Carla J. Dove

Comprehensive DNA barcode coverage of North American birds

DNA barcoding seeks to assemble a standardized reference library for DNA-based identification of eukaryotic species. The utility and limitations of this approach need to be tested on well-characterized taxonomic assemblages. Here we provide a comprehensive DNA barcode analysis for North American birds including 643 species representing 93% of the breeding and pelagic avifauna of the USA and Canada. Most (94%) species possess distinct barcode clusters, with average neighbour-joining bootstrap support of 98%. In the remaining 6%, barcode clusters correspond to small sets of closely related species, most of which hybridize regularly. Fifteen (2%) currently recognized species are comprised of two distinct barcode clusters, many of which may represent cryptic species. Intraspecific variation is weakly related to census population size and species age. This study confirms that DNA barcoding can be effectively applied across the geographical and taxonomic expanse of North American birds. The consistent finding of constrained intraspecific mitochondrial variation in this large assemblage of species supports the emerging view that selective sweeps limit mitochondrial diversity.

PREVALENCE AND DIVERSITY OF AVIAN HEMATOZOAN PARASITES IN ASIA: A REGIONAL SURVEY

Tissue samples from 699 birds from three regions of Asia (Myanmar, India, and South Korea) were screened for evidence of infection by avian parasites in the genera Plasmodium and Haemoproteus. Samples were collected from November 1994 to October 2004. We identified 241 infected birds (34.0%). Base-on-sequence data for the cytochrome b gene from 221 positive samples, 34 distinct lineages of Plasmodium, and 41 of Haemoproteus were detected. Parasite diversity was highest in Myanmar followed by India and South Korea. Parasite prevalence differed among regions but not among host families. There were four lineages of Plasmodium and one of Haemoproteus shared between Myanmar and India and only one lineage of Plasmodium shared between Myanmar and South Korea. No lineages were shared between India and South Korea, although an equal number of distinct lineages were recovered from each region. Migratory birds in South Korea and India originate from two different migratory flyways; therefore cross-transmission of parasite lineages may be less likely. India and Myanmar shared more host species and habitat types compared to South Korea. Comparison between low-elevation habitat in India and Myanmar showed a difference in prevalence of haematozoans.

Migratory Canada geese cause crash of US Airways Flight 1549

In the United States alone, over 7400 bird–aircraft collisions (birdstrikes) were reported in 2007. Most of these strikes occurred during takeoff or landing of the flight, and it is during these flight phases that aircraft experience their highest risk of substantial damage after colliding with birds. Birdstrikes carry enormous potential costs in terms of lives and money. Using feather remains and other tissue samples collected from the engines of US Airways Flight 1549, which crash landed in the Hudson River in New York City on 15 January 2009 after a birdstrike, we apply molecular tools and stable hydrogen isotopes to demonstrate that migratory Canada geese were responsible for the crash. Determining whether the geese involved in this birdstrike event were resident or migratory is essential to the development of management techniques that could reduce the risk of future collisions. Currently, the US civil aviation industry is not required to report birdstrikes, yet information on frequency, timing, and ...

Using DNA Barcodes to Identify Bird Species Involved in Birdstrikes

Abstract We determined effectiveness of using mitochondrial DNA barcodes (cytochrome c oxidase subunit 1 [CO1]) to identify bird–aircraft collision (birdstrike) cases that lacked sufficient feather evidence for morphological diagnosis. From September through December 2006, 821 samples from birdstrike events occurring in the United States were submitted for DNA analysis. We successfully amplified a CO1 DNA barcode product from 554 (67.5%) of the samples; 267 (32.5%) did not contain viable DNA and depended on morphological methods (microscopy) for Order or Family level identification. We deemed 19 cases inconclusive either because the DNA barcode recovered from the sample did not meet our 98% match criteria when compared to the Barcode of Life Database (BoLD) or because the DNA barcode matched to a set of ≥2 closely related species with overlapping barcodes, preventing complete species identification. Age of the sample (≤6 months) did not affect DNA viability, but initial condition of the sample and the collection method was critical to DNA identification success. The DNA barcoding approach has great potential in aiding in identification of birds (and wildlife) for airfield management practices, particularly in regions of the world that lack the vast research collections and individual expertise for morphologic identifications.

Mid-Pleistocene divergence of Cuban and North American ivory-billed woodpeckers

We used ancient DNA analysis of seven museum specimens of the endangered North American ivory-billed woodpecker (Campephilus principalis) and three specimens of the species from Cuba to document their degree of differentiation and their relationships to other Campephilus woodpeckers. Analysis of these mtDNA sequences reveals that the Cuban and North American ivory bills, along with the imperial woodpecker (Campephilus imperialis) of Mexico, are a monophyletic group and are roughly equidistant genetically, suggesting each lineage may be a separate species. Application of both internal and external rate calibrations indicates that the three lineages split more than one million years ago, in the Mid-Pleistocene. We thus can exclude the hypothesis that Native Americans introduced North American ivory-billed woodpeckers to Cuba. Our sequences of all three woodpeckers also provide an important DNA barcoding resource for identification of non-invasive samples or remains of these critically endangered and charismatic woodpeckers.

