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Gary R Bortolotti - One of the best experts on this subject based on the ideXlab platform.
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immunological development in nestling american kestrels Falco sparverius post hatching ontogeny of the antibody response
Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 2008Co-Authors: Judit E G Smits, Gary R BortolottiAbstract:Avian research involving examination of immune function or testing of immunocompetence in wild birds has been based upon information on Galliforms, (chicken and quail) even though they are precocial, whereas most wild species with which ecologists, biologists and toxicologists work are altricial; blind, naked and completely dependent at hatching. Here we begin to address this gap in knowledge, offering insight into the early, post-hatching, humoral immune response in an altricial bird, the American kestrel (Falco sparverius). Over two breeding seasons, nestling kestrels were immunized with a non-pathogenic antigen, dinitrophenol keyhole limpet hemocyanin (DNP-KLH), between 3 and 9 days post-hatching and boostered 6 days later. Background levels, primary and secondary immune responses were measured using an enzyme linked immunosorbent assay. The specificity of our laboratory produced rabbit, anti-kestrel antibody was determined using a double immunodiffusion assay. Results showed the rabbit antiserum to have specific anti-kestrel IgG activity. Birds as young as three days old could successfully mount an antibody response, the magnitude of which increased with age at first vaccination. Early immunization did not compromise growth rate, nor did it affect the maximum secondary response. Comparatively, adult kestrels immunized during the same season and following the same protocol, had antibody levels four times higher than those of the nestlings.
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experimentally prolonging the brood rearing period reveals sex specific parental investment strategies in american kestrels Falco sparverius
The Auk, 2008Co-Authors: Russell D. Dawson, Gary R BortolottiAbstract:Abstract Responses of parent birds to changes in demands by their offspring have typically been investigated by manipulating brood size and testing for altered patterns of provisioning. We applied an alternative method to breeding pairs of American Kestrels (Falco sparverius) by modifying the duration of their nesting periods. Rather than focusing on how hard parents can work on any given day, this novel approach tests how long they can sustain the stress of provisioning and the associated behavioral consequences. We manipulated nesting periods by exchanging nearly fledged young at the age of 20 days with offspring from other nests that were 10 days old. We found that males provisioned their second foster broods at rates similar to those for their original broods. By contrast, females brooded offspring in second foster nests less and also delivered less food to them. As a consequence, male offspring in second nests gained less mass than those in first nests, and nestlings of both sexes had reduced feather...
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reproductive abnormalities teratogenicity and developmental problems in american kestrels Falco sparverius exposed to polychlorinated biphenyls
Journal of Toxicology and Environmental Health, 2003Co-Authors: Kim J Fernie, Gary R Bortolotti, Judit E G SmitsAbstract:This study found abnormalities in multiple reproductive stages in captive American kestrels (Falco sparverius) when exposed to polychlorinated biphenyls (PCBs) through dietary and in ovo exposure. American kestrels laid eggs with environmentally relevant total PCB levels (34.1 μg/g whole egg wet weight) when consuming PCB-spiked (Aroclor 1248:1254:1260) food (5–7 μg/g body weight per day) for 100 d only in 1998. In 1999, the same adults laid eggs with estimated total PCBs of 23 μg/g. Effects of maternal (only female exposed) and paternal (only male expose d) in ovo PCB exposure were investigated. Maternal F1 eggs contained predicted total PCB concentrations of 0.34 μg/g. Specific abnormalities occurred more frequently during dietary F0 exposure, particularly aggressive courtship interactions, clutch abandonment, occurrences of cracked eggs, and developmental effects. Multiple developmental effects were more pronounced during than after dietary PCB exposure of adults, and although these effects were limite...
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carotenoid concentration and coloration of american kestrels Falco sparverius disrupted by experimental exposure to pcbs
Functional Ecology, 2003Co-Authors: Gary R Bortolotti, Kimberly J Fernie, Judit E G SmitsAbstract:Summary 1. Bright coloration in birds is typically a sexually selected trait. Expression of such traits is sensitive to environmental factors, so they can function as bioindicators of environmental contamination. Of particular value may be carotenoid-based coloration because it is commonly used as a social signal and these pigments have important health functions. 2. American Kestrels (Falco sparverius) in captivity were exposed to dietary PCBs in March. Colour and plasma carotenoids of exposed and control birds were evaluated at pairing and courtship in April, and in winter in December. Juveniles produced by these birds (exposed to PCBs only in ovo) were examined at fledging and in winter. 3. The brightly coloured ceres and lores were evaluated by comparison to colour charts and quantified using digital photographs, and plasma carotenoid concentrations were quantified by spectrophotometry. 4. During breeding, PCB-exposed kestrels differed from controls for both colour and carotenoids, although the nature of effects was sex-specific. Carotenoids of juveniles were not related to treatment at fledging. 5. In winter, PCB-exposure resulted in patterns of colour/carotenoid variation opposite to controls; exposed adult males were duller, and juveniles of both sexes were brighter, than controls. PCB juveniles had higher plasma levels of carotenoids. Sexual dimorphism was apparent in colour and carotenoids of control adults, but not for PCB-exposed birds. 6. Our results are consistent with endocrine disruption. Modulation of both colour and carotenoids may have serious consequences to social behaviour and health.
