DIFFERENCES IN THE CALLS OF EUROPEAN AND NORTH AMERICAN BLACK-BILLED MAGPIES AND THE YELLOW-BILLED MAGPIE

ABSTRACT

We compared several features of the chatter call of two races of black-billed magpies, the nominate, European race Pica pica pica and the North American race P.p. hudsonia and the yellow-billed magpie P. nuttalli. The chatter calls of the two North American species were much more similar to each other than either was to the European magpie. This information together with the recently determined similarities in the behaviour and social organisation of the two North American species, suggests that the phylogenetic affinities of these two species are closer than is implied by their taxonomic status.     

Synchronic east–west divergence in azure‐winged magpies (Cyanopica cyanus) and magpies (Pica pica)*

Morphometric and genetic analyses were performed to investigate the relationships between populations of the azure‐winged magpie (Cyanopica cyanus). In the morphometric analysis 193 specimens were included representing seven of the nine currently accepted subspecies. Among eight characters analysed, four showed significant differences between samples from Spain and Asia. In contrast, the Asian populations/subspecies are not differentiated morphologically except Cyanopica cyanus japonica. The genetic analysis was based on two mitochondrial sequences (control region, cytochromeb gene). The results are in accordance with the morphometric analysis, showing a clear distinction between birds from the western and eastern distribution ranges. The differentiation of C. c. japonica is not found at the sequence level. Both genetic and morphological data support species status of C. cyanus and Cyanopica cooki. The magpie (Pica pica) was included in the phylogenetic study for comparing intraspecific variation. As in C. cyanus, two clearly separated groups are found, one of them containing the far‐eastern populations (Pica pica jankowskii and Pica pica sericea) and the other the remaining subspecies studied. For both the azure‐winged magpie and the magpie the sequence data imply an east–west differentiation, probably caused by long lasting isolation that may have even started in the Pliocene or repeated expansions/restrictions of distribution ranges during the Pleistocene.     

Isolation, characterization and chromosome locations of polymorphic black-billed magpie Pica pica (Corvidae, AVES) microsatellite loci

One-hundred and two unique loci were isolated from a microsatellite-enriched black-billed magpie Pica pica genomic library. Sixteen of these new loci, along with 148 existing microsatellite passerine loci, were tested for polymorphism in four unrelated black-billed magpies. We identified a total of 43 unique polymorphic loci (10 and 33 respectively) that we characterized in 24 unrelated individuals from a population in Guadix, Spain. The putative chromosomal locations of loci polymorphic in black-billed magpie were assigned based on the location of their orthologues in the assembled zebra finch and chicken genomes.     

Coevolutionary interactions in a host–parasite system

Interactions between parasitic cuckoos and their hosts represent a classic example of coevolution, where adaptations in the parasite to exploit the host select for defences, which in turn select for new parasite adaptations. Current interactions between the two parties may be at an evolutionary equilibrium or, alternatively, a coevolutionary arms race may be taking place. By taking into account the effect of gene flow in 15 European magpie ( Pica pica ) populations, we studied the coevolutionary interactions with its brood parasite, the great spotted cuckoo ( Clamator glandarius ). Our results suggest that, in Europe, magpies and cuckoos are engaged in an ongoing coevolutionary process because, despite controlling for the large amounts of gene flow among different magpie populations, we still found a positive relationship between host defence (i.e. foreign egg recognition and rejection) and parasite selection pressure.     

Paraphyly of the Blue Tit (Parus caeruleus) suggested from cytochrome b sequences

The phylogenetic relationships of the Blue Tit-Azure Tit assemblage (genus Parus; Aves: Passeriformes) were studied using mitochondrial DNA sequences of 24 specimens representing seven subspecies from Eurasia and North Africa. Previous work based on comparative morphological and acoustic data suggested a division of the Blue Tit (Parus caeruleus) into two species. Our analyses clearly indicate that the Blue Tit represents a paraphyletic assemblage, including a European/Middle Asian clade that is the sister group to the Azure Tit (Parus cyanus) and a North African clade. The North African clade (teneriffae subspecies group) is a sister group to the European Blue Tit/Azure Tit clade. We suggest a division of the Blue Tit into two separate species, Eurasian Blue Tit (Parus caeruleus s. str.) and African Blue Tit (Parus teneriffae). However, our data give no support for assigning species rank to Parus cyanus flavipectus, a subspecies of the Azure Tit, as suggested by several authors on morphological grounds.     

