Blood parasites of birds on the White Sea-Baltic migration route. 4. The ecological aspect

The effect of some ecological factors on the infection of birds with blood Protozoa was studied. Most favourable conditions for circulation of Haemoproteidae on the Kurish Spit were recorded in July. The possibility of the infection of young small passerine birds from the first broods with Haemoproteidae is most high first of all at the expense of their longer stay in the nesting territory in the period of the active transport of parasites. The presence of Leucocytozoidae in Kurish populations is explained mainly by the distribution of birds. The registration of Leucocytozoidae from birds on the Kurish Spit in spring and autumn is the result of the flight of extensively infected northern populations. It is noted that a constant change in the populational composition of the ornithofauna during seasonal migrations should be taken into account when studying the parasites of wild birds. Otherwise the characteristic features of the circulation of parasites in the region in question can be distorted as a result of the overlap of data on the infection of birds of different populations. The dependence of the infection on sex and size of birds--hosts and the role of the nesting period in the distribution of some Haemosporidia are analysed.     

Local adaptation to winter conditions in a passerine spreading north: a common-garden approach

Sedentary passerine birds living in temperate and boreal regions need a high metabolic capacity for thermogenesis to survive winter conditions. As a consequence of the increased thermogenic capacity, basal energetic demands rise at a time when resources and time to acquire them decrease. In a previous study, great tits (Parus major) from two localities in Fennoscandia with contrasting winter conditions differed in their metabolic response to ambient temperature. To investigate the physiological basis underlying interpopulation differences we performed a common-garden experiment to test whether these differences were genetically based. We found basal metabolic rate to be higher in birds originating from transferred eggs from the southern population compared to the ones from the northern population, contrary to the relationship among birds living in their region of origin. Despite previous evidence suggesting that gene flow prevents local adaptation at the northern range limits of a species expanding northward, we found that great tits differ in their reaction norm to winter conditions according to the population of origin.     

Latitudinal extent and natural history characteristics of birds in Nicaragua

This paper assesses the latitudinal extent of terrestrial breeding birds in Nicaragua. In particular, associations among latitudinal midpoint, body mass, and latitudinal extent are examined; significant differences between natural history characteristics (trophic guild, forest dependence, number of forest types) and latitudinal extent are identified; and a test is undertaken of Rapoport's rule for birds at the edge of their northern or southern range in Nicaragua. Birds in Nicaragua were classified into four categories based on latitudinal extent: birds generally restricted to Central America (20%); birds near the edge of their range within Nicaragua (34%); Neotropical birds (42%); and Pan‐American birds (4%). Latitudinal midpoint had a significant negative correlation with latitudinal extent over different taxonomic scales. Natural history characteristics of trophic guild, forest dependence and number of forest types can account for significant differences in species latitudinal extent. Carnivores had greater latitudinal extents than most other trophic guilds, non‐forest birds had greater latitudinal extents than birds that require patchy forest, and birds that occur in four or more forest types had greater latitudinal extents than birds restricted to one or two forest types. Contrary to Rapoport's rule, birds with a northern affinity or latitudinal midpoint north of Nicaragua had significantly smaller latitudinal extents than birds with a southern affinity or latitudinal midpoint south of Nicaragua. A comparison of natural history characteristics of birds with northern and southern affinities found no difference between trophic guild or forest dependence but a significant difference among the number of forest types used by forest birds. Birds with a southern affinity were restricted to fewer forest types than birds with a northern affinity.     

