scholarly journals Body mass of six long-distance migrant passerine species along the autumn migration route

2000 ◽  
Vol 141 (4) ◽  
pp. 441-460 ◽  
Author(s):  
Michael Schaub ◽  
Lukas Jenni
The Condor ◽  
2003 ◽  
Vol 105 (3) ◽  
pp. 420-427 ◽  
Author(s):  
Åke Lindström ◽  
Marcel Klaassen

Abstract The basal metabolic rate (BMR) of Old World long-distance-migrant shorebirds has been found to vary along their migration route. On average, BMR is highest in the Arctic at the start of fall migration, intermediate at temperate latitudes, and lowest on the tropical wintering grounds. As a test of the generality of this pattern, we measured the BMR of one adult and 44 juvenile shorebirds of 10 species (1–18 individuals of each species, body-mass range 19–94 g) during the first part of their southward migration in the Canadian Arctic (68–76°N). The interspecific relationship between BMR and body mass was almost identical to that found for juvenile shorebirds in the Eurasian Arctic (5 species), although only one species appeared in both data sets. We conclude that high BMR of shorebirds in the Arctic is a circumpolar phenomenon. The most likely explanation is that the high BMR reflects physiological adaptations to low ambient temperatures. Whether the BMR of New World shorebirds drops during southward migration remains to be investigated. Altas Tasas Metabólicas Basales de Aves Playeras Mientras Se Encuentran en el Ártico: Una Visión Circumpolar Resumen. Se ha encontrado que la tasa metabólica basal (TMB) de las aves playeras migratorias de larga distancia varía a lo largo de sus rutas de migración en el viejo mundo. En promedio, la TMB es máxima al comienzo de la migración otoñal en el ártico, intermedia en latitudes templadas y mínima en las áreas tropicales de invernada. Para poner a prueba la generalidad de este patrón, medimos la TMB de un individuo adulto y 44 juveniles de diez especies de aves playeras (1–18 individuos de cada especie, rango de peso corporal 19–94 g) durante la primera parte de su migración hacia el sur en el ártico canadiense (68–76°N). La relación interespecífica entre la TMB y el peso corporal fue casi idéntica a la que se había encontrado en juveniles de 5 especies de aves playeras en el ártico de Eurasia, aunque sólo una especie fue considerada en ambos estudios. Concluimos que la alta TMB de las aves playeras en el ártico representa un fenómeno circumpolar. La explicación más probable es que las altas TMBs reflejan adaptaciones fisiológicas a ambientes de bajas temperaturas. Aún no se ha investigado si las TMBs de las aves playeras del nuevo mundo disminuyen durante la migración hacia el sur.


2021 ◽  
Vol 325 (3) ◽  
pp. 339-347
Author(s):  
V.A. Payevsky

According to standardized bird trapping for banding purposes the population trends of Wrynecks (Jynx torquilla Linnaeus, 1758), Lesser Whitethroats (Sylvia curruca Linnaeus, 1758), Tree Pipits (Anthus trivialis Linnaeus, 1758), and Red-backed Shrikes (Lanius collurio Linnaeus, 1758) over 45 years in the Courish Spit, Eastern Baltic, indicate two periods, an initial population growth and a subsequent significant decline. All results, including the already published data on the Barred Warblers, indicate that 5 species of long-distance trans-Saharan migrants experienced a significant decline in numbers since the mid-1970s. Ringing protocol included determination of age and taking biometric measurements, the wing length as a proxy of structural size, and body mass. During the period of population decline, neither wing length, nor body mass of birds changed. None of the indicators of population productivity (clutch size, average brood size, breeding success) did not change, either. Presumably this may mean that the reasons for the population decline of the species are related to factors affecting birds on migration route or in wintering areas, and not on their breeding grounds. It is known that in catastrophic droughts on the African continent, the quality of habitats deteriorates, and competition for food leads to an increase in the mortality rate of wintering birds.


2003 ◽  
Vol 13 (3) ◽  
pp. 213-226 ◽  
Author(s):  
Tomas Aarvak ◽  
Ingar Jostein Øien

In this study we demonstrate that non-breeding adult Lesser White-fronted Geese Anser erythropus from the Fennoscandian breeding population may undertake long-distance moult migration eastwards. Of three individuals equipped with satellite transmitters at a spring staging site in northern Norway, two migrated to moulting sites in the area of Kolgujev Island and Kanin Peninsula, while the third headed towards the Taimyr Peninsula, all in northern Russia. The first leg of the moult migration route for non-breeders was between Finnmark, Norway and the Kanin Peninsula area in north-western Russia, a similar route to that taken on autumn migration by Fennoscandian Lesser White-fronted Geese that had bred successfully. After the moulting period, one of the individuals followed a south-western route to Poland and Germany, where it spent the first part of the winter. The satellite signals from the other two geese ceased abruptly in early autumn, indicating that the birds may have been illegally shot in Russia. Locating new moulting and migration stopover sites is of crucial importance for the conservation of the critically endangered Fennoscandian subpopulation of this species.


