Anseriform Birds Research Articles

A survey of casques, frontal humps, and other extravagant bony cranial protuberances in birds

The occurrence of casques, frontal humps, and other bony cranial protuberances in birds is reviewed. Several previously overlooked examples are reported and casques of some rare taxa are for the first time figured. Bony cranial protuberances are most widespread among galloanserine birds, which is particularly true for helmet-like casques on top of the skull. In the species-rich clade Neoaves, by contrast, bony protuberances rarely occur on top of the skull and are mainly restricted to the beak. Similar structures have a different ontogenetic origin, with the casque of cassowaries being mainly formed by the mesethmoid and that of the Helmeted Guineafowl (Numida meleagris) deriving from the frontal bones. The pneumatic frontal humps of anseriform birds are formed through inflation of diverticula of the antorbital and/or fronto-ethmoidal sinus, and air sac diverticula are likely to be involved in the formation of other casques. In some Galloanseres, bony cranial protuberances are associated with integumentary structures that have a signaling function, but such correlations do not exist for other taxa, for which a physiological, acoustic or sensory function of the protuberances has to be considered. Casques also occur in pterosaurs and non-avian dinosaurs, but most comparisons between these extinct animals and birds were confined to the casques of cassowaries. The full spectrum of bony cranial outgrowths in birds has not yet been considered and the present survey may serve as a basis for future comparisons. Prominent casques on top of the skull are more likely to evolve in terrestrial or aquatic birds, in which the head is particularly exposed and plays a role in intraspecific signaling, but their absence in most neoavian taxa is noteworthy and requires future studies to address possible ontogenetic, ecological, or functional constraints on their formation.

Vocal plasticity in mallards: multiple signal changes in noise and the evolution of the Lombard effect in birds

Signal plasticity is a building block of complex animal communication systems. A particular form of signal plasticity is the Lombard effect, in which a signaler increases its vocal amplitude in response to an increase in the background noise. The Lombard effect is a basic mechanism for communication in noise that is well‐studied in human speech and which has also been reported in other mammals and several bird species. Sometimes, but not always, the Lombard effect is accompanied by additional changes in signal parameters. However, the evolution of the Lombard effect and related vocal adjustments in birds are still unclear because so far only three major avian clades have been studied. We report the first evidence for the Lombard effect in an anseriform bird, the mallard Anas platyrhynchos. In association with the Lombard effect, the fifteen ducklings in our experiment also increased the peak frequency of their calls in noise. However, they did not change the duration of call syllables or their call rates as has been found in other bird species. Our findings support the notion that all extant birds use the Lombard effect to solve the common problem of maintaining communication in noise, i.e. it is an ancestral trait shared among all living avian taxa, which means that it has evolved more than 70 million yr ago. At the same time, our data suggest that parameter changes associated with the Lombard effect follow more complex patterns, with marked differences between taxa, some of which might be related to proximate constraints.

First Old World record of the poorly known, swan-sized anseriform bird Paranyroca from the late Oligocene/early Miocene of France

First Old World record of the poorly known, swan-sized anseriform bird Paranyroca from the late Oligocene/early Miocene of France

Are Poultry or Wild Birds the Main Reservoirs for Avian Influenza in Bangladesh?

Avian influenza viruses (AIV) are of great socioeconomic and health concern, notably in Southeast Asia where highly pathogenic strains, such as highly pathogenic avian influenza (HPAI) H5N1 and other H5 and H7 AIVs, continue to occur. Wild bird migrants are often implicated in the maintenance and spread of AIV. However, little systematic surveillance of wild birds has been conducted in Southeast Asia to evaluate whether the prevalence of AIV in wild birds is higher than in other parts of the world where HPAI outbreaks occur less frequently. Across Bangladesh, we randomly sampled a total of 3585 wild and domestic birds to assess the prevalence of AIV and antibodies against AIV and compared these with prevalence levels found in other endemic and non-endemic countries. Our study showed that both resident and migratory wild birds in Bangladesh do not have a particularly elevated AIV prevalence and AIV sero-prevalence compared to wild birds from regions in the world where H5N1 is not endemic and fewer AIV outbreaks in poultry occur. Like elsewhere, notably wild birds of the orders Anseriformes were identified as the main wild bird reservoir, although we found exceptionally high sero-prevalence in one representative of the order Passeriformes, the house crow (Corvus splendens), importantly living on offal from live bird markets. This finding, together with high sero- and viral prevalence levels of AIV in domestic birds, suggests that wild birds are not at the base of the perpetuation of AIV problems in the local poultry sector, but may easily become victim to AIV spill back from poultry into some species of wild birds, potentially assisting in further spread of the virus.