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developmental toxicity of in ovo exposure to polychlorinated biphenyls i immediate and subsequent effects on first generation nestling american kestrels Falco sparverius
Environmental Toxicology and Chemistry, 2003Co-Authors: Kim J Fernie, Judit E G Smits, Gary R BortolottiAbstract:We determined that in ovo exposure to polychlorinated biphenyls (PCBs) alters growth off first-generation nestlings during and one year after parental exposure. Captive American kestrels (Falco sparverius) laid eggs with environmentally relevant total PCB levels (34.1 μg/g whole-egg wet wt) when fed PCB-spiked (Aroclor® 1248, 1254, and 1260) food (7 mg/kg body wt/d) for 100 d in 1998. In 1999, the same adults laid eggs with estimated total PCBs of 29.0 μg/g. Nonsurviving PCB-exposed chicks were small (mass, bones) in 1998. Survivors showed a strong sex-specific growth response (mass, bones) compared to respective sex controls: Only female hatchlings were larger, and only male nestlings had longer feathers (1998); maximal growth and bone growth rates also differed (males were advanced, faster; females delayed, slower) (1999); and male nestlings fledged earlier and were smaller, while females were larger (1998, 1999). However, regardless of sex, PCB-exposed nestlings generally grew at faster rates in both years. In 1998, greater contaminant burdens and toxic equivalent concentrations in sibling eggs were associated with nestlings being lighter, having longer bones and feathers, and growing at faster rates (mass, bone) for females but slower rates (mass) for males. Both physiological-biochemical and behavioral changes are likely mechanisms. This study supports and expands on the Great Lakes embryo mortality, edema, and deformities syndrome: While PCB exposure alters nestling size, maximal growth and growth rates also change immediately, are sustained, and are sex specific.
David M Bird - One of the best experts on this subject based on the ideXlab platform.
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evaluation of high dosages of oral meloxicam in american kestrels Falco sparverius
Journal of Avian Medicine and Surgery, 2017Co-Authors: Noemie Summa, David M Bird, David Sanchezmigallon Guzman, Eric Troncy, Sylvain Larrat, Stephane Lair, Guy FitzgeraldAbstract:To evaluate the toxicity of short-term high doses of meloxicam in American kestrels (Falco sparverius), 32 male captive-born, 1- to 4-year-old American kestrels were randomly assigned to 4 groups: 3 groups treated with meloxicam (n = 9 per group) and a control group (n = 5). Meloxicam was administered orally via feeding tube in the proventriculus at 2, 10, and 20 mg/kg every 12 hours for 7 days for the treatment groups, while the control group received saline solution. The birds were evaluated for the presence of clinical signs, abnormalities in the complete blood cell count and in the plasma biochemical panel for the 20-mg/kg group, and gross and histopathologic lesions. No clinical signs or mortality were observed in any group. No significant differences of clinical relevance were found in results of the packed cell volume, total solids, and biochemical panel, and no evidence of renal toxicity was found in the treatment or control groups. A significant correlation was found between hepatic lipidosis and meloxicam dose (P = .02). Two of 9 birds in the 20-mg/kg group developed gastric ulcers, although this result was not significant. None of the birds in the 2- and 10-mg/kg groups had similar lesions. Finally, meloxicam dosages up to 20 mg/kg did not result in nephrotoxicity in American kestrels. Further toxicologic studies to evaluate hepatotoxicity and gastrotoxicity of meloxicam in avian species are needed.
