Fall Migration Routes Research Articles

Autumn migration routes of fledgling Chinese Egrets (Egretta eulophotes) in Northeast China and their implications for conservation

The Chinese Egret (Egretta eulophotes) is a globally threatened bird species living on the coast and islands of Liaoning, northeastern China, mainly in summer. To further protect the breeding population of Chinese Egrets, it is important to understand the current protection status of their distribution sites at pre-migration period and migration routes. Thirty-three individuals were tagged with satellite transmitters at Fantuo Island in Changhai and Xingren Island in Zhuanghe, Liaoning Province, northeastern China, in July of 2016, 2017, and 2018, to identify important distribution sites during the pre-migration period, as well as detailed migration routes. The results showed that coastal mudflats in Liaoning and the west coast of North Korea were important feeding and roosting sites for fledgling Chinese Egrets from August to September. The home range sizes in August were significantly larger than in September. The eastern coast from Shandong to Guangdong, as well as Taiwan, China, and Manila Bay and Galileo Islands in the Philippines, were important stopover sites during fall migration. Specifically, we found that the egrets’ autumn migration could be divided into four routes, i.e., sea-crossing migration (SCM), coastal migration (CM), inland migration (IM), and mixed migration (MM). The migration distance, timing, speed, and straightness of the four routes also differed. The SCM routes were the straightest, and had the fastest migration speed and shortest travel time, while the IM routes had the lowest straightness and speed, and the longest duration. Manila Bay and Bohol Island in the Philippines, the west coast of Tanintharyi in Myanmar, and the Zengwun River Estuary in Taiwan, China, were wintering sites. Our findings on the key distribution sites along pre-migration and fall migration routes, including some stopover sites, have important implications for the conservation of and global action plan development for the vulnerable Chinese Egret.

First description of migration and wintering home range of Gray-headed Lapwings (Vanellus cinereus) tracked with GPS-GSM satellite telemetry

Little is known about the migration of the Gray-headed Lapwing (Vanellus cinereus). During the fall migration season of 2018, we tracked 3 birds from Guiyang Airport, China, a stopover site of Gray-headed Lapwing, in order to analyze their migratory and wintering movements by means of GPS-GSM satellite telemetry. We obtained 3 partial fall migration routes and 2 complete spring migration routes from September 2018 to July 2019. We identified E India and Bangladesh as their wintering ground and NE and E China as their breeding area. The spring migration covered 3,380 km and took 12 d on average (n = 2). Gray-headed Lapwings migrated at night, flying at speeds of 29.11–91.12 km/h. In winter, the mean home range area (95% utilization distribution) was 18.56 km2 (SD = 21.74, 3 birds) and the mean core area (50% utilization distribution) was 1.28 km2 (SD = 1.49, 3 birds).

Migration stopover ecology of Cinnamon Teal in western North America.

Identifying migration routes and fall stopover sites of Cinnamon Teal (Spatula cyanoptera septentrionalium) can provide a spatial guide to management and conservation efforts, and address vulnerabilities in wetland networks that support migratory waterbirds. Using high spatiotemporal resolution GPS‐GSM transmitters, we analyzed 61 fall migration tracks across western North America during our three‐year study (2017–2019). We marked Cinnamon Teal primarily during spring/summer in important breeding and molting regions across seven states (California, Oregon, Washington, Idaho, Utah, Colorado, and Nevada). We assessed fall migration routes and timing, detected 186 fall stopover sites, and identified specific North American ecoregions where sites were located. We classified underlying land cover for each stopover site and measured habitat selection for 12 land cover types within each ecoregion. Cinnamon Teal selected a variety of flooded habitats including natural, riparian, tidal, and managed wetlands; wet agriculture (including irrigation ditches, flooded fields, and stock ponds); wastewater sites; and golf and urban ponds. Wet agriculture was the most used habitat type (29.8% of stopover locations), and over 72% of stopover locations were on private land. Relatively scarce habitats such as wastewater ponds, tidal marsh, and golf and urban ponds were highly selected in specific ecoregions. In contrast, dry non‐habitat across all ecoregions, and dry agriculture in the Cold Deserts and Mediterranean California ecoregions, was consistently avoided. Resources used by Cinnamon Teal often reflected wetland availability across the west and emphasize their adaptability to dynamic resource conditions in arid landscapes. Our results provide much needed information on spatial and temporal resource use by Cinnamon Teal during migration and indicate important wetland habitats for migrating waterfowl in the western United States.

