Megaceryle Alcyon Research Articles

Female‐biased offspring sex ratios in birds at a mercury‐contaminated river

Mercury is a ubiquitous environmental pollutant that can negatively impact physiology and behavior of vertebrates, causing sub‐lethal changes in condition and reducing fitness. Here we examine its effect on offspring sex ratio. Previous studies demonstrate the ability of environmental contaminants to skew sex ratios in wild populations toward the production of females, and research in humans has demonstrated a decrease in male births following mercury exposure. We therefore hypothesized that female birds inhabiting the floodplain of a mercury‐contaminated river would produce broods more biased towards the production of females relative to birds from uncontaminated areas. We examined complete broods of three species: the aquatic‐feeding belted kingfisher Megaceryle alcyon, the terrestrial‐feeding eastern bluebird Sialia sialis, and the tree swallow Tachycineta bicolor, which feeds from both aquatic and terrestrial sources. Nestling sex ratios were shifted toward the production of females in all three species on mercury‐contaminated sites when compared to uncontaminated reference sites. These results may be explained by endocrine disruption or the Trivers–Willard theory of sex allocation. Our study is the first to examine the impact of mercury on offspring sex ratios in birds, and therefore contributes to our understanding of the potential for this persistent biomagnifying contaminant to alter fitness and effective population size in wildlife.

Observaciones de Aves Raras en España, 2009

Summary. Report on rare birds in Spain 2009. This is the 26th annual report of the Spanish rarities committee (Comite de Rarezas de SEO/BirdLife). This report includes 291 records on the presence of 84 rare bird taxa, with an acceptance rate of 75%. The report contains nine additions to the Spanish Bird List: Pacific Loon Gavia pacifica, white-backed vulture Gyps africanus, African purple swamphen Porphyrio porphyrio of the race madagascarensis, hudsonian whimbrel Numenius phaeopus of the race hudsonicus, bridled tern Onychoprion anaethetus, belted kingfisher Megaceryle alcyon, Naumann's thrush Turdus naumanni and black-and-white warbler Mniotilta varia. Having agreed acceptance criteria, the first accepted records of Caspian gull Larus cachinnans registered since 2005 are also included in this report. Second records for Spain of hooded merganser Mergus cucullatus, white wagtail Motacilla alba of the race subpersonata, house bunting Emberiza sahari and of a petrel assigned to the species pair Zino's/Fea's...

Helminths of Belted Kingfishers, Megaceryle alcyon Linnaeus, 1758, from a Fish Hatchery in Ohio, U.S.A

Abstract In total, 9 helminth species (6 digenetic trematodes: Cathaemasia reticulata, Crassiphiala bulboglossa, Philophthalmus gralli, Uvulifer ambloplitis, Uvulifer semicircumcisus, unidentified strigeid trematode; 3 nematodes: Aviculariella alcyona, Contracaecum sp., Monopetalonema alcedinis) were found in 11 Megaceryle alcyon specimens examined from a fish hatchery near London, Ohio, in 2008 and 2009. Crassiphiala bulboglossa and U. ambloplitis each had a prevalence of 100%. Crassiphiala bulboglossa has the highest mean intensity and mean abundance. Uvulifer ambloplitis had the next highest mean intensity and mean abundance, followed by U. semicircumcisus. Of the nematodes, A. alcyona had the highest prevalence, mean intensity, and mean abundance. Gravid worms of all helminth species were found, except for Contracaecum sp. The mean helminth species richness for the birds was 4.8. Kingfishers become infected with C. reticulata, C. bulboglossa, P. gralli, U. ambloplitis, U. semicircumcisus, unidentified...

Ecological Effects of Metals in Streams on a Defense Materials Processing Site in South Carolina, USA

ABSTRACT The Savannah River Site (SRS) is a 780 km2 U.S. Department of Energy facility near Aiken, South Carolina, established in 1950 to produce nuclear materials. SRS streams are “integrators” that potentially receive water transportable contaminants from all sources within their drainage basins, necessitating a watershed approach to organize contaminant distribution data and characterize the effects of multiple contaminants on aquatic organisms. This study used several lines-of-evidence to assess the ecological effects of metals in SRS streams, including contaminant exposure models for apex predators and bioassessments of fish and macroinvertebrate assemblages. Concentrations of metals in sediments, fish, and water were elevated in streams affected by SRS operations, but contaminant exposure models for the river otter Lontra Canadensis and belted kingfisher Ceryle alcyon indicated that toxicological reference values were exceeded only by Hg and Al. Macroinvertebrate assemblage structure was unrelated to sediment metal concentrations. Fish assemblage data were inconclusive. This study indicated that (1) modeling studies and field bioassessments provide a complementary basis for addressing the individual and cumulative effects of contaminants, (2) habitat effects must be controlled when assessing contaminant impacts, (3) sensitivity analyses of contaminant exposure models can help to apportion sampling effort, and (4) most individual metals in SRS streams are unlikely to have significant ecological effects.

