Adult-Like Plumage Coloration Predicts Winter Territory Quality and Timing of Arrival on the Breeding Grounds of Yearling Male American Redstarts

The Condor ◽  
2010 ◽  
Vol 112 (4) ◽  
pp. 676-682 ◽  
Author(s):  
Ryan R. Germain ◽  
Peter P. Marra ◽  
T. Kurt Kyser ◽  
Laurene M. Ratcliffe
2011 ◽  
Vol 278 (1723) ◽  
pp. 3437-3443 ◽  
Author(s):  
Colin E. Studds ◽  
Peter P. Marra

Climatic warming has intensified selection for earlier reproduction in many organisms, but potential constraints imposed by climate change outside the breeding period have received little attention. Migratory birds provide an ideal model for exploring such constraints because they face warming temperatures on temperate breeding grounds and declining rainfall on many tropical non-breeding areas. Here, we use longitudinal data on spring departure dates of American redstarts ( Setophaga ruticilla ) to show that annual variation in tropical rainfall and food resources are associated with marked change in the timing of spring departure of the same individuals among years. This finding challenges the idea that photoperiod alone regulates the onset of migration, providing evidence that intensifying drought in the tropical winter could hinder adaptive responses to climatic warming in the temperate zone.


The Auk ◽  
2007 ◽  
Vol 124 (2) ◽  
pp. 594-605
Author(s):  
Craig R. Ely ◽  
Karen S. Bollinger ◽  
Roseann V. Densmore ◽  
Thomas C. Rothe ◽  
Michael J. Petrula ◽  
...  

Abstract Migration and reproductive strategies in waterbirds are tightly linked, with timing of arrival and onset of nesting having important consequences for reproductive success. Whether migratory waterbirds are capital or income breeders is predicated by their spring migration schedule, how long they are on breeding areas before nesting, and how adapted they are to exploiting early spring foods at northern breeding areas. However, for most species, we know little about individual migration schedules, arrival times, and duration of residence on breeding areas before nesting. To document these relationships in a northern nesting goose, we radiotracked winter-marked Tule Greater White-fronted Geese (Anser albifrons elgasi; hereafter “Tule Geese”; n = 116) from the time of their arrival in Alaska through nesting. Tule Geese arrived on coastal feeding areas in mid-April and moved to nesting locations a week later. They initiated nests 15 days (range: 6–24 days) after arrival, a period roughly equivalent to the duration of rapid follicle growth. Tule Geese that arrived the earliest were more likely to nest than geese that arrived later; early arrivals also spent more time on the breeding grounds and nested earlier than geese that arrived later. The length of the prenesting period was comparable to that of other populations of this species, but longer than for goose species that initiate rapid follicle growth before arrival on the breeding grounds. We suggest that Tule Geese nesting in more temperate climates are more likely to delay breeding to exploit local food resources than Arctic-nesting species that may be constrained by short growing seasons. Estrategias Reproductivas de los Gansos del Norte: ¿Por Qué Esperar?


1988 ◽  
Vol 66 (10) ◽  
pp. 2255-2261 ◽  
Author(s):  
Michael M. J. Morris ◽  
Robert E. Lemon

We consider the hypothesis that mate choice in American Redstarts (Setophaga ruticilla) depends primarily on features of territories held by males. We test the hypothesis that the territories of yearling males are demonstrably different from and inferior for reproduction to those of adult males. Territories held by the two age-classes in New Brunswick, Canada, were floristically different, but there were also major differences in territorial features in three microgeographic areas, both within each age-group and without regard to age. There were greater differences in nest success between areas than between the age-classes. We detected no differences in immediate nest site features between nests built by the mates of yearling and adult males. There were differences across the three areas in the species of trees used as nest sites, probably reflecting differences in availability. Support for the claim of different reproductive success in relation to quality of territories held by the two age-classes of males is not convincing.


1984 ◽  
Author(s):  
Richard J. Scully ◽  
Edwin W. Buettner ◽  
Clay Cummins

The Auk ◽  
1986 ◽  
Vol 103 (4) ◽  
pp. 694-700 ◽  
Author(s):  
Hisashi Nagata

Abstract Morphological and territorial factors that influence female mate choice were examined in the monogamous Middendorff's Grasshopper-Warbler (Locustella ochotensis) on an islet near Fukuoka, Japan. I assumed that pairing date corresponded with female mate choice. Pairing date was correlated with both territory size and food abundance but was not correlated with selected morphological characteristics of males. Territorial quality was assumed to be correlated with territory size because preferable food resources and nest sites were distributed randomly. I conclude that female mate choice was influenced by territory quality rather than by the morphological characteristics of males.


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 4 (1) ◽  
Author(s):  
Elena Schall ◽  
Karolin Thomisch ◽  
Olaf Boebel ◽  
Gabriele Gerlach ◽  
Sari Mangia Woods ◽  
...  

AbstractHumpback whales are thought to undertake annual migrations between their low latitude breeding grounds and high latitude feeding grounds. However, under specific conditions, humpback whales sometimes change their migratory destination or skip migration overall. Here we document the surprising persistent presence of humpback whales in the Atlantic sector of the Southern Ocean during five years (2011, 2012, 2013, 2017, and 2018) using passive acoustic data. However, in the El Niño years 2015 and 2016, humpback whales were virtually absent. Our data show that humpback whales are systematically present in the Atlantic sector of the Southern Ocean and suggest that these whales are particularly sensitive to climate oscillations which have profound effects on winds, sea ice extent, primary production, and especially krill productivity.


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