BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access t... more BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.
General and Comparative Endocrinology, Aug 1, 2010
We developed and validated a non-invasive thyroid hormone measure in feces of a diverse array of ... more We developed and validated a non-invasive thyroid hormone measure in feces of a diverse array of birds and mammals. An I 131 radiolabel ingestion study in domestic dogs coupled with High Pressure Liquid Chromatography (HPLC) analysis, showed that peak excretion in feces occurred at 24-48 h post-ingestion, with I 131-labelled thyroid hormone metabolites excreted primarily as triiodothyronine (T3) and relatively little thyroxine (T4), at all excretion times examined. The immunoreactive T3 profile across these same HPLC fractions closely corresponded with the I 131 radioactive profile. By contrast, the T4 immunoreactive profile was disproportionately high, suggesting that T4 excretion included a high percentage of T4 stores. We optimized and validated T3 and T4 extraction and assay methods in feces of wild northern spotted owls, African elephants, howler monkeys, caribou, moose, wolf, maned wolf, killer whales and Steller sea lions. We explained 99% of the variance in high and low T3 concentrations derived from species-specific sample pools, after controlling for species and the various extraction methods tested. Fecal T3 reflected nutritional deficits in two male and three female howler monkeys held in captivity for translocation from a highly degraded habitat. Results suggest that thyroid hormone can be accurately and reliably measured in feces, providing important indices for environmental physiology across a diverse array of birds and mammals.
We tested the hypothesis that men would favor routine paternity testing more than women by admini... more We tested the hypothesis that men would favor routine paternity testing more than women by administering surveys. Indeed, more men (50%) than women (32%) favored paternity testing. We found no support for two secondary hypotheses about ways in which one's attitude would vary with income and marital status. We also present preliminary evidence that many males prefer preserving the ambiguity of paternity.
Journal of the Acoustical Society of America, Nov 1, 2007
Historically, most studies exposing terrestrial wildlife to anthropogenic noise experimentally ha... more Historically, most studies exposing terrestrial wildlife to anthropogenic noise experimentally have failed to prove biologically-significant impact. These counter-intuitive outcomes have given rise to political debate, fueled by marginal effects or weak trends in some studies that might have proved to be significant with better sampling procedures or controls. A number of recent studies have attempted to address these weaknesses by developing adequate sampling designs and balancing exposures with respect to important environmental factors (e.g., habitat type). Examples include studies of: (1) Effects of low-flying NATO aircraft on Mexican spotted owl territory occupancy and reproduction; (2) effects of U.S. Marine Corps. helicopters on passerine reproductive success; (3) effects of operations on a U.S. Air Force bombing range on small mammal abundance; (4) impact of off-highway vehicles on reproduction of northern goshawks in the Plumas National Forest; and (5) impact of Enduro motorcycle races on northern spotted owl physiology in the Mendocino National Forest. To date, preliminary outcomes of the studies suggest that more sophisticated models of effect should be developed, and additional research should focus on long-term cumulative impact.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
General and Comparative Endocrinology, Apr 1, 2006
Previously, we found that experimentally elevated plasma corticosterone was transferred to egg yo... more Previously, we found that experimentally elevated plasma corticosterone was transferred to egg yolk by female Japanese quail (Coturnix coturnix japonica), and that the chicks hatched from these eggs grew more slowly than controls and had higher responsiveness of the hypothalamic-pituitary-adrenal (HPA) axis as adults. Here, we tested whether exposure to high yolk corticosterone was responsible for the slowed growth and elevated HPA responsiveness by manipulating the steroid content of eggs directly. Eggs were injected prior to incubation with a dose of corticosterone calculated to increase total yolk corticosterone concentration by two standard deviations. We found that elevated yolk corticosterone slowed growth in male but not female chicks and decreased the HPA responsiveness of female but not male adults, in contrast to the results of elevated corticosterone in laying females. Our results are consistent with others that demonstrate sex differences in the organizational effects of glucocorticoids. The mechanisms and adaptive value of such differences have yet to be determined.
