Effects of anthropogenic and environmental stress on the corticosterone levels of wintering Northern Pintails (Anas acuta)

2014 ◽  
Vol 92 (3) ◽  
pp. 185-193 ◽  
Author(s):  
D.P. Taylor ◽  
J.N. Vradenburg ◽  
L.M. Smith ◽  
M.B. Lovern ◽  
S.T. McMurry

Winter-specific survival rates for female Northern Pintails (Anas acuta L., 1758; hereafter “Pintails”) at the Bosque del Apache National Wildlife Refuge were found in a previous study to be low relative to other wintering areas, raising concerns that tourism could be impacting the health of the population. Measurements of corticosterone levels enable the assessment and quantification of human-induced stressors that can ultimately affect fitness. We analyzed corticosterone concentrations and the relationship between body condition and maximum stress-induced corticosterone in areas with and without tourism access. Female Pintails were captured in winters of 2008–2009 and 2009–2010. The corticosterone response was similar between areas with and without tourism, but different between winters. In mid-January 2010, levels were 73% greater after 60 min compared with those in 2009. A greater stress response in mid-January 2010 may have been due to colder temperatures and arriving later and in poorer condition. Also in 2009–2010, there was a negative correlation between carcass fat and maximum corticosterone, possibly in response to colder temperatures, arriving in poorer condition, or a combination of both. Our study indicates that in mid- to late winter, activity of the hypothalamic–pituitary–adrenal axis may be higher during winters with comparatively greater environmental hardships, emphasizing the importance of carefully managing waterfowl during periods when they are most sensitive.

The Auk ◽  
2002 ◽  
Vol 119 (2) ◽  
pp. 498-506 ◽  
Author(s):  
Gary L. Krapu ◽  
Glen A. Sargeant ◽  
Alison E. H. Perkins

AbstractWe evaluated spatiotemporal variation in clutch sizes of Northern Pintails (pintails; Anas acuta) nesting in California (1985 to 1996), North Dakota (1982 to 1985), Saskatchewan (1982 to 1985) and Alaska (1991 to 1993) to determine whether seasonal declines in clutch size varied in ways that were consistent with a controlling influence of increasing day length. Pintails began nesting in mid-March in California, mid-April in North Dakota and Saskatchewan, and mid-May in Alaska. Observed durations of nesting were 70 ± 2.6 days (SE) in California, 60 ± 6.3 days in North Dakota, 66 ± 1.3 days in Saskatchewan, and 42 ± 0.7 days in Alaska. Annual differences were the principal source of variation in mean clutch sizes (σ̂Y2 = 0.15, SE = 0.049), which varied little among study locations (σ̂A2 = 0.002, SE = 0.013). Predicted rates of seasonal decline in clutch sizes increased with latitude early in the nesting season, but declined as the nesting season progressed, except in California. Rates of decline in clutch sizes thus were not directly related to rates of increase in day length. Predicted declines in numbers of eggs per clutch over the nesting season were similar for all four locations (range, 3.05–3.12) despite wide variation in durations of nesting. Evidence suggests that reduced nutrient availability during nesting contributes to a higher rate of decline in clutch sizes in Alaska than in temperate regions. Pintails that nest early lay large initial clutches, but thereafter clutch sizes decline rapidly and breeding terminates early. This reproductive strategy is adaptive because young that hatch earliest exhibit the highest survival rates; however, the conversion of grassland to cropland on the primary prairie breeding grounds has reduced hatching rates of clutches laid early in the nesting season. Under these conditions, the limited capacity to renest in late spring on their prairie breeding grounds probably has contributed to Pintail population declines.


