Dramatic intraspecific differences in migratory routes, stopover sites and wintering areas, revealed using light-level geolocators

Migratory divides are contact zones between breeding populations that use divergent migratory routes and have been described in a variety of species. These divides are of major importance to evolution, ecology and conservation but have been identified using limited band recovery data and/or indirect methods. Data from band recoveries and mitochondrial haplotypes suggested that inland and coastal Swainson's thrushes ( Catharus ustulatus ) form a migratory divide in western North America. We attached light-level geolocators to birds at the edges of this contact zone to provide, to our knowledge, the first direct test of a putative divide using data from individual birds over the entire annual cycle. Coastal thrushes migrated along the west coast to Mexico, Guatemala and Honduras. Some of these birds used multiple wintering sites. Inland thrushes migrated across the Rocky Mountains, through central North America to Columbia and Venezuela. These birds migrated longer distances than coastal birds and performed a loop migration, navigating over the Gulf of Mexico in autumn and around this barrier in spring. These findings support the suggestion that divergent migratory behaviour could contribute to reproductive isolation between migrants, advance our understanding of their non-breeding ecology, and are integral to development of detailed conservation strategies for this group.

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Linking Breeding and Wintering Grounds of Bicknell's Thrushes Using Stable Isotope Analyses of Feathers

The Auk ◽

10.1093/auk/118.1.16 ◽

2001 ◽

Vol 118 (1) ◽

pp. 16-23 ◽

Cited By ~ 11

Author(s):

Keith A. Hobson ◽

Kent P. McFarland ◽

Leonard I. Wassenaar ◽

Christopher C. Rimmer ◽

James E. Goetz

Keyword(s):

North America ◽

Catharus Ustulatus ◽

Winter Habitat ◽

Wintering Grounds ◽

Breeding Sites ◽

Breeding Range ◽

Wintering Birds ◽

Breeding Populations ◽

Breeding Grounds ◽

Bicknell's Thrush

Abstract Previous studies have shown that natural abundance of deuterium (D), and to a lesser extent 13C, in feathers of migrant songbirds in North America can be used to infer geographic origins of molt. We used that approach to investigate whether Bicknell's Thrush (Catharus bicknelli) populations could be segregated on the breeding grounds at six sites in eastern North America to evaluate contributions from the breeding areas to wintering populations. Further, we tested our isotopic model using feathers from hatching-year migrant Swainson's Thrush (Catharus ustulatus) and Gray-cheeked Thrush (Catharus minimus) moving through southern Manitoba and Ontario and found that δD values were consistent with northerly boreal forest natal sites in northwestern and central Canada. Despite a strong latitudinal gradient in δD of average growing season precipitation over the breeding range, we found considerable overlap in δD values of Bicknell's Thrush among all breeding sites. No strong pattern in δ13C values of feathers with latitude was apparent. Nevertheless, the more negative δD values of feathers from wintering birds in the Dominican Republic compared to breeding area samples suggested that birds from more northerly locations in North America contributed to this population of wintering birds. High variance in feather δD values within breeding populations also suggested high natal dispersal, considerable movement of birds among island habitats on the breeding grounds, or both. Even higher variances in feather δD values from small study areas on the wintering grounds, compared to similar-sized areas in the breeding range, suggest that many different breeding populations mix in winter habitat.

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Correction to: Winter home range and habitat selection differs among breeding populations of herring gulls in eastern North America

Movement Ecology ◽

10.1186/s40462-019-0157-5 ◽

2019 ◽

Vol 7 (1) ◽

Author(s):

Christine M. Anderson ◽

H. Grant Gilchrist ◽

Robert A. Ronconi ◽

Katherine R. Shlepr ◽

Daniel E. Clark ◽

...

Keyword(s):

Habitat Selection ◽

North America ◽

Home Range ◽

Eastern North America ◽

Herring Gulls ◽

Breeding Populations

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Malarial parasites as geographical markers in migratory birds?

