Contrasting Fattening Strategies in Related Migratory Species: The Blackcap, Garden Warbler, Common Whitethroat and Lesser Whitethroat

2015 ◽  
Vol 52 (1-2) ◽  
pp. 115-127 ◽  
Author(s):  
Agnieszka Ożarowska
The Condor ◽  
2021 ◽  
Author(s):  
Clark S Rushing ◽  
Aimee M Van Tatenhove ◽  
Andrew Sharp ◽  
Viviana Ruiz-Gutierrez ◽  
Mary C Freeman ◽  
...  

Abstract Archival geolocators have transformed the study of small, migratory organisms but analysis of data from these devices requires bias correction because tags are only recovered from individuals that survive and are re-captured at their tagging location. We show that integrating geolocator recovery data and mark–resight data enables unbiased estimates of both migratory connectivity between breeding and nonbreeding populations and region-specific survival probabilities for wintering locations. Using simulations, we first demonstrate that an integrated Bayesian model returns unbiased estimates of transition probabilities between seasonal ranges. We also used simulations to determine how different sampling designs influence the estimability of transition probabilities. We then parameterized the model with tracking data and mark–resight data from declining Painted Bunting (Passerina ciris) populations breeding in the eastern United States, hypothesized to be threatened by the illegal pet trade in parts of their Caribbean, nonbreeding range. Consistent with this hypothesis, we found that male buntings wintering in Cuba were 20% less likely to return to the breeding grounds than birds wintering elsewhere in their range. Improving inferences from archival tags through proper data collection and further development of integrated models will advance our understanding of the full annual cycle ecology of migratory species.


2021 ◽  
Vol 11 (7) ◽  
pp. 337
Author(s):  
Sara Costa Carvalho ◽  
Heitor Oliveira Braga ◽  
Sofia de Santa-Maria ◽  
Beatriz Fonte ◽  
Mário Jorge Pereira ◽  
...  

This study aims at evaluating the environmental education (EE) and communication intervention for the valorization of migratory fish resources in an estuary of northern Portugal. The EE component intervention was implemented among Middle School pupils of that region. Students’ knowledge was quantitatively evaluated with an experimental approach of pre-testing and post-testing, on the ocean and estuarine literacy (OEL) and biology of migratory species, such as sea lamprey. This study also analyzes the communication component developed via social media. Results of the EE component show an evident increment of OEL (p < 0.05). It is also highlighted that students had previous knowledge on issues that are not covered in the curriculum. Social media has shown to be an effective communication tool mostly among the scientific community (e.g., Ethnobiology). The research has various implications to OEL since it brings a new perspective towards the integration of ocean literacy in formal education; as well as the valorization of Students’ local ecological knowledge and of inter-generational dynamics. This study contributed to promoting local biodiversity, OEL, and participatory local governance of these ecosystems.


The Auk ◽  
2021 ◽  
Author(s):  
Jessie L Williamson ◽  
Christopher C Witt

Abstract Elevational migration can be defined as roundtrip seasonal movement that involves upward and downward shifts in elevation. These shifts incur physiological challenges that are proportional to the degree of elevational change. Larger shifts in elevation correspond to larger shifts in partial pressure of oxygen, air density, temperature, and ultraviolet (UV) exposure. Although most avian examples of elevational migration involve subtle shifts that would have minimal impacts on physiology, shifts of any magnitude have previously been considered under the broad umbrella of “elevational migration”. Here, we consider extreme seasonal elevational movements (≥2,000 m), sufficient to shift the elevational dimension of the eco-climatic niche. Migratory bird populations typically maintain inter-seasonal stability in the temperature, precipitation, and elevational aspects of their climatic niches, a tendency that likely reflects genetic physiological specialization on environmental conditions such as atmospheric pressure. A shift of ≥2,000 m involves a ≥20% change in air density and oxygen partial pressure, sufficient to incur functionally impactful declines in arterial blood-oxygen saturation and require compensatory shifts in respiratory physiology. We refer to this phenomenon as elevational niche-shift migration (ENSM). In this review, we analyzed &gt;4 million occurrence records to identify 105 populations, representing 92 bird species, that undergo complete or partial ENSM. We identified key ecological and evolutionary questions regarding the causes and consequences of ENSM. Our synthesis reveals that ENSM has evolved independently in at least 29 avian families spanning 10 orders. Nonetheless, ENSM is rare relative to other forms of seasonal migration, consistent with the general tendency of seasonal niche conservatism by migratory species and evolutionarily conserved elevational range limits. For many migratory species and populations, within-species patterns of migratory connectivity are not sufficiently understood to determine ENSM status. ENSM is distinguished by its scale within the broader phenomenon of elevational migration. Critical examination of ENSM illustrates fundamental constraints on the ecology and evolution of migration systems, topographical influences on geographic patterns of migratory connectivity, and the remarkable metabolic flexibility of certain bird species that allows them to occupy disparate elevations across different seasons.


