Role of the Low‐Affinity Glucocorticoid Receptor in the Regulation of Behavior and Energy Metabolism in the Migratory Red Knot<i>Calidris canutus islandica</i>

Landys, Mėta M.; Piersma, Theunis; Ramenofsky, Marilyn; Wingfield, John C.

doi:10.1086/420942

Cited by 47 publications

(26 citation statements)

References 55 publications

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“…1) and as expected this effect occurred within 20 min of entering the aviaries. Similar baseline levels and increases in corticosterone due to handling stress have been found in both captive (Landys et al 2004) and free-living red knots (Reneerkens et al 2002). In contrast to the immediate response of corticosterone, immune measures appear to respond more slowly to handling stress.…”

Section: Constitutive Immunity and Corticosteronesupporting

confidence: 60%

Constitutive Immune Function Responds More Slowly to Handling Stress than Corticosterone in a Shorebird

Buehler¹,

Bhola²,

Barjaktarov³

et al. 2008

Physiological and Biochemical Zoology

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Ecological immunologists are interested in how immune function changes during different seasons and under different environmental conditions. However, an obstacle to answering such questions is discerning the effects of biological factors of interest and investigation artifacts such as handling stress. Here we examined handling stress and its effects on constitutive (noninduced) immune function via two protocols on captive red knots (Calidris canutus). We investigated how constitutive immunity responds to handling stress, how quickly these changes take place, and the practical implications for researchers interested in sampling baseline immune levels. We found that Staphylococcus aureus and Candida albicans killing increased with handling stress while total leukocyte and lymphocyte concentrations decreased. However, although corticosterone increased significantly and rapidly in response to handling stress, none of the 10 measures of constitutive immunity that we tested differed significantly from baseline within 20 or 30 min of capture. Thus, researchers interested in baseline immune function should sample animals as soon as possible after capture, but studies in species not easily sampled in less than 3 min (such as red knots) could still yield useful results.

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Section: Constitutive Immunity and Corticosteronesupporting

confidence: 60%

Constitutive Immune Function Responds More Slowly to Handling Stress than Corticosterone in a Shorebird

Buehler¹,

Bhola²,

Barjaktarov³

et al. 2008

Physiological and Biochemical Zoology

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“…Departure at unfavorable conditions would have severe impact on the survival and breeding success of birds at breeding sites. Although previous studies have indicated a relationship between fuel stores and migratory restlessness (Able 1977;Yong and Moore 1993;Fusani et al 2009), a study on glucocorticoid receptor in red knots (Calidris canutus) suggested that hyperphagia and migratory restlessness might be regulated by different mechanisms (Landys et al 2004b), which could explain the lack of relationship between body mass and activity intensity in the current study. In addition, wind condition was unsuitable for migration during the tests before departure of birds at YLE, which might cause the negative relationship between wind effects and intensity of migratory activity.…”

Section: Intensity Of Migratory Activitycontrasting

confidence: 76%

Springtime migratory restlessness and departure orientation of Great Knots (Calidris tenuirostris) in the south compared to the north Yellow Sea

et al. 2017

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Background:The motivation of birds to proceed with migration is associated with both endogenous and exogenous factors. According to their migratory situation and to the characteristics of stopover sites, birds might exhibit migratory motivation differently among sites. Although migratory motivation of migrating birds has been well studied in many species, the investigation of the same species in different migratory situations and at different stopover sites is still limited. We predicted that birds at different stopover sites could differ in migratory disposition, including expression of migratory restlessness and responses to environmental cues. Methods:Here we compared migration motivation and orientation of Great Knots (Calidris tenuirostris) at two stopover sites, Chongming Dongtan in the south Yellow Sea, which is a temporary rest site, and Yalujiang Estuary Wetland in the north Yellow Sea, which is a critical refuelling site, during northward migration. Modified Emlen funnels, with thermal paper inside to record scratches of the birds, were used to detect activity (intensity and direction) of birds. Environmental conditions, including wind direction and speed, cloud cover, tide condition, times of the day (before and after sunset) were recorded during experiments. Generalized linear models were used to detect the effects of endogenous and exogenous factors on the migratory motivation of the birds. Results:In the south Yellow Sea, the migratory activity intensity of Great Knots was positively related to wind assistance. In the north Yellow Sea, where birds exhibited higher intensity of migratory activity than in the south, the intensity increased and the motivation to initiate migration grew stronger as the season advanced. The Great Knots exhibited wind-related orientation behaviour in the funnels at both sites. Conclusions:The results suggest that the intensity of migratory motivation differed between the two sites. Departure decisions of Great Knots appear to be affected mainly by external factors at the temporary rest site in the south Yellow Sea but possibly by endogenous factors at the final pre-breeding refuelling site in the north Yellow Sea.

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“…CORT regulates physiological and behavioral responses to challenging environments, including those associated with harsher climatic conditions (Bonier et al 2007;Landys et al 2004;Wingfield et al 1998). The higher baseline CORT levels we observe in highland Z. l. pugetensis and Z. l. gambelii may be indicative of more challenging physiological conditions at high elevation relative to lower altitudes and suggests why baseline levels of CORT do not differ between highland Z. l. pugetensis and Z. l. gambelii breeding in the mountains and from our direct comparison, why highland Z. l. pugetensis have higher baseline CORT than lowland Z. l. pugetensis.…”

Section: Discussionmentioning

confidence: 99%

Variation in circulating corticosterone levels is associated with altitudinal range expansion in a passerine bird

Addis¹,

Davis²,

Miner³

et al. 2011

Oecologia

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Organisms frequently need to adjust physiological mechanisms to successfully breed in novel habitats. To explore how some populations physiologically acclimate to novel environmental conditions while others do not, we examine three subspecies of the white-crowned sparrow, Zonotrichia leucophrys. Of these subspecies, Z. l. pugetensis has expanded its breeding range to high altitude over the last 60 years. We investigate physiological acclimation to high altitude conditions by comparing circulating levels of glucocorticoids among Z. l. gambelii, which only breeds at high altitude, Z. l. nuttalli, which only breeds at low altitude, a population of Z. l. pugetensis that breeds at low altitude, and a Z. l. pugetensis population that now breeds at high altitude. Glucocorticoids mediate physiological and behavioral responses to environmental conditions and are constitutively secreted, but can also be released facultatively. We hypothesized that elevation of the glucocorticoid corticosterone (CORT) may facilitate breeding in high altitude environments. We tested this hypothesis by comparing baseline and stress-induced CORT levels of subspecies breeding at low altitude, Z. l. pugetensis and Z. l. nuttalli, to subspecies breeding at high altitude, Z. l. pugetensis and Z. l. gambelii. We found that populations breeding at high altitude exhibit higher baseline and stress-induced levels of CORT. Additionally, we found that Z. l. pugetensis exhibit greater variation in the stress-induced CORT response. These results suggest an importance of modulation of hormonal mechanisms in facilitating breeding in high altitude environments, and that variation in these mechanisms may be associated with facilitating altitudinal range expansion.

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Role of the Low‐Affinity Glucocorticoid Receptor in the Regulation of Behavior and Energy Metabolism in the Migratory Red KnotCalidris canutus islandica

Cited by 47 publications

References 55 publications

Constitutive Immune Function Responds More Slowly to Handling Stress than Corticosterone in a Shorebird

Constitutive Immune Function Responds More Slowly to Handling Stress than Corticosterone in a Shorebird

Springtime migratory restlessness and departure orientation of Great Knots (Calidris tenuirostris) in the south compared to the north Yellow Sea

Variation in circulating corticosterone levels is associated with altitudinal range expansion in a passerine bird

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