Estimating Montezuma quail hatch date using primary molt at harvest

2019 ◽  
Vol 43 (4) ◽  
pp. 766-768
Author(s):  
Charles J. Randel ◽  
C. Zach Johnson ◽  
Pedro M. Chavarria ◽  
ROEL R. LOPEZ ◽  
Nova J. Silvy ◽  
...  
Keyword(s):  
Hatch Date ◽  
Montezuma Quail

scholarly journals A multiscale assessment of Red-tailed Hawk reproductive success relative to urban density and habitat type

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Justin H White ◽  
Jessi L Brown ◽  
Zachary E Ormsby
Keyword(s):  
Urban Areas ◽  
Urban Expansion ◽  
Habitat Type ◽  
Nesting Success ◽  
Arid Environments ◽  
Hatch Date ◽  
Urban Density ◽  
Landscape Characteristics ◽  
Suburban Areas ◽  
Breeding Seasons

Abstract Despite the unique threats to wildlife in urban areas, many raptors have established successfully reproducing urban populations. To identify variations in raptor breeding ecology within an urban area, we compared metrics of Red-tailed Hawk reproductive attempts to landscape characteristics in Reno and Sparks, NV, USA during the 2015 and 2016 breeding seasons. We used the Apparent Nesting Success and logistic exposure methods to measure nesting success of the Red-tailed Hawks. We used generalized linear models to relate nesting success and fledge rate to habitat type, productivity to hatch date (Julian day) and hatch date to urban density. Nesting success was 86% and 83% for the respective years. Nesting success increased in grassland-agricultural and shrub habitats and decreased in riparian habitat within the urban landscape. Productivity was 2.23 and 2.03 per nest for the breeding seasons. Fledge rates were 72% and 77%, respectively, and decreased in riparian areas. Nestlings hatched earlier with increased urban density and earliest in suburban areas, following a negative quadratic curve. Nesting success and productivity for this population were high relative to others in North America. Productivity increased in habitats where ground prey was more accessible. We suggest that suburban areas, if not frequently disturbed, provide sufficient resources to sustain Red-tailed Hawks over extended periods. As urban expansion continues in arid environments globally, we stress that researchers monitor reproductive output across the urban predator guild to elucidate patterns in population dynamics and adaptation.

Influence of Juniper on Montezuma Quail Habitat Use in Texas

2021 ◽  
Vol 85 (8) ◽  
pp. 1711-1720
Author(s):  
Kristyn G. Stewart ◽  
Fidel HernÁndez ◽  
Eric D. Grahmann ◽  
DAvid B. Wester ◽  
Robert M. Perez ◽  
...  
Keyword(s):  
Habitat Use ◽  
Montezuma Quail

scholarly journals Survival of Western Sandpiper Broods on the Yukon-Kuskokwim Delta, Alaska

The Condor ◽  
2005 ◽  
Vol 107 (3) ◽  
pp. 597-604 ◽  
Author(s):  
Daniel R. Ruthrauff ◽  
Brian J. McCaffery
Keyword(s):  
High Latitude ◽  
High Arctic ◽  
Growth Patterns ◽  
Chick Growth ◽  
Hatch Date ◽  
Calidris Mauri ◽  
Mass Growth ◽  
Brood Survival ◽  
Western Sandpiper ◽  
Brood Movement

