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Christine M. Custer

Publications and source records attributed to Christine M. Custer.

At least 55 records · Page 3Linked to original sources

Corticosterone stress response in tree swallows nesting near polychlorinated biphenyl- and dioxin-contaminated rivers

We assayed baseline and stress-induced corticosterone concentrations from adult female and nestling tree swallows, Tachycineta bicolor, from New England, USA, sites with different levels of contamination with polychlorinated biphenyls (PCBs) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Corticosterone was compared over 2 years from a highly contaminated PCB site along the Housatonic River (Berkshire County, MA, USA), a midrange contaminated site upstream, and a reference site. Adult females (n = 29), sampled only in 2003, showed an inverted-U association with PCBs, with higher stress-induced corticosterone with midrange contamination than at the high-contamination site. In nestlings, stress-induced corticosterone was highest for the highly contaminated site compared with the other sites in 2003 (n = 53, 29 nests), with no difference among sites in 2004 (n = 93, 27 nests). In 2004, we began testing mechanisms underlying these changes in nestlings at the high- and low-PCB sites. Corticosterone response to dexamethasone injection (used to test negative feedback) was not different between sites, but stress-induced corticosterone was reduced at the contaminated site after adrenocorticotropin hormone injection (used to test adrenal responsiveness), suggesting an inhibited ability to mount a stress response. We also compared nestlings from a stretch of the Woonasquatucket River, Rhode Island, USA, heavily contaminated with TCDD (n = 80, 43 nests) with nestlings from an upstream site that had lower levels of TCDD and the Berkshire County reference site. Although there were no stress-induced differences, baseline corticosterone was lower at the higher TCDD site than at the reference site. Altogether these findings suggest that tree swallows chronically exposed to high PCB and TCDD levels exhibit altered baseline and stress-induced corticosterone responses, but the patterns of alteration might not be predictable. ?? 2008 SETAC.

Environmental Toxicology and Chemistry

Mercury and other element exposure to tree swallows (Tachycineta bicolor) nesting on Lostwood National Wildlife Refuge, North Dakota

Elevated mercury concentrations in water were reported in the prairie wetlands at Lostwood National Wildlife Refuge, ND. In order to determine whether wildlife associated with these wetlands was exposed to and then accumulated higher mercury concentrations than wildlife living near more permanent wetlands (e.g. lakes), tree swallow (Tachycineta bicolor) eggs and nestlings were collected from nests near seasonal wetlands, semi-permanent wetlands, and lakes. Mercury concentrations in eggs collected near seasonal wetlands were higher than those collected near semi-permanent wetlands or lakes. In contrast, mercury concentrations in nestling livers did not differ among wetland types. Mercury and other element concentrations in tree swallow eggs and nestlings collected from all wetlands were low. As suspected from these low concentrations, mercury concentrations in sample eggs were not a significant factor explaining the hatching success of the remaining eggs in each clutch.

Environmental Pollution

Mercury and other element exposure to tree swallows (Tachycineta bicolor) nesting on Lostwood National Wildlife Refuge, North Dakota

Elevated mercury concentrations in water were reported in the prairie wetlands at Lostwood National Wildlife Refuge, ND. In order to determine whether wildlife associated with these wetlands was exposed to and then accumulated higher mercury concentrations than wildlife living near more permanent wetlands (e.g. lakes), tree swallow (Tachycineta bicolor) eggs and nestlings were collected from nests near seasonal wetlands, semi-permanent wetlands, and lakes. Mercury concentrations in eggs collected near seasonal wetlands were higher than those collected near semi-permanent wetlands or lakes. In contrast, mercury concentrations in nestling livers did not differ among wetland types. Mercury and other element concentrations in tree swallow eggs and nestlings collected from all wetlands were low. As suspected from these low concentrations, mercury concentrations in sample eggs were not a significant factor explaining the hatching success of the remaining eggs in each clutch.

Environmental Pollution

Contaminant levels in eggs of American white pelicans, Pelecanus erythrorhynchos, from Chase Lake, North Dakota

American White Pelicans (Pelecanus erythrorhynchos) are colonial nesters, making them susceptible to site-specific mortality factors. One of the largest known breeding colonies is at Chase Lake National Wildlife Refuge in North Dakota. In 2004, this colony suffered total reproductive failure. In 2005, we collected abandoned eggs from this colony to test for environmental contaminants. Nine eggs were analyzed for 28 organochlorine pesticides, total polychlorinated biphenyls, and 26 inorganic elements. Based on concentrations in this sample of eggs and levels linked to reproductive problems in birds, adult pelicans in the Chase Lake breeding colony are not at known risk from any of the environmental contaminants we measured.

