bluuebunny/crossref_metadata_2025_split huggingface dataset:
Variation in Foraging and Parental Behavior of King Cormorants
Authors: Kato Akiko , Watanuki Yutaka , Nishiumi Isao , Kuroki Maki , Shaughnessy Peter , Naito Yasuhiko 
Published: September 2019

AbstractWe studied sexual and individual differences in foraging and parental behavior of King Cormorants (Phalacrocorax albiventer) during the brood-rearing period at Macquarie Island. King Cormorants exhibit sexual dimorphism in size, with males being 16% heavier than females. Females foraged mainly in the morning and males in the afternoon. Five females were shallow divers (1.9 to 6.8 m), and seven females were deep divers (19.6 to 28.0 m); males dived deeper (15.6 to 44.2 m) than both groups of females. The amount of time spent on the bottom (“bottom time”) relative to the dive cycle was higher for shallow-diving females (x̄ = 40 ± SD of 13%) than for males (x̄ = 26 ± 4%) and deep-diving females (x̄ = 27 ± 3%). Total daily dive time and bottom time per day did not differ significantly among groups because shallow-diving females dived more often (x̄ = 211 ± 81 dives per day) than males (x̄ = 68 ± 21) and deep-diving females (x̄ = 70 ± 7). Provisioning rate, trip duration, and proportion of time at sea did not differ significantly for males, deep-diving females, and shallow-diving females. Females, especially shallow divers, compensated for their shallow and short dives with more frequent dives. Consequently, male and female King Cormorants provisioned their chicks at similar rates despite large individual variation in foraging behavior.
Mitochondrial DNA Phylogeny and Speciation in the Tragopans
Authors: Randi Ettore , Lucchini Vittorio , Armijo-Prewitt Tara , Kimball Rebecca T. , Braun Edward L. , Ligon J. David 
Published: September 2019

AbstractWe sequenced mitochondrial DNA (mtDNA) from cytochrome b (cyt b) and the control region (CR) for all five extant species in the genus Tragopan. We incorporated information on comparative patterns and rates of molecular evolution into phylogenetic analyses, using both a single-gene and a combined data approach. Sequence variability was distributed heterogeneously among the three domains of CR and the three codon positions of cyt b, but the two genes evolved at comparable rates, on average, and produced concordant topologies independent of the method used for phylogenetic reconstructions. Phylogenetic trees suggest that Tragopan includes two main evolutionary lineages grouping caboti-temminckii (clade A), and blythii-satyra (clade B). A shorter CR sequence from one museum sample could not consistently resolve the position of T. melanocephalus. The mtDNA phylogeny is better supported than alternative topologies inferred from morphological and behavioral traits and is compatible with a mechanism of allopatric speciation of Tragopan in two different episodes about 4 and 2 million years ago. In those periods, the vicariant events that might have fostered allopatric speciation of Tragopan are represented by landscape changes that affected the Indohimalayan region after the sudden rising of the Himalayas less then 8 million years ago, and by climatic fluctuations during the Pleistocene less than 2 million years ago.
Diet and Postnatal Growth in Red-Legged and Black-Legged Kittiwakes: An Interspecies Cross-Fostering Experiment
Authors: Lance Brian K. , Roby Daniel D. 
Published: September 2019

AbstractRed-legged Kittiwakes (Rissa brevirostris) and Black-legged Kittiwakes (R. tridactyla) are morphologically similar, breed in mixed colonies, and nest at the same time, but they exhibit substantial differences in diet, rate of nestling provisioning, and foraging distribution. We cross-fostered nestlings of the two species to test the competing hypotheses that growth in mass of kittiwakes is constrained by diet (i.e. composition, provisioning rate, and quality) or by inherent species-specific physiology. Survival and body mass of cross-fostered nestlings at 30 to 32 days posthatching did not differ from those of conspecific controls. Black-legged Kittiwake fledglings had higher lean mass than Red-legged Kittiwake fledglings regardless of whether they were raised by foster or natural parents. However, nestlings of both species raised by Red-legged Kittiwakes were 50% fatter at 30 to 32 days posthatching than those raised by Black-legged Kittiwakes. Regurgitations from nestlings raised by Red-legged Kittiwakes consisted primarily of lanternfish and contained about twice the lipid (percent dry mass) as regurgitations from nestlings raised by Black-legged Kittiwakes. Consequently, growth rate of lean tissue was genetically and/or physiologically constrained, whereas rate of fat deposition was constrained by diet. We hypothesize that the adaptive significance of lanternfish in diets for Red-legged Kittiwake nestlings is manifest in higher prefledging and/or postfledging survival. Interspecific differences in energy density of food and food provisioning rates balanced each other so that rates of energy provisioning were similar.
Effects of Coccidial and Mycoplasmal Infections on Carotenoid-Based Plumage Pigmentation in Male House Finches
Authors: Brawner William R. , Hill Geoffrey E. , Sundermann Christine A. 
Published: September 2019