Behavior and endocrinology provide complementary measures of population response to environmental... more Behavior and endocrinology provide complementary measures of population response to environmental change and can help evaluate management strategies for conservation. Changes in behavior and hormone levels can be temporally linked to environmental variables of interest (both natural and/or human-influenced) and can indicate disturbance impacts prior to population decline, providing opportunity for effective mitigation. This article gives an overview of endocrine tools and studies that utilize behavior and endocrinology in conservation-related research. We hope that more behaviorists and endocrinologists will design their research to inform conservation efforts and that more managers will use behavior and endocrine data as part of their conservation efforts.
The Healthy Air, Healthy Schools Study was established in January 2020 to better understand the i... more The Healthy Air, Healthy Schools Study was established in January 2020 to better understand the impact of ultrafine particles (UFP) on indoor air quality in communities surrounding Seattle-Tacoma (Sea-Tac) International Airport. The study team took multipollutant measurements indoor and outdoor air pollution at five participating school locations to infiltration indoors. The schools participating in this project were located within a 7-mile radius of Sea-Tac Airport and within 0.5 miles of an active flight path. Based on experimental measures in an unoccupied classroom, infiltration rates of a) Ultrafine particles of aircraft origin b) Ultrafine particles of traffic origin and c) Wildfire smoke or other outdoor pollutants were characterized before and after the introduction of a classroom based portable HEPA filter intervention. The portable HEPA cleaners were an effective short-term intervention to improve the air quality in classroom environments, reducing the ultrafine particles ...
Physiological and Biochemical Zoology, Nov 1, 2005
Poor habitat quality or body condition often correlates with high responsiveness of the hypothala... more Poor habitat quality or body condition often correlates with high responsiveness of the hypothalamo-pituitary-adrenal (HPA) axis rather than with elevated baseline levels of glucocorticoids. We hypothesized that, for egg-laying vertebrates, high responsiveness of the HPA axis would correspond to high concentrations of corticosterone in yolk. We tested the prediction that Japanese quail (Coturnix coturnix japonica) selected for high plasma corticosterone response to brief immobilization (HS quail) would lay eggs with higher yolk corticosterone concentrations than birds selected for low response (LS quail). Quail from both lines were left undisturbed, outside of the stressors associated with daily management, before a first round of egg collection. In a second experiment, quail of both lines were experimentally stressed during the week before egg collection. In both cases we found quail from the HS line to lay eggs with significantly higher yolk corticosterone concentrations than quail of the LS line. After exposure to added experimental stressors, the line difference was more pronounced (increasing from 62% to 96%). There was no line difference in concentrations of yolk testosterone. Our results suggest that (1) genetic differences underly differences in the transfer of maternal corticosterone to yolk and (2) females may be able to control deposition of corticosterone into yolk through a mechanism independent of baseline corticosterone titers.
Http Dx Doi Org 10 1525 Auk 2008 125 1 248, Jan 24, 2009
... The final paper, written by Theunis Piersma, Javier Perez-Tris, Henrik Mouritsen, Ulf Sauchin... more ... The final paper, written by Theunis Piersma, Javier Perez-Tris, Henrik Mouritsen, Ulf Sauchinger, and Franz Bairlein, provides a summary of the consensus among workshop participants. ... click this button to close By Author. Lisa S. Hayward. click this button to close Find In. ...
We applaud Peter Kareiva, Robert Lalasz, and Michelle Marvier for broadening the constituency of ... more We applaud Peter Kareiva, Robert Lalasz, and Michelle Marvier for broadening the constituency of the conservation movement, but regret that the message of "Conservation in the Anthropocene" seems at odds with their larger objective. For a reader outside the conservation community, the paper is likely to reinforce the misconception that the conservation movement is fueled by a dogmatic, nature-before-people ideology. At the same time, a reader within the conservation community is likely to chafe at the incompatibility of the authors' arguments with the consensus of best available science and with the scientific process in general.
Beziehungen zwischen Ei-und Dottermasse, Testosteron im Dotter und Brutgebiet nahe. Unsere Ergebn... more Beziehungen zwischen Ei-und Dottermasse, Testosteron im Dotter und Brutgebiet nahe. Unsere Ergebnisse haben zur Folge, dass in künftigen Studien Testosteroneinlagerung im Dotter als ein regulierter Prozess anstelle eines passiven Vorgangs gesehen werden sollte.
