Pelecanus Erythrorhynchos Research Articles

The phylogenetic relationships of the extant pelicans inferred from DNA sequence data

The pelicans are a charismatic group of large water birds, whose evolutionary relationships have been long debated. Here we use DNA sequence data from both mitochondrial and nuclear genes to derive a robust phylogeny of all the extant species. Our data rejects the widespread notion that pelicans can be divided into white- and brown-plumaged groups. Instead, we find that, in contrast to all previous evolutionary hypotheses, the species fall into three well-supported clades: an Old World clade of the Dalmatian, Spot-billed, Pink-backed and Australian Pelicans, a New World clade of the American White, Brown and Peruvian Pelicans, and monospecific clade consisting solely of the Great White Pelican, weakly grouped with the Old World clade. We discuss possible evolutionary scenarios giving rise to this diversity.

Systemwide Evaluation of Avian Predation on Juvenile Salmonids from the Columbia River Based on Recoveries of Passive Integrated Transponder Tags

AbstractWe recovered passive integrated transponder (PIT) tags from nine piscivorous waterbird colonies in the Columbia River basin to evaluate avian predation on Endangered Species Act (ESA)‐listed salmonid Oncorhynchus spp. populations during 2007–2010. Avian predation rates were calculated based on the percentage of PIT‐tagged juvenile salmonids that were detected as passing hydroelectric dams and subsequently were consumed and deposited by birds on their nesting colonies. Caspian terns Hydroprogne caspia (hereafter, “terns”) and double‐crested cormorants Phalacrocorax auritus (hereafter, “cormorants”) nesting on East Sand Island in the Columbia River estuary consumed the highest proportions of available PIT‐tagged salmonids, with minimum predation rates ranging from 2.5% for Willamette River spring Chinook salmon O. tshawytscha to 16.0% for Snake River steelhead O. mykiss. Estimated predation rates by terns, cormorants, gulls of two species (California gull Larus californicus and ring‐billed gull L. delawarensis), and American white pelicans Pelecanus erythrorhynchos nesting near the confluence of the Snake and Columbia rivers were also substantial; minimum predation rates ranged from 1.4% for Snake River fall Chinook salmon to 13.2% for upper Columbia River steelhead. Predation on ESA‐listed salmonids by gulls and American white pelicans were minor (<2.0% per ESA‐listed salmonid population) relative to predation by terns and cormorants. Cumulative impacts were greater for Snake River and upper Columbia River salmonids than for salmonids originating closer to the estuary because upriver salmonids must migrate past more bird colonies to reach the ocean. Predation rates adjusted for colony size (per capita rates) were significantly higher for terns and cormorants nesting at inland colonies (upstream of Bonneville Dam) than for those nesting in the estuary, suggesting that inland colonies have a greater reliance on salmonids as a food source. Management actions to increase salmonid survival by reducing avian predation in the estuary could be offset if birds that disperse from the estuary relocate to inland nesting sites on or near the Columbia River.

American White Pelicans Feeding on Large Fish in Lanigan Creek, Saskatchewan

American White Pelicans Feeding on Large Fish in Lanigan Creek, Saskatchewan

Nutrient Utilization and Diet Preference of American White Pelicans Consuming Either a Mono- or Multi-Species Diet

Abstract. American White Pelicans (Pelecanus erythrorhynchos) are reported to consume large quantities of commercial catfish in Alabama, Arkansas, Louisiana and Mississippi, negatively impacting aquaculture production. If pelicans consume a single item diet, such as catfish, nutritional deficiencies may result. Therefore, effects of mono-and multi-species diets were examined to determine nutritional impacts on pelicans in addition to determining if preferences for certain fish species exist. Twelve American White Pelicans captured in northwest Mississippi were used for a seven day metabolism trial followed by a two day preference trial. In the metabolism trial, pelicans were assigned to one of three treatment diets (four birds/diet): catfish only, carp only, or both (50% catfish and 50% carp). Pelicans consuming only catfish metabolized less dry matter, organic matter and energy than those consuming only carp or both. Four pelicans were used to determine preference for carp or catfish. Pelicans ate more (...