Habitat loss on the breeding grounds is a major contributor to population declines in a long-distance migratory songbird.

Many migratory species are declining and for most, the proximate causes of their declines remain unknown. For many long-distance Neotropical migratory songbirds, it is assumed that habitat loss on breeding or non-breeding grounds is a primary driver of population declines. We integrated data collected from tracking technology, community science and remote sensing data to quantify migratory connectivity (MC), population trends and habitat loss. We quantified the correlation between forest change throughout the annual cycle and population declines of a long-distance migratory songbird, the Connecticut warbler (Oporornis agilis, observed decline: -8.99% yr-1). MC, the geographic link between populations during two or more phases of the annual cycle, was stronger between breeding and autumn migration routes (MC = 0.24 ± 0.23) than between breeding and non-breeding locations (MC = -0.2 ± 0.14). Different Connecticut warbler populations tended to have population-specific fall migration routes but overlapped almost completely within the northern Gran Chaco ecoregion in South America. Cumulative forest loss within 50 km of breeding locations and the resulting decline in the largest forested patch index was correlated more strongly with population declines than forest loss on migratory stopover regions or on wintering locations in South America, suggesting that habitat loss during the breeding season is a driver of observed population declines for the Connecticut warbler. Land-use practices that retain large, forested patches within landscapes will likely benefit breeding populations of this declining songbird, but further research is needed to help inform land-use practices across the full annual cycle to minimize the impacts to migratory songbirds and abate ongoing population declines.

Widely distributed breeding populations of Canada warbler (Cardellina canadensis) converge on migration through Central America

BackgroundTo effectively conserve migratory species, the entire range encompassed by their annual life cycle needs to be considered. Most research on Nearctic-Neotropical migratory birds has focused on the breeding grounds resulting in a general lack of knowledge regarding the wintering and migratory periods. The Canada Warbler (Cardellina canadensis) has declined by 71% from 1970 to 2012, at a rate of 2.9% per year, and is listed as Threatened in Canada. As with most Nearctic-Neotropical migrants, conservation efforts outside the breeding range are limited by a poor understanding of migration routes and the connectivity between specific breeding and wintering populations.ResultsTo determine migratory routes of multiple breeding populations of Canada Warblers, we directly-tracked individuals using light-level geolocators deployed at four sites across the breeding range, spanning approximately 43 degrees in longitude (Alberta, Manitoba and Québec, Canada, and New Hampshire, USA). Twenty-five geolocators with usable data were recovered from three sites and were analyzed using FlightR to determine fall migration routes (n = 18) and individual wintering sites (n = 25). Individuals from all breeding populations took a western fall migration route at the Gulf of Mexico; with 77.8% of birds funnelling into a narrow geographic space along the western side of the Gulf of Mexico (97°W-99°W). We found no evidence for population-specific, parallel migration routes. Most individuals (72%) overwintered in Colombia. The remaining individuals overwintered in Venezuela.ConclusionsOur results demonstrate convergence of migratory routes around a migration barrier for individuals originating from widely distributed breeding areas. Further, we suggest the potential importance of habitat around the Gulf of Mexico during migration and Andean forest in Colombia as overwintering habitat for this threatened species. Future research should be directed at understanding how these areas are used by Canada Warblers.