North Dakota

Adult tree swallow (Tachycineta bicolor) survival on the polychlorinated biphenyl-contaminated Housatonic River, Massachusetts, USA

Tree swallows ( Tachycineta bicolor ) were captured and banded at six sites that differed in polychlorinated biphenyl (PCB) contamination levels in the Housatonic River watershed, western Massachusetts, USA, from 2000 through 2004 to test the prediction that apparent survival rates of females in more contaminated areas were lower than those from less contaminated areas. We also tested whether plumage coloration affected over-winter survival and whether concentrations of PCBs in eggs differed between birds that did and that did not return the following year. Apparent survival rates were calculated using mark-recapture methods and compared using Akaike's Information Criterion. Model-adjusted survival rates ranged from 0.365 to 0.467 for PCB-contaminated females and between 0.404 and 0.476 for reference females. Models with either survival or capture probability modeled as functions of treatment (degree of PCB contamination), year, and age received some support. The model-averaged parameter estimate reflecting a treatment effect for high-PCB birds was negative ( = −0.046, SE( ) = 0.0939) . Fifty-four percent of the total model weights involved models in which survival was a function of PCB treatment. Eggs were collected for contaminant analyses from a random sample of females that did and that did not return the following year. Concentrations of total PCBs were the same or higher in the eggs of females that returned compared to the eggs of those that did not return at both the highly and the moderately contaminated PCB sites. This may have resulted from higher-quality females with higher lipid reserves being more likely than lower-quality females to return the following year. Percentage lipid was positively correlated with total PCBs in eggs. Survival rates were similar among swallows with brown versus blue plumage.

Massachusetts

Selenium and metal concentrations in waterbird eggs and chicks at Agassiz National Wildlife Refuge, Minnesota

Exceptionally high cadmium (Cd) and chromium (Cr) concentrations were reported in eggs, feathers, or livers of selected waterbird species nesting at Agassiz National Wildlife Refuge (Agassiz) in 1994. Ten- to 15-day-old Franklin's gull (Larus pipixcan), black-crowned night-heron (Nycticorax nycticorax), and eared grebe (Podiceps nigricollis) chicks were collected in 1998, 1999, and 2001 at Agassiz and analyzed for selenium (Se) and metals including Cd and Cr. Freshly laid eggs were collected in 2001 from Franklin's gull, black-crowned night-heron, eared grebe, and pied-billed grebe (Podilymbus podiceps) nests at Agassiz. Based on a multivariate analysis, the pattern of Se and metal concentrations differed among species for eggs, chick feathers, and chick livers. Low Cd and Cr concentrations were measured in eggs, chick livers, and chick feathers of all four species. Mercury concentrations in black-crowned night-heron and eared grebe eggs collected from Agassiz in 2001 were lower than concentrations reported in 1994. Se and metal concentrations, including Cd and Cr, in waterbird eggs and chicks collected at Agassiz in 1998, 1999, and 2001 were not at toxic levels. ?? 2007 Springer Science+Business Media, LLC.

Archives of Environmental Contamination and Toxico

Relationships of cadmium, mercury, and selenium with nutrient reserves of female lesser scaup (Aythya affinis) during winter and spring migration

Trace elements may have important effects on body condition of ducks during spring migration, because individuals are experiencing energetically costly events (e.g., migration, nutrient reserve accumulation, pair formation, feather molt, and ovarian follicle development). We examined relationships among hepatic cadmium, mercury, and selenium concentrations (microg/g dry wt) and nutrient reserves (lipid, protein, and mineral) of female lesser scaup (Aythya affinis) during winter and spring migration at four locations within the Mississippi Flyway (LA, IL, and MN, USA, and MB, Canada). Selenium concentrations (range, 3.73-52.29 microg/g dry wt) were positively correlated with lipid reserves (F1,73 = 22.69, p < 0.001, type III partial r2 = 0.24), whereas cadmium was negatively correlated with lipid reserves (F1,73 = 6.92, p = 0.010, type III partial r2 = 0.09). The observed relationship between cadmium and lipid reserves may be cause for concern, because lipid reserves of females declined by 55 g (47%), on average, within the range of observed cadmium concentrations (0.23-7.24 microg/g dry wt), despite the relatively low cadmium concentrations detected. Mean cadmium concentrations were higher in Minnesota (1.23 microg/g dry wt) and Manitoba (1.11 microg/g dry wt) than in Louisiana (0.80 microg/g dry wt) and Illinois (0.69 microg/g dry wt). However, mean cadmium concentrations predict lipid reserves of females to be only 11 g lower, on average, in Minnesota than in Illinois. Previous research documented that lipid reserves were 100 g lower in Minnesota than in Illinois; consequently, cadmium is unlikely to be the sole cause for decreases in lipid reserves of females during late-spring migration.

