Morphological Variation Among Herring Gulls (Larus Argentatus) And Great Black-Backed Gulls (Larus Marinus) In Eastern North America

Herring Gull (Larus argentatus) and Great Black-backed Gull (L. marinus) morphometric data from various eastern North American locations was collected to examine the sources of variation in body size within and among geographic regions. For Herring Gulls, significant differences in all commonly taken measurements at local and regional scales were found. However, most of the variation in measurements was due to sex differences and the natural variance seen within local populations. Herring Gulls breeding in the Arctic did not show any evidence of being morphologically different from other groups. A discriminant function derived from a Newfoundland, Canada, breeding population of Herring Gulls successfully assigned the sex of birds in Atlantic Canada and Nunavut, Canada, further emphasizing that most of the variation seen is between sexes and not among local or even regional populations. It also indicates that the evitable variation introduced by inter-individual differences in measurements was insufficient to compromise the utility of the discriminant function. The correct classification rate was lower for Great Lakes breeding Herring Gulls, indicating that these birds have different morphologies than those of populations in easterly regions. In contrast, few differences and no clear geographic patterns were found in measurements for Great Black-backed Gulls. These results were consistent with recent genetic information, suggesting an older west to east radiation of Herring Gulls across North America and a lack of isolation among Great Black-Backed Gull populations

New Insight Into Avian Papillomavirus Ecology and Evolution From Characterization of Novel Wild Bird Papillomaviruses

Viruses in the family Papillomaviridae have circular dsDNA genomes of approximately 5.7–8.6 kb that are packaged within non-enveloped, icosahedral capsids. The known papillomavirus (PV) representatives infect vertebrates, and there are currently more than 130 recognized PV species in more than 50 genera. We identified 12 novel avian papillomavirus (APV) types in wild birds that could represent five distinct species and two genera. Viruses were detected in paired oropharyngeal/cloacal swabs collected from six bird species, increasing the number of avian species known to harbor PVs by 40%. A new duck PV (DuPV-3) was found in mallard and American black duck (27.6% estimated prevalence) that was monophyletic with other known DuPVs. A single viral type was identified in Atlantic puffin (PuPV-1, 9.8% estimated prevalence), while a higher genetic diversity was found in other Charadriiformes. Specifically, three types [gull PV-1 (GuPV-1), -2, and -3] were identified in two gull species (estimated prevalence of 17% and 2.6% in American herring and great black-backed gull, respectively), and seven types [kittiwake PV-1 (KiPV-1) through -7] were found in black-legged kittiwake (81.3% estimated prevalence). Significantly higher DuPV-3 circulation was observed in spring compared to fall and in adults compared to juveniles. The studied host species’ tendencies to be in crowded environments likely affect infection rates and their migratory behaviors could explain the high viral diversity, illustrating how host behavior can influence viral ecology and distribution. For DuPV-3, GuPV-1, PuPV-1, and KiPV-2, we obtained the complete genomic sequences, which showed the same organization as other known APVs. Phylogenetic analyses showed evidence for virus–host co-divergence at the host taxonomic levels of family, order, and inter-order, but we also observed that host-specificity constraints are relaxed among highly related hosts as we found cross-species transmission within ducks and within gulls. Furthermore, the phylogeny of viruses infecting the Charadriiformes did not match the host phylogeny and gull viruses formed distinct monophyletic clades with kittiwake viruses, possibly reflecting past host-switching events. Considering the vast PV genotype diversity in other hosts and the large number of bird species, many more APVs likely remain to be discovered

The distribution of subarctic and boreal deep-sea demersal fish assemblages across environmental gradients of the northwest Atlantic

The oceanography of the Labrador Sea is well studied because of its globally important deep-water convection that oxygenates the deep ocean and drives climate-regulating ocean currents. However, little is known about the fish communities that inhabit this area, particularly beyond the depths accessible to standard research surveys and commercial fishing activities. We used baited longline surveys to characterize important components of demersal fish communities across a depth gradient of 200-3000 m and compared these data to a similar dataset collected c. 1200 km to the south in the Flemish Cap Region. We found demersal fish communities in the Labrador Sea to be similar to those of the Flemish Cap Region despite unique oceanography and lower primary productivity in the Labrador Sea. Moreover, both areas had high abundance, biomass, and species richness at intermediate depths that suggests factors beyond depth drive community structure in the deep ocean. These data are important for identifying high-value areas for potential protective measures in the northwest Atlantic and provide necessary data with which to assess potential environmental impacts of extractive industries that are expanding north and to deeper waters.Funding for the Labrador Sea surveys was provided by Fisheries and Oceans' Marine Conservation Targets program. The Flemish Cap longline survey was carried out with the financial support from the DG XIV of the European Commission (contract no. XIV/1810/C1/94), from Spanish Institute of Oceanography (IEO), from Portuguese Institute of Maritime Research (IPIMAR), and from the Department of Industry, Agriculture and Fisheries of the Basque Government (AZTI).Peer reviewe