Chloroplast phylogenomics of the New World grape species (Vitis,Vitaceae)

Vitis L. (the grape genus) is the economically most important fruit crop, as the source of grapes and wine. Phylogenetic relationships within the genus have been highly controversial. Herein, we employ sequence data from whole plastomes to attempt to enhance Vitis phylogenetic resolution. The results support the New World Vitis subgenus Vitis as monophyletic. Within the clade, V. californica is sister to the remaining New World Vitis subgenus Vitis. Furthermore, within subgenus Vitis, a Eurasian clade is robustly supported and is sister to the New World clade. The clade of Vitis vinifera ssp. vinifera and V. vinifera ssp. sylvestris is sister to the core Asian clade of Vitis. Several widespread species in North America are found to be non‐monophyletic in the plastome tree, for example, the broadly defined Vitis cinerea and V. aestivalis each needs to be split into several species. The non‐monophyly of some species may also be due to common occurrences of hybridizations in North American Vitis. The classification of North American Vitis by Munson into nine series is discussed based on the phylogenetic results. Analyses of divergence times and lineage diversification support a rapid radiation of Vitis in North America beginning in the Neogene.     

Phylogeny of Cercis based on DNA sequences of nuclear ITS and four plastid regions: implications for transatlantic historical biogeography

The disjunct genus Cercis has been used to test models of Northern Hemisphere historical biogeography. Previous phylogenetic estimates employing DNA sequences of the ITS region and (in one study) those of ndhF recovered a well supported clade of North American and western Eurasian species that was nested within a paraphyletic group of Chinese species. Resolution and clade support within the tree were otherwise low and the monophyly of Cercis canadensis was uncertain. Here we conduct a phylogenetic analysis of Cercis with a higher number of regions (ITS, ndhF, rpoB-trnC, trnT-trnD, and trnS-trnG) and samples than in previous studies. Results corroborate the initial divergence between the Chinese species Cercis chingii and the rest of the genus. Support is newly found both for a clade of the two North American species as sister to the western Eurasian species, and for the monophyly of C. canadensis. As in a previous study, divergence between North American and western Eurasian Cercis was estimated as mid-Miocene (ca. 13 million years ago), and the ancestor in which this divergence occurred was inferred to be xerophytic. Contrary to previous studies, however, our data infer strictly east-to-west vicariance. The timing of the transatlantic divergence in Cercis is too recent to be explained by a postulated continuous belt of semi-arid vegetation between North America and Europe in the Paleogene, suggesting instead the presence of a Miocene North Atlantic corridor for semi-arid plants. In the absence of strong evidence from other sources, the possibility that Cercis has been able to quickly adapt from mesophytic antecedents to semi-arid conditions whenever the latter have arisen in the Northern Hemisphere can be considered a plausible alternative, although parsimony optimization renders this scenario two steps longer.     

The effect of food supplementation on the reproductive success of Black-billed Magpies Pica pica

The effect of supplementary food on the reproductive success of Black-billed Magpies Pica pica was studied in an urban habitat in the city of Edmonton, Alberta, Canada. We provided supplementary food (pelleted dog food) regularly from August 1986 to June 1988 in a feeder situated outside all known magpie territories. Magpies using the supplementary food showed (i) an advancement of 7 days in the initiation of laying, (ii) no increase in clutch-size, (iii) higher survival of nest contents (eggs and young) during a spring snow storm, (iv) an increase in rate of nestling weight gain, and (v) an increase in fledging success. Supplementary food did not prompt the fed pairs to select nest sites nearer the feeder in 1988 than in 1987. The feeder did not affect the breeding density because the nearest neighbour distances of fed magpies did not differ from unfed magpies in either year, nor did they differ between the two years for either fed or unfed magpies. This study provided evidence that magpies frequently renest even if their initial nests fail after the eggs hatch—a practice that has been reported to be absent or rare in other studies. Although brood reduction was equally frequent in the nests of food-supplemented and control pairs, the actual number of nestlings disappearing from the former (1.56 per nest) was significantly smaller than that from the latter (2.60 per nest), suggesting that the availability of food plays a major role in magpie reproductive success.     