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the flame retardant β 1 2 dibromo 4 1 2 dibromoethyl cyclohexane fate fertility and reproductive success in american kestrels Falco sparverius
Environmental Science & Technology, 2012Co-Authors: Sarah C Marteinson, David M Bird, Robert J Letcher, Ian J Ritchie, Laura Graham, Sarah Kimmins, Gregg T Tomy, Vince P Palace, Lewis T Gauthier, Kim J FernieAbstract:Captive American kestrels (Falco sparverius) were exposed via diet during reproduction to an environmentally relevant concentration of β-1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (β-TBECH). The β-TBECH isomer was injected into the food source at a daily dosing concentration of 0.239 ng/g kestrel/day (22 pairs); control birds were exposed via diet to the safflower oil vehicle only (24 pairs). Eight pairs in each group were exposed for four weeks and sacrificed for tissue analysis; the remaining pairs completed their breeding cycle, with exposure ceasing at the end of incubation (82 days). α- and β-TBECH appeared to be rapidly metabolized and/or eliminated from fat, liver, and plasma; both isomers and potential hydroxylated metabolites of β-TBECH (plasma) were undetected. Notwithstanding, compared to controls, pairs exposed to β-TBECH laid fewer eggs (p = 0.019) and laid lighter eggs (successful eggs: p = 0.009). Exposed pairs also demonstrated poorer egg fertility (p = 0.035) although testis mass and his...
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diet exposure to technical hexabromocyclododecane hbcd affects testes and circulating testosterone and thyroxine levels in american kestrels Falco sparverius
Environmental Research, 2011Co-Authors: Sarah C Marteinson, David M Bird, Robert J Letcher, Ian J Ritchie, Kim J Fernie, Sarah Kimmins, Vince P PalaceAbstract:Hexabromocyclododecane (HBCD) is a high-production-volume, brominated flame-retardant that is used in items such as polystyrene foams. HBCD has been detected in the environment, wildlife tissues and in humans globally with some of the highest recorded levels in predatory birds. This study examined the effects of exposure to environmentally relevant levels of HBCD on the reproductive physiology of captive male American kestrels (Falco sparverius), a predatory bird. Two sets of males were used: one group not housed with females (unpaired: nc=12, nHBCD=10) and the second group housed with females (breeding: nc=10, nHBCD=20). All treatment birds were exposed to 0.51 μg HBCD/g kestrel/day technical HBCD, and controls to safflower oil only, injected into their food during seasonal testicular development. Unpaired males were exposed for 3 weeks and euthanized for testicular analysis. Breeding males were exposed for 3 weeks prior to pairing and throughout the courtship period. The HBCD-exposed unpaired males had heavier testes (p≤0.017) and a trend towards more seminiferous tubules containing elongated spermatids (p=0.052). There was also a moderate increase in plasma testosterone concentrations (p=0.056) compared to controls. In breeding males, testosterone levels increased during courtship to culminate in higher levels than controls by the time the first egg was laid (p=0.010) and circulating free and total T4 was reduced throughout. The number of sperm cells reaching the perivitelline layer of the first egg for breeding males did not differ between the two groups. This study is the first report that HBCD exposure at environmentally relevant levels alters reproductive physiology in male birds and suggests that birds may be more sensitive to HBCD than mammals.
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effects of recent experience and background features on prey detection of foraging american kestrels Falco sparverius in captivity
Folia Zoologica, 2011Co-Authors: Giovanni Leonardi, David M BirdAbstract:Predators activate a search image process for the most frequent prey type as a result of repeated chance encounters with that prey. In addition, selective attention to a limited subset of prey visual features should increase the precision with which the prey is discriminated from the background. In our experiment, we investigated the effects of multiple backgrounds on prey detection by captive American kestrels (Falco sparverius). We predicted that the background itself can serve to cue attention towards the prey type and that a most recent experience provided predictive information. As expected, we observed the effects of search image formation where the background was informative (familiar substrate). Nevertheless, search image effects disappeared with extended practice and kestrels rapidly increased the use of unfamiliar background where prey were completely non-cryptic. Our data suggest that short-term changes in prey detection of a predator cue with the background upon which this prey is found. We discussed the results in the light of related studies on neophobia, visual acuity and achromatic and chromatic contrasts.
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mate choice in captive american kestrels Falco sparverius parasitized by a nematode trichinella pseudospiralis
Ethology, 2010Co-Authors: Derin Henderson, David M Bird, Manfred E Rau, Juan J NegroAbstract:The American kestrel (Falco sparverius) - Trichinella pseudospiralis host-parasite association was used as a laboratory model to study the effect of a nematode infection on (1) mate choice of female kestrels and (2) competitive abilities of male kestrels during the breeding season. Females were given the opportunity to choose between infected and uninfected males. There was no significant difference in the proportion of females that chose uninfected (n = 18) over infected (n = 16) males. Eight of 11 competitions between infected and uninfected males exposed to a caged female and a nest box were dominated by uninfected males. Female kestrels seemed to base their choices on the intensity of display effort by the males; the experimental level of infection did not affect male courtship behaviour. Although T. pseudospiralis is known to debilitate American kestrels, parasitized males in mate-choice tests may have diverted energy from less important functions to court the females.