One of the worst threats currently confronting the federally threatened northern spotted owl (Str... more One of the worst threats currently confronting the federally threatened northern spotted owl (Strix occidentalis caurina) is the ongoing range expansion of the closely related barred owl (Strix varia). In addition to outcompeting spotted owls for territories, barred owls also attack spotted owls directly. As a result, spotted owls call less frequently when in proximity to barred owls. This poses a problem for managers who rely on vocalization surveys to establish spotted owl presence and ensure habitat protection. We addressed this problem by training dogs to locate owl roosts, and by confirming species identity from owl pellets using Restriction Fragment Length Polymorphism analyses of mitochondrial DNA. In 2010, we compared success of detection dog surveys to vocalization surveys using a slightly modified version of the U.S. Fish and Wildlife Service’s Draft 2010 Survey Protocol. Dogs located pellets on all 20 study sites. DNA analysis indicated that 14 sites contained northern sp...
State and federal actions to conserve northern spotted owl (Strix occidentalis caurina) habitat a... more State and federal actions to conserve northern spotted owl (Strix occidentalis caurina) habitat are largely initiated by establishing habitat occupancy. Northern spotted owl occupancy is typically assessed by eliciting their response to simulated conspecific vocalizations. However, proximity of barred owls (Strix varia)-a significant threat to northern spotted owls-can suppress northern spotted owl responsiveness to vocalization surveys and hence their probability of detection. We developed a survey method to simultaneously detect both species that does not require vocalization. Detection dogs (Canis familiaris) located owl pellets accumulated under roost sites, within search areas selected using habitat association maps. We compared success of detection dog surveys to vocalization surveys slightly modified from the U.S. Fish and Wildlife Service's Draft 2010 Survey Protocol. Seventeen 2 km 62 km polygons were each surveyed multiple times in an area where northern spotted owls were known to nest prior to 1997 and barred owl density was thought to be low. Mitochondrial DNA was used to confirm species from pellets detected by dogs. Spotted owl and barred owl detection probabilities were significantly higher for dog than vocalization surveys. For spotted owls, this difference increased with number of site visits. Cumulative detection probabilities of northern spotted owls were 29% after session 1, 62% after session 2, and 87% after session 3 for dog surveys, compared to 25% after session 1, increasing to 59% by session 6 for vocalization surveys. Mean detection probability for barred owls was 20.1% for dog surveys and 7.3% for vocal surveys. Results suggest that detection dog surveys can complement vocalization surveys by providing a reliable method for establishing occupancy of both northern spotted and barred owl without requiring owl vocalization. This helps meet objectives of Recovery Actions 24 and 25 of the Revised Recovery Plan for the Northern Spotted Owl.
Poor habitat quality or body condition often correlates with high responsiveness of the hypothala... more Poor habitat quality or body condition often correlates with high responsiveness of the hypothalamo-pituitary-adrenal (HPA) axis rather than with elevated baseline levels of glucocorticoids. We hypothesized that, for egg-laying vertebrates, high responsiveness of the HPA axis would correspond to high concentrations of corticosterone in yolk. We tested the prediction that Japanese quail (Coturnix coturnix japonica) selected for high plasma corticosterone response to brief immobilization (HS quail) would lay eggs with higher yolk corticosterone concentrations than birds selected for low response (LS quail). Quail from both lines were left undisturbed, outside of the stressors associated with daily management, before a first round of egg collection. In a second experiment, quail of both lines were experimentally stressed during the week before egg collection. In both cases we found quail from the HS line to lay eggs with significantly higher yolk corticosterone concentrations than quail of the LS line. After exposure to added experimental stressors, the line difference was more pronounced (increasing from 62% to 96%). There was no line difference in concentrations of yolk testosterone. Our results suggest that (1) genetic differences underly differences in the transfer of maternal corticosterone to yolk and (2) females may be able to control deposition of corticosterone into yolk through a mechanism independent of baseline corticosterone titers.
The Journal of the Acoustical Society of America, 2007
Historically, most studies exposing terrestrial wildlife to anthropogenic noise experimentally ha... more Historically, most studies exposing terrestrial wildlife to anthropogenic noise experimentally have failed to prove biologically‐significant impact. These counter‐intuitive outcomes have given rise to political debate, fueled by marginal effects or weak trends in some studies ...
