Contrasting Seasonal Survivorship of Two Migratory Songbirds Wintering in Threatened Mangrove Forests

Calvert, Anna M.; Woodcock, John; McCracken, Jon D.

doi:10.5751/ace-00377-050102

Cited by 13 publications

(7 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The mean ± SE annual Φ for male AHY GCWAs was estimated to be 0.47 ± 0.02, which is within the range of annual male AHY Φ estimates reported for other warbler species such as the Black- (Calvert et al 2010); and the Blackburnian (S. fusca) and Black-throated Green Warblers (S. virens) at 0.48 ± 0.09 (Zitske et al 2011). However, our AHY Φ estimate was 16% lower than what was reported for this species in previous Φ analyses.…”

Section: Discussionsupporting

confidence: 48%

Age-specific survival of male Golden-cheeked Warblers on the Fort Hood Military Reservation, Texas

Duarte¹,

Hines²,

Nichols³

et al. 2014

ACE

View full text Add to dashboard Cite

ABSTRACT. Population models are essential components of large-scale conservation and management plans for the federally endangered Golden-cheeked Warbler (Setophaga chrysoparia; hereafter GCWA). However, existing models are based on vital rate estimates calculated using relatively small data sets that are now more than a decade old. We estimated more current, precise adult and juvenile apparent survival (Φ) probabilities and their associated variances for male GCWAs. In addition to providing estimates for use in population modeling, we tested hypotheses about spatial and temporal variation in Φ. We assessed whether a linear trend in Φ or a change in the overall mean Φ corresponded to an observed increase in GCWA abundance during 1992-2000 and if Φ varied among study plots. To accomplish these objectives, we analyzed long-term GCWA capture-resight data from 1992 through 2011, collected across seven study plots on the Fort Hood Military Reservation using a Cormack-Jolly-Seber model structure within program MARK. We also estimated Φ process and sampling variances using a variance-components approach. Our results did not provide evidence of site-specific variation in adult Φ on the installation. Because of a lack of data, we could not assess whether juvenile Φ varied spatially. We did not detect a strong temporal association between GCWA abundance and Φ. Mean estimates of Φ for adult and juvenile male GCWAs for all years analyzed were 0.47 with a process variance of 0.0120 and a sampling variance of 0.0113 and 0.28 with a process variance of 0.0076 and a sampling variance of 0.0149, respectively. Although juvenile Φ did not differ greatly from previous estimates, our adult Φ estimate suggests previous GCWA population models were overly optimistic with respect to adult survival. These updated Φ probabilities and their associated variances will be incorporated into new population models to assist with GCWA conservation decision making. Survie en fonction de l'âge des Parulines à dos noir mâles sur la réserve militaire de Fort Hood, Texas RÉSUMÉ. Les modèles de population sont des éléments essentiels des plans de gestion et de conservation à grande échelle pour la Paruline à dos noir (Setophaga chrysoparia; abrégée PADN ci-dessous), désignée « menacée » par le gouvernement fédéral étatsunien. Toutefois, les modèles existants sont fondés sur des estimations de taux vitaux calculées à partir d'échantillons relativement petits qui datent maintenant de plus d'une décennie. Nous avons actualisé et précisé la probabilité de survie apparente (Φ) adulte et juvénile et calculé les variances associées pour les mâles PADN. En plus de ces estimations destinées à la modélisation des populations, nous avons testé les hypothèses de variations spatiale et temporelle de Φ. Nous avons évalué si une tendance linéaire de Φ ou un changement de Φ moyen correspondait à une augmentation réelle du nombre de PADN de 1992 à 2000, et si Φ avait varié entre les parcelles échantillonnées. Pour atteindre nos objectifs, nous avons analysé les données...

show abstract

Section: Discussionsupporting

confidence: 48%

Age-specific survival of male Golden-cheeked Warblers on the Fort Hood Military Reservation, Texas

Duarte¹,

Hines²,

Nichols³

et al. 2014

ACE

View full text Add to dashboard Cite

show abstract

“…), Prothonotary Warblers Protonotaria citrea and Northern Waterthrushes Parkesia noveboracensis (Calvert et al . ). In contrast, Holmes et al .…”

Section: Discussionmentioning

confidence: 97%

High within‐winter and annual survival rates in a declining Afro‐Palaearctic migratory bird suggest that wintering conditions do not limit populations

