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At least 217 records · Page 12Linked to original sources
USGS2018

Identifying diet of a declining prairie grouse using DNA metabarcoding

Diets during critical brooding and winter periods likely influence the growth of Lesser Prairie-Chicken ( Tympanuchus pallidicinctus ) populations. During the brooding period, rapidly growing Lesser Prairie-Chicken chicks have high calorie demands and are restricted to foods within immediate surroundings. For adults and juveniles during cold winters, meeting thermoregulatory demands with available food items of limited nutrient content may be challenging. Our objective was to determine the primary animal and plant components of Lesser Prairie-Chicken diets among native prairie, cropland, and Conservation Reserve Program (CRP) fields in Kansas and Colorado, USA, during brooding and winter using a DNA metabarcoding approach. Lesser Prairie-Chicken fecal samples ( n = 314) were collected during summer 2014 and winter 2014–2015, DNA was extracted, amplified, and sequenced. A region of the cytochrome oxidase I (COI) gene was sequenced to determine the arthropod component of the diet, and a portion of the trn L intron region was used to determine the plant component. Relying on fecal DNA to quantify dietary composition, as opposed to traditional visual identification of gut contents, revealed a greater proportion of soft-bodied arthropods than previously recorded. Among 80 fecal samples for which threshold arthropod DNA reads were obtained, 35% of the sequences were most likely from Lepidoptera, 26% from Orthoptera, 14% from Araneae, 13% from Hemiptera, and 12% from other orders. Plant sequences from 137 fecal samples were composed of species similar to Ambrosia (27%), followed by species similar to Lactuca or Taraxacum (10%), Medicago (6%), and Triticum (5%). Forbs were the predominant (>50% of reads) plant food consumed during both brood rearing and winter. The importance both of native forbs and of a broad array of arthropods that rely on forbs suggests that disturbance regimes that promote forbs may be crucial in providing food for Lesser Prairie-Chickens in the northern portion of their distribution.

The Auk↗
USGS2018

Extreme drought alters frequency and reproductive success of floaters in Willow Flycatchers

Changes in habitat quality, including those caused by extreme events like droughts and floods, could alter costs and benefits of territoriality and thereby the prevalence and reproductive consequences for individuals capable of breeding that do not do so (floaters). We studied floating behavior in a population of Southwestern Willow Flycatchers ( Empidonax traillii extimus ) in central Arizona during one year of extreme drought, one year of lake inundation, and three years of near average precipitation. In all years, most floaters were second year (SY) males, and most subsequently settled outside of the patch where they were detected in the floating year, suggesting that floaters did not “queue” at high-quality territories in order to achieve higher reproductive success in subsequent years. Instead, cohorts that floated in non-drought years had lower apparent survival and lower reproductive success compared to territorial birds. In the extreme drought year, however, the number of floaters was 1.5 times greater than in all other years combined, more females floated, and apparent survival and mean annual productivity in subsequent years was higher for males that floated in that year than for those that were territorial. Inundation of habitat due to rising reservoir levels did not result in an increase in floaters because many birds nested in inundated areas where trees projected above the water so that the relative amount of available habitat was not reduced to the extent habitat models predicted. Overall, our results indicate that the prevalence and reproductive and demographic consequences of floating can change under extreme climatic events like severe drought.

The Auk↗
USGS2018

Diel fledging patterns among grassland passerines: Relative impacts of energetics and predation risk

The time of day that nestlings fledge from a nest is thought to be shaped by predation risk and energetics. To minimize predation risk, fledging is predicted to start as early in the day as possible so that nestlings can maximize time outside the nest to find a safe place to stay before nightfall. Fledging times are predicted to be tightly grouped and to not be affected by the number of nestlings, given that all nestlings are responding to the same relative risk of predation. Conversely, energetic considerations predict that fledging time of day should vary so that nestlings can maximize energy intake before having to forage for themselves. However, data to evaluate the relative importance of these drivers in grassland birds are scarce because of the difficulty of observing nestlings as they fledge. We used nest surveillance video from 178 nests to evaluate how the initiation and duration of fledging varied among 7 grassland passerine species, as well as by the number of nestlings in the nest and fledging date. Fledging initiation varied most strongly by species, with some effects of date. Across species, the median start time of fledging was 4.55 hr after sunrise. Fledging before the solstice started ∼30 min earlier compared to fledging at or after the solstice. Fledging duration increased with number of nestlings in the nest and was spread over >1 day in 21% of nests. While our results primarily supported the hypothesis that fledging is motivated by energetic considerations, additional data on basic life history traits and behavior will be needed to fully understand how fledging grassland birds balance energetics against predation risk.