Soil Research ◽  
1994 ◽  
Vol 32 (6) ◽  
pp. 1355 ◽  
Author(s):  
RB Garnsey

Earthworms have the ability to alleviate many soil degradational problems in Australia. An attempt to optimize this resource requires fundamental understanding of earthworm ecology. This study reports the seasonal changes in earthworm populations in the Midlands of Tasmania (<600 mm rainfall p.a.), and examines, for the first time in Australia, the behaviour and survival rates of aestivating earthworms. Earthworms were sampled from 14 permanent pastures in the Midlands from May 1992 to February 1994. Earthworm activity was significantly correlated with soil moisture; maximum earthworm activity in the surface soil was evident during the wetter months of winter and early spring, followed by aestivation in the surface and subsoils during the drier summer months. The two most abundant earthworm species found in the Midlands were Aporrectodea caliginosa (maximum of 174.8 m-2 or 55.06 g m-2) and A. trapezoides (86 m-2 or 52.03 g m-2), with low numbers of Octolasion cyaneum, Lumbricus rubellus and A. rosea. The phenology of A. caliginosa relating to rainfall contrasted with that of A. trapezoides in this study. A caliginosa was particularly dependent upon rainfall in the Midlands: population density, cocoon production and adult development of A. caliginosa were reduced as rainfall reduced from 600 to 425 mm p.a. In contrast, the density and biomass of A. trapezoides were unaffected by rainfall over the same range: cocoon production and adult development continued regardless of rainfall. The depth of earthworm aestivation during the summers of 1992-94 was similar in each year. Most individuals were in aestivation at a depth of 150-200 mm, regardless of species, soil moisture or texture. Smaller aestivating individuals were located nearer the soil surface, as was shown by an increase in mean mass of aestivating individuals with depth. There was a high mortality associated with summer aestivation of up to 60% for juvenile, and 63% for adult earthworms in 1993 in the Midlands. Cocoons did not survive during the summers of 1992 or 1994, but were recovered in 1993, possibly due to the influence of rainfall during late winter and early spring.


1994 ◽  
Vol 7 (2) ◽  
pp. 200-212 ◽  
Author(s):  
J F Sheridan ◽  
C Dobbs ◽  
D Brown ◽  
B Zwilling

The mammalian response to stress involves the release of soluble products from the sympathetic nervous system and the hypothalamic-pituitary-adrenal axis. Cells of the immune system respond to many of the hormones, neurotransmitters, and neuropeptides through specific receptors. The function of the immune system is critical in the mammalian response to infectious disease. A growing body of evidence identifies stress as a cofactor in infectious disease susceptibility and outcomes. It has been suggested that effects of stress on the immune system may mediate the relationship between stress and infectious disease. This article reviews recent psychoneuroimmunology literature exploring the effects of stress on the pathogenesis of, and immune response to, infectious disease in mammals.


2021 ◽  
Vol 19 (2) ◽  
pp. 19-27
Author(s):  
A. V. DUBOVAYA ◽  
◽  
S. Ya. IAROSHENKO ◽  
O. A. PRILUTSKAYA ◽  
◽  
...  

The article discusses the influence of stress on the development of nervous tissue, in particular, on the synthesis of neurotrophins (by the example of the brain-derived neurotrophic factor (BDNF), as the most studied class representative). The biological functions of BDNF are discussed as well as its influence on neuroplasticity and the mechanisms by which the protection of neurons is carried out. The article covers the relationship of the stress-implementing system (hypothalamic-pituitary-adrenal axis) and its main active agent (cortisol) with the BDNF synthesis system at its various levels: from the inhibition of mRNA formation to the mechanisms of postsynaptic signal transmission. Information is also provided on changes of BDNF levels due to the maternal deprivation. Epigenetic changes under the influence of glucocorticoids are also reported. However, it is not only glucocorticoids that alter the functioning of the neurotrophin system. The article provides examples of the reverse effect, enabling to consider neurotrophins as a substance with an anti-stress function. In conclusion, the authors give examples of activities that, according to research, can stimulate the synthesis of neurotrophic factor in the brain.


2018 ◽  
Vol 76 (9) ◽  
pp. 622-634 ◽  
Author(s):  
Gabriela Magalhães Pereira ◽  
Nayron Medeiros Soares ◽  
Andreo Rysdyk de Souza ◽  
Jefferson Becker ◽  
Alessandro Finkelsztejn ◽  
...  