Spatial Ecology of White-Winged Scoters (Melanitta deglandi) in Eastern North America: A Multi-Year Perspective

Satellite transmitters were used to describe migration patterns and establish connectivity among breeding and wintering areas for 30 White-winged Scoters (Melanitta deglandi) tagged in August 2010 or August 2012 during remigial molt in the St. Lawrence Estuary, Quebec, Canada. Fourteen potential breeding sites were identified in the boreal forest from Quebec to the Northwest Territories, Canada. Most birds molted at marine sites, except for two females that molted close to their breeding areas and a male that molted in interior Manitoba. Most birds remained near their molting location during fall prior to migrating to their wintering area. Individuals tended to use similar fall migration routes from year to year. Most birds (81%) wintered in the Long Island-Nantucket-Cape Cod region along the eastern seaboard of the USA, while only three birds wintered in Canada. Scoters spent almost half the year on wintering areas, and 83% returned within 150 km of the previous year's site. Spring migration patterns depended on breeding status. Breeding birds covered an average of 6,880 km compared to 2,550 km by non-breeding birds during their annual cycle. The St. Lawrence Estuary in Quebec and the Long Island-Nantucket-Cape Cod region (New York state and Massachusetts) were areas particularly important for tagged birds.

Wetland destruction on migration routes threatens a breeding population of the endangered black-faced spoonbill (Platalea minor)

To further protect the breeding population of black-faced spoonbills (Platalea minor), it is important to understand the current conservation status of breeding distribution sites and migration routes, especially for important stopover and wintering sites of black-faced spoonbills. Six individuals were tagged with satellite transmitters at Zhuanghe, Liaoning Province, northeastern China, in July of 2017 and 2018 to identify important distribution sites during the breeding period and detailed migration routes. The results showed that Zhuanghe Bay, Qingduizi Bay and Dayang Estuary were important feeding and roosting sites for black-faced spoonbills from August to October. Jiaozhou Bay, Shandong Province, and Lianyungang and Yancheng, Jiangsu Province, were important stopover sites during fall migration, and the coastal areas of Yancheng, Jiangsu; Hangzhou Bay, Zhejiang Province; and Tainan, Taiwan of China; and the inland areas of Poyang Lake, Jiangxi Province, and Nanyi Lake, Anhui Province, were important wintering sites. This is the first study to report the inland migration routes of black-faced spoonbills in China. Our findings on the key breeding distribution sites, fall migration routes and current threats (such as aquaculture, mudflat reclamation and dam construction) have important implications for the conservation of and global action plan development for the endangered black-faced spoonbill.

Avian influenza overview May - August 2018.

Between 16 May and 15 August 2018, three highly pathogenic avian influenza (HPAI) A(H5N8) outbreaks in poultry establishments and three HPAI A(H5N6) outbreaks in wild birds were reported in Europe. Three low pathogenic avian influenza (LPAI) outbreaks were reported in three Member States. Few HPAI and LPAI bird cases have been detected in this period of the year, in accordance with the seasonal expected pattern of LPAI and HPAI. There is no evidence to date that HPAI A(H5N8) and A(H5N6) viruses circulating in Europe have caused any human infections. The risk of zoonotic transmission to the general public in Europe is considered to be very low. Several HPAI outbreaks in poultry were reported during this period from Russia. The presence of the A(H5N2) and A(H5N8) viruses in parts of Russia connected with fall migration routes of wild birds is of concern for possible introduction and spread with wild birds migrating to the EU. Although few AI outbreaks were observed in Africa, Asia and the Middle East during the reporting period, the probability of AI virus introductions from non‐EU countries via wild birds particularly via the north‐eastern route from Russia is increasing, as the fall migration of wild birds will start in the coming weeks. Further, the lower temperatures in autumn and winter may facilitate the environmental survival of avian influenza viruses potentially introduced to Europe.