Interactions Between Double-crested Cormorants and Other Ground-Nesting Species

Increasing populations of Double-crested Cormorants (Phalacrocorax auritus; hereafter cormorants) are of concern regarding the displacement of other species from breeding colonies, but little is known about such interactions. Agonistic interactions between ground-nesting cormorants and American White Pelicans (Pelecanus erythrorhynchos; hereafter pelicans) were investigated and compared to those involving cormorants and Herring Gulls (Larus argentatus). Also, a survey of cormorant eggs in nests of other ground-nesting species was conducted. Of 158 agonistic interactions between cormorants and pelicans, 83% were threat displays, 9% attempts to steal nest material and 8% involved some form of physical contact. Pelicans defended their nests less frequently and engaged in fewer physical contacts (8%) in colonies mixed with cormorants compared to areas with only pelicans (33%). Herring Gulls engaged in more physical contact (26%) with cormorants in a mixed colony than when nesting only with other gulls (4%). Cormorant eggs were found in 1–26% of Herring and Ring-billed Gull (L. delawarensis) nests searched in the Great Lakes, and 0.3% of Caspian Tern (Hydroprogne caspia) nests at one location. The results indicate cormorants routinely engage in agonistic interactions with other ground-nesting birds; however, the type and importance of interactions varies. Site- and species-specific evaluation of interactions involving cormorants and other birds is recommended before taking management steps to reduce nest site competition.

Vector Competence of the Stable Fly (Diptera: Muscidae) for West Nile Virus

In 2006-2007, stable flies, Stomoxys calcitrans (L.) (Diptera: Muscidae), were suspected of being enzootic vectors of West Nile virus (family Flaviviridae, genus Flavivirus, WNV) during a die-off of American white pelicans (Pelecanus erythrorhynchos Gmelin) (Pelecanidae) in Montana, USA. WNV-positive stable flies were observed feeding en masse on incapacitated, WNV-positive pelicans, arousing suspicions that the flies could have been involved in WNV transmission among pelicans, and perhaps to livestock and humans. We assessed biological transmission by infecting stable flies intrathoracically with WNV and testing them at 2-d intervals over 20 d. Infectious WNV was detected in fly bodies in decreasing amounts over time for only the first 6 d postinfection, an indication that WNV did not replicate within fly tissues and that stable flies cannot biologically transmit WNV. We assessed mechanical transmission using a novel technique. Specifically, we fed WNV-infected blood to individual flies by using a cotton swab (i.e., artificial donor), and at intervals of 1 min-24 h, we allowed flies to refeed on a different swab saturated with WNV-negative blood (i.e., artificial recipient). Flies mechanically transmitted viable WNV from donor to recipient swabs for up to 6 h postinfection, with the majority of the transmission events occurring within the first hour. Flies mechanically transmitted WNV RNA to recipient swabs for up to 24 h, mostly within the first 6 h. Given its predilection to feed multiple times when disturbed, these findings support the possibility that the stable fly could mechanically transmit WNV.

Panmixia on a continental scale in a widely distributed colonial waterbird

Many highly mobile species, such as migratory birds, can move and disperse over long distances, yet exhibit high levels of population genetic structuring. Although movement capabilities may enable dispersal, gene flow may be restricted by behavioural constraints such as philopatry. In the present study, we examined patterns of genetic differentiation across the range of a highly mobile, colonial waterbird. American white pelicans (Pelecanus erythrorhynchos) breed across continental North America and are currently experiencing a range expansion, especially on the eastern range limit. To assess patterns of genetic structuring, we sampled 333 individuals from 19 colonies across their North American range. The use of ten variable microsatellite markers revealed high levels of allelic richness with no population differentiation. Both Bayesian and frequentist approaches to examining genetic structuring revealed a single panmictic population. We found no evidence of genetic structuring across the Continental Divide or between migratory and non-migratory colonies. The lack of any genetic structure across the range indicates that, unlike other waterbirds with similar life-history characteristics, extensive gene flow and presumably low philopatry appear to preclude genetic differentiation. The lack of population genetic structure in American white pelicans provides an example of range-wide panmixia, a rare phenomenon in any terrestrial species. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102, 583‐592.