Bending Properties of the Jugal Bone in Mallard Ducks and its Significance for Cranial Biomechanics

Few species evolved skulls as derived as ducks and other Anseriform birds, which employ rapid, dexterous movements of the palate and jaws to feed. Despite their exceptional behavior and morphology, little is known about the structure and biomechanics of their jaw muscles, cranial joints, and linkages that facilitate cranial kinesis. In particular, the jugal bone is capable of bending considerably as it links the quadrate and the upper beak. Here we employ a series of methods including microCT imaging, morphometrics, 3D modeling and histology to discover how and why the jugal is capable of such astounding flexibility. Although a narrow suture connects the caudal limb of the jugal with the quadratojugal, flexibility instead appears to occur at narrow regions of the bone. This gross morphology is further complemented by changes to the skeletal tissues that compose the element. Moreover, the orientation of jaw muscle resultants and loading of the skull indicate the jugal experiences a range of loading during different instances of the gape cycle. These findings illustrate the complicated series of adaptations in morphology, histology and biomechanics ducks and other vertebrates employ to engage in derived forms of cranial kinesis and feeding.In birds, cranial kinesis implies the ability to move the upper bill relative to the braincase, contributing to the evolution of the flexible skulls found in birds. The mechanism for elevation of the upper beak consists of a forward movement of the quadrate, exerting force through the jugal and the pterygoid that connect the quadrate to the upper jaw, and elevate the upper beak by bending of the nasofrontal hinge joint and possibly a flexion zone in the jugal. The jugal bone plays a significant role in Mallard feeding as it links the posterior part of the skull with the flexible anterior part of the skull. Interestingly the jugal is quite flexible and when removed from the skull; it is capable of bending 90 degrees while still returning to its original conformation. For the first time, we are studying the biomechanics of birds to determine how their skulls work; while primarily investigating the cause of the flexibility in the jugal bone. We have studied a sample of duck skulls through CT data, 3D modeling, and measurement of cross‐sectional properties of the element. From this data we have found areas of the jugal bone that afford greater consideration in determining the flexibility throughout the jugal bone. This project will create new data about the jugal bone's flexibility, which will contribute to the study of biomechanics of bones and cranial kinesis.

The nasal salt gland of extant birds: anatomical structure and its relevance for inferring the behavior and habitat preferences of extinct birds

The kidneys of extant sauropsids (birds, crocodylians, turtles, lepidosaurs) tend to be less efficient at removing excess salt from the blood than are those of mammals, and consequently, sites of extrarenal salt excretion are common in sauropsids. In birds, the nasal gland is involved with concentrating and excreting salt from the blood. In many marine birds (e.g., charadriiforms, procellariiforms), the nasal gland is hypertrophied and occupies a supraorbital position, but other positions are known in birds, such as within the orbit (e.g., suliforms). The basic physiology of avian nasal salt glands has been well‐understood for generations, but the detailed anatomy, particularly with regard to its osteology, is poorly documented. We present the results of our preliminary survey of nasal gland structure in birds to better resolve the osteological correlates of the gland, its ducts, and its vascular supply. The resulting osteological correlates (e.g., bony fossa, supraorbital process of the lacrimal, foramina/grooves for ducts) allow a more rigorous and informed assessment of the presence, position, and size of the nasal gland in extinct birds, potentially allowing rough assessments of salt loads and hence habitat preferences (e.g., marine vs. terrestrial). The extant studies emphasize marine and aquatic birds (e.g., albatrosses, shearwaters, gulls, gannets, cormorants, anseriforms), among others, such as, non‐marine outgroups (e.g., ostrich), drawing on the following anatomical approaches: (1) gross dissection, (2) diceCT (iodine enhanced microCT), and (3) radio‐opaque vascular injection followed by microCT. These studies allow not only detailed information about the relevant soft tissues and their osteological correlates, but also permit quantification of gland volumes and other metrics for comparative analysis. These extant studies shed new light on the interpretation of the nasal glands of extinct birds. Study of original fossil material and microCT scan data provide more refined information on the nasal glands of the Cretaceous marine toothed birds Hesperornis and Ichthyornis. The flightless diver Hesperornis had enormous nasal glands, suggesting that it was forced to consume seawater exclusively, whereas the volant and hence more vagile Ichthyornis had smaller salt glands suggesting that it perhaps also had access to fresh water sources. The Paleogene anseriform bird Presbyornis, typically regarded as inhabiting saline soda lakes, also was sampled and provides new evidence for a modest nasal salt gland.Support or Funding InformationUS National Science Foundation (IOB‐0517257, IOS‐1050154, IOS‐1456503), the Ohio University Honors Tutorial College, and the Ohio University Heritage College of Osteopathic Medicine