2006 ◽  
Vol 63 (8) ◽  
pp. 1752-1762 ◽  
Author(s):  
Matthew L Keefer ◽  
Christopher C Caudill ◽  
Christopher A Peery ◽  
Theodore C Bjornn

Upstream-migrating adult salmon must make a series of correct navigation and route-selection decisions to successfully locate natal streams. In this field study, we examined factors influencing migration route selections early in the migration of 4361 radio-tagged adult Chinook salmon (Oncorhynchus tshawytscha) as they moved upstream past dams in the large (~1 km wide) Columbia River. Substantial behavioral differences were observed among 11 conspecific populations, despite largely concurrent migrations. At dams, Chinook salmon generally preferred ladder passage routes adjacent to the shoreline where their natal tributaries entered, and the degree of preference increased as salmon proximity to natal tributaries increased. Columbia River discharge also influenced route choices, explaining some route selection variability. We suggest that salmon detect lateral gradients in orientation cues across the Columbia River channel that are entrained within tributary plumes and that these gradients in cues can persist downstream for tens to hundreds of kilometres. Detection of tributary plumes in large river systems, using olfactory or other navigation cues, may facilitate efficient route selection and optimize energy conservation by long-distance migrants.


2009 ◽  
Vol 82 (5) ◽  
pp. 549-560 ◽  
Author(s):  
François Vézina ◽  
Magali Petit ◽  
Deborah M. Buehler ◽  
Anne Dekinga ◽  
Theunis Piersma

2011 ◽  
Vol 7 (6) ◽  
pp. 833-835 ◽  
Author(s):  
Raymond H. G. Klaassen ◽  
Thomas Alerstam ◽  
Peter Carlsson ◽  
James W. Fox ◽  
Åke Lindström

Migratory land birds perform extreme endurance flights when crossing ecological barriers, such as deserts, oceans and ice-caps. When travelling over benign areas, birds are expected to migrate by shorter flight steps, since carrying the heavy fuel loads needed for long non-stop flights comes at considerable cost. Here, we show that great snipes Gallinago media made long and fast non-stop flights (4300–6800 km in 48–96 h), not only over deserts and seas but also over wide areas of suitable habitats, which represents a previously unknown migration strategy among land birds. Furthermore, the great snipes achieved very high ground speeds (15–27 m s −1 ), which was not an effect of strong tailwind support, and we know of no other animal that travels this rapidly over such a long distance. Our results demonstrate that some migratory birds are prepared to accept extreme costs of strenuous exercise and large fuel loads, even when stopover sites are available along the route and there is little tailwind assistance. A strategy of storing a lot of energy before departure, even if migration is over benign habitats, may be advantageous owing to differential conditions of fuel deposition, predation or infection risk along the migration route.


Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2208
Author(s):  
Bernice Goffin ◽  
Marcial Felgueiras ◽  
Anouschka R. Hof

Many long-distance migratory bird species are in decline, of which environmental changes, such as climate change and land-use changes, are thought to be important drivers. The effects of environmental change on the migration of these birds have often been studied during spring migration. Fewer studies have explored the impacts of environmental change on autumn migration, especially at stopover sites. However, stopover sites are important, as the quality of these sites is expected to change over time. We investigated impacts of local environmental conditions on the migration strategy and body condition of the Pied Flycatcher (Ficedula hypoleuca) at an autumn migration stopover site using long-term ringing data (1996–2018) and local environmental conditions. We found that although the arrival and departure dates of birds at the stopover site remained unchanged, the body condition (fat score) of the individuals caught decreased, and the stopover duration increased. This suggests that conditions at the stopover site during the autumn migration period have deteriorated over time. This study emphasizes the importance of suitable stopover sites for migratory birds and stresses that changes in environmental conditions during the autumn migration period may be contributing to the current decline in long-distance migratory passerines.


The Auk ◽  
2020 ◽  
Vol 137 (4) ◽  
Author(s):  
José M Abad-Gómez ◽  
Auxiliadora Villegas ◽  
Jorge S Gutiérrez ◽  
Manuel Parejo ◽  
Juan G Navedo ◽  
...  

Abstract Migratory shorebirds (Charadrii) show a strong dichotomy in their breeding and wintering strategies: Arctic-breeding species typically spend the wintering season in marine habitats, while more southerly breeding species tend to do so in freshwater habitats where pathogens and parasites, particularly vector-borne blood parasites, are generally more abundant. Thus, it has been hypothesized that the former group may reduce their investment in immunity, but experimental data supporting this hypothesis are lacking. Moreover, whether this contrasting habitat selection can shape investments in immunocompetence among populations within a species is uncertain. We experimentally tested the hypothesis that there is a significant association between habitat occupancy and the strength of a pro-inflammatory immune response in the Dunlin (Calidris alpina), a widely distributed long-distance migratory shorebird that breeds in (sub-)arctic areas and winters mainly, but not exclusively, in coastal habitats. Overwintering Dunlins occupying inland freshwater and marine habitats at a similar latitude were captured and acclimated under identical conditions in outdoor aviaries. After an acclimation period, they were challenged with phytohemagglutinin to assess the pro-inflammatory immune response and its associated energetic costs, measured by basal metabolic rate (BMR) and body mass changes. We found that freshwater Dunlins exhibited a higher (63%) pro-inflammatory immune response than marine Dunlins. Although this difference did not involve significant BMR changes, the time course of body mass response differed between freshwater and marine individuals. Our findings point to the existence of different pro-inflammatory immune responses and body mass adjustments associated with the wintering habitat. These intraspecific differences are likely due to population adaptation rather than phenotypic plasticity, where not only disease risk but also physiological adaptations to different salinity levels could play an important role.


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