Complete taxon sampling of the avian genus Pica (magpies) reveals ancient relictual populations and synchronous Late‐Pleistocene demographic expansion across the Northern Hemisphere

Previous studies have suggested that bird populations in east Asia were less affected by Pleistocene climatic fluctuations than those in Europe and North America. However, this is mainly based on comparisons among species. It would be more relevant to analyse geographical populations of widespread species or species complexes. We analyzed two mitochondrial genes and two nuclear introns for all taxa of Pica to investigate 1) which Earth history factors have shaped the lineage divergence, and 2) whether different geographical populations were differently affected by the Pleistocene climatic changes. Our mitochondrial tree recovered three widespread lineages, 1) in east Asia, 2) across north Eurasia, and 3) in North America, respectively, with three isolated lineages in northwest Africa, Arabia and the Qinghai‐Tibet Plateau, respectively. Divergences among lineages took place 1.4–3.1 million yr ago. The northwest African population was sister to the others, which formed two main clades. In one of these, Arabia was sister to Qinghai‐Tibet, and these formed the sister clade to the east Asia clade. The other main clade comprised the North American and north Eurasian clades. There was no or very slight structure within these six geographical clades, including a lack of differentiation between the two North American species black‐billed magpie P. hudsonia and yellow‐billed magpie P. nutalli. Demographic expansion was recorded in the three most widespread lineages after 0.06 Ma. Asymmetric gene flow was recorded in the north Eurasian clade from southwestern Europe eastward, whereas the east Asian clade was rooted in south central China. Our results indicate that the fragmentation of the six clades of Pica was related to climatic cooling and aridification during periods of the Pliocene–Pleistocene. Populations on both sides of the Eurasian continent were similarly influenced by the Pleistocene climate changes and expanded concomitantly with the expansion of steppes. Based on results we also propose a revised taxonomy recognising seven species of Pica.     

Distribution of sleep and wakefulness in 24-h light-dark cycles in the juvenile and adult magpie, Pica pica

The daily organization of sleep and wakefulness was examined electrographically under natural conditions in captive juvenile and adult magpies, Pica pica. Electrographic indices of sleep in the magpie were found to be similar to those of other avian species. The daily amount of TS in juveniles was 17% greater than in adults. The amount of paradoxical sleep (PS) in adults was one-fifth that of juveniles. In adults sleep was confined to darkness, while in juveniles it also occurred during the light period. SWS in adults was almost constant, while PS slightly increased across the night. No systematic trends were observed in juveniles. In both groups of birds, the longest sleep episodes appeared around midnight.     

Evolution of tolerance by magpies to brood parasitism by great spotted cuckoos

Hosts may use two different strategies to ameliorate negative effects of a given parasite burden: resistance or tolerance. Although both resistance and tolerance of parasitism should evolve as a consequence of selection pressures owing to parasitism, the study of evolutionary patterns of tolerance has traditionally been neglected by animal biologists. Here, we explore geographical covariation between tolerance of magpies (Pica pica) and brood parasitism by the great spotted cuckoo (Clamator glandarius) in nine different sympatric populations. We estimated tolerance as the slope of the regression of number of magpie fledglings (i.e. host fitness) on number of cuckoo eggs laid in non-depredated nests (which broadly equals parasite burden). We also estimated prevalence of parasitism and level of host resistance (i.e. rejection rates of mimetic model eggs) in these nine populations. In accordance with the hypothetical role of tolerance in the coevolutionary process between magpies and cuckoos we found geographical variation in tolerance estimates that positively covaried with prevalence of parasitism. Levels of resistance and tolerance were not associated, possibly suggesting the lack of a trade-off between the two kinds of defences against great spotted cuckoo parasitism for magpies. We discuss the results in the framework of a mosaic of coevolutionary interactions along the geographical distribution of magpies and great spotted cuckoos for which we found evidence that tolerance plays a major role.     