Patterns of organic contaminants in eggs of an insectivorous, an omnivorous, and a piscivorous bird nesting on the Hudson River, New York, USA

Belted kingfisher (Ceryle alcyon), spotted sandpiper (Actitus macularia), and tree swallow (Tachycineta bicolor) eggs were collected in 2004 from the upper Hudson River, New York, USA. This area is one of the most polychlorinated biphenyl (PCB)-contaminated locations in North America. Multivariate analyses indicated among species differences in the concentration and composition of PCB congeners, polychlorinated dibenzo-p-dioxin (PCDD), and dibenzofuran (PCDF, PCDD-F when combined with PCDDs) congeners, and chlorinated pesticides. Total PCB concentrations followed the typical food chain biomagnification paradigm of higher concentrations in piscivorous bird eggs and lower concentrations in eggs of species that feed at lower trophic levels. Concentrations in the insectivorous swallows (geometric mean = 6.8 µg/g wet wt) were approximately half the concentrations present in the piscivorous kingfisher (11.7 µg/g) or omnivorous sandpiper (12.6 µg/g). In contrast, PCB toxic equivalents (TEQs) were higher in swallows (1,790 pg/g wet wt) than in either kingfishers (776 pg/g) or sandpipers (881 pg/g). This difference can be mainly attributed to higher PCB77 concentrations in swallows relative to the other two species. Also contrary to the accepted food-chain paradigm, the sum of PCDD-F concentrations and the sum of their TEQs were higher in swallows than in either sandpipers or kingfishers. Metabolic pathway differences in the respective food chains of the three species probably accounted for the differences observed in PCB TEQ, total PCDD-F, and PCDD-F TEQ concentrations among species.

Mercury Contamination in Fish in Midcontinent Great Rivers of the United States: Importance of Species Traits and Environmental Factors

We measured mercury (Hg) concentrations in whole fish from the Upper Mississippi, Missouri, and Ohio Rivers to characterize the extent and magnitude of Hg contamination and to identify environmental factors influencing Hg accumulation. Concentrations were generally lower (80% of values between 20-200 ng g(-1) wet weight) than those reported for other regions (e.g., upper Midwest and Northeast U.S.). Mercury exceeded the risk threshold for belted kingfisher (Ceryle alcyon, the most sensitive species considered) in 33-75% of river length and 1-7% of river length for humans. Concentrations were lower in the Missouri than in the Mississippi and Ohio Rivers, consistent with continental-scale patterns in atmospheric Hg deposition. Body size and trophic guild were the best predictors of Hg concentrations, which were highest in large-bodied top predators. Site geochemical and landscape properties were weakly related with fish Hg. Moreover, relationships often ran contrary to conventional wisdom, and the slopes of the relationships (positive or negative) were inconsistent among fish guilds and rivers. For example, sulfate is positively associated with fish Hg concentrations but was negatively correlated with Hg in five of six regression models of tissue concentrations. Variables such as pH, acid neutralizing capacity, and total phosphorus did not occur at levels associated with high fish Hg concentrations, partially explaining the relatively low Hg values we observed.

Nesting Habitat Characteristics of Bank Swallows and Belted Kingfishers on the Connecticut River

Ceryle alcyon (Belted Kingfisher) and Riparia riparia (Bank Swallow) rely on vertical eroded banks for nesting. We inventoried Belted Kingfisher and Bank Swallow nesting banks along a 91.6-km section of the Connecticut River in Massachusetts, New Hampshire, and Vermont, including stretches where bank stabilization projects are completed, under construction, or planned. In the case of Bank Swallows, we also assessed the availability of potential nesting habitat in the study area. Forty-four Belted Kingfisher nesting sites and 12 Bank Swallow colonies were detected in the study area. Both species used banks with a low percentage of vegetative cover and a steep slope. Belted Kingfishers used high narrow banks. Bank Swallows used wide banks composed of well-drained, fine sandy loam soils. Potential Bank Swallow nesting sites were limited and in comparison to the sites actually used by Bank Swallows, they were narrower, more vegetated, and composed of more coarse soils. The impact of bank stabilization on Belted Kingfishers is probably minimal. However, bank stabilization eliminated three of twelve Bank Swallow colony sites that served as habitat for ≈20% of nesting pairs in the study area between 1999 and 2005.

