Avian Communities of the Northern Mackenzie Mountains, Northwest Territories, Canada

Basic knowledge of the abundance and distribution of birds and their habitats and the relationships between them is limited for many parts of Arctic Canada, including montane regions. This information is important for conservation purposes as bird populations and habitats shift and as interest in development of northern areas increases. We characterized bird communities in the Mackenzie Mountains of the Northwest Territories by conducting point counts (n = 376) in June 2009 and 2010 and using community analysis metrics (multiple response permutation procedures, indicator species analysis, non-metric multidimensional scaling) to statistically and graphically describe bird data in six habitat types: coniferous forest, deciduous forest, shrub (short and tall), alpine tundra, and open water wetlands. Distinct habitats had significantly different bird communities, as shown by using multiple response permutation procedures (p < 0.005). Of 51 species, 32 had significant (p < 0.05) indicator values for one habitat type (n = 15) or groups of habitats (n = 17) in an indicator species analysis. The tall shrub habitat type had the most indicator species (six species) followed by alpine tundra (five species), then the combined conifer, deciduous, and wetland habitat group (four species) and the deciduous forest habitat types (three species). Species richness was highest in the tall shrub (n = 37), alpine (n = 30), and conifer and short shrub (n = 29) habitats. We also observed eight bird species not previously known to occur in the area, or which were outside published ranges. Our results highlight the variability in bird community composition between the major habitat types in the Mackenzie Mountains, serve as a baseline for future bird studies in the region, and underscore the need for more research in the area with impending anthropogenic changes.Pour de nombreuses parties de l’Arctique canadien, y compris les régions montagnardes, les connaissances de base portant sur l’abondance et la répartition des oiseaux et de leurs habitats, de même que sur leurs relations entre eux, sont restreintes. Ces renseignements revêtent de l’importance en matière de conservation, au moment où les habitats et les populations d’oiseaux changent et où l’on s’intéresse de plus en plus au développement des régions du nord. Nous avons caractérisé les communautés d’oiseaux des monts Mackenzie, dans les Territoires du Nord-Ouest, en effectuant des dénombrements ponctuels (n = 376) en juin 2009 et 2010 et en recourant à diverses mesures d’analyse des communautés (test de permutations multiples, analyse des espèces indicatrices, analyse multidimensionnelle non métrique) afin de décrire à l’aide de statistiques et de graphiques les données relatives aux oiseaux de six types d’habitats : forêts de conifères, forêts de feuillus, arbustaies (petits arbustes et grands arbustes), toundra alpine et terres humides avec étendues d’eaux libres. D’après les tests de permutations multiples (p < 0,005), les communautés d’oiseaux diffèrent considérablement en présence d’habitats distincts. L’analyse des espèces indicatrices a également permis de démontrer que parmi les 51 espèces, 32 avaient des valeurs indicatrices importantes (< 0,05) pour un type d’habitat (n = 15) ou des groupes d’habitats (n = 17). L’habitat des grands arbustes comptait le plus grand nombre d’espèces indicatrices (six espèces), suivi de la toundra alpine (cinq espèces), puis du groupe composé de la forêt de conifères, de la forêt de feuillus et des terres humides (quatre espèces), et de la forêt de feuillus (trois espèces). La richesse des espèces était plus grande dans les habitats des grands arbustes (n = 37), de la toundra alpine (n = 30) et des conifères et petits arbustes (n = 29). Nous avons également observé huit espèces d’oiseaux qui n’avaient jamais été répertoriées dans la région ou qui se trouvaient en dehors de leur parcours naturel. Nos résultats mettent en évidence la variabilité de la composition des communautés d’oiseaux dans les principaux types d’habitats des monts Mackenzie. Ils serviront également de référence aux autres études d’oiseaux qui seront effectuées dans la région, et font ressortir la nécessité de faire d’autres recherches dans la région à la lumière des changements anthropiques imminents

Off-road sampling reveals a different grassland bird community than roadside sampling: implications for survey design and estimates to guide conservation