Natural and anthropogenic influences on the population structure of white‐tailed eagles in the Carpathian Basin and central Europe

European populations of the white‐tailed eagle Haliaeetus albicilla suffered a drastic decline during the 20th century. In many countries, only a few dozen breeding pairs survived or the species disappeared completely. By today, the populations have recovered, naturally or through restocking (e.g. in Scotland or the Czech Republic). In the Carpathian Basin, which is now a stronghold in southern Europe for the species in the southern part of the distribution range with more than 500 breeding pairs, only about 50 pairs survived the bottleneck. This region provides important wintering places for individuals arriving from different regions of Eurasia. In the present study, we investigated 249 DNA samples from several European countries, using 11 microsatellites and mitochondrial control region sequences (499 bp), to answer two main questions: 1) did the Carpathian Basin population recover through local population expansion or is there a significant gene flow from more distant populations as well? 2) Does the Czech population show signs in its genetic structure of the restocking with birds of unknown origin? Our microsatellite data yielded three genetically separate lineages within Europe: northern, central and southern, the latter being present exclusively in the Carpathian Basin. Sequencing of mitochondrial DNA revealed that there is one haplotype (B12) which is not only exclusive to the Carpathian Basin but it is frequent in this population. Our results suggest that in accordance with the presumably philopatric behaviour of the species, recovery of the Carpathian Basin population was mainly local, but some of the wintering birds coming from the northern and central populations contributed to its genetic composition as well. We detected considerably higher proportions of northern birds within the Czech Republic compared to the neighbouring areas, making it likely that parents of the reintroduced birds came from northern populations.     

A Method for Investigating Population Declines of Migratory Birds Using Stable Isotopes: Origins of Harvested Lesser Scaup in North America

Background

Elucidating geographic locations from where migratory birds are recruited into adult breeding populations is a fundamental but largely elusive goal in conservation biology. This is especially true for species that breed in remote northern areas where field-based demographic assessments are logistically challenging.

Methodology/Findings

Here we used hydrogen isotopes (δD) to determine natal origins of migrating hatch-year lesser scaup (Aythya affinis) harvested by hunters in the United States from all North American flyways during the hunting seasons of 1999–2000 (n = 412) and 2000–2001 (n = 455). We combined geospatial, observational, and analytical data sources, including known scaup breeding range, δD values of feathers from juveniles at natal sites, models of δD for growing-season precipitation, and scaup band-recovery data to generate probabilistic natal origin landscapes for individual scaup. We then used Monte Carlo integration to model assignment uncertainty from among individual δD variance estimates from birds of known molt origin and also from band-return data summarized at the flyway level. We compared the distribution of scaup natal origin with the distribution of breeding population counts obtained from systematic long-term surveys.

Conclusions/Significance

Our analysis revealed that the proportion of young scaup produced in the northern (above 60°N) versus the southern boreal and Prairie-Parkland region was inversely related to the proportions of breeding adults using these regions, suggesting that despite having a higher relative abundance of breeding adults, the northern boreal region was less productive for scaup recruitment into the harvest than more southern biomes. Our approach for evaluating population declines of migratory birds (particularly game birds) synthesizes all available distributional data and exploits the advantages of intrinsic isotopic markers that link individuals to geography.     

Phylogeny and biogeography of ratite birds inferred from DNA sequences of the mitochondrial ribosomal genes

The origin of the flightless ratite birds of the southern continents has been debated for over a century. Whether dispersal or vicariance (continental breakup) best explains their origin depends largely on their phylogenetic relationships. No consensus has been reached on this issue despite many morphological and molecular studies. To address this question further we sequenced a 2.8-kb region of mitochondrial DNA containing the ribosomal genes in representative ratites and a tinamou. Phylogenetic analyses indicate that Struthio (Africa) is basal and Rhea (South America) clusters with living Australasian ratites. This phylogeny agrees with transferrin and DNA hybridization studies but not with sequence analyses of some protein-coding genes. These results also require reevaluation of the phylogenetic position of the extinct moas of New Zealand. We propose a new hypothesis for the origin of ratites that combines elements of dispersal and vicariance.      