BIRDS CONSUMED BY THE INVASIVE BURMESE PYTHON (PYTHON MOLURUS BIVITTATUS) IN EVERGLADES NATIONAL PARK, FLORIDA, USA

Abstract We identified 25 species of birds representing nine avian Orders from remains in digestive tracts of 85 Burmese pythons (Python molurus bivittatus) collected in Everglades National Park, Florida, USA, from 2003 to 2008. Four species of birds identified in this study are of special concern in Florida and a fifth, the Wood Stork (Mycteria americana), is listed as federally endangered. This represents the first detailed analysis of the avian component of the diet of the introduced Burmese python, now established in Everglades National Park, Florida and highlights the potential for considerable negative impact of this invasive species on native bird populations.

Quantification of microscopic feather characters used in the identification of North American plovers

Variation in microscopic characters of plumulaceous barbs of six species of Charadrius was studied to quantify characters and test differences among taxa. Pluvialis squatarola was used for intergeneric comparisons. Intraspecific variation in feathers from the sternopectoral tract of C. vociferus was examined to define character parameters and to determine within-vane variation and vane symmetry. A significant difference was observed among the barbs of four regions within each vane of the same feather, but barbs from opposing vanes were not significantly different from one another. Interspecific variation then was studied using discriminant function analysis. Pluvialis separated from all species of Charadrius. Two subgroups were apparent within Charadrius: semipalmatus, vociferus and montanus separated from wilsonia, alexandrinus and melodus.

Seeking carotenoid pigments in amber-preserved fossil feathers

Plumage colours bestowed by carotenoid pigments can be important for visual communication and likely have a long evolutionary history within Aves. Discovering plumage carotenoids in fossil feathers could provide insight into the ecology of ancient birds and non-avian dinosaurs. With reference to a modern feather, we sought chemical evidence of carotenoids in six feathers preserved in amber (Miocene to mid-Cretaceous) and in a feather preserved as a compression fossil (Eocene). Evidence of melanin pigmentation and microstructure preservation was evaluated with scanning electron and light microscopies. We observed fine microstructural details including evidence for melanin pigmentation in the amber and compression fossils, but Raman spectral bands did not confirm the presence of carotenoids in them. Carotenoids may have been originally absent from these feathers or the pigments may have degraded during burial; the preservation of microstructure may suggest the former. Significantly, we show that carotenoid plumage pigments can be detected without sample destruction through an amber matrix using confocal Raman spectroscopy.

DIFFERENCES IN PLUMULACEOUS FEATHER CHARACTERS OF DABBLING AND DIVING DUCKS

Abstract ABSTRACT We examined variation in five microscopic plumulaceous (downy) feather characters of eighteen species of dabbling (Anatini) and diving (Aythyini, Mergini) ducks to quantify the differences between these tribes, and to explain how the plumulaceous feather ultrastructure in ducks may be influenced by different ecological requirements. Over 75% of the variation in feather characters among these ducks was explained by the first two components of a principal components analysis (PCA). Component 1 explained 51% of the variation and was positively correlated with the characters that quantified the number of barbules with expanded nodes and the number of expanded nodes on barbules. The microscopic feather characters of dabbling ducks (Anatini) have triangular-shaped, expanded nodes on most proximal barbules, whereas diving ducks (Aythyini and Mergini) lack expanded nodes on some barbules. Anatini also have a greater density of expanded nodes per barbule, wider nodes, shorter distance between expanded nodes, and longer barbule length. Further analysis of node density across all taxa showed that as dive depths increase, the number of expanded nodes per barbule decreases, and in the deepest divers many of the barbules completely lack expanded nodes. The significantly greater density of expanded nodes in dabbling ducks suggests that the downy nodes may function to trap more air. Diving species have fewer expanded nodes, less buoyant plumage, and are more efficient at foraging in deeper water than dabbling ducks.

A Curious Pellet From a Great Horned Owl (Bubo Virginianus)

Abstract One of the traditional methods of determining the dietary preferences of owls relies upon the identification of bony remains of prey contained in regurgitated pellets. Discovery of a pellet containing a large, complete primary feather from an adult, male Ring-necked Pheasant (Phasianus colchicus) prompted us to examine in detail a small sample of pellets from a Great Horned Owl (Bubo virginianus). Our analyses of feather and hair remains in these pellets documented the presence of three species of birds and two species of mammals, whereas bones in the pellets represented only mammals. This finding indicates an important bias that challenges the reliability of owl pellet studies making use of only osteological remains.