A Continent-Wide Migratory Divide in North American Breeding Barn Swallows (Hirundo rustica)

Populations of most North American aerial insectivores have undergone steep population declines over the past 40 years but the relative importance of factors operating on breeding, wintering, or stopover sites remains unknown. We used archival light-level geolocators to track the phenology, movements and winter locations of barn swallows (Hirdundo rustica; n = 27) from populations across North America to determine their migratory connectivity. We identified an east-west continental migratory divide for barn swallows with birds from western regions (Washington State, USA (n = 8) and Saskatchewan, Canada (n = 5)) traveling shorter distances to wintering areas ranging from Oregon to northern Colombia than eastern populations (Ontario (n = 3) and New Brunswick (n = 10), Canada) which wintered in South America south of the Amazon basin. A single swallow from a stable population in Alabama shared a similar migration route to eastern barn swallows but wintered farther north in northeast Brazil indicating a potential leap frog pattern migratory among eastern birds. Six of 9 (67%) birds from the two eastern populations and Alabama underwent a loop migration west of fall migration routes including around the Gulf of Mexico travelling a mean of 2,224 km and 722 km longer on spring migration, respectively. Longer migration distances, including the requirement to cross the Caribbean Sea and Gulf of Mexico and subsequent shorter sedentary wintering periods, may exacerbate declines for populations breeding in northeastern North America.

Vertical and horizontal habitat use by white marlin Kajikia albida (Poey, 1860) in the western North Atlantic Ocean

Abstract Pop-up satellite archival tags were deployed on 40 white marlin Kajika albida (synonym: Tetrapturus albidus) off the coasts of Maryland and North Carolina (United States), and the island nation of Aruba in the Caribbean. Useful data were available for analysing vertical and horizontal habitat use from 28 individuals. Time at liberty ranged from 10 to 181 d (mean 115, SD 53.3). Seasonal southerly fall migration routes were documented for fish released off the northeastern United States, while those released off Aruba remained in the Caribbean basin. Horizontal movements ranged from 228 to 8084 km (19–100 km d−1) based on light-level geolocation estimates using a sea surface temperature and bathymetry-corrected Kalman filter. Analyses included an evaluation of vertical movements using ΔT, the time spent at temperature relative to the uniform temperature surface layer. Movements included exploration of depths as great as 387 m and ambient temperatures as low as 7.8°C. However, the greatest proportion of time was spent in the upper 20 m of the water column for both day (50.8%) and night (81.6%), and time spent in water colder than 7°C below the uniform temperature surface layer was negligible. Overall, this group showed less variability in vertical movement, and less tolerance to colder temperatures compared with similar studies for blue marlin Makaira nigricans and sailfish Istiophorus platypterus. Values for ΔT are presented in tabular format to allow direct input into habitat standardization models used to estimate vertical distribution and population abundance. The large spatial dispersion and disparate tracks illustrated in the present study serve to underscore the complexity of white marlin behaviour and habitat use, and further emphasize the many challenges facing the management and conservation of this overexploited species.

Migratory connectivity of a Neotropical migratory songbird revealed by archival light-level geolocators.

Understanding migratory connectivity is critical for interpreting population dynamics, seasonal interactions, and for the implementation of conservation strategies of migratory species. We evaluated the migratory connectivity of a Neotropical migratory songbird, the Ovenbird (Seiurus aurocapilla) using archival light-level geolocators deployed at two breeding and four nonbreeding locations while incorporating Ovenbird abundance as prior information using Bayes' Rule. We also included band recoveries submitted to the United States Geological Survey's Bird Banding Laboratory to assess connectivity of areas where geolocators were not deployed. We created a probabilistic map of origin for each capture site and mapped spring migration routes between nonbreeding and breeding locations. We found a complete separation of eastern and western populations of Ovenbirds throughout the annual cycle. Breeding Ovenbirds from western Canada spent the nonbreeding season throughout Central America and migrated through central North America during spring migration. Birds breeding in the northeastern United States were distributed throughout the central Greater Antilles in the Caribbean and migrated through eastern North America during spring migration. Fall migration routes were not included because the timing of migration coincided with fall equinox when latitudinal estimates are unreliable. However, longitudinal estimates suggest no overlap between eastern and western populations during fall migration. Ovenbirds with geolocators attached in Jamaica bred in the northeastern United States with the highest posterior probability of origin found in Massachusetts, while Ovenbirds captured in Florida and Puerto Rico bred primarily in the mid-Atlantic. Incorporating Ovenbird abundance as a prior into geolocator estimates decreased the area of origin by 90.37% ± 1.05% (mean ± SE) for the breeding season and 62.30% ± 1.69% for the nonbreeding season, compared to geolocator estimates alone. Ovenbirds exhibited strong migratory connectivity between breeding and nonbreeding season, which has important implications for various aspects of the ecology, evolution, and conservation.

