Daniel R. Ruthrauff
United States Geological Survey
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Featured researches published by Daniel R. Ruthrauff.
The Condor | 2005
Daniel R. Ruthrauff; Brian J. McCaffery
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.
Journal of Zoo and Wildlife Medicine | 2011
Daniel M. Mulcahy; Brett D. Gartrell; Robert E. Gill; T. Lee Tibbitts; Daniel R. Ruthrauff
Abstract Intravenous propofol was used as a general anesthetic with a 2∶1 (mg∶mg) adjunctive mixture of lidocaine and bupivacaine as local anesthetics infiltrated into the surgical sites for implantation of satellite transmitters into the right abdominal air sac of 39 female and 4 male bar-tailed godwits (Limosa lapponica baueri and Limosa lapponica menzbeiri) and 11 female and 12 male bristle-thighed curlews (Numenius tahitiensis). The birds were captured on nesting grounds in Alaska, USA, and on overwintering areas in New Zealand and Australia from 2005 through 2008. As it was developed, the mass of the transmitter used changed yearly from a low of 22.4 ± 0.2 g to a high of 27.1 ± 0.2 g and weighed 25.1 ± 0.2 g in the final year. The mean load ratios ranged from 5.2% to 7.7% for godwits and from 5.7% to 7.5% for curlews and exceeded 5% for all years, locations, and genders of both species. The maximum load ratio was 8.3% for a female bar-tailed godwit implanted in Australia in 2008. Three godwits and no curlews died during surgery. Most birds were hyperthermic upon induction but improved during surgery. Two godwits (one in New Zealand and one in Australia) could not stand upon release, likely due to capture myopathy. These birds failed to respond to treatment and were euthanized. The implanted transmitters were used to follow godwits through their southern and northern migrations, and curlews were followed on their southern migration.
Bird Conservation International | 2017
James W. Pearce-Higgins; Daniel J. Brown; David J. T. Douglas; José A. Alves; Mariagrazia Bellio; Pierrick Bocher; Graeme M. Buchanan; Rob P. Clay; Jesse R. Conklin; Nicola J. Crockford; Peter Dann; Jaanus Elts; Christian Friis; Richard A. Fuller; Jennifer A. Gill; Ken Gosbell; James A. Johnson; Rocío Márquez-Ferrando; José A. Masero; David S. Melville; Spike Millington; Clive Minton; Taej Mundkur; Erica Nol; Hannes Pehlak; Theunis Piersma; Frédéric Robin; Danny I. Rogers; Daniel R. Ruthrauff; Nathan R. Senner
The Numeniini is a tribe of 13 wader species (Scolopacidae, Charadriiformes) of which seven are Near Threatened or globally threatened, including two Critically Endangered. To help inform conservation management and policy responses, we present the results of an expert assessment of the threats that members of this taxonomic group face across migratory flyways. Most threats are increasing in intensity, particularly in non-breeding areas, where habitat loss resulting from residential and commercial development, aquaculture, mining, transport, disturbance, problematic invasive species, pollution and climate change were regarded as having the greatest detrimental impact. Fewer threats (mining, disturbance, problematic native species and climate change) were identified as widely affecting breeding areas. Numeniini populations face the greatest number of non-breeding threats in the East Asian-Australasian Flyway, especially those associated with coastal reclamation; related threats were also identified across the Central and Atlantic Americas, and East Atlantic flyways. Threats on the breeding grounds were greatest in Central and Atlantic Americas, East Atlantic and West Asian flyways. Three priority actions were associated with monitoring and research: to monitor breeding population trends (which for species breeding in remote areas may best be achieved through surveys at key non-breeding sites), to deploy tracking technologies to identify migratory connectivity, and to monitor land-cover change across breeding and non-breeding areas. Two priority actions were focused on conservation and policy responses: to identify and effectively protect key non-breeding sites across all flyways (particularly in the East Asian- Australasian Flyway), and to implement successful conservation interventions at a sufficient scale across human-dominated landscapes for species’ recovery to be achieved. If implemented urgently, these measures in combination have the potential to alter the current population declines of many Numeniini species and provide a template for the conservation of other groups of threatened species.