ABSTRACT Multiple sclerosis (MS) is a demyelinating, progressive and neurodegenerative disease. A disturbance on the hypothalamic-pituitary-adrenal axis can be observed in patients with MS, showing altered cortisol levels. We aimed to identify basal cortisol levels and verify the relationship with clinical symptoms in patients with MS. A systematic search was conducted in the databases: Pubmed, Web of Science and SCOPUS. Both higher and lower cortisol levels were associated with MS. Higher cortisol levels were associated with depression and anxiety, while lower levels were associated with depression, fatigue and urinary dysfunction. Higher cortisol levels may be associated with the progression and severity of MS.


2018 ◽  
Vol 29 (2) ◽  
pp. 327-337 ◽  
Author(s):  
JENNIFER L. LAVERS ◽  
SIMEON LISOVSKI ◽  
ALEXANDER L. BOND

SummarySeabirds face diverse threats on their breeding islands and while at sea. Human activities have been linked to the decline of seabird populations, yet over-wintering areas typically receive little or no protection. Adult survival rates, a crucial parameter for population persistence in long-lived species, tend to be spatially or temporally restricted for many seabird species, limiting our understanding of factors driving population trends at some sites. We used bio-loggers to study the migration of Western Australian Flesh-footed Shearwaters Ardenna carneipes carneipes and estimated adult survival over five years. Western Australia is home to around 35% of the world’s breeding Flesh-footed Shearwaters, a population which was up-listed to Vulnerable in 2015. During the austral winter, shearwaters migrated across the central Indian Ocean to their non-breeding grounds off western Sri Lanka. Low site fidelity on breeding islands, mortality of adult birds at sea (e.g. fisheries bycatch), and low annual breeding frequency likely contributed to the low estimated annual adult survival (2011–2015: ϕ = 0.634-0.835).


2012 ◽  
Vol 58 (No. 12) ◽  
pp. 560-568 ◽  
Author(s):  
E.W. Mbuthia ◽  
J.H. Shariff ◽  
A. Raman ◽  
D.S. Hodgkins ◽  
H.I. Nicol ◽  
...  

Shelterbelts are important for the sustainability of agriculture because they provide a variety of benefits to farmers and the society. Several published papers demonstrate that integration of shelterbelts with agroecosystems offers positive outcomes, such as better yield, more congenial microclimate, and greater organic matter levels. Nonetheless, soil biological diversity, the driver of greater organic matter levels, has not been convincingly tested and verified yet. In addressing this gap, we measured abundance and diversity of populations of arthropods and fungi in three<br />11-year old shelterbelts integrated with pasture to determine whether a correlation exists between the abundance of and diversity in populations of arthropods and fungi in two seasons: late autumn-early winter (May&ndash;June 2011) and late winter-early spring (August&ndash;September 2011). Litter from the soil surface and soil from two depths were sampled at increasing distance from the midpoint of shelterbelts for the extraction of arthropods and isolation culturing of fungi. The relationship among distance, depth and biodiversity of different groups of arthropods and fungi was analysed using linear regression. We found that over both seasons arthropod abundance in the litter and soil declined with increasing distance from the midpoint of the shelterbelts, and with soil depth. However, fungi abundance in either season was not affected by proximity to the shelterbelt but increased with greater soil depth. Distance from the shelterbelt midpoints did not bear an impact on the diversity richness of both arthropods and fungi.


2002 ◽  
Vol 282 (2) ◽  
pp. E466-E473 ◽  
Author(s):  
Junko Hanafusa ◽  
Tomoatsu Mune ◽  
Tetsuya Tanahashi ◽  
Yukinori Isomura ◽  
Tetsuya Suwa ◽  
...  

