, including outreach, contribute to the overall goals of the program. The Peregrine Fund's American Kestrel Partnership (AKP) is one such citizen science program that relies on outreach to engage participants in effective monitoring of a declining falcon species. Here, we examine whether various communication strategies were associated with desired outreach goals of the AKP. We demonstrate how social media, webcams, discussion boards, and newsletters were associated with perception of learning, agreement with our conservation messaging, and participation in our box monitoring program. Our results thus help us to improve our outreach methodology, suggest areas where other citizen science programs might improve their outreach efforts, and highlight future research priorities.
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American Kestrel (Falco sparverius) scavenging on domestic turkey (Meleagris gallopavo) carcass
The Wilson Journal of Ornithology, 2019Co-Authors: Sarah E. Schulwitz, Michael C. Griffith, Christopher J. W. McclureAbstract:ABSTRACT Despite the American Kestrel (Falco sparverius) being one of the most commonly occurring and one of the most thoroughly studied raptors in North America, it has only been documented consum...
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webcams as an untapped opportunity to conduct citizen science six years of the American Kestrel partnership s Kestrelcam
Global Ecology and Conservation, 2018Co-Authors: Sarah E. Schulwitz, Paul D. Spurling, Tala S. Davis, Christopher J. W. McclureAbstract:Abstract Hundreds of zoo-based or wildlife webcams have become available during the past twenty years, mostly with the goal of educating the public. However, there has been virtually no peer-reviewed research that evaluates the education, conservation, or scientific impact of webcams. Here, we provide one of the few examples of a webcam used for citizen science, and the only test of efficacy for crowd-sourced data collection using webcams. The Peregrine Fund streamed six seasons of American Kestrel (Falco sparverius) nests using the same nest box from 2012 through 2017 and viewers input observations into an online portal. We analyze trends in participant and Kestrel behavior and test for sources of bias in this citizen scientist-generated dataset by independently reviewing a subset of recordings to determine accuracy of viewer-logged data. Citizen scientists logged a maximum of approximately 5.25% of all footage, but with an accuracy of 88%. Although number of participants declined yearly, on average, participants became more engaged. Sources of bias were related to people's daily activity periods (i.e., less participation at night) and activity within the nest box (i.e., less participation when there were no birds in the box). This citizen scientist-generated dataset generally corroborated the literature regarding American Kestrel biology. Researchers may be cautiously optimistic that datasets generated by citizen scientists can provide valuable information on a given system or study species. Given the ubiquity of webcams and their potential competition for conservation dollars, more research evaluating any aspect of their impact or application is sorely needed.
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Webcams as an untapped opportunity to conduct citizen science: Six years of the American Kestrel Partnership's KestrelCam
'Elsevier BV', 2018Co-Authors: Sarah E. Schulwitz, Paul D. Spurling, Tala S. Davis, Christopher J. W. McclureAbstract:Hundreds of zoo-based or wildlife webcams have become available during the past twenty years, mostly with the goal of educating the public. However, there has been virtually no peer-reviewed research that evaluates the education, conservation, or scientific impact of webcams. Here, we provide one of the few examples of a webcam used for citizen science, and the only test of efficacy for crowd-sourced data collection using webcams. The Peregrine Fund streamed six seasons of American Kestrel (Falco sparverius) nests using the same nest box from 2012 through 2017 and viewers input observations into an online portal. We analyze trends in participant and Kestrel behavior and test for sources of bias in this citizen scientist-generated dataset by independently reviewing a subset of recordings to determine accuracy of viewer-logged data. Citizen scientists logged a maximum of approximately 5.25% of all footage, but with an accuracy of 88%. Although number of participants declined yearly, on average, participants became more engaged. Sources of bias were related to people's daily activity periods (i.e., less participation at night) and activity within the nest box (i.e., less participation when there were no birds in the box). This citizen scientist-generated dataset generally corroborated the literature regarding American Kestrel biology. Researchers may be cautiously optimistic that datasets generated by citizen scientists can provide valuable information on a given system or study species. Given the ubiquity of webcams and their potential competition for conservation dollars, more research evaluating any aspect of their impact or application is sorely needed. Keywords: Webcam, Nest cam, Wildlife, Citizen science, American Kestrel, Falco sparveriu