Integrating information from geolocators, weather radar, and citizen science to uncover a key stopover area of an aerial insectivore

ABSTRACT. Determining the distribution of stopover and overwintering areas of migratory animals is essential for understanding population dynamics and building predictive models. Tree Swallows (Tachycineta bicolor) are small songbirds that breed across North America. Data from Doppler weather radar and eBird indicate that Tree Swallow numbers increase throughout October and November in southeastern Louisiana, but then decrease during December. We thus hypothesized that southeastern Louisiana is a stopover area used by Tree Swallows during fall migration before they move to farther overwintering areas. We tested this hypothesis by attaching light-logging geolocators to Tree Swallows at five breeding sites spanning the species' breeding range from British Columbia to Nova Scotia, and then tracking their fall migration routes, stopover sites, and wintering locations. Of 38 individuals that returned in the following breeding season, 11 birds from three breeding sites (Saskatchewan, Wisconsin, and Ontario) use...

Migration and Wintering Areas of American Bitterns (Botaurus lentiginosus) that Summer in Central North America as Determined by Satellite and Radio Telemetry, 1998–2003

Abstract. Twenty adult male American Bitterns (Botaurus lentiginosus) were marked on summer range in central North America with satellite tracking Platform Transmitter Terminals (PTTs) to document migration routes and wintering range. Nineteen complete fall migration routes were documented for 17 individuals. Of the successful migrations, 63% (n = 12) went to southern Florida, 32% (n = 6) to southern Louisiana, and 5% (n = 1) to the Gulf coast of Texas. Spring migrations for nine birds were documented, and 78% (n = 7) showed fidelity to breeding range. Two complete migrations for two individuals were documented, and they demonstrated fidelity to winter range. The longest, fastest movement documented was 2,300 km in less than 74 hr. Extensive, post-breeding dispersal was not observed in the adult male American Bitterns in this study. Six male American Bitterns were marked with PTTs on winter range in Florida and Texas. Spring migration for these birds was documented to Nebraska, North Dakota, Saskatchewan,...

Fall Migration and Habitat Use of American Woodcock in the Central United States

Abstract: Little is known about the migration ecology of the American woodcock (Scolopax minor). From 2001 to 2003, we began a 3‐year study to document woodcock fall migration routes, rates, and habitat use from Minnesota, Wisconsin, and Michigan, USA. Some 586 radiomarked woodcock initiated migration. During 224 hours of aerial telemetry, we located 42 radiomarked woodcock in 6 states. Using locations of radiomarked birds, we speculated woodcock migration routes in the central United States. Stopover duration often exceeded 4 days, with some birds stopping longer than a week. Radiomarked birds were located in upland habitats more frequently than bottomland habitats, and used a higher proportion of mature forest than expected. A Geographic Information System was used to map potential woodcock habitat in the Central Region. Based on our results, we identified possible fall migration routes and priority areas for woodcock management in the Central Region. Our results should be used by land managers to prioritize future land acquisition and management of woodcock habitat.