Possible Ways of Development of the Breeding Bird Communities of the Lower Dnipro

Abstract Anthropogenic and natural factors of transformation of breeding bird communities of the Lower Dnipro affect mainly the territory of the Kakhovka Reservoir. Transformation processes of natural systems will result in a decrease of numbers and even the disappearance of some species of nesting birds of Ciconiiformes and Anseriformes. Podicipediformes and Charadriiformes birds remain less vulnerable, especially species that nest on the overwater vegetation. The birds nesting in hollows and in trees and shrub plantations are among the most successful. It is also possible to predict that some species would change their priorities from rock to tree-nesting. The wetlands below Nova Kakhovka will remain a natural sanctuary for the nesting birds of the forest and wetland natural complexes of the floodplain of the Lower Dnipro. Any changes in this area can occur in case of further human activity in the floodplain of the Dnipro lowland.

Structure and homology ofPsittacosaurustail bristles

AbstractWe examined bristle‐like appendages on the tail of the Early Cretaceous basal ceratopsian dinosaurPsittacosauruswith laser‐stimulated fluorescence imaging. Our study reveals previously unknown details of these structures and confirms their identification as integumentary appendages. For the first time, we show that most bristles appear to be arranged in bundles and that they exhibit a pulp that widens towards the bristle base. We consider it likely that the psittacosaur bristles are structurally and developmentally homologous to similar filamentous appendages of other dinosaurs, namely the basal heterodontosauridTianyulongand the basal therizinosauroid theropodBeipiaosaurus, and attribute the greater robustness of the bristles ofPsittacosaurusto a higher degree of cornification and calcification of its integument (both skin and bristles). Although the psittacosaur bristles are probably homologous with avian feathers in their origin from discrete cell populations, it is uncertain whether they developed from a follicle, one of the developmental hallmarks of true feathers. In particular, we note a striking resemblance between the psittacosaur bristles and the cornified spine on the head of the horned screamer,Anhima cornuta, an extant anseriform bird. Similar, albeit thinner keratinous filaments of extant birds are the ‘beard’ of the turkey,Meleagris gallopavo, and the crown of the Congo peafowl,Afropavo congensis. All of these structures of extant birds are distinct from true feathers, and because at least the turkey beard does not develop from follicles, detailed future studies of their development would be invaluable towards deepening our understanding of dinosaur filamentous integumentary structures.

Neopsilotrema n. g. (Digenea: Psilostomidae) and three new species from ducks (Anseriformes: Anatidae) in North America and Europe.

Neopsilotrema n. g. (Digenea: Psilostomidae) and three new species of psilostomid digeneans are described from birds in North America and Europe: Neopsilotrema lakotae n. sp. from Aythya americana (Eyton) in North Dakota, USA, Neopsilotrema affine n. sp. from Aythya affinis (Eyton) in Minnesota, USA and Neopsilotrema lisitsynae n. sp. from Anas crecca L. in Kherson Region, Ukraine. Neopsilotrema n. g. shares a bipartite seminal vesicle with only three genera within the Psilostomidae, Psilotornus Byrd & Prestwood, 1969, Psilostomum Looss, 1899 and Grysoma Byrd, Bogitsh & Maples, 1961. The new genus differs from Psilotornus in the presence of a muscular pharynx and a massive ventral sucker; the location of the cirrus-sac in relation to the ventral sucker and more posterior location of ovary; the nature of the vitellarium (i.e. comprising large, compact follicles with small vitelline cells vs weakly defined follicles with large vitelline cells); a proportionately shorter forebody; and in parasitisation in anseriform (vs passeriform) birds. Differences between the new genus and Psilostomum comprise the shape of the body, the relative size of the suckers, somewhat longer forebody and a more anterior location of the testes. Neopsilotrema n. g. differs from Grysoma in the relative size of the suckers, the degree of development of prostatic cells, the nature of the vitellarium and the size of the eggs in relation to body length. The European species Neopsilotrema lisitsynae n. sp. is distinguished from its congeners in having a longer, narrower and distinctly more elongate body with a longer post-testicular region and anterior limits of the vitelline fields posterior to ventral sucker. The two North American forms, Neopsilotrema lakotae n. sp. and Neopsilotrema affine n. sp., are cryptic species with largely overlapping metrical data; these are distinguished by comparing genetic data. The phylogenetic hypotheses for the Psilostomidae developed from sequence data analyses based on partial 28S rDNA support the erection of the new genus and the distinction of the three new species. Grysoma marilae (Price, 1942) agrees more closely with the generic diagnosis of Neopsilotrema, especially in relation to the size and shape of the body, the relative length of the forebody and post-testicular field, the structure of the vitellarium, the location of the reproductive organs and the sucker ratio. Consequently, it is here transferred to the new genus as Neopsilotrema marilae (Price, 1942) n. comb.