We developed and validated a non-invasive thyroid hormone measure in feces of a diverse array of ... more We developed and validated a non-invasive thyroid hormone measure in feces of a diverse array of birds and mammals. An I(131) radiolabel ingestion study in domestic dogs coupled with High Pressure Liquid Chromatography (HPLC) analysis, showed that peak excretion in feces occurred at 24-48h post-ingestion, with I(131)-labelled thyroid hormone metabolites excreted primarily as triiodothyronine (T3) and relatively little thyroxine (T4), at all excretion times examined. The immunoreactive T3 profile across these same HPLC fractions closely corresponded with the I(131) radioactive profile. By contrast, the T4 immunoreactive profile was disproportionately high, suggesting that T4 excretion included a high percentage of T4 stores. We optimized and validated T3 and T4 extraction and assay methods in feces of wild northern spotted owls, African elephants, howler monkeys, caribou, moose, wolf, maned wolf, killer whales and Steller sea lions. We explained 99% of the variance in high and low T3 concentrations derived from species-specific sample pools, after controlling for species and the various extraction methods tested. Fecal T3 reflected nutritional deficits in two male and three female howler monkeys held in captivity for translocation from a highly degraded habitat. Results suggest that thyroid hormone can be accurately and reliably measured in feces, providing important indices for environmental physiology across a diverse array of birds and mammals.
Previously, we found that experimentally elevated plasma corticosterone was transferred to egg yo... more Previously, we found that experimentally elevated plasma corticosterone was transferred to egg yolk by female Japanese quail (Coturnix coturnix japonica), and that the chicks hatched from these eggs grew more slowly than controls and had higher responsiveness of the hypothalamic-pituitary-adrenal (HPA) axis as adults. Here, we tested whether exposure to high yolk corticosterone was responsible for the slowed growth and elevated HPA responsiveness by manipulating the steroid content of eggs directly. Eggs were injected prior to incubation with a dose of corticosterone calculated to increase total yolk corticosterone concentration by two standard deviations. We found that elevated yolk corticosterone slowed growth in male but not female chicks and decreased the HPA responsiveness of female but not male adults, in contrast to the results of elevated corticosterone in laying females. Our results are consistent with others that demonstrate sex differences in the organizational effects of glucocorticoids. The mechanisms and adaptive value of such differences have yet to be determined.
BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access t... more BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.
General and Comparative Endocrinology, Aug 1, 2010
We developed and validated a non-invasive thyroid hormone measure in feces of a diverse array of ... more We developed and validated a non-invasive thyroid hormone measure in feces of a diverse array of birds and mammals. An I 131 radiolabel ingestion study in domestic dogs coupled with High Pressure Liquid Chromatography (HPLC) analysis, showed that peak excretion in feces occurred at 24-48 h post-ingestion, with I 131-labelled thyroid hormone metabolites excreted primarily as triiodothyronine (T3) and relatively little thyroxine (T4), at all excretion times examined. The immunoreactive T3 profile across these same HPLC fractions closely corresponded with the I 131 radioactive profile. By contrast, the T4 immunoreactive profile was disproportionately high, suggesting that T4 excretion included a high percentage of T4 stores. We optimized and validated T3 and T4 extraction and assay methods in feces of wild northern spotted owls, African elephants, howler monkeys, caribou, moose, wolf, maned wolf, killer whales and Steller sea lions. We explained 99% of the variance in high and low T3 concentrations derived from species-specific sample pools, after controlling for species and the various extraction methods tested. Fecal T3 reflected nutritional deficits in two male and three female howler monkeys held in captivity for translocation from a highly degraded habitat. Results suggest that thyroid hormone can be accurately and reliably measured in feces, providing important indices for environmental physiology across a diverse array of birds and mammals.
We tested the hypothesis that men would favor routine paternity testing more than women by admini... more We tested the hypothesis that men would favor routine paternity testing more than women by administering surveys. Indeed, more men (50%) than women (32%) favored paternity testing. We found no support for two secondary hypotheses about ways in which one's attitude would vary with income and marital status. We also present preliminary evidence that many males prefer preserving the ambiguity of paternity.