Fall Migration Routes, Timing, and Wintering Sites of North American Ospreys as Determined by Satellite Telemetry

AbstractSatellite telemetry was used to determine fall migratory movements of Ospreys (Pandion haliaetus) breeding in the United States. Study areas were established along the lower Columbia River between Oregon and Washington; in north-central Minnesota; on Shelter Island, New York; and in southern New Jersey. Seventy-four adults (25 males, 49 females) were tracked from 1995 through 1999. Migration routes differed among populations but not by sex. Western Ospreys migrated through California and to a lesser degree other western states and wintered in Mexico (88%), El Salvador (6%), and Honduras (6%) (25.9°N to 13.0°N and 108.3°W to 87.3°W). Minnesota Ospreys migrated along three routes: (1) through the Central U.S. and then along the east coast of Mexico, (2) along the Mississippi River Valley, then across the Gulf of Mexico, or (3) through the southeastern U.S., then across the Caribbean. East Coast birds migrated along the eastern seaboard of the U.S., through Florida, and across the Caribbean. Midwestern birds wintered from Mexico south to Bolivia (22.35°N to 13.64°S, and 91.75°W to 61.76°W), while East Coast birds wintered from Florida to as far south as Brazil (27.48°N to 18.5°S and 80.4°W to 57.29°W). Dates of departure from breeding areas differed significantly between sexes and geographic regions, with females leaving earlier than males. Western birds traveled a shorter distance than either midwestern or eastern Ospreys. Females traveled farther than males from the same population, which resulted in females typically wintering south of males.Rutas de Migración Otoñales, Coordinación y Sitios de Invernada de Pandion haliaetus Determinados por Telemetría SatelitalResumen. Se utilizó telemetría satelital para determinar los movimientos de migración de otoño de individuos de Pandion haliaetus que nidifican en los Estados Unidos. Las áreas de estudio se establecieron a lo largo del Río Columbia entre Oregon y Washington; en el centro-norte de Minnesota; en la Isla Shelter, Nueva York; y en el sur de Nueva Jersey. Setenta y cuatro adultos (25 machos, 49 hembras) fueron seguidos mediante telemetría desde 1995 hasta 1999. Las rutas de migración se diferenciaron entre poblaciones pero no entre sexos. Los individuos de P. haliaetus del oeste, migraron a través de California y en menor grado a través de otros estados del oeste e invernaron en México (88%), El Salvador (6%) y Honduras (6%) (25.9°N a 13.0°N y 108.3°O a 87.3°O). Las aves de Minnesota migraron a lo largo de tres rutas: (1) a través del los E.E.U.U. centrales y luego a lo largo de la costa este de México, (2) a lo largo del valle del Río Mississippi y luego a través del Golfo de México, o (3) a través del sur de los E.E.U.U. y luego a través del Caribe. Las aves de la costa este, migraron a lo largo de la costa este de los E.E.U.U., por Florida y a través del Caribe. Las aves del medio-oeste, invernaron desde México hacia el sur hasta Bolivia (22.35°N a 13.64°S, y 91.75°O a 61.76°O), mientras que las aves de la costa este invernaron desde Florida hasta tan al sur como Brasil (27.48°N a 18.5°S y 80.4°O a 57.29°O). Las fechas de partida desde las áreas de nidificación difirieron significativamente entre sexos y regiones geográficas, partiendo las hembras antes que los machos. Las aves del oeste viajaron distancias más cortas que las aves del medio-oeste y del este. Considerando una misma población, las hembras viajaron más lejos que los machos, lo que resultó en que las hembras invernaron típicamente más al sur que los machos.

