Population structure of Purple Sandpipers (Calidris maritima) as revealed by mitochondrial DNA and microsatellites

The Purple Sandpiper (Calidris maritima) is a medium‐sized shorebird that breeds in the Arctic and winters along northern Atlantic coastlines. Migration routes and affiliations between breeding grounds and wintering grounds are incompletely understood. Some populations appear to be declining, and future management policies for this species will benefit from understanding their migration patterns. This study used two mitochondrial DNA markers and 10 microsatellite loci to analyze current population structure and historical demographic trends. Samples were obtained from breeding locations in Nunavut (Canada), Iceland, and Svalbard (Norway) and from wintering locations along the coast of Maine (USA), Nova Scotia, New Brunswick, and Newfoundland (Canada), and Scotland (UK). Mitochondrial haplotypes displayed low genetic diversity, and a shallow phylogeny indicating recent divergence. With the exception of the two Canadian breeding populations from Nunavut, there was significant genetic differentiation among samples from all breeding locations; however, none of the breeding populations was a monophyletic group. We also found differentiation between both Iceland and Svalbard breeding populations and North American wintering populations. This pattern of divergence is consistent with a previously proposed migratory pathway between Canadian breeding locations and wintering grounds in the United Kingdom, but argues against migration between breeding grounds in Iceland and Svalbard and wintering grounds in North America. Breeding birds from Svalbard also showed a genetic signature intermediate between Canadian breeders and Icelandic breeders. Our results extend current knowledge of Purple Sandpiper population genetic structure and present new information regarding migration routes to wintering grounds in North America.     

THE MIGRATION PATTERNS OF THE PURPLE SANDPIPER CALIDRIS MARITIMA

Summers, R. W. 1994. The migration patterns of the Purple Sandpiper Calidris maritima. Ostrich 65: 167–173.

The Purple Sandpiper breeds largely in the Arctic, and winters (boreal season) on the rocky shores of the north Atlantic, further north than any other sandpiper. As the populations from Canada, Greenland, Iceland, Svalbard, Norway and Russia differ in wing and bill lengths it is possible to match measurements taken from breeding birds with samples of birds caught in winter. Ringing recoveries, especially from colour marked birds, have also helped to determine migration routes and wintering areas. Four populations move to the nearest ice-free coast. Two populations move south of the nearest ice-free coast, being replaced by larger birds from a more northerly population (“chain migration”). Only the north Canadian population is believed to migrate a long distance, “leap-frogging” other winter populations. These patterns are discussed in relation to theories for the migration patterns of waders.     

Morphological differentiation of Icelandic Redpolls,Acanthis flammea islandica

Capsule The analyses support the grouping of the three Acanthis species, although a large split is observed between the A. hornemanni subspecies.

Aims To investigate the morphological variation in A. f. islandica among different periods of the year and its morphological differentiation from the other subspecies A. f. flammea and A. f. rostrata, and also from the redpoll species, A. cabaret and the two subspecies of A. hornemanni, exilipes and hornemanni.

Methods The subspecies status of the Icelandic population was evaluated with Amadon's rule, by comparing its variation of traits to the distribution of the traits in different species/subspecies of the group.

Results A. f. islandica is characterized by intermediate wing, bill and tail lengths. Based on the 75% rule, wing length and bill depth can be used to discriminate A. f. islandica from both extreme morphs of redpolls (currently classified as different species); A. hornemanni and A. cabaret, and tail and wing length can distinguish A. f. islandica from its conspecifics A. f. flammea. The overall morphological divergence within the redpoll complex is not supported by association to the studied nuclear markers.

Conclusion The taxonomic status of the three redpoll species is supported by Amadon's rule, however the subspecies status of the Icelandic Redpoll remains unclear.     

Morpho-anatomical differentiation of Suaeda maritima (L.) Dumort. 1827. (Chenopodiaceae) populations from inland and maritime saline area

Morphological analysis of four populations of Suaeda maritima was undertaken in order to examine the variation between populations from inland and maritime saline area, as well as between the two subspecies. Variability and significance of morpho-anatomical differentiation were examined using principal component analysis (PCA), discriminant component analysis (DCA) and cluster analysis. Plants of each population exhibited halomorphic and xeromorphic characteristics. The results of PCA and DCA showed that S. maritima subsp. prostrata and S. maritima subsp. maritima could be clearly separated based on their quantitative anatomical characteristics. Based on our analysis, climate and the amount of salt and ions in the soil, are important factors that enhance the adaptive potential of S. maritima.     