Mitochondrial Evidence for Panmixia despite Perceived Barriers to Gene Flow in a Widely Distributed Waterbird

We examined the mitochondrial genetic structure of American white pelicans (Pelecanus erythrorhynchos) to: 1) verify or refute whether American white pelicans are panmictic and 2) understand if any lack of genetic structure is the result of contemporary processes or historical phenomena. Sequence analysis of mitochondrial DNA control region haplotypes of 367 individuals from 19 colonies located across their North American range revealed a lack of population genetic or phylogeographic structure. This lack of structure was unexpected because: 1) Major geographic barriers such as the North American Continental Divide are thought to limit dispersal; 2) Differences in migratory behavior are expected to promote population differentiation; and 3) Many widespread North American migratory bird species show historic patterns of differentiation resulting from having inhabited multiple glacial refugia. Further, high haplotype diversity and many rare haplotypes are maintained across the species' distribution, despite frequent local extinctions and recolonizations that are expected to decrease diversity. Our findings suggest that American white pelicans have a high effective population size and low natal philopatry. We suggest that the rangewide panmixia we observed in American white pelicans is due to high historical and contemporary gene flow, enabled by high mobility and a lack of effective physical or behavioral barriers.

Sex and Age Bias in American White Pelicans Captured and Collected on Wintering Grounds

Abstract. While conducting research examining the impact of American White Pelicans (Pelecanus erythrorhynchos) on the aquaculture industry in the southeastern United States, an apparent age and sex bias was observed among captured and collected pelicans. Data from 284 pelicans captured or collected at loafing sites located near aquaculture ponds during 1998 to 2009 were analyzed. A sampling bias could suggest segregation of pelicans by sex or age on wintering grounds. Captured pelicans were strongly biased towards immature males (73%) and collected pelicans were male biased (38% Adult Male, 47% Immature Male). Although the underlying mechanisms are not understood, observed pelican use of loafing areas may be related to numerous, readily available prey at aquaculture facilities.

Detection of West Nile Virus in Stable Flies (Diptera: Muscidae) Parasitizing Juvenile American White Pelicans

Stable flies, Stomoxys calcitrans (L.) (Diptera: Muscidae), an economically important pest of livestock and humans, were observed parasitizing prefledged American white pelicans, Pelecanus erythrorhynchos (Pelecaniformes: Pelecanidae), in a pelican breeding colony in northeastern Montana where die-offs attributed to West Nile virus (family Flaviviridae, genus Flavivirus, WNV) have occurred since 2002. Engorged and unengorged flies were collected off nine moribund chicks. Of 29 blood-engorged flies testing positive for vertebrate DNA, all 29 contained pelican DNA. Virus isolation was performed on 60 pools (1,176 flies) of unengorged flies using Vero cell plaque assay. Eighteen pools were positive for WNV for an estimated infection rate of 18.0 per 1,000 flies. Fifty-four percent (36/67) of abdomens from blood-engorged flies tested positive for WNV. Pelican viremia levels from the blood-engorged fly abdomens revealed that at least one of the ill pelicans circulated a viremia capable of infecting Culex mosquito vectors. Stable flies may be involved in WNV transmission within the pelican breeding colony by serving as either a mechanical vector or as a source for oral infection if ingested by predators.

Influenza A Viruses in American White Pelican (Pelecanus erythrorhynchos)

The role of many wild waterbird species in the ecology and epidemiology of avian influenza viruses (AIV) remains unclear. We report the first isolation of AIV from American White Pelicans (Pelecanus erythrorhynchos; Pelecaniformes) in North America. Two H13N9 AIVs were isolated from hatchling birds in breeding colonies in Minnesota, USA, during 2007 and 2008. Based on molecular sequencing of the hemagglutinin and neuraminidase genes, the 2008 virus was genetically related to AIVs previously isolated from gulls and shorebirds in North America. The 2007 isolate was most related to AIVs from Eurasian gulls and North American ducks, reflecting both global movement of these viruses and reassortment between viruses associated with duck and gull reservoirs.