The effects of long-term captivity on the metabolic parameters of a small Afrotropical bird

The few within-species studies on the effects of long-term captivity on avian physiological variables have small samples sizes and contradictory results. Nevertheless, many physiological studies make use of long-term captive birds, assuming the results will be applicable to wild populations. Here we investigated the effects of long-term captivity on a variety of physiological measurements in a relatively small (~12 g) southern African endemic bird, the Cape white-eye (Zosterops virens). Whole animal basal metabolic rate (BMR) and body mass (Mb) were influenced more by long-term captivity than by season, while mass-specific BMR, standard and basal whole animal and mass-specific evaporative water loss (EWL), and respiratory quotient (RQ), were all affected primarily by season, with long-term captivity having less of an effect. We therefore caution that whole animal BMR and Mb of long-term captive birds should not be used as representative of wild populations, and that the origin of study birds should be considered when comparing EWL and RQ of wild and long-term captive birds.     

Hyalomma ticks on northward migrating birds in southern Spain: Implications for the risk of entry of Crimean‐Congo haemorrhagic fever virus to Great Britain

Crimean‐Congo haemorrhagic fever virus (CCHFV) is a zoonotic virus transmitted by Hyalomma ticks, the immature stages of which may be carried by migratory birds. In this study, a total of 12 Hyalomma ticks were recovered from five of 228 migratory birds trapped in Spring, 2012 in southern Spain along the East Atlantic flyway. All collected ticks tested negative for CCHFV. While most birds had zero Hyalomma ticks, two individuals had four and five ticks each and the statistical distribution of Hyalomma tick counts per bird is over‐dispersed compared to the Poisson distribution, demonstrating the need for intensive sampling studies to avoid underestimating the total number of ticks. Rates of tick exchange on migratory birds during their northwards migration will affect the probability that a Hyalomma tick entering Great Britain is positive for CCHFV. Drawing on published data, evidence is presented that the latitude of a European country affects the probability of entry of Hyalomma ticks on wild birds. Further data on Hyalomma infestation rates and tick exchange rates are required along the East Atlantic flyway to further our understanding of the origin of Hyalomma ticks (i.e., Africa or southern Europe) and hence the probability of entry of CCHFV into GB.     

广西大明山鸟类群落组成、区系成分和垂直分布

为了了解鸟类组成和海拔分布状况,利用样线法和固定调查点法于2007~2015年对广西大明山的鸟类进行了研究。在大明山共记录鸟类337种,隶属于17目56科。繁殖鸟类(包括留鸟和夏候鸟)共计234种,占大明山鸟类种数的69.4%,具有明显优势,构成了大明山鸟类区系组成的主体。大明山具有典型的华南区向华中区过渡的鸟类区系特征,67.1%的繁殖鸟类属于东洋型的种类。随着海拔的增加,东洋型的种类逐渐减少。依据海拔梯度和植被的不同,可以将大明山鸟类分成6个类群,鸟类总种数和繁殖鸟类种数均以海拔500~900 m的范围内最多,海拔200~500 m范围内鸟类次之。由于大明山地处热带南缘,本研究将为今后监测气候变暖对鸟类的影响提供依据。     

Does the niche breadth or trade‐off hypothesis explain the abundance–occupancy relationship in avian Haemosporidia?

Two hypotheses have been proposed to explain the abundance–occupancy relationship (AOR) in parasites. The niche breadth hypothesis suggests that host generalists are more abundant and efficient at colonizing different host communities than specialists. The trade‐off hypothesis argues that host specialists achieve high density across their hosts' ranges, whereas generalists incur the high cost of adaptation to diverse immuno‐defence systems. We tested these hypotheses using 386 haemosporidian cytochrome‐b lineages (1894 sequences) recovered from 2318 birds of 103 species sampled in NW Africa, NW Iberia, W Greater Caucasus and Transcaucasia. The number of regions occupied by lineages was associated with their frequency suggesting the presence of AOR in avian Haemosporidia. However, neither hypothesis provided a better explanation for the AOR. Although the host generalist Plasmodium SGS1 was over three times more abundant than other widespread lineages, both host specialists and generalists were successful in colonizing all study regions and achieved high overall prevalence.     