Phylogenetic relationships and biogeographic patterns in North American members of Carex section Acrocystis (Cyperaceae) using nrDNA ITS and ETS sequence data

Carex section Acrocystis currently includes 27 taxa in North America. Recent phylogenetic studies have suggested that the North American and some but not all of the Eurasian species form a clade. Relationships and biogeographic patterns among species in this core-Acrocystis group are explored here using nuclear ribosomal (nrDNA) internal transcribed spacer region (ITS) and nrDNA external transcribed spacer region (ETS) sequence data. While maximum parsimony analysis of the ITS and ETS data provides only a moderately resolved branching structure for species relationships within the core-Acrocystis clade, maximum likelihood analysis provides a more resolved hypothesis of relationships in the section. The core-Acrocystis clade consists of a grade of Eurasian and primarily western North American species, with a well-supported clade of only eastern North American species nested within this grade. ITS and ETS types do not coalesce within many species or species complexes. Possible explanations for the non-coalescent nature of ITS and ETS copies in Acrocystis are explored, including lineage sorting, hybridization, and cryptic species.     

Reassortant H9N2 influenza viruses containing H5N1-like PB1 genes isolated from black-billed magpies in Southern China

H9N2 influenza A viruses have become endemic in different types of terrestrial poultry and wild birds in Asia, and are occasionally transmitted to humans and pigs. To evaluate the role of black-billed magpies (Pica pica) in the evolution of influenza A virus, we conducted two epidemic surveys on avian influenza viruses in wild black-billed magpies in Guangxi, China in 2005 and characterized three isolated black-billed magpie H9N2 viruses (BbM viruses). Phylogenetic analysis indicated that three BbM viruses were almost identical with 99.7 to 100% nucleotide homology in their whole genomes, and were reassortants containing BJ94-like (Ck/BJ/1/94) HA, NA, M, and NS genes, SH/F/98-like (Ck/SH/F/98) PB2, PA, and NP genes, and H5N1-like (Ck/YN/1252/03, clade 1) PB1 genes. Genetic analysis showed that BbM viruses were most likely the result of multiple reassortments between co-circulating H9N2-like and H5N1-like viruses, and were genetically different from other H9N2 viruses because of the existence of H5N1-like PB1 genes. Genotypical analysis revealed that BbM viruses evolved from diverse sources and belonged to a novel genotype (B46) discovered in our recent study. Molecular analysis suggested that BbM viruses were likely low pathogenic reassortants. However, results of our pathogenicity study demonstrated that BbM viruses replicated efficiently in chickens and a mammalian mouse model but were not lethal for infected chickens and mice. Antigenic analysis showed that BbM viruses were antigenic heterologous with the H9N2 vaccine strain. Our study is probably the first report to document and characterize H9N2 influenza viruses isolated from black-billed magpies in southern China. Our results suggest that black-billed magpies were susceptible to H9N2 influenza viruses, which raise concerns over possible transmissions of reassortant H9N2 viruses among poultry and wild birds.     

A systematic study of North American Angelica species (Apiaceae) based on nrDNA ITS and cpDNA sequences and fruit morphology

Angelica is a taxonomically complex genus widespread throughout the North Temperate Zone. Previous phylogenetic studies of the genus have focused primarily on its East Asian species. The relationships among its North American members, the monophyly of these species, and the value of fruit morphology in circumscribing its taxa have yet to be examined. This study represents the most comprehensive sampling of Angelica to date (100 species) and includes all 26 species in North America. Relationships are inferred using Bayesian inference, maximum likelihood, and maximum parsimony analyses of ITS sequences and, for multiple accessions of each North American species, cpDNA ndhF-rpl32, rpl32-trnL, and psbM-psbD sequences. The fruit morphological characters examined were those considered phylogenetically important in East Asian Angelica. The results revealed that the North American species fell into three major clades: North American Angelica clade, Archangelica clade, and the Eurasian Angelica clade. Angelica dawsonii has affinities with Lomatium brandegeei. Fourteen species within the North American Angelica clade were strongly supported as monophyletic. Two paraphyletic species resulted in new combinations in A. lineariloba and A. venenosa. Conflict between the ITS-derived and cpDNA-derived phylogenies and the lack of resolution in portions of the trees may be due to chloroplast capture and rapid species radiation. Fruit morphology supported some interspecific relationships based on molecular data, and relationships revealed by ITS and cpDNA data were roughly in accordance with fruit classification type and geographic distribution region, respectively. A diagnostic key based on fruit morphology is provided for the identification of the North American Angelica taxa.     