Russell D. Dawson - One of the best experts on this subject based on the ideXlab platform.
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Risk of Nest Predation Influences Reproductive Investment in American Kestrels (Falco sparverius): an Experimental Test
Journal of Raptor Research, 2011Co-Authors: Jennifer L. Greenwood, Russell D. DawsonAbstract:Abstract Nest predation is the primary cause of nest failure in birds. Individuals should therefore adjust parental investment to minimize the costs associated with this constraint; evidence suggests that nest predation influences nest-site selection, and drives variation in both clutch size and parental behavior. Here, we test how the perception of the risk of nest predation from red squirrels (Tamiasciurus hudsonicus) influenced nest-site selection and reproductive investment of American Kestrels (Falco sparverius) breeding in the boreal forest. For this purpose, we conducted audio playbacks of squirrel vocalizations and altered nest boxes to experimentally increase cues of the presence of Red Squirrels in the vicinity of potential nests. Experimental manipulations of the risk of nest predation did not influence nest-site selection; however, experimentally increasing the perceived risk of nest predation induced kestrels to initiate breeding later, and to lay larger clutches. Parents did not appreciably ...
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why are american kestrel Falco sparverius populations declining in north america evidence from nest box programs
Journal of Raptor Research, 2009Co-Authors: John A Smallwood, Mark F Causey, David H Mossop, James R Klucsarits, Bob Robertson, Sue Robertson, Joey Mason, Michael J Maurer, Richard J Melvin, Russell D. DawsonAbstract:Abstract Declines in American Kestrel (Falco sparverius) populations are widely reported, and Breeding Bird Survey (BBS) data suggest that the North American population declined significantly from 1984 to 2007. Potential causes include the spread of West Nile virus (WNV), increases in populations of Cooper's Hawks (Accipiter cooperii), and loss of suitable habitat. We examined trends in the numbers of both migratory and resident kestrel populations that use nest boxes in eight study areas in Florida, Georgia, Virginia and Maryland, New Jersey, Massachusetts, Pennsylvania, Saskatchewan, and the Yukon Territory, 1984–2007. All eight populations underwent significant declines; the mean annual decline in nest-box occupancy rate was 3.0% and ranged from 0.6% in Pennsylvania to 4.7% in New Jersey. Except for the most recent nest-box program, established in 1995 and declining since 2002, all nest-box populations began to experience declines before WNV arrived in North America in 1999. To test whether changes in ...
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why are american kestrel Falco sparverius populations declining in north america evidence from nest box programs
Journal of Raptor Research, 2009Co-Authors: John A Smallwood, Mark F Causey, David H Mossop, James R Klucsarits, Bob Robertson, Sue Robertson, Joey Mason, Michael J Maurer, Richard J Melvin, Russell D. DawsonAbstract:Abstract Declines in American Kestrel (Falco sparverius) populations are widely reported, and Breeding Bird Survey (BBS) data suggest that the North American population declined significantly from 1984 to 2007. Potential causes include the spread of West Nile virus (WNV), increases in populations of Cooper's Hawks (Accipiter cooperii), and loss of suitable habitat. We examined trends in the numbers of both migratory and resident kestrel populations that use nest boxes in eight study areas in Florida, Georgia, Virginia and Maryland, New Jersey, Massachusetts, Pennsylvania, Saskatchewan, and the Yukon Territory, 1984–2007. All eight populations underwent significant declines; the mean annual decline in nest-box occupancy rate was 3.0% and ranged from 0.6% in Pennsylvania to 4.7% in New Jersey. Except for the most recent nest-box program, established in 1995 and declining since 2002, all nest-box populations began to experience declines before WNV arrived in North America in 1999. To test whether changes in ...