The conservation value of paddock trees for birds in a variegated landscape in southern New South Wales. 2. Paddock trees as stepping stones

The use of paddock trees as stepping stones by birds was assessedin a grazing landscape in southern New South Wales, Australia. A totalof 70 paddock tree sites was surveyed for 20 min each inthe morning, and 36 sites were surveyed again in the afternoon in March2000. During the surveys, the presence, direction of arrival, anddirection of departure to and from sites was recorded for each bird. Astepping stone effect of paddock trees was examined in two ways: (1) byanalysing the arrival and departure direction of birds relative tosurrounding vegetation cover, and (2) by analysing the departuredirection of birds relative to their arrival direction. An arrivaldirection was obtained for 150 independently acting groups of birds, anda departure direction was obtained for 203 independently acting groupsof birds. Both arrival and departure direction were obtained for 87independently acting groups. Foliage-foraging birds tended to followrelatively densely vegetated areas. There was some indication thatgranivores and nectarivores also preferred to move along denselyvegetated areas. This trend was absent for open-country species. Allgroups of birds examined tended to return to their place of origin ormove in the opposite direction of their arrival. This trend was mostpronounced for nectarivores and the foliage-foraging White-plumedHoneyeater (Lichenostomus penicillatus), and lesspronounced for open-country species and parrots. The results arediscussed in relation to the biology and ecology of the various speciesof birds. We conclude that paddock trees have the potential to enhancelandscape connectivity by acting as stepping stones to assist movement.This further highlights their conservation value as demonstrated in thefirst paper of this series.     

A new breeding population of Mediterranean Gulls Larus melanocephalus in the species' main wintering area maintains independent spatial dynamics

We studied a newly established breeding population of the range‐expanding Mediterranean Gull Larus melanocephalus in eastern Spain, situated in close proximity to the species' main wintering area. By investigating the origin, population composition and wintering area of the new breeders, we found that recruitment from locally wintering birds was unlikely and that the emerging colonies were probably attracting birds from populations wintering 700–1200 km away in Portugal and southern Spain. Our findings reveal that expanding populations may follow their own dynamics, independently of other populations of the same species, and may consist of different individuals altogether.     

Climate change affects populations of northern birds in boreal protected areas

Human land-use effects on species populations are minimized in protected areas and population changes can thus be more directly linked with changes in climate. In this study, bird population changes in 96 protected areas in Finland were compared using quantitative bird census data, between two time slices, 1981-1999 and 2000-2009, with the mean time span being 14 years. Bird species were categorized by distribution pattern and migratory strategy. Our results showed that northern bird species had declined by 21 per cent and southern species increased by 29 per cent in boreal protected areas during the study period, alongside a clear rise (0.7-0.8 °C) in mean temperatures. Distribution pattern was the main factor, with migratory strategy interacting in explaining population changes in boreal birds. Migration strategy interacted with distribution pattern so that, among northern birds, densities of both migratory and resident species declined, whereas among southern birds they both increased. The observed decline of northern species and increase in southern species are in line with the predictions of range shifts of these species groups under a warming climate, and suggest that the population dynamics of birds are already changing in natural boreal habitats in association with changing climate.     

Repeat intercontinental dispersal and Pleistocene speciation in disjunct Mediterranean and desert Senecio (Asteraceae)

To explore the biogeographic history of Mediterranean/arid plant disjunctions, Old and New World Senecio sect. Senecio were analyzed phylogenetically using nuclear ribosomal DNA sequences (ITS). A clade corresponding to sect. Senecio was strongly supported. Area optimization indicated this clade to be of southern African origin. The Mediterranean and southern African floras were not distinguishable as sources of the main New World lineage, estimated to have become established during the middle Pliocene. Another previously suspected recent dispersal to the New World from the Mediterranean was confirmed for the recently recognized disjunction in S. mohavensis. The loss of suitable land connections by the Miocene means that both New World lineages must represent long-distance dispersal, providing the first evidence of repeat intercontinental dispersal in a Mediterranean group. In contrast, migration within Africa may have utilized an East African arid corridor. Recent dispersal to northern Africa is supported for S. flavus, which formed part of a distinct southern African lineage. Novel pappus modifications in both disjunct species may have enabled dispersal by birds. An estimated early Pliocene origin of sect. Senecio coincides with the appearance of summer-dry climate. However, diversification from 1.6 BP highlights the importance of Pleistocene climate fluctuations for speciation.     