Body condition of American black ducks (Anas rubripes) wintering in Atlantic Canada using carcass composition and a scaled mass index

Body condition is commonly used in ecology to assess the physiological health of an organism or population, and can be used to predict individual survival or breeding success. Waterfowl have been the focus of much research on body condition, and we studied body condition via carcass composition and using a scaled mass index (SMI) in American black ducks (Anas rubripes) wintering in coastal, agricultural, and urban areas of Atlantic Canada. Carcass composition varied between sexes and body mass decreased through winter as fat reserves depleted. Carcass composition was compared to black ducks wintering in the United States, and black ducks wintering in Atlantic Canada were structurally smaller yet proportionally fatter than those wintering in the United States, likely as a mechanism to survive Atlantic Canadaâ s harsher winters. SMI did not differ between coastal, agricultural or urban black ducks, indicating that despite known differences in the diets of the ducks from these three areas, they can maintain similar body conditions capable of surviving the winter. We show that the SMI is a non-destructive alternative to study body condition in waterfowl. Our research highlights the adaptability and hardiness of black ducks at the northern limit of their winter range.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Investigating the Diversity and Host Range of Novel Parvoviruses from North American Ducks Using Epidemiology, Phylogenetics, Genome Structure, and Codon Usage Analysis

Parvoviruses are small single-stranded DNA viruses that can infect both vertebrates and invertebrates. We report here the full characterization of novel viruses we identified in ducks, including two viral species within the subfamily Hamaparvovirinae (duck-associated chapparvovirus, DAC) and a novel species within the subfamily Densovirinae (duck-associated ambidensovirus, DAAD). Overall, 5.7% and 21.1% of the 123 screened ducks (American black ducks, mallards, northern pintail) were positive for DAC and DAAD, respectively, and both viruses were more frequently detected in autumn than in winter. Genome organization and predicted transcription profiles of DAC and DAAD were similar to viruses of the genera Chaphamaparvovirus and Protoambidensovirus, respectively. Their association to these genera was also demonstrated by subfamily-wide phylogenetic and distance analyses of non-structural protein NS1 sequences. While DACs were included in a highly supported clade of avian viruses, no definitive conclusions could be drawn about the host type of DAAD because it was phylogenetically close to viruses found in vertebrates and invertebrates and analyses of codon usage bias and nucleotide frequencies of viruses within the family Parvoviridae showed no clear host-based viral segregation. This study highlights the high parvoviral diversity in the avian reservoir with many avian-associated parvoviruses likely yet to be discovered

Investigating the Diversity and Host Range of Novel Parvoviruses from North American Ducks Using Epidemiology, Phylogenetics, Genome Structure, and Codon Usage Analysis

Parvoviruses are small single-stranded DNA viruses that can infect both vertebrates and invertebrates. We report here the full characterization of novel viruses we identified in ducks, including two viral species within the subfamily Hamaparvovirinae (duck-associated chapparvovirus, DAC) and a novel species within the subfamily Densovirinae (duck-associated ambidensovirus, DAAD). Overall, 5.7% and 21.1% of the 123 screened ducks (American black ducks, mallards, northern pintail) were positive for DAC and DAAD, respectively, and both viruses were more frequently detected in autumn than in winter. Genome organization and predicted transcription profiles of DAC and DAAD were similar to viruses of the genera Chaphamaparvovirus and Protoambidensovirus, respectively. Their association to these genera was also demonstrated by subfamily-wide phylogenetic and distance analyses of non-structural protein NS1 sequences. While DACs were included in a highly supported clade of avian viruses, no definitive conclusions could be drawn about the host type of DAAD because it was phylogenetically close to viruses found in vertebrates and invertebrates and analyses of codon usage bias and nucleotide frequencies of viruses within the family Parvoviridae showed no clear host-based viral segregation. This study highlights the high parvoviral diversity in the avian reservoir with many avian-associated parvoviruses likely yet to be discovered