Biology Letters ◽

10.1098/rsbl.2005.0429 ◽

2006 ◽

Vol 2 (2) ◽

pp. 213-216 ◽

Cited By ~ 31

Author(s):

Sylvia M Fallon ◽

Robert C Fleischer ◽

Gary R Graves

Keyword(s):

North America ◽

Migratory Birds ◽

Wide Distribution ◽

Specific Information ◽

Population Movements ◽

Site Specific ◽

Dendroica Caerulescens ◽

Bird Populations ◽

Breeding Populations ◽

Wintering Range

We tested the hypothesis that malarial parasites ( Plasmodium and Haemoproteus ) of black-throated blue warblers ( Dendroica caerulescens ) provide sufficient geographical signal to track population movements between the warbler's breeding and wintering habitats in North America. Our results from 1083 warblers sampled across the species' breeding range indicate that parasite lineages are geographically widespread and do not provide site-specific information. The wide distribution of malarial parasites probably reflects postnatal dispersal of their hosts as well as mixing of breeding populations on the wintering range. When compared to geographically structured parasites of sedentary Caribbean songbirds, patterns of malarial infections in black-throated blue warblers suggest that host–malaria dynamics of migratory and sedentary bird populations may be subject to contrasting selection pressures.

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Firearms and Suicide in Australia

Australian & New Zealand Journal of Psychiatry ◽

10.3109/00048679009062906 ◽

1990 ◽

Vol 24 (4) ◽

pp. 500-509 ◽

Cited By ~ 26

Author(s):

Christopher H. Cantor ◽

Terry Lewin

Keyword(s):

North America ◽

Suicide Rate ◽

Regional Analysis ◽

The Elderly ◽

Cultural Attitudes ◽

Young Males ◽

Suicide Rates ◽

Firearm Suicide ◽

Proportional Increase ◽

Using Data

Australia has a moderate overall suicide rate but an extremely high male firearm suicide rate. Using data covering the years 1961–1985, a series of multiple regression based analyses were performed. During this period, overall suicide rates fell but firearm suicides remained constant with a resulting increase in the proportion of suicides by firearms. There has been an increase in suicides in the young offset by a decline in the elderly. Young males showed the greatest proportional increase in the use of firearms. A limited regional analysis supported the hypothesis that lack of legislative restrictions on long guns in Queensland with a greater household prevalence of such weapons and different cultural attitudes were associated with higher overall and firearm suicide rates. Such findings are consistent with reports from North America, although trends in Australia are more modest. Reducing the availability and cultural acceptance of firearms is likely to decrease suicide rates, especially in males.

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Seasonal survival and migratory connectivity of the Eurasian Oystercatcher revealed by citizen science

The Auk ◽

10.1093/auk/uky001 ◽

2019 ◽

Vol 136 (1) ◽

Cited By ~ 1

Author(s):

Andrew M Allen ◽

Bruno J Ens ◽

Martijn Van de Pol ◽

Henk Van der Jeugd ◽

Magali Frauendorf ◽

...

Keyword(s):

Citizen Science ◽

Avian Species ◽

Future Research ◽

Migratory Connectivity ◽

Space And Time ◽

Demographic Rates ◽

Breeding Populations ◽

Spatio Temporal ◽

Using Data ◽

Model Structures

Abstract Migratory connectivity describes linkages between breeding and non-breeding areas. An ongoing challenge is tracking avian species between breeding and non-breeding areas and hence estimating migratory connectivity and seasonal survival. Collaborative color-ringing projects between researchers and citizen scientists provide opportunities for tracking the annual movements of avian species. Our study describes seasonal survival and migratory connectivity using data from more than 4,600 individuals with over 51,000 observations, predominantly collected by citizen scientists. Our study focuses on the Eurasian Oystercatcher (Haematopus ostralegus), a species that has experienced a substantial and ongoing decline in recent decades. Multiple threats have been described, and given that these threats vary in space and time, there is an urgent need to estimate demographic rates at the appropriate spatio-temporal scale. We performed a seasonal multi-state (5 geographical areas within The Netherlands) live- and dead-recoveries analysis under varying model structures to account for biological and data complexity. Coastal breeding populations were largely sedentary, while inland breeding populations were migratory and the direction of migration varied among areas, which has not been described previously. Our results indicated that survival was lower during winter than summer and that survival was lower in inland areas compared with coastal areas. A concerning result was that seasonal survival of individuals over-wintering in the Wadden Sea, an internationally important site for over-wintering shorebirds, appeared to decline during the study period. We discuss the outcomes of our study, and how citizen science was integral for conducting this study. Our findings identify how the demographic rates of the oystercatcher vary in space and time, knowledge that is vital for generating hypotheses and prioritizing future research into the causes of decline.