Fall Migration Routes, Timing, and Wintering Sites of North American Ospreys as Determined by Satellite Telemetry

Abstract Satellite telemetry was used to determine fall migratory movements of Ospreys (Pandion haliaetus) breeding in the United States. Study areas were established along the lower Columbia River between Oregon and Washington; in north-central Minnesota; on Shelter Island, New York; and in southern New Jersey. Seventy-four adults (25 males, 49 females) were tracked from 1995 through 1999. Migration routes differed among populations but not by sex. Western Ospreys migrated through California and to a lesser degree other western states and wintered in Mexico (88%), El Salvador (6%), and Honduras (6%) (25.9°N to 13.0°N and 108.3°W to 87.3°W). Minnesota Ospreys migrated along three routes: (1) through the Central U.S. and then along the east coast of Mexico, (2) along the Mississippi River Valley, then across the Gulf of Mexico, or (3) through the southeastern U.S., then across the Caribbean. East Coast birds migrated along the eastern seaboard of the U.S., through Florida, and across the Caribbean. Midwest...

A Possible Relationship between Reversed Sexual Size Dimorphism and Reduced Male Survivorship in the Ruby-Throated Hummingbird

An examination of 28 years of banding data from Powdermill Nature Reserve in southwestern Pennsylvania showed the following trends in the sex ratio (female: male) of Ruby-throated Hummingbirds (Archilochus colubris): 1.1:1 for immature hummingbirds caught in late summer and fall; 1.4:1 for adults in spring (April-May); 3.1:1 for adults in summer (June-7 August); and 4.1:1 for adults in fall (8 August-October). Hypotheses to explain these increasingly female-biased sex ratios include differential migration, capture bias and differential mortality. Banding data from eight other stations in eastern North America provided no evidence of different fall migration routes for males and females. We detected no capture bias at Powdermill, with respect to mesh size of mist nets, net wariness or net avoidance ability, but there was seasonal variation in the number of overlapping captures of males and females at individual mist nets: spring (81.5%); summer (27.6%); fall (44.7%). A capture bias resulting from differences between the sexes in the use of habitats sampled by our mist nets has likely contributed to observed sex ratio variation. Differential mortality, with males suffering greater losses than females, probably also contributed to this variation. Estimated annual survivorship calculated from returns of banded hummingbirds to Powdermill was lower for males (0.294) than females (0.446), but this difference was not significant. The mean minimum known age for returning male hummingbirds at Powdermill was significantly less than that for females; furthermore, the oldest known age for a returning male (three years) was half that observed for a female. The lower inferred survivorship for males may be related to reversed sexual size dimorphism in this species. The body mass of female Ruby-throated Hummingbirds was significantly greater than that of males and did not vary between May and August, whereas males weighed significantly less in June and July than they did in May and August. Low mid-summer mass in males, coupled with increased metabolic demands during the breeding season, may lead to a fatal "energy crisis" in this sex during nocturnal fasting or periods of inclement weather.