Environmental Toxicology and Chemistry

Water level management and contaminant exposure to tree swallows nesting on the Upper Mississippi River

The U.S. Army Corps of Engineers conducted a water drawdown on Navigation Pool 8 of the Upper Mississippi River during the summers of 2001 and 2002 to increase aquatic vegetation production and thereby improve fish and wildlife habitat. Flooding of previously dried wetlands, however, may increase the rate of mercury methylation and make mercury more available to terrestrial vertebrates that feed in aquatic environments. Our objective was to determine if mercury, other elements, and organochlorine contaminants were more available to vertebrates following the 2001 drawdown. Tree swallow (Tachycineta bicolor) eggs and nestlings were collected at two sites on Pool 8 and a nearby Reference site in 2000 (pre-2001 drawdown), 2001 (pre-2001 drawdown) and 2002 (post-2001 drawdown) and tissues were analyzed for mercury, other elements, and organochlorine contaminants. Bioindicator measurements of genetic damage, oxidative stress, ethoxyresorufin-O-dealkylase activity, and the ratio of liver to nestling mass were also measured in nestlings at all sites and all years. Based on a multivariate analysis, the 2001 drawdown of Pool 8 did not influence element concentrations, organochlorine concentrations, or bioindicator response. Concentrations of inorganic and organochlorine contaminants in tree swallow eggs and nestlings were not at toxic levels. Hatching success did not differ among years and was comparable to the nationwide average.

Environmental Monitoring and Assessment

Mercury exposure and effects on cavity-nesting birds from the Carson River, Nevada

Mercury (Hg) concentrations were 15-40 times higher in the eggs and livers of tree swallows (Tachycineta bicolor) and house wrens (Troglodytes aedon) that nested along the Carson River at and below Dayton, Nevada than in the same species above the mining-impacted areas. Hg contamination was mainly the result of processing mills in the 1800s that used Hg to separate gold and silver from ore. The exposure pattern of tree swallows and house wrens along the Carson River was consistent with their trophic status (i.e., lower levels in liver tissue of aquatic insectivores than in piscivorous birds nesting nearby). Even though they are aquatic insectivores, tree swallows and house wrens were exposed to the same amount of Hg as piscivores in the Florida Everglades; this indicated the extreme level of Hg contamination in the Carson River. Only 70-74% of the eggs hatched. This was less than the nationwide average for these two species that generally hatch ???85% of eggs. Although the sample size was small, Hg might be impacting reproductive end points in cavity-nesting birds from the Carson River. Other trace elements were present at background concentrations. ?? 2006 Springer Science+Business Media, Inc.

Archives of Environmental Contamination and Toxico

Contaminant exposure of barn swallows nesting on Bayou d'Inde, Calcasieu Estuary, Louisiana, USA.

Current and historical point source discharges, storm water runoff, and accidental spills have contaminated the water, sediment, and biota within the Calcasieu Estuary in southwestern Louisiana. In 2003, barn swallow (Hirundo rustica) eggs and nestlings were collected beneath two bridges that cross Bayou d'Inde, the most contaminated waterway within the Calcasieu Estuary. Samples were also collected from a bridge over Bayou Teche, a reference site in south central Louisiana. Polychlorinated biphenyl (PCB) concentrations in barn swallow eggs and nestlings were significantly higher at the downstream site on Bayou d'Inde (2.8 micro g/g PCBs in eggs and 1.5 micro g/g PCBs in nestlings) than at the other two sites (< 0.2 micro g/g PCBs in eggs and nestlings at both sites). Ethoxyresorufin-O-dealkylase activity in nestling livers was significantly higher at the downstream site on Bayou d'Inde (50 pmol/min/mg) compared to the other two locations (24 pmol/min/mg, each), probably because of exposure to PCBs. Polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran concentrations in eggs and polycyclic aromatic hydrocarbons in nestlings were at background concentrations at all sites. Trace element concentrations in barn swallow eggs and nestling livers were at background levels and did not differ among the three sites. A biomarker of DNA damage did not differ among sites.