Avian Piscivores as Vectors forMyxobolus cerebralisin the Greater Yellowstone Ecosystem

AbstractMyxobolus cerebralis, the cause of whirling disease in salmonids, has dispersed to waters in 25 states within the USA, often by an unknown vector. Its incidence in Yellowstone cutthroat troutOncorhynchus clarkii bouvieriwithin the highly protected environment of Yellowstone Lake, Yellowstone National Park, is a prime example. Given the local abundances of piscivorous birds, we sought to clarify their potential role in the dissemination ofM. cerebralis. Six individuals from each of three bird species (American white pelicanPelecanus erythrorhynchos, double‐crested cormorantPhalacrocorax auritus, and great blue heronArdea herodias) were fed known‐infected or uninfected rainbow troutO. mykiss. Fecal material produced during 10‐d periods before and after feeding was collected to determine whetherM. cerebraliscould be detected and, if so, whether it remained viable after passage through the gastrointestinal tract of these birds. For all (100%) of the nine birds fed known‐infected fish, fecal samples collected during days 1–4 after feeding tested positive forM. cerebralisby polymerase chain reaction. In addition, tubificid wormsTubifex tubifexthat were fed fecal material from known‐infected great blue herons produced triactinomyxons in laboratory cultures, confirming the persistent viability of the parasite. No triactinomyxons were produced fromT. tubifexfed fecal material from known‐infected American white pelicans or double‐crested cormorants, indicating a potential loss of parasite viability in these species. Great blue herons have the ability to concentrate and release viable myxospores into shallow‐water habitats that are highly suitable forT. tubifex, thereby supporting a positive feedback loop in which the proliferation ofM. cerebralisis enhanced. The presence of avian piscivores as an important component of aquatic ecosystems should continue to be supported. However, given the distances traveled by great blue herons between rookeries and foraging areas in just days, any practices that unnaturally attract them may heighten the probability ofM. cerebralisdispersal and proliferation within the Greater Yellowstone Ecosystem.

Superabundant Food at Catfish Aquaculture Facilities Improves Body Condition in American White Pelicans

Abstract. Few studies have investigated the use of aquaculture-produced foods by piscivorous birds. American White Pelicans (Pelecanus erythrorhynchos) were collected from four locations (two aquaculture, one riverine and one coastal) in the southeastern United States during winter and spring 1998–1999 to assess the contribution (biomass, frequency of occurrence) of aquaculture-produced foods and their effect on body condition. Pelican diets reflected opportunistic foraging across locations. Diet near catfish ponds consisted mostly of Channel Catfish (Ictalurus punctatus). Diets along the Mississippi River had similarly high biomass of catfish, but otolith counts suggested lower use of catfish. Diets near crawfish (Procambarus spp.) ponds included shad (Dorsomis spp.), crawfish and sunfish (Lepomis spp.); whereas diets from coastal Louisiana were predominantly salt water fish. Pelican body condition, as indexed by percent omental fat, was similar between seasons but higher at catfish ponds. Foraging at cr...

American White Pelicans and Double-Crested Cormorants in Saskatchewan: Population Trends Over Five Decades

American White Pelicans and Double-Crested Cormorants in Saskatchewan: Population Trends Over Five Decades

Surveillance for West Nile Virus in American White Pelicans, Montana, USA, 2006–2007

West Nile virus (WNV)-associated deaths of American white pelican (Pelecanus erythrorhynchos) chicks have been recognized at various nesting colonies in the United States since 2002. We evaluated American white pelican nesting colonies in Sheridan County, Montana, USA, for an association between WNV-positive pelican carcasses and human West Nile neuroinvasive disease. Persons in counties hosting affected colonies had a 5x higher risk for disease than those in counties with unaffected colonies. We also investigated WNV infection and blood meal source among mosquitoes and pelican tissue type for greatest WNV detection efficacy in carcasses. WNV-infected Culex tarsalis mosquitoes were detected and blood-engorged Cx. tarsalis contained pelican DNA. Viral loads and detection consistency among pelican tissues were greatest in feather pulp, brain, heart, and skin. Given the risks posed to wildlife and human health, coordinated efforts among wildlife and public health authorities to monitor these pelican colonies for WNV activity are potentially useful.