Journal of the Acoustical Society of America, Nov 1, 2007
Historically, most studies exposing terrestrial wildlife to anthropogenic noise experimentally ha... more Historically, most studies exposing terrestrial wildlife to anthropogenic noise experimentally have failed to prove biologically-significant impact. These counter-intuitive outcomes have given rise to political debate, fueled by marginal effects or weak trends in some studies that might have proved to be significant with better sampling procedures or controls. A number of recent studies have attempted to address these weaknesses by developing adequate sampling designs and balancing exposures with respect to important environmental factors (e.g., habitat type). Examples include studies of: (1) Effects of low-flying NATO aircraft on Mexican spotted owl territory occupancy and reproduction; (2) effects of U.S. Marine Corps. helicopters on passerine reproductive success; (3) effects of operations on a U.S. Air Force bombing range on small mammal abundance; (4) impact of off-highway vehicles on reproduction of northern goshawks in the Plumas National Forest; and (5) impact of Enduro motorcycle races on northern spotted owl physiology in the Mendocino National Forest. To date, preliminary outcomes of the studies suggest that more sophisticated models of effect should be developed, and additional research should focus on long-term cumulative impact.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
General and Comparative Endocrinology, Apr 1, 2006
Previously, we found that experimentally elevated plasma corticosterone was transferred to egg yo... more Previously, we found that experimentally elevated plasma corticosterone was transferred to egg yolk by female Japanese quail (Coturnix coturnix japonica), and that the chicks hatched from these eggs grew more slowly than controls and had higher responsiveness of the hypothalamic-pituitary-adrenal (HPA) axis as adults. Here, we tested whether exposure to high yolk corticosterone was responsible for the slowed growth and elevated HPA responsiveness by manipulating the steroid content of eggs directly. Eggs were injected prior to incubation with a dose of corticosterone calculated to increase total yolk corticosterone concentration by two standard deviations. We found that elevated yolk corticosterone slowed growth in male but not female chicks and decreased the HPA responsiveness of female but not male adults, in contrast to the results of elevated corticosterone in laying females. Our results are consistent with others that demonstrate sex differences in the organizational effects of glucocorticoids. The mechanisms and adaptive value of such differences have yet to be determined.
Behavior and endocrinology provide complementary measures of population response to environmental... more Behavior and endocrinology provide complementary measures of population response to environmental change and can help evaluate management strategies for conservation. Changes in behavior and hormone levels can be temporally linked to environmental variables of interest (both natural and/or human-influenced) and can indicate disturbance impacts prior to population decline, providing opportunity for effective mitigation. This article gives an overview of endocrine tools and studies that utilize behavior and endocrinology in conservation-related research. We hope that more behaviorists and endocrinologists will design their research to inform conservation efforts and that more managers will use behavior and endocrine data as part of their conservation efforts.
The Healthy Air, Healthy Schools Study was established in January 2020 to better understand the i... more The Healthy Air, Healthy Schools Study was established in January 2020 to better understand the impact of ultrafine particles (UFP) on indoor air quality in communities surrounding Seattle-Tacoma (Sea-Tac) International Airport. The study team took multipollutant measurements indoor and outdoor air pollution at five participating school locations to infiltration indoors. The schools participating in this project were located within a 7-mile radius of Sea-Tac Airport and within 0.5 miles of an active flight path. Based on experimental measures in an unoccupied classroom, infiltration rates of a) Ultrafine particles of aircraft origin b) Ultrafine particles of traffic origin and c) Wildfire smoke or other outdoor pollutants were characterized before and after the introduction of a classroom based portable HEPA filter intervention. The portable HEPA cleaners were an effective short-term intervention to improve the air quality in classroom environments, reducing the ultrafine particles ...
Physiological and Biochemical Zoology, Nov 1, 2005
Poor habitat quality or body condition often correlates with high responsiveness of the hypothala... more Poor habitat quality or body condition often correlates with high responsiveness of the hypothalamo-pituitary-adrenal (HPA) axis rather than with elevated baseline levels of glucocorticoids. We hypothesized that, for egg-laying vertebrates, high responsiveness of the HPA axis would correspond to high concentrations of corticosterone in yolk. We tested the prediction that Japanese quail (Coturnix coturnix japonica) selected for high plasma corticosterone response to brief immobilization (HS quail) would lay eggs with higher yolk corticosterone concentrations than birds selected for low response (LS quail). Quail from both lines were left undisturbed, outside of the stressors associated with daily management, before a first round of egg collection. In a second experiment, quail of both lines were experimentally stressed during the week before egg collection. In both cases we found quail from the HS line to lay eggs with significantly higher yolk corticosterone concentrations than quail of the LS line. After exposure to added experimental stressors, the line difference was more pronounced (increasing from 62% to 96%). There was no line difference in concentrations of yolk testosterone. Our results suggest that (1) genetic differences underly differences in the transfer of maternal corticosterone to yolk and (2) females may be able to control deposition of corticosterone into yolk through a mechanism independent of baseline corticosterone titers.