Environmental Monitoring and Assessment

Trace element concentrations and bioindicator responses in tree swallows from northwestern Minnesota

Extremely high concentrations of cadmium (3.5 μ g/g dry wgt.) and elevated concentrations of chromium (>10 μ g/g dry wgt.) and mercury (1.6 μ g/g dry wgt.) were reported in waterbird tissues at Agassiz National Wildlife Refuge in northwestern Minnesota in 1994. Tree swallows ( Tachycineta bicolor) were studied during 1998–2001 at three drainages into the Refuge, two pools on the Refuge, and at a nearby reference location to document whether high levels of contaminants were still present, and if so to quantify the source and severity of the contamination. Trace elements were measured in tree swallow eggs, livers, and diet. Reproductive success and bioindicator responses were monitored. In 2000, water was drawn down on Agassiz Pool, one of the main pools on the Refuge. This presented an opportunity to evaluate the response of trace element concentrations in the diet and tissues of tree swallows after reflooding. High concentrations of trace elements were not detected in swallow tissues, nor were there differences among locations. Less than 20% of swallow samples had detectable concentrations of cadmium or chromium. Mercury concentrations were low and averaged <0.25 μ g/g dry wgt. in swallow tissues. Trace elements, including mercury, did not increase in tree swallows following the 2000 drawdown at Agassiz Pool. Hatching success and survival of nestlings to 12 days-of-age for tree swallows on the Refuge were similar to the national average and consistent with background trace element concentrations. Bioindicator measurements were within the normal ranges as well.

Minnesota

Polychlorinated biphenyl congener patterns in tree swallows (Tachycineta bicolor) nesting in the Housatonic River watershed, western Massachusetts, USA, using a novel statistical approach

A novel application of a commonly used statistical approach was used to examine differences in polychlorinated biphenyl (PCB) congener Patterns among locations and sample matrices in tree swallows (Tachycineta bicolor) nesting in the Housatonic River watershed in western Massachusetts. USA. The most prevalent PCB congeners in tree swallow tissue samples from the Housatonic River watershed were Ballsmitter Zell numbers 153. 138 180, 187 149, 101, and 170. These congeners were seven of the eight most prevalent congeners in Aroclor (R) 1260, the PCB mixture that was the primary source of contamination in the Housatonic River system. Using paired-Euclidean distances and tolerance limits, it was demonstrated that conuener patterns in swallow tissues from sites on the main stem of the Housatonic River were more similar to one another than to two sites upstream of the contamination or from a nearby reference area. The congener patterns also differed between the reference area and the two upstream tributaries and between the two tributaries. These pattern differences were the same in both pipper (eggs or just hatched nestlings) and 12-day-old nestling samples. Lower-chlorinated congeners appeared to be metabolized in nestlings and pippers compared to diet. and metabolized more in pippers compared to nestlings. Euclidean distances and tolerance limits provide a simple and statistically valid method to compare PCB congener patterns among groups. Published by Elsevier Ltd.

Environmental Pollution

Exposure and effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin in tree swallows (Tachycineta bicolor) nesting along the Woonasquatucket River, Rhode Island, USA

Concentrations of 2,3,7,8-tetrachlorodibenzo- p -dioxin (TCDD) in tree swallows ( Tachycineta bicolor ) nesting along the Woonasquatucket River northwest of Providence (RI, USA) in 2000 and 2001 were some of the highest ever reported in avian tissues. Mean concentrations in eggs ranged from 300 to > 1,000 pg/g wet weight at the two most contaminated ponds, Allendale and Lyman. Mean egg concentrations at Greystone, the upstream reference pond, were 12 and 29 pg/g. Positive accumulation rates and concentrations in diet samples from 12-day-old nestlings indicated that the contamination was accumulated locally. Concentrations in diet of between 71 and 219 pg/g wet weight were more than 6 and 18 times higher than concentrations considered safe for birds (10–12 pg/g). Hatching success was negatively associated with concentration of TCDD in eggs. Only about half the eggs hatched at Allendale compared with >77% at Greystone. The national average for hatching success in successful nests is 85%. No other contaminants, such as polychlorinated biphenyls and mercury, were present in any sample at concentrations known to affect avian reproduction. Three bioindicators, half-peak coefficient of geometric variation, ethoxyresorufin- O -dealkylase activity, and brain asymmetry were assessed relative to TCDD contamination.