Blackburn

Cresswell

2015

Ibis

View full text Add to dashboard Cite

For migratory birds, it is necessary to estimate annual and overwinter survival rates, identify factors that influence survival, and assess whether survival varies with age and sex if we are to understand population dynamics and thus inform conservation. This study is one of the first to document overwinter and annual survival from the wintering grounds of a declining Afro-Palaearctic migrant bird, the Whinchat Saxicola rubetra. We monitored a population of marked individuals for which dispersal was low and detectability was high, allowing accurate estimates of survival. Annual survival was at least 52% and did not differ significantly across demographic groups or with habitat characteristics or residency time in the previous winter. Overwinter survival was very high and monthly survival at least 98% at some sites. Although winter residency varied spatially and with age, lower residency did not correlate with reduced annual survival, suggesting occupancy of multiple wintering sites rather than higher winter mortality of individuals with shorter residency. Our results suggest that mortality occurs primarily outside the wintering period, probably during migration, and that wintering conditions have minimal influence on survival. The similarity between survival rates for all age and sex classes when measured on the wintering grounds implies that any difference in survival with age or sex occurs only during the first migration or during the post-fledging stage, and that selection of wintering habitat, or territory quality, makes little difference to survival in Whinchats. Our findings suggest that the wintering grounds do not limit populations as much as the migratory and breeding stages, with implications for the conservation of declining Afro-Palaearctic migrants more widely.

show abstract

“…The apparent underestimation of durations when calculating ‘stopover after’ durations may reflect the difficulties of accounting for birds that leave the netting area but remain at the study site when working in large habitat patches (Calvert et al . ).…”

Section: Discussionmentioning

confidence: 97%

“…3), and when 'total stopover' durations were entered into body mass change models, resulting estimates of departure mass were well supported by recorded masses. The apparent underestimation of durations when calculating 'stopover after' durations may reflect the difficulties of accounting for birds that leave the netting area but remain at the study site when working in large habitat patches (Calvert et al 2010). Table 3.…”

Section: Spring Stopover By Gray-cheeked Thrushes In Northern Colombiamentioning

confidence: 99%

Energy reserves stored by migrating Gray‐cheeked Thrushes Catharus minimus at a spring stopover site in northern Colombia are sufficient for a long‐distance flight to North America

Bayly

Gómez

Hobson

2013

Ibis

View full text Add to dashboard Cite

Stopover sites used to accumulate the energy that fuels migration, especially those used prior to crossing ecological barriers, are regarded as critically important for the survival of Nearctic−Neotropical migratory birds. To assess whether South American stopover sites are used to store the energy required to cross the Caribbean Sea and the Gulf of Mexico to North America by a Neotropical migratory landbird, we studied Gray‐cheeked Thrushes in northern Colombia through constant effort mist‐netting during spring migration in 2010 and 2011. We combined stopover duration estimates and models of body mass change based on recaptures to estimate departure body mass and potential flight range from our study site. We recaptured 62 birds, the majority of which gained mass. Models indicated significant differences in rates of mass gain between years and age groups and with arrival date. Estimated total stopover durations varied between 15.4 (2010) and 12.5 days (2011). Predicted departure mass ranged between 41.3 and 44.9 g, and potential flight range was estimated at between 2727 and 4270 km. Gray‐cheeked Thrushes therefore departed our study site with sufficient energy reserves to cross the Caribbean Sea and the Gulf of Mexico (2550 km). As the first demonstration that birds departing from South American stopover sites can reach North America without refuelling, this has important implications for stopover site protection. Strategic conservation measures in the Sierra Nevada de Santa Marta could protect habitats in which up to 40% of the energy required to complete spring migration is stored by a Neotropical migratory land bird.

show abstract

Contrasting Seasonal Survivorship of Two Migratory Songbirds Wintering in Threatened Mangrove Forests

Cited by 13 publications

References 23 publications

Age-specific survival of male Golden-cheeked Warblers on the Fort Hood Military Reservation, Texas

Age-specific survival of male Golden-cheeked Warblers on the Fort Hood Military Reservation, Texas

High within‐winter and annual survival rates in a declining Afro‐Palaearctic migratory bird suggest that wintering conditions do not limit populations

Energy reserves stored by migrating Gray‐cheeked Thrushes Catharus minimus at a spring stopover site in northern Colombia are sufficient for a long‐distance flight to North America

Contact Info

Product

Resources

About