A rare case of Plasmodium (Haemamoeba) relictum infection in a free-living Red Knot (Calidris canutus rufa, Scolopacidae)

The Red Knot (Calidris canutus rufa) is a Nearctic migrant shorebird that breeds in the Canadian Arctic and spends the winter season in coastal sites in South America. A rare case of a blood protozoan was found by molecular analyses from an adult bird captured during spring migration at the last refuelling stopover in Delaware Bay USA in 2006. The parasite was identified as Plasmodium relictum belonging to subgenus Haemamoeba based on the shape of meronts, roundish gametocytes, and its position in the erythrocytes from the blood smears examination. A partial cytochrome b sequence was a 100% match to a sequence of Plasmodium relictum, sequence Genbank accession number: id DQ659543.1 (lineage code haplotype P5). This is the first report of avian malaria in a wild individual of C. c. rufa.     

Chromosome evolution in the genus Cicindela: physical mapping and activity of rDNA loci in the tiger beetle species Cicindela littoralis and C. flexuosa

Cicindela littoralis and Cicindela flexuosa were analysed at population level to determine the localization and activity of ribosomal genes. Fluorescence in situ hybridization (FISH), using a PCR‐amplified 18S rDNA fragment as a probe, revealed the presence of polymorphism regarding the number of chromosomes with ribosomal genes as well as their localization within the genome. Nine populations of C. littoralis showed a consistent pattern of two loci located in an autosomal pair (active during spermatogenesis as shown by silver staining) and one locus located in one of the multiple X chromosomes (silent during spermatogenesis), whereas individuals from the population of Punta Entinas showed only signals in the autosomal pair, lacking the heterosomal locus. In C. flexuosa, two patterns were also observed. Nine populations showed two loci in an autosomal pair whereas individuals from the population of San Pedro del Pinatar showed the two loci located in the heterosomes (one of the multiple Xs and in the Y). The hypothesis that these two different populations may reflect a status of well‐differentiated phylogenetic entities is not supported for C. littoralis after the phylogenetic analysis of a fragment of the cytochrome oxidase I gene.     

Migratory connectivity and temporal segregation of dunlin (Calidris alpina) in Portugal: evidence from morphology, ringing recoveries and mtDNA

Migratory connectivity plays an important role in conservation of long-distance migrant birds. Here, we study migratory links of dunlin (Calidris alpina), focusing on a stopover and wintering region (Portugal) where it is known that migration routes of dunlin from a broad geographic range (three subspecies) converge, and populations occur simultaneously or separated in time. We combine three methods (ringing recoveries, morphometrics and molecular genetics) to assess breeding origins and extent of temporal segregation of dunlin assemblages. Ringing recoveries show temporal separation of dunlin from different migration routes. Birds found in Portugal during August and September, migrating via Britain, reveal links to breeding areas in Iceland and Greenland. In October, a clear shift to more eastern migration routes occurs, with most Portuguese winter records from stopover sites along migration routes of populations from northern Scandinavia and Russia. Mitochondrial DNA (mtDNA) of Portuguese dunlin was compared with breeding populations. Spring and autumn migrants in Portugal corresponded to C. a. schinzii and C. a. arctica populations, while the Portuguese winter population clearly differs by including mtDNA haplotypes of C. a. alpina. For genetically sexed individuals, we found significant differences in morphology (bill and tarsus length) supporting the temporal separation of populations/subspecies revealed by recoveries and mtDNA. Our results give evidence for migratory connectivity of dunlin populations between geographic areas previously not considered connected. They confirm the existence of clear differences in breeding origin between birds in Portugal at different times of year. These results are important in the consideration of future long-term conservation plans.     