To evaluate the effects of altered corticosteroid metabolism on the hypothalamic-pituitary-adrenal axis, we examined rats treated with glycyrrhizic acid (G rats) or rifampicin (R rats) for 7 days. The half-life of exogenously administered hydrocortisone as a substitute for corticosterone was longer in G rats and shorter in R rats, with no differences in basal plasma levels of ACTH or corticosterone. The ACTH responses to human corticotropin-releasing factor (CRF) or insulin-induced hypoglycemia were greater in G rats and tended to be smaller in R rats compared with those in the control rats, whereas the corticosterone response was similar. No difference was observed in the content and mRNA level of hypothalamic CRF among the groups. The number and mRNA level of CRF receptor and type 1 11β-hydroxysteroid dehydrogenase (11-HSD1) mRNA level in the pituitary were increased in G rats but not changed in R rats, suggesting that chronically increased intrapituitary corticosterone upregulates pituitary CRF receptor expression. In contrast, CRF mRNA levels in the pituitary were increased in R rats. Our data indicate novel mechanisms of corticosteroid metabolic modulation and the involvement of pituitary 11-HSD1 and CRF in glucocorticoid feedback physiology.


1978 ◽  
Vol 56 (1) ◽  
pp. 121-127 ◽  
Author(s):  
R. E. Mirarchi ◽  
B. E. Howland ◽  
P. F. Scanlon ◽  
R. L. Kirkpatrick ◽  
L. M. Sanford

Blood samples were collected monthly from captive and wild adult (12 months old or older) male white-tailed deer (Odocoileus virginianus) over 1 year in southwest Virginia. Plasma was assayed for luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin (PRL), and testosterone (T) using radioimmunoassays. LH and T levels for the captive and wild deer were essentially similar and followed a distinct annual cycle. LH concentrations (nanograms per millilitre) peaked earlier (October, captive, 4.5 ± 1.8 (mean ± standard error); September, wild, 3.3 ± 0.9) than T concentrations (nanograms per millilitre) (November, captive, 13.3 ± 2.7; November, wild, 23.7 ± 7.8) and dropped off sharply prior to, or concomitant with, T concentrations. LH and T levels were lowest during the late winter and spring. T concentrations were closely correlated with androgen levels (Mirarchi, R. E., P. F. Scanlon, R. L. Kirkpatrick, and C. B. Schreck. J. Wildl. Manage. 41: 178–183 (1977)) determined by competitive protein binding assay. Mean PRL and FSH concentrations in wild and captive deer also displayed seasonal variations. Prolactin concentrations (nanograms per millilitre) were highest in May (147.5 ± 0.0) and lowest in November while FSH levels (nanograms per millilitre) peaked in September (180.2 ± 22.4) and were lowest in March. Differences in hormone concentrations between deer and sheep, and the relationship between PRL and antler growth and FSH and spermatozoan production, are discussed.


2019 ◽  
Vol 73 (1) ◽  
Author(s):  
J. J. Beukema ◽  
R. Dekker

Abstract For a better understanding of functioning and stability of ecosystems, it is important to know to what extent constituent species show similarity in their long-term fluctuation patterns, i.e. whether their numbers and biomass frequently show simultaneous peaks and lows. Synchronic peaks and lows of important species would enhance variability in the functioning of the entire system and might affect its stability. When fluctuation patterns of individual species are largely independent, their peaks and lows would tend to extinguish each other’s effect on overall parameters (such as total zoobenthic biomass), thus promoting system stability. A long-term (46 years) monitoring study of the macrozoobenthos in a large (50 km2) tidal-flat area revealed that the 4 most important bivalve species (3 suspension feeders: Cerastoderma edule, Mytilus edulis, Mya arenaria and 1 deposit/suspension feeder: Limecola (Macoma) balthica) frequently showed peak numbers of their recruits in the same years. The annual growth rates of the three suspension feeding species showed some synchrony as well. Annual survival rates, on the other hand, did not show any synchronization, wiping out the initial synchrony of numbers within less than 2 years. As a result, annual biomass values did not show any positive between-species correlations. Annual amounts of bivalves that are accessible as bird food rarely declined to levels below 5 g AFDW m−2 and showed limited (5 to 10 fold difference between maximal and minimal values) variation. Oystercatchers left the area quicker in late winter and showed increased death rates at very low levels of food supply. Total bivalve bird food did not show any significant long-term trend. However, biomass of Mya arenaria showed an increasing trend and that of Limecola balthica a declining trend.


Sign in / Sign up

Export Citation Format

Share Document