Polychlorinated biphenyls, dioxins, furans, and organochlorine pesticides in belted kingfisher eggs from the upper Hudson River basin, New York, USA

Nesting belted kingfishers (hereafter kingfishers, Ceryle alcyon) were studied on the Hudson River near Fort Edward south to New Baltimore (NY, USA) and three nearby river drainages in 2004. Concentrations of 28 organochlorine pesticides, 160 polychlorinated biphenyl (PCB) congeners, and 17 dioxin and furan (PCDD-F) congeners were quantified in kingfisher eggs. The pattern of organochlorine pesticides and PCDD-F congeners did not differ significantly between 14 eggs collected from individual nests on the Hudson River and five eggs similarly collected on three other nearby rivers. In contrast, the pattern of PCB congeners in eggs collected on the Hudson River differed significantly from the other rivers. The differences in patterns of PCB congeners were associated with a higher representation of lower-numbered congeners on the Hudson River than the other rivers. The higher prevalence of the lower-numbered congeners and lower prevalence of the higher-numbered congeners is consistent with Aroclor 1016 and 1242 being the source of the PCBs on the Hudson River. Concentrations in a sample egg collected at each nest were compared to nest survival and egg success (the proportion of eggs hatching in a clutch if at least one egg hatched) of the remaining eggs in the clutch. Models that predicted nest survival and egg success as functions of contaminant levels were poorly distinguished from models that presumed no such associations. Small sample sizes could have contributed to the inability to distinguish among contaminant and no toxicant models. However, we cannot rule out the possibility that contaminant concentrations on the Hudson River were not sufficiently high to demonstrate a relationship between contaminant concentrations and reproductive success in kingfishers.

Foraging Ecology of Peregrine Falcons (Falco peregrinus) Along the Colorado River, Grand Canyon, Arizona

We compiled 355 observations of foraging events of peregrine falcons (Falco peregrinus) in Grand Canyon, downstream from Glen Canyon Dam on the Colorado River during 1973–1995, and documented abundance of prey, foraging behavior, and success in foraging. Peregrine falcons attempted to forage on ≥44 species, including ≥40 species of birds: swifts and swallows (29%), waterfowl (Anseriformes, Podicipediformes, and similar birds, 27%), other waterbirds (waders and other large, non-anseriform waterbirds, 11%), bats (10%), large wasps (8%), and other species (15%). Frequency of foraging during the breeding season was positively related to overall abundance of prey, but relative intensity of predation (ratio of relative frequency of attack on a species to mean abundance of that species) increased on most species of prey in the usually turbid lower reach, where prey were less abundant. Air-to-air strikes were most common (94% of 271 cases for which data were available), followed by air-to-water strikes (4%), and air-to-ground strikes (2%). Tandem attacks occurred in ≥43% of cases. Overall foraging success was ≥52%, and was highest on large wasps (100%) and bats (87%), intermediate on large waterbirds (63%), swifts, swallows, and small terrestrial birds (42%), and waterfowl (40%), and lowest on belted kingfishers (Ceryle alcyon; 18%) and small shorebirds (<3%). Foraging success was related to abundance of prey and number of co-foraging falcons, and was negatively related to relative body mass of prey. Most dietary biomass was derived from waterfowl (64%) and large waterbirds (25%), whereas swallows and swifts contributed only 3%. The low and variably turbid segment near the dam had greater abundance of prey and lower relative intensity of predation compared to the usually turbid segment downstream, but distribution and overall frequency and success of foraging by peregrine falcons were not affected by regulation of flow.

Reduced anti-predator responses in multi-generational hybrids of farmed and wild Atlantic salmon (Salmo salar L.)