Foods of Lesser Scaups on Breeding, Migration, and Wintering Areas

This food habits study was based on stomach contents of 164 lesser scaups (Aythya affinis): 39 from a breeding area in Manitoba, 88 from a fall concentration area on the Mississippi River in Illinois, and 37 from two wintering areas on the Louisiana coast. Animal foods made up the bulk of the diet of all three groups: 91.1 percent on the breeding area, 93.5 percent on the fall concentration area, and 63.7 percent on the wintering areas. The most important animal foods were amphipod crustaceans on the breeding area, molluscs on the fall concentration area, and fishes on the wintering areas. The percentages of animal foods are similar to those found in other recent investigations, but they differ from earlier findings which show the lesser scaup to be chiefly vegetarian. Additional collecting is needed, especially in early spring, for a more accurate picture of seasonal food habits but present information shows that lesser scaups feed chiefly, and sometimes almost exclusively, on animals most of the year. Animal foods decrease in the diet from summer to winter and probably reach a low point in late winter and early spring. Food habits data reflect the close relationship of the lesser and the greater scaup and show that they differ sharply from other North American members of their genus, which are chiefly vegetarians. A general picture of the food habits of the lesser scaup was given by Cottam (1939:38-46) who presented data on 1,051 stomachs from various localities in North America and reviewed the findings of earlier investigators. Since then, additional information has been obtained from scaups collected along fall migration routes (Korschgen 1955, Anderson 1959) and on wintering areas (Cronan 1957, Harmon 1962), but little attention has been given to food habits on the breeding ground. Munro (1941:134-137) reported the foods of 45 lesser scaups from British Columbia breeding areas. Cottam's (1939) data also included specimens from breeding areas but they were not discussed separately, except for 17 juveniles collected in western Canada. No information from other parts of the breeding range was found in the literature. This paper reports the foods eaten by adult lesser scaups on a breeding area in southwestern Manitoba, a fall concentration area on the Mississippi River in Illinois, and two wintering areas in Louisiana. Comparisons are made with previously published studies. Data from breeding and wintering areas were derived from 76 stomachs taken from specimens collected primarily for a study of the reproductive organs. Nineteen specimens in 1959 and 20 in 1960 were obtained in the pothole country around Erickson, Manitoba, during spring and summer. The other 37 were collected in marshes around Lake Borgne near New Orleans, Louisiana, in December, 1959 (20 specimens), and f om roadside ditches and ponds near Grand Chenier, southwestern Louisiana, in late February and early March, 1960 (17 specimens). Data from the fall concentration area are based on 88 stomachs taken from lesser scaups shot by hunters at Keokuk Pool on the Mississippi River, Hancock County, Illinois, during fall, 1948. Illinois specimens were provided by George C. Arthur, Illinois Department of Conservation, who generously contributed them to this study. The authors are in1 Contribution from the Gaylord Memorial Laboratory, the Delta Waterfowl Research Station, the Missouri Department of Conservation, and the Missouri Cooperative Wildlife Research Unit.

The Ring-Necked Duck as a Transient in the Northeastern States

IN Mendall's important announcement (Auk, 55: 401-404, 1938) of the breeding of the Ring-necked Duck (Nyroca collaris) in some numbers in northern Maine and New Brunswick, field workers in the northeastern States have at last found an explanation of why this species has changed to a regular transient in recent years, whereas it was formerly an accidental visitant. The degree to which this has become increasingly true in the past five years is information as yet unpublished or scattered in local publications, and a summary of it is offered here as a matter of general record. The facts of chief interest are: (1) the number of birds is far greater than realized; (2) definite spring and fall migration routes have been established; (3) the Ring-necked Duck has very definite habitat preference in the area considered; (4) all these factors suggest very strongly the inference that the local transients are not going to or coming from the original northwestern breeding area, as they do not behave in the way that the other species in this group( do. From 1922 on, in New Jersey and the New York City region, the Ringnecked Duck became a regular spring transient in certain inland ponds, marshes and reservoirs. It was several years later that the bird became of regular occurrence on Long Island, and then chiefly in fall and winter (Griscom, Auk, 46: 52, 1929). Farther south in New Jersey, we learn (Stone, 'Bird Studies at Old Cape May') that Delaware City is a good place in spring with a maximum of 83 on April 14, 1935. At Barnegat Bay on the outer coast, however, the late Charles A. Urner found no real spring migration at all. The bird is an uncommon fall migrant, the maximum only thirty-one birds in an entire season, and when wintering lingers to April 1. Farther north, judging from the records in the 'Proceedings' of the Linnaean Society of New York, the Ring-necked Duck is rapidly increasing on the inland ponds and reservoirs of northern New Jersey and New York State (reservoirs of Westchester County). Where we used to see from one to twelve birds in spring, flocks of thirty to a hundred individuals are now of annual occurrence. The spring migration amounts to much less elsewhere, and is often entirely lacking on Long Island. The final point of interest is the lateness of this migration. As with the Blue-winged Teal, early April is often the peak of the flight, and a few birds linger to April 20. Proceeding northward into New England, the Ring-neck is regularly recorded in the lakes of western Connecticut. In Massachusetts it was not until 1930 (eight years later than in New Jersey) that it became a regular