The unexpected survival of an ancient lineage of anseriform birds into the Neogene of Australia: the youngest record of Presbyornithidae.

Presbyornithids were the dominant birds in Palaeogene lacustrine assemblages, especially in the Northern Hemisphere, but are thought to have disappeared worldwide by the mid-Eocene. Now classified within Anseriformes (screamers, ducks, swans and geese), their relationships have long been obscured by their strange wader-like skeletal morphology. Reassessment of the late Oligocene South Australian material attributed to Wilaru tedfordi, long considered to be of a stone-curlew (Burhinidae, Charadriiformes), reveals that this taxon represents the first record of a presbyornithid in Australia. We also describe the larger Wilaru prideauxi sp. nov. from the early Miocene of South Australia, showing that presbyornithids survived in Australia at least until ca 22 Ma. Unlike on other continents, where presbyornithids were replaced by aquatic crown-group anatids (ducks, swans and geese), species of Wilaru lived alongside these waterfowl in Australia. The morphology of the tarsometatarsus of these species indicates that, contrary to other presbyornithids, they were predominantly terrestrial birds, which probably contributed to their long-term survival in Australia. The morphological similarity between species of Wilaru and the Eocene South American presbyornithid Telmabates antiquus supports our hypothesis of a Gondwanan radiation during the evolutionary history of the Presbyornithidae. Teviornis gobiensis from the Late Cretaceous of Mongolia is here also reassessed and confirmed as a presbyornithid. These findings underscore the temporal continuance of Australia’s vertebrates and provide a new context in which the phylogeny and evolutionary history of presbyornithids can be examined.

Checklist of tapeworms (Platyhelminthes, Cestoda) of vertebrates in Finland.

A checklist of tapeworms (Cestoda) of vertebrates (fishes, birds and mammals) in Finland is presented, based on published observations, specimens deposited in the collections of the Finnish Museum of Natural History (Helsinki) and the Zoological Museum of the University of Turku, and additional specimens identified by the present author. The checklist includes 170 tapeworm species from 151 host species, comprising 447 parasite species/host species combinations. Thirty of the tapeworm species and 96 of the parasite/host species combinations have not been previously reported from Finland. The total number of tapeworm species in Finland (170 spp.) is significantly lower than the corresponding figure for the Iberian Peninsula (257 spp.), Slovakia (225 spp.) and Poland (279 spp.). The difference between Finland and the other three regions is particularly pronounced for anseriform, podicipediform, charadriiform and passeriform birds, reflecting inadequate and/or biased sampling of these birds in Finland. It is predicted that there are actually ca. 270 species of tapeworms in Finland, assuming that true number of bird tapeworms in Finland corresponds to that in other European countries with more comprehensive knowledge of the local tapeworm fauna. The other main pattern emerging from the present data is the seemingly unexplained absence in (northern) Fennoscandia of several mammalian tapeworms that otherwise have extensive distributions in the Holarctic region or in Eurasia, including the northern regions. Previously unknown type specimens, that is, the holotype of Bothrimonus nylandicus Schneider, 1902 (a junior synonym of Diplocotyle olrikii Krabbe, 1874) (MZH 127096) and the syntypes of Caryophyllaeides fennica (Schneider, 1902) (MZH 127097) were located in the collections of the Finnish Museum of Natural History.