Cultured organisms undergo genetically-based behavioural changes that may reduce their ability to sur- vive in the wild. This has raised concerns that interbreeding between escaped cultured and wild organisms will generate hybrids exhibiting maladaptive behaviours which may ultimately reduce the fitness of the wild counterpart. We compared anti-predator responses in Atlantic salmon (Salmo salar) from two wild North American populations, the major farmed strain used in regional aquaculture, and their wild-farmed hybrids (F1 ,F 2, and wild backcross). Anti-predator responses of fry (age 0? parr) were mea- sured under common environmental conditions, using a model of a natural predator (belted kingfisher, Ceryle alcyon). Farmed fry exhibited significantly reduced anti- predator responses relative to fry from both wild popula- tions. The anti-predator responses of wild-farmed hybrid fry were intermediate to those of the parental populations (pure farmed or wild). The magnitude by which wild- farmed hybrids differed in anti-predator responses from pure wild fish also depended on the wild population. These results suggest that: (1) the observed behavioural differ- ences have a genetic basis; (2) wild-farmed hybrids have, on average, reduced anti-predator responses relative to wild fish; and that (3) the effects of wild-farmed interbreeding on anti-predator responses will differ between wild popu- lations. Our study is consistent with the general hypothesis that continual farmed-wild interbreeding may have detri- mental effects on the fitness of wild organisms.

Belted Kingfisher (Megaceryle alcyon)

Belted Kingfisher (Megaceryle alcyon)

Belted Kingfisher (Megaceryle alcyon)

Belted Kingfisher (Megaceryle alcyon)

Relating stream physical habitat condition and concordance of biotic productivity across multiple taxa

To explore the potential of assessments of stream geomorphic condition and habitat quality in evaluating lotic productivity, we investigated concordance of stream biotic productivity (aquatic macroinvertebrates, crayfish, fish, and belted kingfishers ( Ceryle alcyon )) and their physical habitat correlates in 18 streams in the Champlain Valley, Vermont, USA. Pearson correlation analysis indicated significant concordance between macroinvertebrate density and fish biomass (r = 0.76), between the density of macroinvertebrates in the orders Ephemeroptera, Plecoptera, and Trichoptera and fish biomass (r = 0.81), and between fish biomass and kingfisher brood weight (r = 0.54). We used principal component analysis followed by linear regression to investigate relationships between physical habitat condition and biotic productivity and to identify key components of physical habitat condition assessments. Our analysis supported the combined use of geomorphic and habitat assessments as a comprehensive indicator of stream physical habitat condition. We found relationships between habitat assessment scores and productivity measures of all taxa except crayfish, suggesting similar responses to physical condition across trophic levels. Our results encourage the use of additional taxa, in addition to widely used macroinvertebrate metrics, as indicators of the composite effects of physical habitat impairment in stream ecosystems.

British Ornithologists’ Union Records Committee: 36th Report (November 2007)

British Ornithologists’ Union Records Committee: 36th Report (November 2007)

Taxonomic recommendations for British birds: Fourth report

Taxonomic recommendations for British birds: Fourth report

Differences in the Reproductive Ecology of Belted Kingfishers (Ceryle alcyon) Across Streams with Varying Geomorphology and Habitat Quality

We evaluated the influence of stream geomorphology and habitat quality on brood weight, offspring growth rate, and territory length of Belted Kingfishers (Ceryle alcyon) in northwestern Vermont, USA. We gathered measurements of habitat use, fish abundance and biomass, and reproductive success at breeding territories in stream reaches of differing geomorphic and habitat conditions during spring and early summer 2002. We used model selection based on AICc to examine the effects of stream geomorphology, habitat quality, and fish abundance and biomass on the selected reproductive measures. Geomorphic condition emerged as the most important predictor variable for models of both brood weight and territory length. We tested two viable models during the 2003 breeding season at new, independent breeding territories and found them to be well-supported. Our results provide evidence that stream geomorphic condition plays both direct and indirect roles in the habitat use and reproduction of Belted Kingfishers, suggesting that stream and riparian management strategies focused on protecting and restoring functional morphology will have ecological benefits for riverine birds.

Territorial Behavior in Belted Kingfishers, &lt;em&gt;Ceryle alcyon&lt;/em&gt;, During Fall Migration

The Belted Kingfisher (Ceryle alcyon) exhibits territorial behavior during breeding and on the wintering grounds. However, behavior during migration is poorly documented. Here, I report on kingfishers exhibiting territorial behavior during fall migration along the shoreline of northern Lake Huron, Michigan.