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experimentally prolonging the brood rearing period reveals sex specific parental investment strategies in american kestrels Falco sparverius
The Auk, 2008Co-Authors: Russell D. Dawson, Gary R BortolottiAbstract:Abstract Responses of parent birds to changes in demands by their offspring have typically been investigated by manipulating brood size and testing for altered patterns of provisioning. We applied an alternative method to breeding pairs of American Kestrels (Falco sparverius) by modifying the duration of their nesting periods. Rather than focusing on how hard parents can work on any given day, this novel approach tests how long they can sustain the stress of provisioning and the associated behavioral consequences. We manipulated nesting periods by exchanging nearly fledged young at the age of 20 days with offspring from other nests that were 10 days old. We found that males provisioned their second foster broods at rates similar to those for their original broods. By contrast, females brooded offspring in second foster nests less and also delivered less food to them. As a consequence, male offspring in second nests gained less mass than those in first nests, and nestlings of both sexes had reduced feather...
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experimental evidence for food limitation and sex specific strategies of american kestrels Falco sparverius provisioning offspring
Behavioral Ecology and Sociobiology, 2002Co-Authors: Russell D. Dawson, Gary R BortolottiAbstract:For birds with altricial young, the brood-rearing period is one of the most energetically expensive periods in their lives and may be the bottleneck for fitness. Because parents are expected to be prudent in allocating resources between reproduction and self-maintenance, food supply should be an important factor determining reproductive decisions during brood rearing. Parents with abundant food are expected to have enhanced fitness because they are able to reduce their work rates and increase their own survival chances, because their offspring may be of higher quality, or some combination of these. However, few studies have simultaneously documented all of these variables in a single investigation. We performed a food supplementation experiment to test how food supply influenced provisioning decisions by parent American kestrels (Falco sparverius). Female kestrels showed a strong response to extra food and reduced their provisioning rates. As a result, supplemented females had higher return rates than control females, suggesting significant effects of food on female survival. Because females used extra food to increase their fitness, our results suggest that kestrels raising offspring are limited by food. Male kestrels whose nests were supplemented also responded to extra food by reducing provisioning, but to a much lesser extent than their mates. Male parents did not appear to benefit from supplementation, as their return rates were similar to control males. The total amount of food received on a daily basis by nestlings was similar between supplemented and control nests. Supplemented offspring therefore did not fledge in better condition or have higher survival rates than control nestlings; the only significant factor consistently affecting offspring condition and survival was weather.
Kim J Fernie - One of the best experts on this subject based on the ideXlab platform.
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inhaling benzene toluene nitrogen dioxide and sulfur dioxide disrupts thyroid function in captive american kestrels Falco sparverius
Environmental Science & Technology, 2016Co-Authors: Kim J Fernie, Luis Cruzmartinez, Lisa E Peters, Vince Palace, Judit E G SmitsAbstract:Research investigating the effects of air contaminants on biota has been limited to date. Captive adult female American kestrels (Falco sparverius) were exposed to a mixture of benzene (0.6 ppm), toluene (1 ppm), nitrogen dioxide (NO2; 2 ppm) and sulfur dioxide (SO2; 5.6 ppm), in a whole-body inhalation chamber. Thyroid axis responses to meet metabolic demands were examined through thyroid histology, plasma thyroxine (T4), and triiodothyronine (T3), and hepatic outer ring deiodination (T4-ORD). Plasma free (F) T3 and T4 were measured at baseline, and at 9 days and 18 days of exposure, whereas total (T) T3 and TT4, thyroid histology and hepatic T4-ORD were determined at the final 18 day exposure. Inhalation of these contaminants significantly suppressed plasma FT4 and TT4, and depleted follicular colloid and increased epithelial cell height at 18 days, and significantly altered the temporal pattern of plasma FT4. Significant histological changes in the follicular colloid:epithelial cell height ratio indica...
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uptake distribution depletion and in ovo transfer of isomers of hexabromocyclododecane flame retardant in diet exposed american kestrels Falco sparverius
Environmental Toxicology and Chemistry, 2015Co-Authors: Robert J Letcher, Lisa C Mattioli, Sarah C Marteinson, David F Bird, Ian J Ritchie, Kim J FernieAbstract:Hexabromocyclododecane (HBCDD) is a flame retardant and a global contaminant, yet the toxicokinetics of HBCDD diastereoisomers remains unknown in wildlife species. The present study examined in captive American kestrels (Falco sparverius) (diastereo) isomer-specific HBCDD uptake, depletion, tissue distribution, and transfer to eggs in a dietary dosing study with an HBCDD technical mixture (HBCDD-TM). Adult tissue and plasma collections were from separate cohorts of unpaired individual males (n = 10) and females (n = 10) exposed for 21 d to 800 ng/g wet weight of HBCDD-TM (in safflower oil and injected into their cockerel [brain] diet), followed by a 25-d depuration period. A separate cohort of 12 males only was used for control adult tissue and plasma collections. For egg collections, separate cohorts of 11 control pairs (n = 22 birds) and 20 HBCDD-exposed pairs (n = 40 birds) were allowed to breed, and their eggs were collected (n = 19 exposed eggs and n = 10 control eggs). The sum (Σ) HBCDD concentrations were near or below detection ( 0.05] between males and females). Arithmetic mean ΣHBCDD concentrations were highest in fat >> eggs > liver > plasma. The mean ΣHBCDD depletion rate in plasma between the uptake and depuration periods was estimated to be 0.22 ng/g/d with a half-life of approximately 15 d. The γ-HBCDD diastereoisomer was >60% of the ΣHBCDD in plasma after the uptake period and similar to the HBCDD-TM (∼80%). After the depuration period, α-HBCDD was >70% of the HBCDD in plasma, fat, liver, and eggs; and this α-HBCDD domination indicated isomer-specific accumulation as a result of selective metabolism, uptake, protein binding, and/or in ovo transport.