Genetic diversity and host specificity varies across three genera of blood parasites in ducks of the Pacific Americas Flyway.

Birds of the order Anseriformes, commonly referred to as waterfowl, are frequently infected by Haemosporidia of the genera Haemoproteus, Plasmodium, and Leucocytozoon via dipteran vectors. We analyzed nucleotide sequences of the Cytochrome b (Cytb) gene from parasites of these genera detected in six species of ducks from Alaska and California, USA to characterize the genetic diversity of Haemosporidia infecting waterfowl at two ends of the Pacific Americas Flyway. In addition, parasite Cytb sequences were compared to those available on a public database to investigate specificity of genetic lineages to hosts of the order Anseriformes. Haplotype and nucleotide diversity of Haemoproteus Cytb sequences was lower than was detected for Plasmodium and Leucocytozoon parasites. Although waterfowl are presumed to be infected by only a single species of Leucocytozoon, L. simondi, diversity indices were highest for haplotypes from this genus and sequences formed five distinct clades separated by genetic distances of 4.9%–7.6%, suggesting potential cryptic speciation. All Haemoproteus and Leucocytozoon haplotypes derived from waterfowl samples formed monophyletic clades in phylogenetic analyses and were unique to the order Anseriformes with few exceptions. In contrast, waterfowl-origin Plasmodium haplotypes were identical or closely related to lineages found in other avian orders. Our results suggest a more generalist strategy for Plasmodium parasites infecting North American waterfowl as compared to those of the genera Haemoproteus and Leucocytozoon.

The complete mitochondrial genome of Aix galericulata and Tadorna ferruginea: bearings on their phylogenetic position in the Anseriformes.

Aix galericulata and Tadorna ferruginea are two Anatidae species representing different taxonomic groups of Anseriformes. We used a PCR-based method to determine the complete mtDNAs of both species, and estimated phylogenetic trees based on the complete mtDNA alignment of these and 14 other Anseriforme species, to clarify Anseriform phylogenetics. Phylogenetic trees were also estimated using a multiple sequence alignment of three mitochondrial genes (Cyt b, ND2, and COI) from 68 typical species in GenBank, to further clarify the phylogenetic relationships of several groups among the Anseriformes. The new mtDNAs are circular molecules, 16,651 bp (Aix galericulata) and 16,639 bp (Tadorna ferruginea) in length, containing the 37 typical genes, with an identical gene order and arrangement as those of other Anseriformes. Comparing the protein-coding genes among the mtDNAs of 16 Anseriforme species, ATG is generally the start codon, TAA is the most frequent stop codon, one of three, TAA, TAG, and T-, commonly observed. All tRNAs could be folded into canonical cloverleaf secondary structures except for tRNASer (AGY) and tRNALeu (CUN), which are missing the "DHU" arm.Phylogenetic relationships demonstrate that Aix galericula and Tadorna ferruginea are in the same group, the Tadorninae lineage, based on our analyses of complete mtDNAs and combined gene data. Molecular phylogenetic analysis suggests the 68 species of Anseriform birds be divided into three families: Anhimidae, Anatidae, and Anseranatidae. The results suggest Anatidae birds be divided into five subfamilies: Anatinae, Tadorninae, Anserinae, Oxyurinae, and Dendrocygninae. Oxyurinae and Dendrocygninae should not belong to Anserinae, but rather represent independent subfamilies. The Anatinae includes species from the tribes Mergini, Somaterini, Anatini, and Aythyini. The Anserinae includes species from the tribes Anserini and Cygnini.

Cloning, Expression and Bioactivity of Wild Ruddy Shelduck (Tadorna ferruginea) Interleukin-2