The Auk↗
USGS2018

Using automated radio telemetry to quantify activity patterns of songbirds during stopover

During migration, birds require stopover habitat to rest and refuel before resuming flight. While long-distance migratory flights represent a large energy investment, stopover accounts for roughly two-thirds of a bird's total energy expenditure during migration. Therefore, birds should minimize energy expenditure while also minimizing time and predation risk during stopover. To understand activity during migration, we recorded activity patterns (i.e. fine-scale movements associated with a range of behaviors) of 3 species, Red-eyed Vireo ( Vireo olivaceus ), Swainson's Thrush ( Catharus ustulatus ), and Wood Thrush ( Hylocichla mustelina ), at a stopover site along the northern coast of the Gulf of Mexico during autumn migration using automated radio telemetry. We found Red-eyed Vireos to be the most active and Swainson's Thrushes the least active. For each species, we used boosted regression trees to investigate associations between activity and factors known to influence bird behavior during stopover. While species differed, day of year and temperature were important predictors of activity for all species. Vireos were active early in the season, under light winds and warmer temperatures, and on evenings when winds were more favorable. Thrushes were more active as the season progressed and when temperatures were cooler. Thrush activity also differed between years, although thrushes increased activity later in the season during all years. Our results illustrate automated radio telemetry as a unique and valuable tool for understanding fine-scale behaviors of birds during stopover.

Alabama↗
USGS2017

Fifty-eighth supplement to the American Ornithologists' Union: Check-list of North American Birds

This is the 17th supplement since publication of the 7th edition of the Check-list of North American Birds (American Ornithologists' Union [AOU] 1998). It summarizes decisions made between April 15, 2016, and April 15, 2017, by the AOS's Committee on Classification and Nomenclature—North and Middle America. The Committee has continued to operate in the manner outlined in the 42nd Supplement

The Auk↗
USGS2018

Variation in inbreeding rates across the range of Northern Spotted Owls (Strix occidentalis caurina): Insights from over 30 years of monitoring data

Inbreeding has been difficult to quantify in wild populations because of incomplete parentage information. We applied and extended a recently developed framework for addressing this problem to infer inbreeding rates in Northern Spotted Owls ( Strix occidentalis caurina ) across the Pacific Northwest, USA. Using pedigrees from 14,187 Northern Spotted Owls, we inferred inbreeding rates for 14 types of matings among relatives that produce pedigree inbreeding coefficients of F = 0.25 or F = 0.125. Inbreeding was most common in the Washington Cascades, where an estimated 15% of individuals are inbred. Inbreeding was lowest in western Oregon (3.5%) and northern California (2.7%), and intermediate for the Olympic Peninsula of Washington (6.1%). Estimates from the Olympic Peninsula were likely underestimates because of small sample sizes and the presence of few pedigrees capable of resolving inbreeding events. Most inbreeding resulted from matings between full siblings or half siblings, although a high rate of inbreeding from mother–son pairs was identified in the Olympic Peninsula. Geographic variation in inbreeding rates may reflect population declines and bottlenecks that have been detected in prior investigations. We show that there is strong selection against inbred birds. Only 3 of 44 inbred birds were later identified as parents (6.8%), whereas 2,823 of 10,380 birds that represented a comparable cross section of the data were later seen as reproducing parents (27.2%). Habitat loss and competition with Barred Owls ( S. varia ) remain primary threats to Northern Spotted Owls. However, given the negative consequences of inbreeding, Spotted Owl populations in Washington with suitable habitat and manageable numbers of Barred Owls may benefit from translocations of individuals from Oregon and California to introduce new genetic variation and reduce future inbreeding events.

California, Oregon, Washington↗
USGS1941

Banded birds recovered in El Salvador

Three records of birds banded in the United States and recovered in El Salvador have recently been received and seem of sufficient importance to warrant immediate publication.

The Auk↗
USGS1943

A comparative study of the breeding bird population of Shenandoah Mountains, Virginia

WHILE working on habitat studies of the Ruffed Grouse ( Bonasa umbellus ) in the George Washington National Forest during the late spring and early summer of 1941, the author found it possible to carry out a supplemental study on the relative abundance of the breeding birds of the area. Since considerable time was spent in traversing certain sections of the forest in search of Ruffed Grouse broods, an unusual opportunity was afforded to make a general comparative census of the species of birds found therein.

The Auk↗
USGS1943

Bachman's sparrow in Maryland

The Bachman's Sparrow ( Aimophila aestivalis bachmani ) is known to be quite rare and irregular in distribution in the northern part of its range. Because of this the northern limits of its range have been rather ill-defined. According to the A. 0. U. Check-List, Fourth Edition: 343, 1931, this bird ranges north to central Virginia in the eastern part of its range and is casual near Washington, D. C. Its distribution in the north-central portion of its range, including the Appalachian Mountains, is discussed in detail by Brooks (Wilson Bull., 50: 86-109, 1938). The discovery in May, 1942, of three pairs of these birds nesting on the Beltsville Research Center, Prince George County, Maryland, considerably extends the northern limits of the known breeding range of this species in the Piedmont and coastal-plain region east of the Appalachian Mountains.