Abstract The rate of chick growth in high-latitude breeding shorebirds is rapid, but little is known about the effect of chick mass, growth, and brood movements on subsequent brood survival. To address these topics, we monitored chick growth patterns, daily brood movements, and survival of Western Sandpipers (Calidris mauri) on the Yukon-Kuskokwim Delta, Alaska. We assessed the effect of chick age, mass, and hatch date on brood survival using Program MARK. We mapped brood locations daily, and compared brood movement patterns between successful and unsuccessful broods. Younger chicks survived at lower rates and moved shorter distances than older chicks. The overall probability of one or more chicks from a brood surviving to 15 days of age was 0.73 ± 0.05 SE. Brood survival declined seasonally, and broods with heavier chicks survived at higher rates than those with lighter chicks. On average, successful broods fledged 1.7 ± 0.1 SE chicks. Rate of chick growth was intermediate between those of high arctic and temperate-breeding shorebirds, and chick mass at hatching declined seasonally. Western Sandpiper brood survival was lowest when chicks were young, spatially clumped, and unable to maintain homeothermy, probably because young chicks were more vulnerable to both complete depredation events and extreme weather. Our data suggest that larger, older chicks are able to avoid predators by being spatially dispersed and highly mobile; thermal independence, achieved after approximately day five, enables chicks to better endure prolonged periods of cold and low food availability. Supervivencia de Nidadas de Calidris mauri en el Delta Yukon-Kuskokwim, Alaska Resumen. La tasa de crecimiento de polluelos en aves que se reproducen a latitudes altas es rápida, pero se conoce poco sobre el efecto del peso y el crecimiento de los polluelos y de los movimientos de las crías sobre la supervivencia de las nidadas. Para evaluar estos tópicos, monitoreamos los patrones de crecimiento de polluelos, el movimiento diario de las crías, y la sobrevivencia de Calidris mauri en el Delta Yukon-Kuskokwim, Alaska. Determinamos el efecto de la edad, el peso y la fecha de eclosión de los polluelos sobre la supervivencia de la nidada utilizando el programa MARK. Mapeamos la localización de las crías diariamente, y comparamos los patrones de movimientos entre nidadas exitosas y no exitosas. Los polluelos más jóvenes tuvieron tasas de supervivencia menores y se movieron distancias más cortas que los polluelos de más edad. La probabilidad general de que uno o más polluelos de una nidada sobreviviera hasta 15 días de edad fue 0.73 ± 0.05 EE. La supervivencia de las nidadas disminuyó estacionalmente y las nidadas con polluelos de mayor peso tuvieron tasas de supervivencia mayores que las nidadas con polluelos más livianos. En promedio, las nidadas exitosas produjeron 1.7 ± 0.1 EE polluelos. La tasa de crecimiento de los polluelos fue intermedia con respecto a las aves playeras que se reproducen en el ártico y las que lo hacen en zonas templadas. El peso de los polluelos al momento de eclosionar disminuyó estacionalmente. La supervivencia de las nidadas de C. mauri fue mínima cuando los polluelos eran jóvenes, estaban agrupados y no eran capaces de mantener la homeotermia, probablemente debido a que los polluelos jóvenes eran más vulnerables a eventos de depredación completa y al clima extremo. Nuestros datos sugieren que los polluelos más grandes y de mayor edad son capaces de evitar a los depredadores al encontrarse espacialmente dispersos y ser altamente móviles; la independencia térmica que es alcanzada aproximadamente luego del día cinco permite a los polluelos soportar periodos prolongados de frío y de baja disponibilidad de alimento.

scholarly journals Climate change relaxes the time constraints for late-born offspring in a long-distance migrant

2016 ◽  
Vol 283 (1839) ◽  
pp. 20161366 ◽  
Author(s):  
Barbara M. Tomotani ◽  
Phillip Gienapp ◽  
Domien G. M. Beersma ◽  
Marcel E. Visser
Keyword(s):  
Climate Change ◽  
Annual Cycle ◽  
Migratory Birds ◽  
Climate Change Impacts ◽  
Egg Laying ◽  
Time Constraints ◽  
Long Distance ◽  
Hatch Date ◽  
Breeding Bird ◽  
And Migration

Animals in seasonal environments need to fit their annual-cycle stages, such as moult and migration, in a tight schedule. Climate change affects the phenology of organisms and causes advancements in timing of these annual-cycle stages but not necessarily at the same rates. For migratory birds, this can lead to more severe or more relaxed time constraints in the time from fledging to migration, depending on the relative shifts of the different stages. We tested how a shift in hatch date, which has advanced due to climate change, impacts the organization of the birds' whole annual cycle. We experimentally advanced and delayed the hatch date of pied flycatcher chicks in the field and then measured the timing of their annual-cycle stages in a controlled laboratory environment. Hatch date affected the timing of moult and pre-migratory fattening, but not migration. Early-born birds hence had a longer time to fatten up than late-born ones; the latter reduced their interval between onset of fattening and migration to be able to migrate at the same time as the early-born birds. This difference in time constraints for early- and late-born individuals may explain why early-born offspring have a higher probability to recruit as a breeding bird. Climate change-associated advancements of avian egg-lay dates, which in turn advances hatch dates, can thus reduce the negative fitness consequences of reproducing late, thereby reducing the selection for early egg-laying migratory birds.

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