ALLOZYME VARIATION WITHIN AND BETWEEN LASTHENIA MINOR AND ITS DERIVATIVE SPECIES,L. MARITIMA (ASTERACEAE)

Enzyme electrophoresis was employed to examine genetic variation at 20 loci in 16 populations of Lasthenia minor and 18 populations of its presumed derivative species L. maritima. The purposes of the study were to ascertain levels of genetic variation in each species, to assess how the variation at enzyme-coding genes is apportioned within and among populations of each species, and to determine the level of divergence between the two species. The two species are both diploid annuals, similar morphologically, and produce fertile F₁ hybrids when crossed. Lasthenia minor is self-incompatible and restricted to mainland California, whereas L. maritima is self-compatible and probably largely autogamous; it occurs on seabird rocks from central California to British Columbia. Mean genetic identities for pair-wise comparisons of populations of the two species are similar to values for populations of the same species, indicating they have not diverged at the 20 genes coding for soluble enzymes. Despite its more extensive geographical range, L. maritima exhibits only 50% of the genetic diversity of L. minor. The latter species apportions a greater amount of its diversity within populations, whereas the former harbors more diversity among populations than within them. This is probably a reflection of the different breeding systems of the two species. Six unique alleles were detected in L. minor, whereas only one novel allele was found in a single individual of L. maritima. The electrophoretic data are concordant with the suggestion that L. maritima is relatively recently derived from L. minor. The switch from outcrossing to selfing and selection of genotypes adapted to the chemically and physically unusual substrate on the seabird rocks are considered the critical steps in the evolution of L. maritima.     

Weak population genetic differentiation in the most numerous Arctic seabird,the little auk

Quantifying patterns of genetic diversity and differentiation among populations of Arctic birds is fundamental for understanding past and ongoing population processes in the Arctic. However, the genetic differentiation of many important Arctic species remains uninvestigated. Here, phylogeography and population genetics were examined in the worldwide population of a small seabird, the little auk (dovekie, Alle alle)—the most numerous avian species of the Arctic ecosystem. Blood samples or feathers were collected from 328 little auks (325 from the nominate subspecies and 3 from the A. a. polaris) in nine main breeding aggregations in the northern Atlantic and one location from the Pacific Ocean. The mtDNA haplotypes of the two subspecies were not segregated into separate groups. Also, no genetic structure was found within the nominate race based on microsatellite markers. The level of genetic differentiation among populations was low yet significant (mean F _ST = 0.005). Some pairwise F _ST comparisons revealed significant differences, including those involving the most distant Pacific colony as well as among some Atlantic populations. Weak population differentiation following the model of isolation by distance in the little auk is similar to the patterns reported in other high-Arctic bird species, indicating that a lack of distinct genetic structure is a common phenomenon in the Arctic avifauna.     

Contrasting physiological responses to future ocean acidification among Arctic copepod populations

Widespread ocean acidification (OA) is modifying the chemistry of the global ocean, and the Arctic is recognized as the region where the changes will progress at the fastest rate. Moreover, Arctic species show lower capacity for cellular homeostasis and acid‐base regulation rendering them particularly vulnerable to OA. In the present study, we found physiological differences in OA response across geographically separated populations of the keystone Arctic copepod Calanus glacialis. In copepodites stage CIV, measured reaction norms of ingestion rate and metabolic rate showed severe reductions in ingestion and increased metabolic expenses in two populations from Svalbard (Kongsfjord and Billefjord) whereas no effects were observed in a population from the Disko Bay, West Greenland. At pH_T 7.87, which has been predicted for the Svalbard west coast by year 2100, these changes resulted in reductions in scope for growth of 19% in the Kongsfjord and a staggering 50% in the Billefjord. Interestingly, these effects were not observed in stage CV copepodites from any of the three locations. It seems that CVs may be more tolerant to OA perhaps due to a general physiological reorganization to meet low intracellular pH during hibernation. Needless to say, the observed changes in the CIV stage will have serious implications for the C. glacialis population health status and growth around Svalbard. However, OA tolerant populations such as the one in the Disko Bay could help to alleviate severe effects in C. glacialis as a species.     