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the flame retardant β 1 2 dibromo 4 1 2 dibromoethyl cyclohexane fate fertility and reproductive success in american kestrels Falco sparverius
Environmental Science & Technology, 2012Co-Authors: Sarah C Marteinson, David M Bird, Robert J Letcher, Ian J Ritchie, Laura Graham, Sarah Kimmins, Gregg T Tomy, Vince P Palace, Lewis T Gauthier, Kim J FernieAbstract:Captive American kestrels (Falco sparverius) were exposed via diet during reproduction to an environmentally relevant concentration of β-1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (β-TBECH). The β-TBECH isomer was injected into the food source at a daily dosing concentration of 0.239 ng/g kestrel/day (22 pairs); control birds were exposed via diet to the safflower oil vehicle only (24 pairs). Eight pairs in each group were exposed for four weeks and sacrificed for tissue analysis; the remaining pairs completed their breeding cycle, with exposure ceasing at the end of incubation (82 days). α- and β-TBECH appeared to be rapidly metabolized and/or eliminated from fat, liver, and plasma; both isomers and potential hydroxylated metabolites of β-TBECH (plasma) were undetected. Notwithstanding, compared to controls, pairs exposed to β-TBECH laid fewer eggs (p = 0.019) and laid lighter eggs (successful eggs: p = 0.009). Exposed pairs also demonstrated poorer egg fertility (p = 0.035) although testis mass and his...
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diet exposure to technical hexabromocyclododecane hbcd affects testes and circulating testosterone and thyroxine levels in american kestrels Falco sparverius
Environmental Research, 2011Co-Authors: Sarah C Marteinson, David M Bird, Robert J Letcher, Ian J Ritchie, Kim J Fernie, Sarah Kimmins, Vince P PalaceAbstract:Hexabromocyclododecane (HBCD) is a high-production-volume, brominated flame-retardant that is used in items such as polystyrene foams. HBCD has been detected in the environment, wildlife tissues and in humans globally with some of the highest recorded levels in predatory birds. This study examined the effects of exposure to environmentally relevant levels of HBCD on the reproductive physiology of captive male American kestrels (Falco sparverius), a predatory bird. Two sets of males were used: one group not housed with females (unpaired: nc=12, nHBCD=10) and the second group housed with females (breeding: nc=10, nHBCD=20). All treatment birds were exposed to 0.51 μg HBCD/g kestrel/day technical HBCD, and controls to safflower oil only, injected into their food during seasonal testicular development. Unpaired males were exposed for 3 weeks and euthanized for testicular analysis. Breeding males were exposed for 3 weeks prior to pairing and throughout the courtship period. The HBCD-exposed unpaired males had heavier testes (p≤0.017) and a trend towards more seminiferous tubules containing elongated spermatids (p=0.052). There was also a moderate increase in plasma testosterone concentrations (p=0.056) compared to controls. In breeding males, testosterone levels increased during courtship to culminate in higher levels than controls by the time the first egg was laid (p=0.010) and circulating free and total T4 was reduced throughout. The number of sperm cells reaching the perivitelline layer of the first egg for breeding males did not differ between the two groups. This study is the first report that HBCD exposure at environmentally relevant levels alters reproductive physiology in male birds and suggests that birds may be more sensitive to HBCD than mammals.