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Breeding ecology and habitat use of North America’s rarest Ardeidae: the Reddish Egret Egretta rufescens

Avian Conservation and Ecology ◽

10.5751/ace-01258-130210 ◽

2018 ◽

Vol 13 (2) ◽

Cited By ~ 1

Author(s):

Lianne M. Koczur ◽

Bart M. Ballard ◽

M. Clay Green ◽

David G. Hewitt ◽

Scott E. Henke

Keyword(s):

North America ◽

Habitat Use ◽

Breeding Ecology ◽

Egretta Rufescens

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Light-level geolocators reveal strong migratory connectivity and within-winter movements for a coastal California Swainson's Thrush (Catharus ustulatus) population

The Auk ◽

10.1525/auk.2013.12228 ◽

2013 ◽

Vol 130 (2) ◽

pp. 283-290 ◽

Cited By ~ 30

Author(s):

Renée L. Cormier ◽

Diana L. Humple ◽

Thomas Gardali ◽

Nathaniel E. Seavy

Keyword(s):

Light Level ◽

Migratory Connectivity ◽

Catharus Ustulatus ◽

Swainson’S Thrush

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Continent-wide tracking to determine migratory connectivity and tropical habitat associations of a declining aerial insectivore

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2012.2207 ◽

2012 ◽

Vol 279 (1749) ◽

pp. 4901-4906 ◽

Cited By ~ 78

Author(s):

Kevin C. Fraser ◽

Bridget J. M. Stutchbury ◽

Cassandra Silverio ◽

Patrick M. Kramer ◽

John Barrow ◽

...

Keyword(s):

North American ◽

Agricultural Landscape ◽

Ground Cover ◽

Light Level ◽

Agricultural Landscapes ◽

Habitat Associations ◽

Migratory Connectivity ◽

Population Declines ◽

Long Distance ◽

Breeding Populations

North American birds that feed on flying insects are experiencing steep population declines, particularly long-distance migratory populations in the northern breeding range. We determine, for the first time, the level of migratory connectivity across the range of a songbird using direct tracking of individuals, and test whether declining northern populations have higher exposure to agricultural landscapes at their non-breeding grounds in South America. We used light-level geolocators to track purple martins, Progne subis , originating from North American breeding populations, coast-to-coast ( n = 95 individuals). We show that breeding populations of the eastern subspecies, P. s. subis , that are separated by ca . 2000 km, nevertheless have almost completely overlapping non-breeding ranges in Brazil. Most (76%) P. s. subis overwintered in northern Brazil near the Amazon River, not in the agricultural landscape of southern Brazil. Individual non-breeding sites had an average of 91 per cent forest and only 4 per cent agricultural ground cover within a 50 km radius, and birds originating from declining northern breeding populations were not more exposed to agricultural landscapes than stable southern breeding populations. Our results show that differences in wintering location and habitat do not explain recent trends in breeding population declines in this species, and instead northern populations may be constrained in their ability to respond to climate change.

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A Note on Overseas Chinese Political Participation in Urban Malaya

American Political Science Review ◽

10.2307/1955621 ◽

1970 ◽

Vol 64 (1) ◽

pp. 177-178

Author(s):

Alvin Rabushka

Keyword(s):

North America ◽

Political Participation ◽

Voter Turnout ◽

Western Europe ◽

Large Measure ◽

Transitional Societies ◽

Using Data ◽

The Relationship ◽

Industrial Societies

The object of this note is to demonstrate that generalizations about political participation may be invalid when applied to “developing” or “transitional” societies. Specifically, the relationship between rates of voter turnout and levels of education for urban Chinese in Malaya is not consistent with results reported for Western societies.A geographical classification of bibliographic entries in Lester Milbrath's Political Participation discloses a very interesting statistic: only 3 of the 288 listed entries concern the transitional societies of Asia, Africa and Latin America. The lack of data on developing areas may, in large measure, explain the emphasis placed on studies of political participation in North America and Western Europe. Although there is more research on transitional societies today, most studies still focus on advanced industrial societies. The validity of the generalizations presented in Political Participation, therefore, is restricted to North America and Western Europe.Using data collected in Malaya (1957), I examine four of Milbrath's hypotheses. These include:(1) higher education increases participation (p.122);(2) middle-aged persons participate more than young or old persons (p. 134);(3) men are more likely to participate than women (p. 133); and(4) religion affects participation (p. 137).

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