Interleukin-2 (IL-2) is one of the most actively studied interleukins. It is a powerful growth factor for a variety of cell types, plays a central role in the cell differentiation and stimulates the activity of many kinds of killer cells. However, little information is available on the IL-2 genes in migratory waterfowl, ecologically important species potentially involved in virus transmission. In this study, the cDNA of wild ruddy shelduck IL-2 was cloned by RT-PCR from peripheral blood lymphocytes stimulated with Concanavalin A (ConA), and the recombinant ruddy shelduck IL-2 (rRSIL-2) mature protein was expressed in Escherichia coli. In vitro bioactivity of rRSIL-2 was demonstrated in a lymphocyte proliferation assay. The results showed that RSIL-2 cDNA contained an open reading frame (ORF) of 423 bp encoding a protein of 140 amino acids (aa) with a putative signal peptide of 21 aa. Phylogenetic analysis based on nucleotide sequences showed that RSIL-2 was most closely related to IL-2s of the muscovy duck and mallard (homology of 97.4% and 96.2%), and to a lesser extent to spot-billed duck and swan goose sequences (homology of 95.8% and 93.6%). The RSIL-2 showed genetic diversity compared with other birds of anseriformes. Fusion protein expressed in E. coli had the molecular weight of around 31.7 kDa, as shown by SDS-PAGE and western blotting. The rRSIL-2 affected the duck, chicken, and goose lymphocyte proliferation in the same concentration, although the effect on goose and chicken lymphocytes was relatively weak. Our study reported the molecular signatures and bioactivity of IL-2 in a migratory waterfowl species.

On the true affinities of Chenornis graculoides Portis, 1884, and Anas lignitifila Portis, 1884—an albatross and an unusual duck from the Miocene of Italy

ABSTRACTWe revise two avian fossils from the Miocene of Italy, which were described as anseriform birds by Alessandro Portis in 1884. One of these, the holotype of Chenornis graculoides, from the early Miocene of Ceva (Piemonte, northwestern Italy), is found to be a stem group representative of Diomedeidae (albatrosses), and is here classified as Plotornis graculoides, comb. nov. The fossil allows the recognition of previously unknown osteological details of Plotornis and is the first record of an albatross from the Mediterranean Sea. The second specimen, from the late Miocene of Montebamboli (Toscana, central Italy), was described as Anas lignitifila and is here recognized as a highly unusual anseriform that is transferred to the new taxon Bambolinetta. The species belongs to Anatinae but is outside a clade including Anatini, Mergini, and Aythyini. It is distinguished from all extant Anseriformes by unusually robust wing bones, and the ulna and radius appear to have been very short. The Montebamboli site was part of the Tusco-Sardinian Island in the late Miocene, and we consider it likely that Bambolinetta lignitifila was an insular species with reduced flight capabilities, possibly specialized for wing-propelled diving.

Calamicoptes anatidus sp. nov., a new quill wall mite (Acari: Laminosioptidae) from the Greater Scaup Aythya marila (L.) (Aves: Anseriformes).

Calamicoptes anatidus sp. nov., a new species of rarely found parasitic mites of the family Laminosioptidae (Acari: Astigmata) is described from quill walls of wing covert feathers of Aythya marila Linnaeus (Anseriformes: Anatidae) captured in Poland. This is the first record of the family Laminosioptidae on birds of the order Anseriformes and the first record of this mite family in the fauna of Poland. Females of the new species are most similar to those of C. arenariae Lombert, Gaud et Lukoschus, 1984 and differ from them by the presence of the pygidial shield, which covers dorsal and ventro-lateral parts of the opisthosoma, and by having setae c2 and d2 short and subequal in length, and setae se and cp not reaching the metapodonotal shield.

Two avian schistosome cercariae from Nepal, including a Macrobilharzia-like species from Indoplanorbis exustus

As part of a global survey of schistosomes, a total of 16,109 freshwater snails representing 14 species were collected from lakes, ponds, rivers, rice fields and swamps mostly in the Terai region of southern Nepal. Only two snails were found to harbor avian schistosome cercariae even though Nepal is well known for its rich avian diversity. One schistosome infection was from an individual of Radix luteola and on the basis of phylogenetic analyses using 28S rDNA and cox1 sequences, grouped as a distinctive and previously unknown lineage within Trichobilharzia. This genus is the most speciose within the family Schistosomatidae. It includes 40 described species worldwide, and its members mostly infect anseriform birds (ducks) and two families of freshwater snails (Lymnaeidae and Physidae). The second schistosome cercaria was recovered from an individual of Indoplanorbis exustus that was also actively emerging a Petasiger-like echinostome cercaria. Although I. exustus is commonly infected with mammalian schistosomes of the Schistosoma indicum species group on the Indian subcontinent, this is the first specifically documented avian schistosome reported in this snail. Both cercariae reported here are among the largest of all schistosome cercariae recovered to date. The I. exustus-derived schistosome clustered most closely with Macrobilharzia macrobilharzia, although it seems to represent a distinct lineage. Specimens of Macrobilharzia have thus far not been recovered from snails, being known only as adult worms from anhingas and cormorants. This study is the first to characterize by sequence data avian schistosomes recovered from Asian freshwater habitats. This approach can help unravel the complex of cryptic species causing cercarial dermatitis here and elsewhere in the world.