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changes in the growth but not the survival of american kestrels Falco sparverius exposed to environmentally relevant polybrominated diphenyl ethers
Journal of Toxicology and Environmental Health, 2006Co-Authors: Kim J Fernie, Robert J Letcher, Ken G Drouillard, Laird J Shutt, Ian J Ritchie, David M BirdAbstract:Polybrominated diphenyl ether (PBDEs) concentrations are increasing exponentially in biota. We studied the growth of American kestrel (Falco sparverius) nestlings exposed in ovo and during development to environmentally relevant PBDE congeners and concentrations. Eggs within each clutch, divided between groups by laying sequence, were injected into the air cell at 19 days of incubation with safflower oil or penta-BDE congeners BDE-47, -99, -100, and -153 dissolved in safflower oil (18.7 microg total sigmaPBDEs/egg), approximating current levels in Great Lakes herring gulls. The measured proportions of BDE congeners found in the dosing oil were 56.4% of BDE-47; 27.2% of BDE-99; 24.8% of BDE-100; and 0.6% of BDE-153. For 29 days, nestlings were orally gavaged daily with the same sigmaPBDE mixture (15.6 +/- 0.3 ng/g body weight/day). Relative congener abundances in the dosing mixture compared to the carcasses suggest biotransformation of BDE-47; BDE-183 was also detected. PBDE exposure did not affect hatching or fledging success. PBDE-exposed nestlings were larger (weight, bones, feathers) as they gained weight more quickly and ate more food, the latter in association with their SigmaPBDE body burdens. BDE-100 was most influential on nestling growth, being positively associated with size, weight gain, and food consumption. Increasing concentrations of BDE-183 and -153 were related to longer bones, and BDE-99 to longer feathers. The larger size of the PBDE-exposed birds may be detrimental to their bone structure and have excessive energetic costs. The repeated relationships with BDE-100 and growth may be important for wild Falconidae, since this is the predominant penta-BDE congener in these raptors.
Judit E G Smits - One of the best experts on this subject based on the ideXlab platform.
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inhaling benzene toluene nitrogen dioxide and sulfur dioxide disrupts thyroid function in captive american kestrels Falco sparverius
Environmental Science & Technology, 2016Co-Authors: Kim J Fernie, Luis Cruzmartinez, Lisa E Peters, Vince Palace, Judit E G SmitsAbstract:Research investigating the effects of air contaminants on biota has been limited to date. Captive adult female American kestrels (Falco sparverius) were exposed to a mixture of benzene (0.6 ppm), toluene (1 ppm), nitrogen dioxide (NO2; 2 ppm) and sulfur dioxide (SO2; 5.6 ppm), in a whole-body inhalation chamber. Thyroid axis responses to meet metabolic demands were examined through thyroid histology, plasma thyroxine (T4), and triiodothyronine (T3), and hepatic outer ring deiodination (T4-ORD). Plasma free (F) T3 and T4 were measured at baseline, and at 9 days and 18 days of exposure, whereas total (T) T3 and TT4, thyroid histology and hepatic T4-ORD were determined at the final 18 day exposure. Inhalation of these contaminants significantly suppressed plasma FT4 and TT4, and depleted follicular colloid and increased epithelial cell height at 18 days, and significantly altered the temporal pattern of plasma FT4. Significant histological changes in the follicular colloid:epithelial cell height ratio indica...
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immunological development in nestling american kestrels Falco sparverius post hatching ontogeny of the antibody response
Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 2008Co-Authors: Judit E G Smits, Gary R BortolottiAbstract:Avian research involving examination of immune function or testing of immunocompetence in wild birds has been based upon information on Galliforms, (chicken and quail) even though they are precocial, whereas most wild species with which ecologists, biologists and toxicologists work are altricial; blind, naked and completely dependent at hatching. Here we begin to address this gap in knowledge, offering insight into the early, post-hatching, humoral immune response in an altricial bird, the American kestrel (Falco sparverius). Over two breeding seasons, nestling kestrels were immunized with a non-pathogenic antigen, dinitrophenol keyhole limpet hemocyanin (DNP-KLH), between 3 and 9 days post-hatching and boostered 6 days later. Background levels, primary and secondary immune responses were measured using an enzyme linked immunosorbent assay. The specificity of our laboratory produced rabbit, anti-kestrel antibody was determined using a double immunodiffusion assay. Results showed the rabbit antiserum to have specific anti-kestrel IgG activity. Birds as young as three days old could successfully mount an antibody response, the magnitude of which increased with age at first vaccination. Early immunization did not compromise growth rate, nor did it affect the maximum secondary response. Comparatively, adult kestrels immunized during the same season and following the same protocol, had antibody levels four times higher than those of the nestlings.