The Condor | 2013
Robert E. Gill; Colleen M. Handel; Daniel R. Ruthrauff
Abstract. The Dunlin (Calidris alpina) is a polytypic shorebird with complex patterns of distribution and migration throughout its holarctic range. We analyzed mark-re sighting data obtained between 1977 and 2010 from birds captured at two major staging areas in western Alaska to test the hypothesis that the migration patterns of Alaskan populations are a mixture of parallel and chain, similar to those of Dunlin populations in the western Palearctic. Birds marked on the Yukon—Kuskokwim Delta were found wintering in both Asia and North America, which documented the unexpected mixing of C. a. arcticola from northern Alaska and C. a. pacifica from western Alaska and contradicted our initial prediction of parallel migration pathways for these two subspecies. In its North American winter range C. a. pacifica segregated according to location of marking, confirming our prediction of a chain migration pattern within this population. Individuals of C. a. pacifica marked on the delta were resighted significantly farther north, mostly in southern British Columbia and Washington, than birds marked on the second, more southerly staging area on the Alaska Peninsula, which were resighted primarily in the San Francisco Bay area of northern California. We recommend additional studies use a combination of intrinsic and extrinsic markers to quantify the strength of migratory connectivity between breeding, staging, and wintering areas. Such information is needed to guide conservation efforts because the Dunlin and other waterbirds are losing intertidal habitats at an unprecedented rate and scale, particularly in the Yellow Sea and other parts of Asia.
The Auk | 2011
Jesse R. Conklin; Phil F. Battley; Murray A. Potter; Daniel R. Ruthrauff
ABSTRACT. Among scolopacid shorebirds, Bar-tailed Godwits (Limosa lapponica) have unusually high intra- and intersexual differences in size and breeding plumage. Despite historical evidence for population structure among Alaska-breeding Bar-tailed Godwits (L. l. baueri), no thorough analysis, or comparison with the populations nonbreeding distribution, has been undertaken. We used live captures, field photography, museum specimens, and individuals tracked from New Zealand to describe geographic variation in size and plumage within the Alaska breeding range. We found a north-south cline in body size in Alaska, in which the smallest individuals of each sex occurred at the highest latitudes. Extent of male breeding plumage (proportion of nonbreeding contour feathers replaced) also increased with latitude, but female breeding plumage was most extensive at mid-latitudes. This population structure was not maintained in the nonbreeding season: morphometrics of captured birds and timing of migratory departures indicated that individuals from a wide range of breeding latitudes occur in each region and site in New Zealand. Links among morphology, phenology, and breeding location suggest the possibility of distinct Alaska breeding populations that mix freely in the nonbreeding season, and also imply that the strongest selection for size occurs in the breeding season.
Journal of Wildlife Diseases | 2012
John M. Pearce; Daniel R. Ruthrauff; Jeffrey S. Hall
Surveillance has revealed low prevalence of avian influenza viruses (AIV) in shorebirds except Ruddy Turnstones (Arenaria interpres) on the North American Atlantic coast. Similarly, of five species of shorebirds surveyed in Alaska in 2010, Ruddy Turnstones had the highest AIV antibody prevalence; prevalence of AIV RNA was low or zero.
Journal of Wildlife Diseases | 2014
James A. Johnson; Lucas H. DeCicco; Daniel R. Ruthrauff; Scott Krauss; Jeffrey S. Hall
Abstract Prevalence of avian influenza virus (AIV) antibodies in the western Atlantic subspecies of Red Knot (Calidris canutus rufa) is among the highest for any shorebird. To assess whether the frequency of detection of AIV antibodies is high for the species in general or restricted only to C. c. rufa, we sampled the northeastern Pacific Coast subspecies of Red Knot (Calidris canutus roselaari) breeding in northwestern Alaska. Antibodies were detected in 90% of adults and none of the chicks sampled. Viral shedding was not detected in adults or chicks. These results suggest a predisposition of Red Knots to AIV infection. High antibody titers to subtypes H3 and H4 were detected, whereas low to intermediate antibody levels were found for subtypes H10 and H11. These four subtypes have previously been detected in shorebirds at Delaware Bay (at the border of New Jersey and Delaware) and in waterfowl along the Pacific Coast of North America.
Archive | 2007
Daniel R. Ruthrauff; T. Lee Tibbitts; Robert E. Gill; Colleen M. Handel
............................................................................................................... iii Executive Summary ............................................................................................. iv TABLE OF CONTENTS...................................................................................... vii LIST OF FIGURES .............................................................................................. ix LIST OF TABLES................................................................................................. xi APPENDICES..................................................................................................... xi
Journal of Fish and Wildlife Management | 2018
Courtney L. Amundson; Colleen M. Handel; Daniel R. Ruthrauff; T. Lee Tibbitts; Robert E. Gill
Abstract Between 2004 and 2008, biologists conducted an inventory of breeding birds during May–June primarily in montane areas (>100 m above sea level) of Aniakchak National Monument and Preserve (...
Canadian Journal of Zoology | 2001
Steven M. Matsuoka; Colleen M. Handel; Daniel R. Ruthrauff