The Auk↗
USGS1943

Hooded warbler in North Dakota

he 1942 warbler migration at Kenmare, Ward County, North Dakota, was rich in species (seventeen) for a locality so far west on the Great Plains. On June 1, near the end of the northward flight, I found a male Hooded Warbler singing in shrubby undergrowth on a wooded coulee slope on the Des Lacs National Wildlife Refuge, about two miles south of Kenmare. The bird was observed at close range for several minutes, both without and with 7-power binoculars. It behaved as in the vicinity of Washington, D. C., where I have been familiar with the species for several years, the song being vigorous and loud and the movements leisurely.

The Auk↗
USGS1945

Inbreeding among pen-reared quail

The effect of inbreeding in wildlife species has received attention from several sources. Recently the 'inbreeding theory' as a possible explanation of cycles in game populations was given careful consideration by a group of wildlife experts and geneticists. Scott's symposium (1944) consisting of comments received from eight authorities revealed unanimity in a decision that inbreeding is not the causative factor.

The Auk↗
USGS1949

Wilson's warbler in Maryland in late December

On December 22, 1947, while participating in a Christmas Bird Count on the eastern shore of Maryland, I observed a Wilson's warbler ( Wilsonia pusilla ) feeding along a sunny margin of a woods near the Pocomoke River, three miles north of Snow Hill. It was with a flock of myrtle warblers ( Dendroica coronata ), white-throated sparrows ( Zonotrichia albicollis ), Carolina chickadees ( Parus carolinensis ), and several other species. My attention was first attracted to the Wilson's warbler by the distinctive call note which it repeated about once a minute. The bird was actively feeding among the dead leaves on a group of young oak trees. The bird was collected and proved to be a female. The skin was preserved for the collection of the Fish and Wildlife Service. The stomach was full, and the contents were identified by Robert T. Mitchell as: fragments of Araneida, 80 per cent; Coleoptera, 10 per cent; Hymenoptera, 10 per cent.

The Auk↗
USGS1947

Recent observations on Maryland birds

In the course of working on a study of the 'Geographical and Ecological Distribution of the Birds of Maryland,' a considerable number of records of occurrence have been obtained, which have helped to clarify the status of many Maryland birds. Some of these records are new for the state and many serve to extend the known breeding or wintering ranges within Maryland. Others will serve as additional information on the seasonal and geographical distribution of certain species whose ranges are imperfectly known.

The Auk↗
USGS1949

White-crowned sparrows wintering in Maryland and West Virginia

During the Christmas holidays (1947) five white-crowned sparrows ( Zonotrichia l. leucophrys ) were trapped and banded at McCoole, Allegany County, Maryland. On January 31 and February 1, 1948, 11 more were banded and a flock of at least 21 white-crowns was counted feeding in the snow under pigweed ( Amaranthus hybridus ). On the latter date five others were observed feeding under the same type of vegetation near the Potomac River in Keyser, Mineral County, West Virginia. All birds ob- served were immatures. So far as is known this is the first published record for this species wintering in Maryland. It has been previously reported in winter from West Virginia in Hampshire, Kanawha, and Cabell Counties (Maurice G. Brooks, 'A Check List of West Virginia Birds,' 1944).

The Auk↗
USGS1951

Removal and repopulation of breeding birds in a spruce-fir forest community

IN 1949, while engaged in population studies of birds in northern Maine, the authors accumulated considerable information concerning population dynamics of birds inhabiting the Spruce-Fir forest community. This information was obtained in connection with investigations of the effective control by breeding birds of an infestation of the spruce budworm, Choristoneura fumiferana Clem.

The Auk↗
USGS1952

Hybridization of Canada geese with blue geese in the wild

While carrying out hunter bag checks in the vicinity of Sand Lake National Wildlife Refuge, Columbia, South Dakota, during the 1950 waterfowl hunting season, the author examined two adult male geese which proved to be crosses between one of the smaller Canada Geese (possibly Richardson's Goose, Branta canadensis hutchinsi ) and the Blue Goose, Chen caerulescens .

South Dakota↗
USGS1951

In Memoriam: Albert Kenrick Fisher

Dr. Albert Kenrick Fisher, a Founder and Past President of the American Ornithologists' Union and one of its best known Fellows for nearly 65 years, died in Washington, D. C. on June 12, 1948, after a brief illness from circulatory complications that developed as a result of advanced age. With his passing, the American Ornithologists' Union has lost one of its last links with that eminent group of bird students who founded this organization in the autumn of 1883.

The Auk↗