Inferences on the phylogeography of the fungal pathogen Heterobasidion annosum, including evidence of interspecific horizontal genetic transfer and of human-mediated, long-range dispersal

Fungi in the basidiomycete species complex Heterobasidion annosum are significant root-rot pathogens of conifers throughout the northern hemisphere. We utilize a multilocus phylogenetic approach to examine hypotheses regarding the evolution and divergence of two Heterobasidion taxa associated with pines: the Eurasian H. annosum sensu stricto and the North American H. annosum P intersterility group (ISG). Using DNA sequence information from portions of two nuclear and two mitochondrial loci, we infer phylogenetic relationships via parsimony, Bayesian and median-joining network analysis. Analysis of isolates representative of the entire known geographic range of the two taxa results in monophyletic sister Eurasian and North American lineages, with North America further subdivided into eastern and western clades. Genetically anomalous isolates from the Italian presidential estate of Castelporziano are always part of a North American clade and group with eastern North America, upholding the hypothesis of recent, anthropogenically mediated dispersal. P ISG isolates from Mexico have phylogenetic affinity with both eastern and western North America. Results for an insertion in the mitochondrial rDNA suggest this molecule was obtained from the Heterobasidion S ISG, a taxon sympatric with the P ISG in western North America. These data are compatible with an eastern Eurasian origin of the species, followed by dispersal of two sister taxa into western Eurasia and into eastern North America over a Beringean land bridge, a pattern echoed in the phylogeography of other conifer-associated basidiomycetes.     

Evolution of 4-coumarate:coenzyme A ligase (4CL) gene and divergence of Larix (Pinaceae)

The evolutionary dynamics of the 4CL gene encoding 4-coumarate:coenzyme A ligase was investigated in the genus Larix (Pinaceae) by comparing copy number, GC content and codon usage, sequence divergence, and phylogenetic analysis. All 4CL clones of Larix formed a strongly supported monophyletic group, in which two robust clades (4clA and 4clB) derived from an ancient gene duplication event in the common ancestor of Larix were identified. Further gene duplication in the 4clA clade gave rise to two subclades 4clA(1) and 4clA(2). Frequent duplication/deletion appears to be a common evolutionary phenomenon in the 4CL gene family and paralogous genes differ greatly in their evolution rate. The existence of L. speciosa in subclades 4clA(1) and 4clA(2) suggests that this species may represent a primitive form of Larix or the closest relative of the common ancestor of the Eurasian Sect. Multiserialis. In addition, cpDNA and nrDNA ITS analyses support the hypothesis of an early separation of Larix into a North American and a Eurasian clade, which is congruent with the results of previous allozyme and very recent AFLP analyses. The unexpected close relationship between North American larches and the short-bracted species L. gmelinii in East Asia, based on the 4CL gene tree, may stem from lineage sorting.     

Differences in intestinal microbiota between avian brood parasites and their hosts

The intestinal microbiota determines the effectiveness of digestion in vertebrates, and is influenced by the external environment (mainly the diet), gut characteristics, and phylogeny. Avian brood-parasitic nestlings of the sub-family Cuculinae develop in nests of phylogenetically distant passerines and can be fed with the host diet. If the shaping of bacterial communities is dominated by phylogenetic constraints, and therefore the microbiota of parasitic nestlings differs from that of host nestlings, the energy and micronutrients that parasites and hosts obtain from a similar amount of food would be different. In this case, the bacterial communities of parasitic and host nestlings would have important consequences with respect to brood parasite development. By experimentally creating mixed broods of magpies ( Pica pica ) and great spotted cuckoos ( Clamator glandarius ), we investigated their cloacal microbiota using ribosomal intergenic spacer analysis. We found significant differences in bacterial assemblages of the parasitic and host nestlings, although none of the phylotypes were specific in either great spotted cuckoos or magpies. Cuckoos presented more complex communities, which could help the brood parasitic life style and allow the digestion of food provided by different potential hosts. Moreover, the intestinal morphology is different between the two species due to phylogenetic differences in the two taxa, which would influence the dissimilar bacterial assemblages. The detected differences in microbiota of great spotted cuckoo and magpie nestlings, which might occur in other brood parasite–host systems, may imply a lower digestion efficiency in parasites. Thus, the higher level requirements of cuckoo nestlings may be explained, at least in part, by cuckoos having a suboptimal bacterial community for processing the host diet.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 96 , 406–414.     