Grassland bird species continue to decline steeply across North America. Road-based surveys such as the North American Breeding Bird Survey (BBS) are often used to estimate trends and population sizes and to build species distribution models for grassland birds, although roadside survey counts may introduce bias in estimates because of differences in habitats along roadsides and in off-road surveys. We tested for differences in land cover composition and in the avian community on 21 roadside-based survey routes and in an equal number of adjacent off-road walking routes in the grasslands of southern Alberta, Canada. Off-road routes (n = 225 point counts) had more native grassland and short shrubs and less fallow land and road area than the roadside routes (n = 225 point counts). Consequently, 17 of the 39 bird species differed between the two route types in frequency of occurrence and relative abundance, measured using an indicator species analysis. Six species, including five obligate grassland species, were more prevalent at off-road sites; they included four species listed under the Canadian federal Species At Risk Act or listed by the Committee on the Status of Endangered Wildlife in Canada: Sprague's Pipit (Anthus spragueii), Baird's Sparrow (Ammodramus bairdii), the Chestnut-collared Longspur (Calcarius ornatus), and McCown's Longspur (Rhynchophanes mccownii). The six species were as much as four times more abundant on off-road sites. Species more prevalent along roadside routes included common species and those typical of farmland and other human-modified habitats, e.g., the European Starling (Sturnus vulgaris), the Black-billed Magpie (Pica hudsonia), and the House Sparrow (Passer domesticus). Differences in avian community composition between roadside and off-road surveys suggest that the use of BBS data when generating population estimates or distribution models may overestimate certain common species and underestimate others of conservation concern. Our results highlight the need to develop appropriate corrections for bias in estimates derived from roadside sampling, and the need to design surveys that sample bird communities across a more representative cross-section of the landscape, both near and far from roads

Identifying the winter grounds of the recently described Barbary Reed Warbler (Acrocephalus baeticatus ambiguus)

The Iberian and North African populations of reed warblers have been described recently as a separate taxon, ambiguus, forming a sister clade to the Sahelian subspecies minor of African Reed Warbler Acrocephalus baeticatus. Although the breeding range of ambiguus has been identified, the migration strategy of its populations remained unknown. We deployed geolocators and sampled the innermost primary from breeding adults in Spain for stable hydrogen (d2H) analyses and also analysed stable carbon (d13C) and nitrogen (d15N) isotopes in feathers collected in two reed warbler taxa (Acrocephalus scirpaceus and Acrocephalus baeticatus ambiguus) in Morocco, to identify the moulting and wintering sites of these populations. Ring recoveries, geolocator tracks and probabilistic assignments to origin from d2H values indicate that Spanish ambiguus are likely to moult south of the Sahara and winter in West Africa, probably from Mauretania to southern Mali and Ivory Coast. Moroccan ambiguus, however, undergo post-breeding moult north of the Sahara, and possibly then migrate to West Africa. With other populations of ambiguus breeding from Algeria to Libya and probably wintering further east in the Sahelian belt, the Barbary Reed Warbler can therefore be considered a trans-Saharan migrant, with a post-breeding moult strategy that varies between populations, and probably structured according to breeding latitude

Unravelling migration connectivity reveals unsustainable hunting of the declining ortolan bunting

In France, illegal hunting of the endangered ortolan bunting Emberiza hortulana has been defended for the sake of tradition and gastronomy. Hunters argued that ortolan buntings trapped in southwest France originate from large and stable populations across the whole of Europe. Yet, the European Commission referred France to the Court of Justice of the European Union (EU) in December 2016 for infringements to legislation (IP/16/4213). To better assess the impact of hunting in France, we combined Pan-European data from archival light loggers, stable isotopes, and genetics to determine the migration strategy of the species across continents. Ortolan buntings migrating through France come from northern and western populations, which are small, fragmented and declining. Population viability modeling further revealed that harvesting in southwest France is far from sustainable and increases extinction risk. These results provide the sufficient scientific evidence for justifying the ban on ortolan harvesting in France.Peer reviewe

Multi-isotope (δ 2H, δ 13C, δ 15N) feather profiles and morphometrics inform patterns of migratory connectivity in three species of North American swallows