Http Dx Doi Org 10 1525 Auk 2008 125 1 248, Jan 24, 2009
... The final paper, written by Theunis Piersma, Javier Perez-Tris, Henrik Mouritsen, Ulf Sauchin... more ... The final paper, written by Theunis Piersma, Javier Perez-Tris, Henrik Mouritsen, Ulf Sauchinger, and Franz Bairlein, provides a summary of the consensus among workshop participants. ... click this button to close By Author. Lisa S. Hayward. click this button to close Find In. ...
We applaud Peter Kareiva, Robert Lalasz, and Michelle Marvier for broadening the constituency of ... more We applaud Peter Kareiva, Robert Lalasz, and Michelle Marvier for broadening the constituency of the conservation movement, but regret that the message of "Conservation in the Anthropocene" seems at odds with their larger objective. For a reader outside the conservation community, the paper is likely to reinforce the misconception that the conservation movement is fueled by a dogmatic, nature-before-people ideology. At the same time, a reader within the conservation community is likely to chafe at the incompatibility of the authors' arguments with the consensus of best available science and with the scientific process in general.
Beziehungen zwischen Ei-und Dottermasse, Testosteron im Dotter und Brutgebiet nahe. Unsere Ergebn... more Beziehungen zwischen Ei-und Dottermasse, Testosteron im Dotter und Brutgebiet nahe. Unsere Ergebnisse haben zur Folge, dass in künftigen Studien Testosteroneinlagerung im Dotter als ein regulierter Prozess anstelle eines passiven Vorgangs gesehen werden sollte.
One of the worst threats currently confronting the federally threatened northern spotted owl (Str... more One of the worst threats currently confronting the federally threatened northern spotted owl (Strix occidentalis caurina) is the ongoing range expansion of the closely related barred owl (Strix varia). In addition to outcompeting spotted owls for territories, barred owls also attack spotted owls directly. As a result, spotted owls call less frequently when in proximity to barred owls. This poses a problem for managers who rely on vocalization surveys to establish spotted owl presence and ensure habitat protection. We addressed this problem by training dogs to locate owl roosts, and by confirming species identity from owl pellets using Restriction Fragment Length Polymorphism analyses of mitochondrial DNA. In 2010, we compared success of detection dog surveys to vocalization surveys using a slightly modified version of the U.S. Fish and Wildlife Service’s Draft 2010 Survey Protocol. Dogs located pellets on all 20 study sites. DNA analysis indicated that 14 sites contained northern sp...
State and federal actions to conserve northern spotted owl (Strix occidentalis caurina) habitat a... more State and federal actions to conserve northern spotted owl (Strix occidentalis caurina) habitat are largely initiated by establishing habitat occupancy. Northern spotted owl occupancy is typically assessed by eliciting their response to simulated conspecific vocalizations. However, proximity of barred owls (Strix varia)-a significant threat to northern spotted owls-can suppress northern spotted owl responsiveness to vocalization surveys and hence their probability of detection. We developed a survey method to simultaneously detect both species that does not require vocalization. Detection dogs (Canis familiaris) located owl pellets accumulated under roost sites, within search areas selected using habitat association maps. We compared success of detection dog surveys to vocalization surveys slightly modified from the U.S. Fish and Wildlife Service's Draft 2010 Survey Protocol. Seventeen 2 km 62 km polygons were each surveyed multiple times in an area where northern spotted owls were known to nest prior to 1997 and barred owl density was thought to be low. Mitochondrial DNA was used to confirm species from pellets detected by dogs. Spotted owl and barred owl detection probabilities were significantly higher for dog than vocalization surveys. For spotted owls, this difference increased with number of site visits. Cumulative detection probabilities of northern spotted owls were 29% after session 1, 62% after session 2, and 87% after session 3 for dog surveys, compared to 25% after session 1, increasing to 59% by session 6 for vocalization surveys. Mean detection probability for barred owls was 20.1% for dog surveys and 7.3% for vocal surveys. Results suggest that detection dog surveys can complement vocalization surveys by providing a reliable method for establishing occupancy of both northern spotted and barred owl without requiring owl vocalization. This helps meet objectives of Recovery Actions 24 and 25 of the Revised Recovery Plan for the Northern Spotted Owl.