Phylogenetic relationships of Pelobatoidea re-examined using mtDNA

Pelobatoidea is a clade of ancient anurans with obscure relationships to the remaining clades of frogs. We used partial sequences of two mitochondrial genes (cytochrome b and 16S RNA) from all Pelobatoidea subclades, including all species of Pelobatidae and Pelodytidae and four outgroup taxa (Xenopus, Ascaphus, Discoglossus, and Rana), to propose a phylogenetic hypothesis for relationships within Pelobatoidea. Maximum likelihood and Bayesian analyses support the monophyly of Pelobatoidea, but our hypothesis of internal relationships differs substantially from all previous hypotheses. Megophryidae is sister to Pelobates, and this clade is sister to Pelodytes. The most basal clade within Pelobatoidea is formed by Scaphiopus and Spea. The family Pelobatidae, as previously defined is not monophyletic, and it is split into Eurasian spadefoot toads Pelobates which retain the name Pelobatidae and North American spadefoot toads Scaphiopus and Spea which comprise the revived taxon Scaphiopodidae. Our analysis uncovers the existence of morphologically cryptic taxa within previously recognized species of the genus Spea and reveals marked genetic differentiation within Iberian Pelodytes. We discuss biogeographic implications and the evolution of fossoriality in the light of the new phylogenetic hypothesis.     

Effects of opportunistic predation on anti-predator behavioural responses in a guild of ground foragers

We studied factors that affect prey selection by a generalist predator that opportunistically attacks prey species, and the associated inter- and intra-specific responses of prey to this type of predation. Our model system was a guild of ground-foraging birds that are preyed upon by magpies (Pica pica) during the breeding season. We found that magpies attacked up to 12 species during three consecutive breeding seasons. The overall capture success was estimated to be 4.9%. Magpies tended to attack from the air, targeting solitary prey, either on the ground or flying. Inter-specific prey responses to the risk of magpie predation included a reduction in the mean number of species occupying a foraging patch when magpies were present and a decrease in the distance between heterospecific neighbours. Intra-specific responses to magpie predation varied between species that were subject to different attack rates. Preferentially attacked prey enhanced their risk responses (increase in scanning time and scanning rate in the presence of magpies) relative to those species attacked in proportion to their abundance (increase only in scanning rate with magpies). Species attacked infrequently, relative to their abundance, showed no antipredator response. The probability of being attacked, rather than mortality rate, appears to be the factor to which prey species respond.     

Phylogeography of the fungal pathogen Histoplasma capsulatum

Until recently, Histoplasma capsulatum was believed to harbour three varieties, var. capsulatum (chiefly a New World human pathogen), var. duboisii (an African human pathogen) and var. farciminosum (an Old World horse pathogen), which varied in clinical manifestations and geographical distribution. We analysed the phylogenetic relationships of 137 individuals representing the three varieties from six continents using DNA sequence variation in four independent protein‐coding genes. At least eight clades were idengified: (i) North American class 1 clade; (ii) North American class 2 clade; (iii) Latin American group A clade; (iv) Latin American group B clade; (v) Australian clade; (vi) Netherlands (Indonesian?) clade; (vii) Eurasian clade and (viii) African clade. Seven of eight clades represented genetically isolated groups that may be recognized as phylogenetic species. The sole exception was the Eurasian clade which originated from within the Latin American group A clade. The phylogenetic relationships among the clades made a star phylogeny. Histoplasma capsulatum var. capsulatum individuals were found in all eight clades. The African clade included all of the H. capsulatum var. duboisii individuals as well as individuals of the other two varieties. The 13 individuals of var. farciminosum were distributed among three phylogenetic species. These findings suggest that the three varieties of Histoplasma are phylogenetically meaningless. Instead we have to recognize the existence of genetically distinct geographical populations or phylogenetic species. Combining DNA substitution rates of protein‐coding genes with the phylogeny suggests that the radiation of Histoplasma started between 3 and 13 million years ago in Latin America.