Unravelling the migration and moult strategies of a long-distance migrant using stable isotopes: Red Knot Calidris canutus movements in the Americas

For long‐distance migrants, such as many of the shorebirds, understanding the demographic implications of behavioural strategies adopted by individuals is key to understanding how environmental change will affect populations. Stable isotopes have been used in the terrestrial environment to infer migratory strategies of birds but rarely in marine or estuarine systems. Here, we show that the stable isotope ratios of carbon and nitrogen in flight feathers can be used to identify at least three discrete wintering areas of the Red Knot Calidris canutus on the eastern seaboard of the Americas, ranging from southeastern USA to Patagonia and Tierra del Fuego. In spring, birds migrate northwards via Delaware Bay, in the northeastern USA, the last stopping point before arrival in Arctic breeding areas, where they fatten up on eggs of spawning Horseshoe Crabs Limulus polyphemus. The isotope ratios of feather samples taken from birds caught in the Bay during May 2003 were compared with feathers obtained from known wintering areas in Florida (USA), Bahia Lomas (Chile) and Rio Grande (Argentina). In May 2003, 30% of birds passing through the Bay had Florida‐type ‘signatures’, 58% were Bahia Lomas‐type, 6% were Rio Grande‐type and 7% were unclassified. Some of the southern wintering birds had started moulting flight feathers in northern areas, suspended this, and then finished their moult in the wintering areas, whereas others flew straight to the wintering areas before commencing moult. This study shows that stable isotopes can be used to infer migratory strategies of coastal‐feeding shorebirds and provides the basis for identifying the moult strategy and wintering areas of birds passing through Delaware Bay. Coupled with banding and marking birds as individuals, stable isotopes provide a powerful tool for estimating population‐specific demographic parameters and, in this case, further our understanding of the migration systems of the declining Nearctic populations of Red Knot.     

Autumn migration and wintering of northern fulmars (<Emphasis Type="Italic">Fulmarus glacialis</Emphasis>) from the Canadian high Arctic

Five northern fulmars (Fulmarus glacialis) were tracked by satellite transmitters from their breeding colony in the Canadian high Arctic (Cape Vera, Devon Island, NT) to their wintering grounds in the northwest Atlantic Ocean. In both 2004 and 2005, fulmars left northern Baffin Bay in mid- to late September, and migrated south to Davis Strait in less than 1 week, after which movements were erratic. In October and November, the birds were widely distributed, but by December through March, they tended to remain in the Labrador Sea between 50 and 55°N. Average flight speed was 35 km/h with a maximum of 64 km/h, and over their entire transmission periods, the five traveled on average 84 km/day. Our work suggests that the North Atlantic northern fulmar population may be panmictic in winter, with the Labrador Sea as a key wintering site for fulmars from high Arctic Canada.     

Genetic divergence of Troglodytes troglodytes islandicus from other subspecies of Eurasian wren in northwestern Europe

The Icelandic subspecies of Eurasian wren Troglodytes troglodytes islandicus has been described as a large wren which is sedentary on the island. It is one member of a large passerine complex which is widely distributed over the Holarctic except the Arctic. The taxonomic affiliation of the subspecies is mainly based on variation in plumage and on the song complexity. This study investigated the genetic differentiation of T. t. islandicus among the Eurasian wren subspecies in northwestern Europe, and especially in relation to its geographically proximate populations in the Faroe Islands, Scotland, southern Norway, Sweden and Denmark. Troglodytes t. islandicus and the Faroese subspecies (T. t. borealis) were genetically differentiated from the other subspecies (T. t. indigenus and T. t. troglodytes) with an estimated time of divergence from this group during the last glacial maximum; 21 thousand years before present (KYBP) [44–8]. A clear but a more recent split was observed between T. t. islandicus and T. t. borealis 12 KYBP [28–4].     

海刀豆的抗逆生理生化特征分析

为了解西沙群岛上海刀豆(Canavalia maritima)的抗逆特性,对其叶片解剖结构、生理学特征和养分状况进行了分析。结果表明,海刀豆叶片的栅栏组织发达,气孔密度大;叶绿素a/b低于3∶1;抗氧化酶活性普遍较高,以SOD活性最大;脯氨酸含量高;在土壤养分含量较低的情况下,叶片中的营养元素含量仍然较高。因此,海刀豆具有耐干旱、强光、高温和贫瘠等抗逆生物学特性,可以作为热带珊瑚岛(礁)防风固沙和植被恢复物种。     