Forensic bird-strike identification techniques used in an accident investigation at Wiley Post Airport, Oklahoma, 2008

On March 4, 2008, a Cessna Citation 1 (Model 500) crashed in a wooded area near Wiley Post Airport, Oklahoma, killing all 5 people on board. This paper describes the detailed forensic methods and expertise used by the Smithsonian Institution’s Feather Identification Lab to identify the bird that caused this bird-strike incident. We used standard methods of whole-feather analysis, microscopic examination, and DNA barcoding in this case to identify American white pelican (Pelecanus …

EXPERIMENTAL BOLBOPHORUS DAMNIFICUS (DIGENEA: BOLBOPHORIDAE) INFECTIONS IN PISCIVOROUS BIRDS

In order to determine potential definitive hosts of the digenetic trematode, Bolbophorus damnificus, two American White Pelicans (Pelecanus erythrorhynchos), two Double-crested Cormorants (Phalacrocorax auritus), two Great Blue Herons (Ardea herodias), and two Great Egrets (Ardea alba) were captured, treated with praziquantel, and fed channel catfish (Ictalurus punctatus) infected with B. damnificus metacercariae. Patent infections of B. damnificus, which developed in both American White Pelicans at 3 days postinfection, were confirmed by the presence of trematode ova in the feces. Mature B. damnificus trematodes were recovered from the intestines of both pelicans at 21 days postinfection, further confirming the establishment of infection. No evidence of B. damnificus infections was observed in the other bird species studied. This study provides further evidence that Double-crested Cormorants, Great Blue Herons, and Great Egrets do not serve as definitive hosts for B. damnificus.

Biomphalaria havanensis Identified as a Potential Intermediate Host for the Digenetic Trematode Bolbophorus damnificus

AbstractThe digenetic trematode Bolbophorus damnificus has been associated with mortalities in commercial channel catfish Ictalurus punctatus in the Mississippi Delta. In the life cycle of B. damnificus, the only confirmed first intermediate host is the ram's horn snail Planorbella trivolvis. Recently, the exotic snail Biomphalaria havanensis has been isolated in several channel catfish ponds in the Mississippi Delta. The aim of this study was to determine whether this invasive snail species could also serve as a first intermediate host in the B. damnificus life cycle. Bolbophorus damnificus ova were collected from an American white pelican Pelecanus erythrorhynchos that had been artificially infected with B. damnificus metacercariae; the ova were then introduced into an aquarium with parasite‐negative B. havanensis. Bolbophorus damnificus cercariae (confirmed by polymerase chain reaction) were detected in B. havanensis 45 d after exposure to B. damnificus ova. The snails continued to shed B. damnificus cercariae throughout the 80‐d postexposure examination period. Before this research, the only reported natural B. damnificus infection of snails involved P. trivolvis. This study indicates that the range of snail hosts is broader than previously suspected. A survey should be implemented to identify additional snail species that can serve as hosts for B. damnificus. Further research should determine whether B. havanensis is a natural host for B. damnificus, and if so the prevalence of B. havanensis in commercial channel catfish ponds should be assessed.

Size and Composition of Foraging Flights in Two Species of Piscivorous Colonial Birds: Limited Evidence for Intra- or Interspecific Information Transfer

Colonial birds must derive benefits from living in conspecific groups and with other species. One possible benefit is that they follow previously successful individuals to foraging sites (information center hypothesis). To test for evidence of intra- and interspecific information transfer, we assessed the group size and composition of flights of double- crested cormorants (Phalacrocorax auritus) and American white pelicans (Pelecanus erythrorhynchos) at two mixed colonies. Flights by solo individuals were the most common outbound type, suggesting that the birds do not immediately follow others. However, the majority of the total number of outbound birds traveled in groups. In comparison, groups in- bound to colonies and flying between feeding locations were large. Regardless of flight direction, groups were almost al- ways largest during the late chick-rearing period. This suggests that groups may have some function, although likely not to share information about foraging-sites. Mixed-species groups in general were rare, so it is unlikely that these birds commonly locate prey by following other species in flight.

Development and characterization of microsatellite loci in the American white pelican (Pelecanus erythrorhynchos)

We isolated and characterized nine microsatellite loci from the American white pelican, Pelecanus erythrorhynchos. The loci were screened in 23 individuals from the eastern and western populations of North America and were polymorphic, with the number of alleles per locus ranging from two to eight. Polymorphic information content ranged from 0.185 to 0.820 and observed heterozygosity from 0.217 to 0.957. These new loci will provide tools for studies of population structure in this species, thereby aiding conservation planning.