Biogeography and history of the Mediterranean bird fauna

With 366 species of breeding birds, the Mediterranean region is a "hot spot" of species diversity. Many biogeographic realms contributed to the establishment of the extant fauna, which makes this region a crossroads for birds, but the two most important realms are the large forest blocks that extend today over Eurasia and the semi-arid belts of the southern and southwestern Palaearctic. The few groups that presumably differentiated within the Mediterranean basin are mostly birds of open habitats and shrublands (e.g. Sylvia spp.), whereas few species evolved in Mediterranean forests dominated by sclerophyllous evergreen tree species. We suggest this results from the history of vegetation belts and their associated faunas during the Pleistocene. On the whole, in contrast to other groups of vertebrates, the bird fauna is fairly homogeneously distributed all over the basin although there are some regional-specific trends in species assemblages, mostly on the basis of habitat selection and biogeographic origin. Many species of eastern and southeastern origin invaded the Mediterranean basin on the northern side of the sea up to the Balkan peninsula and the southern side to the Atlantic coast. The extant biogeographic patterns of the Mediterranean bird fauna are interpreted in the light of the Quaternary history shared by the biotas of the western Palaearctic in relation to the cycle of climatic changes which produced periodic huge spatiotemporal migrations of communities and populations. The severe human impact that started c. 8000-10,000 years ago resulted not so much in species extinctions as in dramatic changes in distributional patterns, complicating the reconstruction of biogeographic scenarios.     

Evolution of flightless land birds on southern continents: Transferrin comparison shows monophyletic origin of ratites

Summary A biochemical approach was used to study the evolution of ratite birds, i.e., the ostriches, rheas, cassowaries, emus, and kiwis. Quantitative immunological comparison of transferrin from ratites, tinamous, and other flying birds indicates that all the ratites and tinamous are allied phylogenetically and that they are of monophyletic origin relative to other birds. To explain the current geographic distribution of ratites and the magnitude of the transferrin distances, it is supposed that the ancestors of these flightless birds walked across land bridges between the southern continents during Cretaceous times.Supported in part by grants GB-42028X from NSF and GM-21509 from NIH to ACW and by grants HD-00122 from NIH and GA-12607 from NSF to REF The following abbreviation is used in this work MCF micro-complement fixation     

The genotyping of the West Nile virus in birds in the far eastern region of Russia in 2002-2004

Samples from 20 species of trapped and dead birds were collected in the Far Eastern Region in 2002-2004 and were analyzed by the anti-WNV MAb-modified immunoenzyme assay for antigen detection and RT-PCR for viral RNA detection. Five positive samples from cinereous vultures (Aegypius monachus) and two positive samples from cattle egret (Bubulcus ibis) were found in both tests. The sequencing of the 322 bp fragments of protein E gene showed 99-99.67% homology with the strain WNV/LEIV-VlgOO-27924 of the WNV isolated in Volgograd, Russia, 2000. Additionally, five positive samples from birds (Pica pica, Corvus macrorhynchos, Larus crossirostris, Parus minor, Emberiza spodocephala) collected in autumn 2004 were found during screening with anti-WNV MAb-modified ELISA. These results confirm that the WNV is circulating in the Far Eastern Region of Russia and outbreaks of WN fever in humans may be possible. This demonstrates that the genotype 1a of the West Nile virus could spread in the southern regions of the Far East by migrating birds and introduction of the WNV into other southern regions of the Asian part of Russia are probably.     