Phthiraptera and Acari Collected from 13 Species of Waterfowl from Alabama and Georgia

Waterfowl, including ducks, geese, rails and others, are host to a great di- versity of ectosymbiotic arthropods. In this study, we collected ectosymbionts from waterfowl and analyzed taxon richness and total abundance to determine whether there were differences in the mite and louse assemblages of waterfowl of different species, genera, sexes, and feeding behaviors. Data were collected from 53 individual birds from 13 waterfowl species and 5 waterfowl genera taken from Georgia and Ala- bama. A total of 11 louse species and 7 feather and nasal mite species were collected from the waterfowl samples. Fulica americana (American Coot) harbored the high- est louse abundance and taxon richness but had the lowest abundance of mites. Most significant results were driven by the Fulica assemblage. Significant sex differences were detected only between male and female anseriform birds, in which female hosts demonstrated higher mean numbers of ischnoceran lice than male hosts. No significant differences in mite abundance between waterfowl sex or genera were observed, but more mite taxa were found on diving waterfowl than on dabbling species. These data will help to provide a foundation for future research on the ecology of waterfowl ecto- symbionts in the southeastern United States.

The Complete Mitochondrial Genome of Bean Goose (Anser fabalis) and Implications for Anseriformes Taxonomy

Mitochondrial DNA plays an important role in living organisms, and has been used as a powerful molecular marker in a variety of evolutionary studies. In this study, we determined the complete mtDNA of Bean goose (Anser fabalis), which is 16,688 bp long and contains 13 protein-coding genes, 2 rRNAs, 22 tRNAs and a control region. The arrangement is similar to that of typical Anseriform species. All protein-coding genes, except for Cyt b, ND5, COI, and COII, start with an ATG codon. The ATG start codon is also generally observed in the 12 other Anseriform species, including 2 Anser species, with sequenced mitochondrial genomes. TAA is the most frequent stop codon, one of three–TAA, TAG, and T- –commonly observed in Anseriformes. All tRNAs could be folded into canonical cloverleaf secondary structures except for tRNASer(AGY) and tRNALeu(CUN), which are missing the dihydrouridine (DHU) arm. The control region of Bean goose mtDNA, with some conserved sequence boxes, such as F, E, D, and C, identified in its central domain. Phylogenetic analysis of complete mtDNA data for 13 Anseriform species supports the classification of them into four major branches: Anatinae, Anserinae, Dendrocygninae and Anseranatidae. Phylogenetic analyses were also conducted on 36 Anseriform birds using combined Cyt b, ND2, and COI sequences. The results clearly support the genus Somateria as an independent lineage classified in its own tribe, the Somaterini. Recovered topologies from both complete mtDNA and combined DNA sequences strongly indicate that Dendrocygninae is an independent subfamily within the family Anatidae and Anseranatidae represents an independent family. Based on the results of this study, we conclude that combining ND2, Cyt b, and COI sequence data is a workable solution at present for resolving phylogenetic relationships among Anseriform species in the absence of sufficient complete mtDNA data.

Hepatitis and splenitis due to systemic tetratrichomoniasis in an American white pelican (Pelecanus erythrorhynchos)

A free-ranging, young adult, female American white pelican (Pelecanus erythrorhynchos), found dead on the grounds of the San Diego Zoo Safari Park in Southern California, had severe multifocal to coalescing necrotizing hepatitis and splenitis on postmortem examination. Histologically, within the large areas of necrosis were myriad pleomorphic, 5-20 µm in diameter, protozoal organisms with 1 to multiple nuclei. Ultrastructurally, the organisms were consistent with a trichomonad flagellate. Polymerase chain reaction and sequencing of the small subunit ribosomal RNA gene identified nucleotide sequences with 99% identity to Tetratrichomonas gallinarum, which is a common inhabitant of the intestinal tract of galliform and anseriform birds that has occasionally been associated with disease, including typhlitis and hepatitis. Damage to the cecal mucosa in the pelican from trematodes and secondary bacterial infection could have allowed invasion and systemic dissemination of the organism. Exposure of the pelican to a variety of native and exotic anseriform and galliform birds at the zoological institution could have led to cross-species infection and severe manifestation of disease in a novel host.