Patterns and Interpretation of Mercury Exposure in Freshwater Avian Communities in Northeastern North America

A large data set of over 4,700 records of avian mercury (Hg) levels in northeastern North America was compiled and evaluated. As Hg emissions remain poorly regulated in the United States and Canada, atmospheric deposition patterns and associated ecological responses continue to elicit interest by landscape managers, conservation biologists, policy makers, and the general public. How avian Hg exposure is interpreted greatly influences decision-making practices. The geographic extent and size of this data set is valuable in understanding the factors that affect the exposure of Hg to birds. Featured are differences found among tissues, major aquatic habitats and geographic areas, between age class and gender, and among species. While Hg concentrations in egg and blood reflect short-term Hg exposure, Hg concentrations in liver and feather provide insight into long-term Hg exposure. Blood is a particularly important matrix for relating site-specific exposure to methylmercury (MeHg). The level of MeHg is generally 5-10x greater in adults compared to nestlings. Age also influences MeHg bioaccumulation, particularly for individuals where MeHg intake exceeds elimination. Gender is of interpretive concern when evaluating Hg exposure for species exhibiting sexual dimorphism and niche partitioning. Based on two indicator species, the belted kingfisher (Ceryle alcyon) and bald eagle (Haliaeetus leucocephalus), we found MeHg availability increased from marine, to estuarine and riverine systems, and was greatest in lake habitats. A large sample of > 1,800 blood and egg Hg levels from the common loon (Gavia immer) facilitated a suitable comparison of geographic differences. Although some clusters of highly elevated Hg exposure (i.e., blood levels > 3.0 microg/g, ww and egg levels > 1.3 microg/g, ww) were associated with hydrological and biogeochemical factors known to increase MeHg production and availability, others were not. Geographic areas without a relationship between Hg exposure and biogeochemical processes were associated with emission or waterborne point sources. Differences in Hg exposure among species are primarily correlated with trophic position and availability of MeHg. Although piscivorous species were repeatedly shown to have some of the highest MeHg levels of the 38 species analyzed, insectivorous birds in both aquatic and terrestrial habitats (such as montane areas) were also found with elevated MeHg levels. A better understanding of the factors confounding interpretation of Hg exposure provides an effective basis for choice of indicator species and tissues according to 12 selected scenarios. This and the national need for spatiotemporal monitoring of MeHg availability require careful consideration of indicator species choice. Only then will local, regional, continental, and even global monitoring efforts be effective.

BIRDS ARE OVERLOOKED TOP PREDATORS IN AQUATIC FOOD WEBS

Most freshwater food web models assume that fish occupy the top trophic level. Yet many diet studies and a few caging and artificial stream experiments suggest that birds may be top predators in many freshwater systems. We conducted a large-scale field experiment to test whether avian predators affect the size distribution and abundance of fish in two midwestern streams. We used a combination of netting and perches to manipulate predation by Great Blue Herons (Ardea herodias) and Belted Kingfishers (Ceryle alcyon), and measured the response in the fish assemblage. Bird exclusions caused significant increases in medium size classes of two common prey, striped shiners (Luxilus chrysocephalus) and central stonerollers (Campostoma anomalum). We show that these species of piscivorous birds can alter the abundance of common prey and thus need to be considered more fully when attempting to explain the structure of aquatic food webs. Corresponding Editor: O. J. Schmitz.

Response of Birds to Grazing of Riparian Zones

Livestock grazing of streams and associated riparian areas may negatively impact avian communities through direct disturbance and alteration of vegetation structure. We determined the effects of grazing on vegetation, avian abundance, species richness, and reproductive success on pasture streams and associated riparian habitats in southwest Pennsylvania. Bird counts, nest monitoring, and vegetation sampling were conducted on 12 pairs (grazed and control) of streams in 1996 and 10 pairs in 1997. Compared with control streams, grazed areas had lower avian species richness and abundance. Several wetland-and riparian-dependent species (e.g., common snipe [Gallinago gallinago], great blue heron [Ardea herodias], green-backed heron [Butorides striatus], belted kingfisher [Ceryle alcyon], and solitary sandpiper [Tringa solitatia]) were found more often or only on control areas. Although nest density was higher and nest destruction rates by livestock were lower on control streams, nest success (all species combined) was not affected by grazing. Avian communities in control areas appear to benefit primarily from improved vegetative cover and structure. Thus, management should focus on excluding livestock from such areas.