Significant genetic admixture after reintroduction of peregrine falcon (<Emphasis Type="Italic">Falco peregrinus</Emphasis>) in Southern Scandinavia

The peregrine falcon (Falco peregrinus) population in southern Scandinavia was almost extinct in the 1970’s. A successful reintroduction project was launched in 1974, using captive breeding birds of northern and southern Scandinavian, Finnish and Scottish origin. We examined the genetic structure in the pre-bottleneck population using eleven microsatellite markers and compared the data with the previously genotyped captive breeding population and contemporary wild population. Museum specimens between 53 and 130 years old were analyzed. Despite an apparent loss of historical genetic diversity, the contemporary population shows a relatively high level of genetic variation. Considerable gene introgression from captive breeding stock used to repopulate the former range of southern Scandinavian peregrines may have altered the genetic composition of this population. Both the historical and contemporary northern and southern Scandinavian populations are genetically differentiated. The reintroduction project implemented in the region and the use of non-native genetic stock likely prevented the southern Scandinavian population from extinction and thus helped maintain the level of genetic diversity and prevent inbreeding depression. The population is rapidly increasing in numbers and range and shows no indication of reduced fitness or adaptive capabilities in the wake of the severe bottleneck and the reintroduction.     

Second intermediate host land snails and definitive host animals of Brachylaima cribbi in southern Australia

This study of infection of southern Australian land snails with Brachylaima cribbi metacercariae has shown that all commonly encountered native and introduced snails are susceptible second intermediate hosts. The range of infected snails is extensive with metacercariae-infected snails being present in all districts across southern Australia. C. virgata has the highest average natural metacercarial infection intensity of 6.1 metacercariae per infected snail. The susceptibility of birds, mammals and reptiles to B. cribbi infection was studied in South Australia by capturing, dissecting and examining the intestinal tract contents of animals which commonly eat land snails as a food source. Indigenous Australian little ravens (Corvus mellori), which are a common scavenger bird, and two other passeriform birds, the black bird (Turdus merula) and the starling (Sturnus vulgaris), which are both introduced European birds, were found to have the highest infection rates of all animals examined. Other birds found infected with B. cribbi were an emu (Dromaius novaehollandiae), chickens (Gallus gallus) and a pigeon (Columba livia). Natural infections were also detected in field mice (Mus domesticus) and shingleback lizards (Tiliqua rugosa) although the intensity of infection was lower than that observed in birds. Susceptibility studies of laboratory mice, rats and ducks showed that mice developed patent infections which persisted for several weeks, rats developed a short-lived infection of three weeks' duration and ducks did not support infection. This study has shown for the first time that a brachylaimid can infect a wide host range of birds, mammals and reptiles in nature.     

Source areas of Blue-winged Teal harvested in Ontario and Prairie Canada based on stable isotopes: implications for sustainable management

Determining the source areas of harvested individuals is important for effective conservation and management of migratory game birds. Banding has provided much information about source areas, but obtaining samples of marked individuals representative of all potential breeding areas is difficult for most species. To add to previous knowledge of harvest derivation based on banding data and to assist with regulatory decisions, we used stable hydrogen isotope (δ²H) techniques to estimate natal and molt source areas of Blue-winged Teal (Spatula discors) harvested in southern Canada in 2014 and 2017. We found that most birds harvested in southern Saskatchewan, southern Manitoba, northern Ontario, and southern Ontario likely originated in the prairie and boreal plains regions of Canada and the United States, which is the core production area for the species. Based on feather δ²H values, some birds harvested in Ontario may have also originated in Ontario. Our results differ from those of a long-term analysis of band recovery data that revealed that most Blue-winged Teal harvested in Ontario originated in the eastern part of the province and areas along the lower Great Lakes and southwestern Quebec. We found that nearly all birds harvested in Ontario in our study likely originated from areas north and west of the province. Together, banding and stable isotopes likely provide the best information available on source areas of harvested birds for regulatory decision making.