2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Andrea Ferretti ◽  
Scott R McWilliams ◽  
Niels C Rattenborg ◽  
Ivan Maggini ◽  
Massimiliano Cardinale ◽  
...  

Synopsis Little is known about how songbirds modulate sleep during migratory periods. Due to the alternation of nocturnal endurance flights and diurnal refueling stopovers, sleep is likely to be a major constraint for many migratory passerine species. Sleep may help to increase the endogenous antioxidant capacity that counteracts free radicals produced during endurance flight and reduces energy expenditure. Here, we investigated the relationship between sleep behavior, food intake, and two markers of physiological condition—the amount of energy reserves and oxidative status—in two migratory songbird species, the garden warbler (Sylvia borin) and the whitethroat (Sylvia communis). In garden warblers, birds with high energy stores were more prone to sleep during the day, while this condition-dependent sleep pattern was not present in whitethroats. In both species, birds with low energy stores were more likely to sleep with their head tucked in the feathers during nocturnal sleep. Moreover, we found a positive correlation between food intake and the extent of energy reserves in garden warblers, but not in whitethroats. Finally, we did not find significant correlations between oxidative status and sleep, or oxidative status and energy stores. Despite our study was not comparative, it suggests that different species might use different strategies to manage their energy during stopover and, additionally, it raises the possibility that migrants have evolved physiological adaptations to deal with oxidative damage produced during migration.


Author(s):  
Conor Ryan ◽  
Pádraig Whooley ◽  
Simon D. Berrow ◽  
Colin Barnes ◽  
Nick Massett ◽  
...  

Knowledge on the ecology of humpback whales in the eastern North Atlantic is lacking by comparison with most other ocean basins. Humpback whales were historically over-exploited in the region and are still found in low relative abundances. This, coupled with their large range makes them difficult to study. With the aim of informing more effective conservation measures in Ireland, the Irish Whale and Dolphin Group began recording sightings and images suitable for photo-identification of humpback whales from Irish waters in 1999. Validated records submitted by members of the public and data from dedicated surveys were analysed to form a longitudinal study of individually recognizable humpback whales. The distribution, relative abundance and seasonality of humpback whale sighting records are presented, revealing discrete important areas for humpback whales in Irish coastal waters. An annual easterly movement of humpback whales along the southern coast of Ireland is documented, mirroring that of their preferred prey: herring and sprat. Photo-identification images were compared with others collected throughout the North Atlantic (N = 8016), resulting in matches of two individuals between Ireland and Iceland, Norway and the Netherlands but no matches to known breeding grounds (Cape Verde and West Indies). This study demonstrates that combining public records with dedicated survey data is an effective approach to studying low-density, threatened migratory species over temporal and spatial scales that are relevant to conservation and management.


2004 ◽  
Vol 31 (3) ◽  
pp. 177-180 ◽  
Author(s):  
HENRY P. HUNTINGTON ◽  
ROBERT S. SUYDAM ◽  
DANIEL H. ROSENBERG

The integration or co-application of traditional knowledge and scientific knowledge has been the subject of considerable research and discussion (see Johannes 1981; Johnson 1992; Stevenson 1996; McDonald et al. 1997; Huntington et al. 1999, 2002), with emphasis on various specific topics including environmental management and conservation (see Freeman & Carbyn 1988; Ferguson & Messier 1997; Ford & Martinez 2000; Usher 2000; Albert 2001). In most cases, examples of successful integration compare traditional and scientific observations at similar spatial scales to increase confidence in understanding or to fill gaps that appear from either perspective. We present a different approach to integration, emphasizing complementarity rather than concordance in spatial perspective, using two migratory species as examples.


Sign in / Sign up

Export Citation Format

Share Document