Use of Museum Specimens to Refine Historical Pronghorn Subspecies Boundaries

Endangered Sonoran (Antilocapra americana sonoriensis) and Peninsular (A. a. peninsularis) pronghorn persist largely because of captive breeding and reintroduction efforts. Recovery team managers want to re-establish pronghorn in their native range, but there is currently uncertainty regarding the subspecies status of extinct pronghorn populations that historically inhabited southern California, USA, and northern Baja California, Mexico. To address this uncertainty, we genotyped museum specimens and conducted phylogenetic and population genetic analyses of historical data in the context of 3 contemporary pronghorn populations. The historical northern Baja California pronghorn share the most ancestry with contemporary Peninsular pronghorn, whereas pronghorn in southern California share more ancestry with contemporary American (A. a. americana) pronghorn. For reintroductions into northern Baja California, the Peninsular subspecies is more appropriate based on museum genetic data. For reintroductions into Southern California, ecological and genetic factors are both important, as the subspecies most genetically related to historical populations (American) may not be well-adapted to the hot, low-elevation deserts of the reintroduction area. © 2019 The Wildlife Society.     

Do Armeria maritima (Mill.) Willd. ecotypes from metalliferous soils and non-metalliferous soils differ in growth response under Zn stress? A comparison by a new artificial soil method

Morphological and biogeographical evidence suggests that theheavy-metal ecotype of Armeria maritima (Mill.) Willd. has evolvedfrom a hybrid group between the subspecies maritima from saltmarshes and the subspecies elongata from sandy soils. As partof a study on the ecotypic differentiation in A. maritima, Znresistance was compared in populations from these three ecotypes.To study the long-term growth response to elevated Zn concentrations,an artificial soil was made from ion-exchange resin embeddedin an inert sand matrix, in which metal ions were buffered byan ion-exchange system as in natural soils. In contrast to hydroponics,this artificial soil systems is suitable for long-term cultivationand it provides more reproducible growth conditions than a soilsystem. The long-term growth response in the artificial soilsystem was compared to the growth response to elevated Zn concentrationsin a sand nutrient-solution system. In short-term tests, populationsfrom non-metalliferous soils were more sensitive to Zn concentrationsof 1.0 mmol ^–1 than the heavy-metal populations. However,in long-term tests, the growth of adult plants from all populationswas not inhibited by Zn concentrations up to 2.8 mmol kg^–1dry soil (equivalent 26% of cation-exchange capacity). The Znresistance of all populations could therefore be sufficientfor their survival on Zn mine soils. The discrepancy betweenlong-term tests and short-term tests is discussed with respectto the hypothesis that ‘sensitive’ populations maydiffer from ‘resistant’ populations in the expressionof Zn-resistance mechanisms. Key words: Armeria maritima, growth tests, heavymetal resistance, synthetic ionexchange resins, Zn     

Adaptive strategies and life history characteristics in a warming climate: Salmon in the Arctic?

In the warming Arctic, aquatic habitats are in flux and salmon are exploring their options. Adult Pacific salmon, including sockeye (Oncorhynchus nerka), coho (O. kisutch), Chinook (O. tshawytscha), pink (O. gorbuscha) and chum (O. keta) have been captured throughout the Arctic. Pink and chum salmon are the most common species found in the Arctic today. These species are less dependent on freshwater habitats as juveniles and grow quickly in marine habitats. Putative spawning populations are rare in the North American Arctic and limited to pink salmon in drainages north of Point Hope, Alaska, chum salmon spawning rivers draining to the northwestern Beaufort Sea, and small populations of chum and pink salmon in Canada’s Mackenzie River. Pacific salmon have colonized several large river basins draining to the Kara, Laptev and East Siberian seas in the Russian Arctic. These populations probably developed from hatchery supplementation efforts in the 1960’s. Hundreds of populations of Arctic Atlantic salmon (Salmo salar) are found in Russia, Norway and Finland. Atlantic salmon have extended their range eastward as far as the Kara Sea in central Russian. A small native population of Atlantic salmon is found in Canada’s Ungava Bay. The northern tip of Quebec seems to be an Atlantic salmon migration barrier for other North American stocks. Compatibility between life history requirements and ecological conditions are prerequisite for salmon colonizing Arctic habitats. Broad-scale predictive models of climate change in the Arctic give little information about feedback processes contributing to local conditions, especially in freshwater systems. This paper reviews the recent history of salmon in the Arctic and explores various patterns of climate change that may influence range expansions and future sustainability of salmon in Arctic habitats. A summary of the research needs that will allow informed expectation of further Arctic colonization by salmon is given.     