Abstract Aerial insectivorous birds have suffered steep population declines in North America over the last 60 years. A lack of information on migratory connectivity between breeding and non-breeding grounds for these species limits our ability to interpret factors affecting their population-specific trends. We determined likely Latin American non-breeding regions of Bank (Riparia riparia), Barn (Hirundo rustica) and Cliff (Petrochelidon pyrrhonota) swallow from populations across their breeding ranges. We used predicted feather hydrogen (δ 2Hf) and carbon (δ 13Cf) isoscapes for winter-grown feathers to indicate areas of highest probability of moult origin and incorporated these results into a cluster analysis to determine likely broad non-breeding regions. We also assessed variation in wing length among populations to determine the potential for this metric to differentiate population moult origins. We then investigated patterns of multi-isotopic (δ 2Hf, δ 13Cf, δ 15Nf) and wing-length niche occupancy by quantifying niche size and overlap among populations under the assumption that broad niches were consistent with low within-species migratory connectivity and narrow and non-overlapping niches with higher connectivity. Multivariate assignment identified different non-breeding regions and potential clusters of moult origin generally corresponding to Central America and northern South America, eastern and south-central South America, and the western and southern part of that continent, with variation within and among populations and species. Separate niche space indicated different wintering habitat or areas used by species or populations whereas niche overlap indicated only potential spatial similarity. Wing length varied significantly among populations by species, being longer in the west and north for Bank and Cliff Swallow and longer in eastern Canadian Barn Swallow populations. Barn Swallow occupied consistently larger isotopic and wing length niche space than the other species. Comparisons among populations across species showed variable isotopic and wing-length niche overlap generally being greater within breeding regions and lower between western and eastern breeding populations supporting a general North American continental divide for all species with generally low migratory connectivity for all species. We present a novel approach to assessing connectivity using inexpensive and broad isotopic approaches that provides the basis for hypothesis testing using more spatially explicit expensive techniques

Long-term responses of birds to the creation of a community fuel break in the western boreal forest of Canada: implications for management within protected areas

Encroachment, including human settlement, into the North American boreal forest has increased substantially in recent decades. This has resulted in changes in the dynamics, distribution, and functioning of this system with potential negative implications for avifaunal communities. Fuel breaks are often constructed around human settlements in forested landscapes to reduce the potential of damage to infrastructure from wildfires. The frequency and intensity of wildfire in boreal landscapes is projected to increase under future climate change scenarios. Thus, fuel breaks may become a more common management system around communities in the boreal forest. We assessed the responses of 21 bird species to the creation of a fuel break constructed around the village of Waskesiu in Prince Albert National Park, Saskatchewan, Canada. We surveyed birds for 2 years before (2000, 2001) and in 11 of 16 years after clearing (2002-2017; n = 14 sites) relative to reference sites (n = 3 sites surveyed since 2000 and n = 14 sites surveyed since 2006). The fuel break (~247 ha) was created in mature aspen-spruce forests and resulted in habitats resembling open parkland and open deciduous forest through removal of ~95% of the coniferous trees and continuous firebreak management. A community-level analysis indicated that open- and shrub-dwelling bird species became dominant following fuel break creation and for the duration of the study. Individual species-level analyses indicated declines in four avian species associated with older boreal forests (e.g., Bay-breasted Warbler, Setophaga castanea) and increases of six avian species typical of open and shrub habitats (e.g., White-throated Sparrow, Zonotrichia albicollis). However, trends of most species were similar in reference and fuel break sites likely due to the close proximity of reference sites to the fuel break. The fuel break in our study negatively affected most avian species that require older forests and, with ongoing maintenance, fuel breaks represent an unnatural component of the landscape in protected areas. Planned and ongoing expansion of the Waskesiu fuel break and creation of another fuel break (additional ~395 ha) in Prince Albert National Park including clearing to protect commercial property outside the park warrant additional investigations into the impacts of fuel breaks on birds and other wildlife

Origins of Wilson’s Warblers migrating through southwest Canada: Adding value to banding data by using stable isotopes and genetic markers