Rhode Island

Nontarget bird exposure to DRC-1339 during fall in North Dakota and spring in South Dakota

Blackbirds frequently use ripening sunflower ( Heltantbus annuus ) as a food source in the northern Great Plains. In 1999 and 2000, the avicide DRC-1339 (3-chloro-4-methylaniline hydrochloride) was used experimentally on fall-ripening sunflower fields in North Dakota so researchers could evaluate its effectiveness for reducing crop depredations by blackbirds. DRC-1339 was applied to rice and broadcast on the ground in a confined area within ripening sunflower fields. One objective of this study was to determine whether nontarget birds, birds other than blackbirds, were eating rice and were exposed to the DRC-1339. In 1999, 8 of 11 (73%) sparrows collected by shotgun in sunflower fields treated with DRe-1339 had rice in their gastrointestinal (GI) tracts. In 2000, 5 mourning doves ( Zenaida macroura ) and 3 sparrows were collected by shotgun in sunflower fields treated with DRC-1339. Three doves had rice in their GI tracts, 4 doves and all 3 sparrows had measurable DRC1339 concentrations in their GI tracts, and 3 mourning doves and 1 savannah sparrow ( Passerculus sanduncbensis ) exhibited histopathological signs of kidney damage. In April 2002, untreated rice was applied to corn stubble plots in South Dakota to determine which bird species ate rice. In 2002, 3 of 3 song sparrows ( Melospiza melodia ) collected by shotgun had rice in their GI tracts. Our results demonstrate that the use of DRC-1339 to control blackbirds in the northern Great Plains will likely expose nontarget birds to the DRC-1339 bait.

North Dakota, South Dakota

Dioxins and congener-specific polychlorinated biphenyls in three avian species from the Wisconsin River, Wisconsin

Sediments from the Wisconsin River, WI, USA are contaminated with 2,3,7,8-tetrachloro- p -dioxin (TCDD) and polychlorinated biphenyls (PCBs). Wet weight concentrations of TCDD and PCBs in eggs were at background levels and highest in the piscivorous hooded merganser ( Lophodytes cucullatus ; geometric mean=7 pg/g TCDD and 0.92 μg/g PCBs) and lowest in the omnivorous wood duck ( Aix sponsa ) (<1 pg/g and 0.07 μg/g); concentrations in eggs of the insectivorous tree swallow ( Tachycineta bicolor ) were intermediate (<1 pg/g and 0.33 μg/g). Positive accumulation rates of TCDD (8–19 pg/day) and PCBs (0.4–0.7 μg/day) in tree swallow nestlings suggest that the Wisconsin River is the source of these contaminants for tree swallow nestlings. The lower representation of trichlorobiphenyls and tetrachorobiphenyls in hooded merganser eggs compared to wood duck or tree swallow eggs suggests that the hooded merganser or its diet has a greater ability to metabolize lower-numbered PCB congeners than wood ducks or tree swallows.

Wisconsin

Feeding habitat selection by Great Blue Herons and Great Egrets nesting in east central Minnesota

Great Blue Herons ( Ardea herodias ) and Great Egrets ( Casmerodius albus ) partitioned feeding habitat based on wetland size at Peltier Lake rookery in east central Minnesota. Great Blue Herons preferred large waterbodies (350 ha), whereas Great Egrets fed most often at small ponds (<25 ha). Forty-nine percent of Great Blue Herons used wetlands 301-400 hectares in size and 83% of Great Egrets fed in wetlands <100 ha in size. Great Blue Herons selected large wetlands more often than expected both at the regional (30-km radius) and local (4-km radius) scales. Habitat use by Great Egrets was in proportion to availability at the regional scale, but they selected smaller wetlands for feeding more often than expected at a local scale. The median flight distance of Great Blue Herons was 2.7 km, similar to distances reported elsewhere. Great Egrets flew farther to feeding sites than Great Blue Herons, and flew farther (median = 13.5 km) than reported in other geographic areas.

Minnesota