Poor habitat quality or body condition often correlates with high responsiveness of the hypothala... more Poor habitat quality or body condition often correlates with high responsiveness of the hypothalamo-pituitary-adrenal (HPA) axis rather than with elevated baseline levels of glucocorticoids. We hypothesized that, for egg-laying vertebrates, high responsiveness of the HPA axis would correspond to high concentrations of corticosterone in yolk. We tested the prediction that Japanese quail (Coturnix coturnix japonica) selected for high plasma corticosterone response to brief immobilization (HS quail) would lay eggs with higher yolk corticosterone concentrations than birds selected for low response (LS quail). Quail from both lines were left undisturbed, outside of the stressors associated with daily management, before a first round of egg collection. In a second experiment, quail of both lines were experimentally stressed during the week before egg collection. In both cases we found quail from the HS line to lay eggs with significantly higher yolk corticosterone concentrations than quail of the LS line. After exposure to added experimental stressors, the line difference was more pronounced (increasing from 62% to 96%). There was no line difference in concentrations of yolk testosterone. Our results suggest that (1) genetic differences underly differences in the transfer of maternal corticosterone to yolk and (2) females may be able to control deposition of corticosterone into yolk through a mechanism independent of baseline corticosterone titers.
The Journal of the Acoustical Society of America, 2007
Historically, most studies exposing terrestrial wildlife to anthropogenic noise experimentally ha... more Historically, most studies exposing terrestrial wildlife to anthropogenic noise experimentally have failed to prove biologically‐significant impact. These counter‐intuitive outcomes have given rise to political debate, fueled by marginal effects or weak trends in some studies ...
We developed and validated a non-invasive thyroid hormone measure in feces of a diverse array of ... more We developed and validated a non-invasive thyroid hormone measure in feces of a diverse array of birds and mammals. An I(131) radiolabel ingestion study in domestic dogs coupled with High Pressure Liquid Chromatography (HPLC) analysis, showed that peak excretion in feces occurred at 24-48h post-ingestion, with I(131)-labelled thyroid hormone metabolites excreted primarily as triiodothyronine (T3) and relatively little thyroxine (T4), at all excretion times examined. The immunoreactive T3 profile across these same HPLC fractions closely corresponded with the I(131) radioactive profile. By contrast, the T4 immunoreactive profile was disproportionately high, suggesting that T4 excretion included a high percentage of T4 stores. We optimized and validated T3 and T4 extraction and assay methods in feces of wild northern spotted owls, African elephants, howler monkeys, caribou, moose, wolf, maned wolf, killer whales and Steller sea lions. We explained 99% of the variance in high and low T3 concentrations derived from species-specific sample pools, after controlling for species and the various extraction methods tested. Fecal T3 reflected nutritional deficits in two male and three female howler monkeys held in captivity for translocation from a highly degraded habitat. Results suggest that thyroid hormone can be accurately and reliably measured in feces, providing important indices for environmental physiology across a diverse array of birds and mammals.
Previously, we found that experimentally elevated plasma corticosterone was transferred to egg yo... more Previously, we found that experimentally elevated plasma corticosterone was transferred to egg yolk by female Japanese quail (Coturnix coturnix japonica), and that the chicks hatched from these eggs grew more slowly than controls and had higher responsiveness of the hypothalamic-pituitary-adrenal (HPA) axis as adults. Here, we tested whether exposure to high yolk corticosterone was responsible for the slowed growth and elevated HPA responsiveness by manipulating the steroid content of eggs directly. Eggs were injected prior to incubation with a dose of corticosterone calculated to increase total yolk corticosterone concentration by two standard deviations. We found that elevated yolk corticosterone slowed growth in male but not female chicks and decreased the HPA responsiveness of female but not male adults, in contrast to the results of elevated corticosterone in laying females. Our results are consistent with others that demonstrate sex differences in the organizational effects of glucocorticoids. The mechanisms and adaptive value of such differences have yet to be determined.
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