Stopovers used by birds during migration concentrate individuals from broad geographic areas potentially providing important information on catchment areas of birds moving through these sites. We combined stable isotope (δ2H), genetic fingerprinting and band recovery data to delineate the molt origins of Wilson’s Warblers (Cardellina pusilla) migrating through a stopover site in southwestern Canada in the fall. We assessed changes in δ2Hf indicating latitudinal origins with ordinal date to show this species likely underwent leapfrog migration through this site. Using the combined approach to determine origins, Wilson’s Warblers migrating through southwestern Alberta in 2015 were mostly from the western boreal population (n = 155, 96%) with some individuals from the Pacific Northwest (n = 1, 0.6%), Rocky Mountain (n = 2, 1.2%) and eastern boreal (n = 3, 1.8%) populations. Our results suggest that individuals migrating through our study site come from a broad catchment area potentially from a large part of northwestern North America. Future studies should link population changes at banding stations with other information to determine associations with large-scale landscape-level drivers (e.g. climate, land use)

Off-road sampling reveals a different grassland bird community than roadside sampling: implications for survey design and estimates to guide conservation

ABSTRACT. Grassland bird species continue to decline steeply across North America. Road-based surveys such as the North American Breeding Bird Survey (BBS) are often used to estimate trends and population sizes and to build species distribution models for grassland birds, although roadside survey counts may introduce bias in estimates because of differences in habitats along roadsides and in off-road surveys. We tested for differences in land cover composition and in the avian community on 21 roadside-based survey routes and in an equal number of adjacent off-road walking routes in the grasslands of southern Alberta, Canada. Off-road routes (n = 225 point counts) had more native grassland and short shrubs and less fallow land and road area than the roadside routes (n = 225 point counts). Consequently, 17 of the 39 bird species differed between the two route types in frequency of occurrence and relative abundance, measured using an indicator species analysis. Six species, including five obligate grassland species, were more prevalent at off-road sites; they included four species listed under the Canadian federal Species At Risk Act or listed by the Committee on the Status of Endangered Wildlife in Canada: Sprague's Pipit (Anthus spragueii), Baird's Sparrow (Ammodramus bairdii), the Chestnut-collared Longspur (Calcarius ornatus), and McCown's Longspur (Rhynchophanes mccownii). The six species were as much as four times more abundant on off-road sites. Species more prevalent along roadside routes included common species and those typical of farmland and other human-modified habitats, e.g., the European Starling (Sturnus vulgaris), the Black-billed Magpie (Pica hudsonia), and the House Sparrow (Passer domesticus). Differences in avian community composition between roadside and off-road surveys suggest that the use of BBS data when generating population estimates or distribution models may overestimate certain common species and underestimate others of conservation concern. Our results highlight the need to develop appropriate corrections for bias in estimates derived from roadside sampling, and the need to design surveys that sample bird communities across a more representative cross-section of the landscape, both near and far from roads. L'échantillonnage hors route révèle une communauté d'oiseaux de prairie différente de celle issue de l'échantillonnage le long des routes : répercussions sur la conception des relevés et les estimations pour orienter la conservation RÉSUMÉ. Le déclin prononcé des espèces d'oiseaux de prairie se poursuit en Amérique du Nord. Les relevés le long des routes, comme le Relevé des oiseaux nicheurs (BBS) en Amérique du Nord, sont souvent utilisés pour estimer les tendances et la taille des populations, ainsi que pour élaborer des modèles de répartition d'espèces de prairie, même si les dénombrements le long des routes peuvent introduire des biais relatifs aux estimations étant donné que les milieux le long des routes sont différents de ceux hors route. Nous avons examiné s'il y avait des différences dans l'occupation du sol et les communautés aviaires pour 21 routes en bordure desquelles se font des relevés et pour 21 trajets hors route adjacents dans les prairies du sud de l'Alberta, Canada. Avian Conservation and Ecology 9(1): 4 http://www.ace-eco.org/vol9/iss1/art4/ composition des communautés aviaires entre les relevés le long des routes et hors route laissent croire que l'utilisation des données du BBS pour générer des estimations de population ou des modèles de répartition surestime peut-être certaines espèces communes et sousestiment possiblement des espèces dont la conservation est préoccupante. Nos résultats soulignent le besoin d'élaborer des correctifs appropriés pour les biais relatifs aux estimations générées à partir de l'échantillonnage le long des routes, et le besoin de concevoir des relevés qui mesurent les communautés aviaires dans un échantillon plus représentatif du paysage, tant près que loin des routes