Pathways of introduction of the invasive aquatic plant Cabomba caroliniana

The pathway and frequency of species' introductions can affect the extent, impact, and management of biological invasions. Here, we examine the pathway of introduction of the aquatic plant Cabomba caroliniana (fanwort) into Canada and the northern United States using plastid DNA sequence (intergenic spacers atpF‐atpH, trnH‐psbA, and trnL‐trnF) and DNA content analyses. We test the hypothesis that the spread of fanwort is a result of commercial trade by comparing a Canadian population (Kasshabog Lake, ON) to native populations from southern U.S., introduced populations in northern U.S., and plants from commercial retailers. Thirteen plastid haplotypes were identified throughout North America, including one dominant haplotype, which was present in all C. caroliniana populations. Several rare haplotypes were used to infer shared colonization history. In particular, the Canadian population shared two rare alleles with a population from Massachusetts, suggesting range expansion of C. caroliniana from the northern U.S. However, the possibility of a commercial introduction cannot be excluded, as common alleles were shared between the Canadian population and both commercial and southern U.S. sources. Variation in C. caroliniana genome size was bimodal and populations were classified into “high” and “low” categories. The Canadian population had DNA contents similar to several northern U.S. populations (low DNA content). This may provide additional support for range expansion from these introduced populations rather than from commercial sources or populations in the southern U.S., which had high DNA content.     

Geographic variation in the Japanese white-toothed shrew<Emphasis Type="Italic">Crocidura dsinezumi</Emphasis>

I investigated geographic variation in the Japanese white-toothed shrewCrocidura dsinezumi (Temminck, 1842) (Insectivora, Soricidae) from the Japanese Archipelago and the northern part of the Ryukyu Archipelago. Univariate and multivariate analyses were conducted based on 11 cranial measurements from 14 sampling localities. Overall size variation seemed to follow clinal changes correlated with latitude and longitude of localities, such that northeastern populations were smaller than southwestern ones. The Hokkaido population and the Kuchinoerabujima population were larger than expected based on estimated values, likely due to changes reflecting environmental factors. In contrast, the Tanegashima population was smaller than its estimated value. The northern Ryukyu populations were divergent from the Kyushu population and from each other. Based on patterns of geographic variation, I suggest that all previously described subspecies ofC. dsinezumi are junior synonyms ofC. dsinezumi; and that the Kuchinoerabujima population and the Nakanoshima population likely represent un- described subspecies.     

The Arctic Warbler Phylloscopus borealis– three anciently separated cryptic species revealed

The Arctic Warbler Phylloscopus borealis breeds across the northern Palaearctic and northwestern‐most Nearctic, from northern Scandinavia to Alaska, extending south to southern Japan, and winters in Southeast Asia, the Philippines and Indonesia. Several subspecies have been described based on subtle morphological characteristics, although the taxonomy varies considerably among different authors. A recent study (T. Saitoh et al. (2010) BMC Evol. Biol. 10 : 35) identified three main mitochondrial DNA clades, corresponding to: (1) continental Eurasia and Alaska, (2) south Kamchatka, Sakhalin and northeast Hokkaido, and (3) most of Japan (Honshu, Shikoku, Kyushu). These three clades were estimated to have diverged during the late Pliocene to early Pleistocene (border at c. 2.6 million years ago). Differences in morphometrics have also been reported among members of the three clades (T. Saitoh et al. (2008) Ornithol. Sci. 7 : 135–142). Here we analyse songs and calls from throughout the range of the Arctic Warbler, and conclude that these differ markedly and consistently among the populations representing the three mitochondrial clades. Kurile populations, for which no sequence data are available, are shown to belong to the second clade. To determine the correct application of available scientific names, mitochondrial DNA was sequenced from three name‐bearing type specimens collected on migration or in the winter quarters. Based on the congruent variation in mitochondrial DNA, morphology and vocalizations, we propose that three species be recognized: Arctic Warbler Phylloscopus borealis (sensu stricto) (continental Eurasia and Alaska), Kamchatka Leaf Warbler Phylloscopus examinandus (Kamchatka (at least the southern part), Sakhalin, Hokkaido and Kurile Islands), and Japanese Leaf Warbler Phylloscopus xanthodryas (Japan except Hokkaido).