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reproductive abnormalities teratogenicity and developmental problems in american kestrels Falco sparverius exposed to polychlorinated biphenyls
Journal of Toxicology and Environmental Health, 2003Co-Authors: Kim J Fernie, Gary R Bortolotti, Judit E G SmitsAbstract:This study found abnormalities in multiple reproductive stages in captive American kestrels (Falco sparverius) when exposed to polychlorinated biphenyls (PCBs) through dietary and in ovo exposure. American kestrels laid eggs with environmentally relevant total PCB levels (34.1 μg/g whole egg wet weight) when consuming PCB-spiked (Aroclor 1248:1254:1260) food (5–7 μg/g body weight per day) for 100 d only in 1998. In 1999, the same adults laid eggs with estimated total PCBs of 23 μg/g. Effects of maternal (only female exposed) and paternal (only male expose d) in ovo PCB exposure were investigated. Maternal F1 eggs contained predicted total PCB concentrations of 0.34 μg/g. Specific abnormalities occurred more frequently during dietary F0 exposure, particularly aggressive courtship interactions, clutch abandonment, occurrences of cracked eggs, and developmental effects. Multiple developmental effects were more pronounced during than after dietary PCB exposure of adults, and although these effects were limite...
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carotenoid concentration and coloration of american kestrels Falco sparverius disrupted by experimental exposure to pcbs
Functional Ecology, 2003Co-Authors: Gary R Bortolotti, Kimberly J Fernie, Judit E G SmitsAbstract:Summary 1. Bright coloration in birds is typically a sexually selected trait. Expression of such traits is sensitive to environmental factors, so they can function as bioindicators of environmental contamination. Of particular value may be carotenoid-based coloration because it is commonly used as a social signal and these pigments have important health functions. 2. American Kestrels (Falco sparverius) in captivity were exposed to dietary PCBs in March. Colour and plasma carotenoids of exposed and control birds were evaluated at pairing and courtship in April, and in winter in December. Juveniles produced by these birds (exposed to PCBs only in ovo) were examined at fledging and in winter. 3. The brightly coloured ceres and lores were evaluated by comparison to colour charts and quantified using digital photographs, and plasma carotenoid concentrations were quantified by spectrophotometry. 4. During breeding, PCB-exposed kestrels differed from controls for both colour and carotenoids, although the nature of effects was sex-specific. Carotenoids of juveniles were not related to treatment at fledging. 5. In winter, PCB-exposure resulted in patterns of colour/carotenoid variation opposite to controls; exposed adult males were duller, and juveniles of both sexes were brighter, than controls. PCB juveniles had higher plasma levels of carotenoids. Sexual dimorphism was apparent in colour and carotenoids of control adults, but not for PCB-exposed birds. 6. Our results are consistent with endocrine disruption. Modulation of both colour and carotenoids may have serious consequences to social behaviour and health.
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developmental toxicity of in ovo exposure to polychlorinated biphenyls i immediate and subsequent effects on first generation nestling american kestrels Falco sparverius
Environmental Toxicology and Chemistry, 2003Co-Authors: Kim J Fernie, Judit E G Smits, Gary R BortolottiAbstract:We determined that in ovo exposure to polychlorinated biphenyls (PCBs) alters growth off first-generation nestlings during and one year after parental exposure. Captive American kestrels (Falco sparverius) laid eggs with environmentally relevant total PCB levels (34.1 μg/g whole-egg wet wt) when fed PCB-spiked (Aroclor® 1248, 1254, and 1260) food (7 mg/kg body wt/d) for 100 d in 1998. In 1999, the same adults laid eggs with estimated total PCBs of 29.0 μg/g. Nonsurviving PCB-exposed chicks were small (mass, bones) in 1998. Survivors showed a strong sex-specific growth response (mass, bones) compared to respective sex controls: Only female hatchlings were larger, and only male nestlings had longer feathers (1998); maximal growth and bone growth rates also differed (males were advanced, faster; females delayed, slower) (1999); and male nestlings fledged earlier and were smaller, while females were larger (1998, 1999). However, regardless of sex, PCB-exposed nestlings generally grew at faster rates in both years. In 1998, greater contaminant burdens and toxic equivalent concentrations in sibling eggs were associated with nestlings being lighter, having longer bones and feathers, and growing at faster rates (mass, bone) for females but slower rates (mass) for males. Both physiological-biochemical and behavioral changes are likely mechanisms. This study supports and expands on the Great Lakes embryo mortality, edema, and deformities syndrome: While PCB exposure alters nestling size, maximal growth and growth rates also change immediately, are sustained, and are sex specific.