AbstractCarotenoid pigments produce the ornamental red, orange, and yellow integumentary coloration of many species of animals. Among individuals of a population, the hue and saturation of carotenoid-based ornaments can be extremely variable, and studies of fish and birds have shown that females generally prefer males that display the most saturated and reddest coloration. Consequently, there has been a great deal of interest in determining the proximate factors that affect individual expression of carotenoid-based pigmentation. Parasites might affect production of ornamental coloration, and the Hamilton-Zuk hypothesis proposes that parasitized males will show decreased expression of the secondary sexual traits preferred by females. We found that captive male House Finches (Carpodacus mexicanus) experimentally infected with Isospora spp. (coccidians) and/or Mycoplasma gallisepticum produced carotenoid-based plumage coloration that was significantly less red and less saturated than that of noninfected males. These observations validate a necessary condition of the Hamilton-Zuk hypothesis, but heritable resistance to the pathogens we examined remains to be demonstrated.
Tiny Hoopoe-Like Birds From the Middle Eocene of Messel (Germany)
Authors: Mayr Gerald 
Published: September 2019

AbstractTiny hoopoe-like birds of the extinct family Messelirrisoridae are among the predominant small perching birds in the Middle Eocene (ca. 49 million years ago) avifauna of Messel (Hessen, Germany). Members of the Messelirrisoridae are the earliest-known representatives of the hoopoe/wood-hoopoe lineage and are sister taxa of recent Upupidae (hoopoes) and Phoeniculidae (wood-hoopoes). Outgroup comparison with the Messelirrisoridae facilitates character-state analysis within the Phoeniculidae and Upupidae. In this study, I describe a new species, Messelirrisor grandis, which is the largest species of the Messelirrisoridae known so far.
Nutrient Reserves and Clutch-Size Regulation of Northern Shovelers in Alaska
Authors: MacCluskie Margaret C. , Sedinger James S. 
Published: September 2019

Abstract
We determined patterns of nutrient-reserve use by female Northern Shovelers (Anas clypeata) nesting at Minto Flats, Alaska, and compared them with those of female shovelers nesting in the Prairie Pothole Region of Manitoba, Canada. Individual variation in somatic lipid was best explained by nest initiation date; females that initiated nests early had larger lipid reserves than females that delayed nest initiation. These results contrast with those from Manitoba, which showed that females used lipid reserves and stored protein during egg production. Incubating females from Alaska did not use protein or mineral reserves, but lipid reserves decreased significantly throughout incubation. Females in Alaska and Manitoba used lipid reserves similarly during incubation. We conclude that endogenous nutrient availability does not proximately limit clutch size during laying for this population of shovelers, possibly due to the high productivity of wetlands in interior Alaska and/or the long photoperiod that allow females to forage extensively. Successful completion of incubation or brood rearing may be an ultimate factor that controls clutch size for this population of shovelers.
Possible Effects of PCB Contamination on Female Plumage Color and Reproductive Success in Hudson River Tree Swallows
Authors: McCarty John P. , Secord Anne L. 
Published: September 2019

AbstractChemical contaminants in the environment can influence both morphological and behavioral traits. Ornamental traits such as plumage color may be especially valuable in detecting the effects of toxic chemicals in the environment, although they have been little used to date. We examined patterns of plumage color in subadult female Tree Swallows (Tachycineta bicolor) breeding in an area on the Hudson River that had high levels of PCB contamination and compared them with specimens from other parts of the species' range and with data from two previous studies of plumage color. Tree Swallows are one of the few species of birds where females, but not males, have a distinctive subadult plumage during their first breeding season. Females from four breeding colonies in contaminated areas had significantly more adult-type blue-green coloring than females from the rest of the species' range. Subadult female plumage color at these sites formed a continuum between the normal dull brown plumage found elsewhere and the blue-green plumage of older females. Among these subadults, more colorful individuals bred earlier, and earlier breeding in turn led to larger clutches. The patterns of plumage anomalies described here are consistent with disruption of the endocrine system resulting in the early expression of an adult trait. This study supports recent suggestions that examining variation in ornamental traits of animals is an efficient means of detecting effects of chemical contaminants in the environment.
The Role of Development, Parental Behavior, and Nestmate Competition in Fledging of Nestling Tree Swallows
Authors: Michaud Trista , Leonard Marty 
Published: September 2019

AbstractFledging (i.e. leaving the nest) in altricial birds is a major step toward independence. The timing of this important event may be influenced by nestling development, parental behavior, and sibling interactions. In this study, we examine the effect of these factors on fledging in Tree Swallows (Tachycineta bicolor). Wing length explained a significant proportion of the variance in fledging age across broods. Similarly, within broods, longer-winged nestlings fledged before shorter-winged nestlings. Feeding rate per nestling did not decrease in the period leading up to fledging, as might be expected if parents stimulated fledging by decreasing their feeding rate. Parental activity near the nest varied in that the frequency of parental passes and hovers within 1 m of the nest opening increased in the period before fledging. Brood size also explained a significant proportion of the variance in fledging age independent of wing length, although the direction of the relationship was not consistent across years. Finally, longer-winged nestlings spent more time in the nest opening and initiated fledging of the brood more often than did shorter-winged nestlings. Overall, our study suggests that nestling development is the most important determinant of fledging age in this species. Once a critical wing length has been reached, sibling interactions, and possibly parental behavior, may influence the timing of fledging.
No Evidence for Effects of Breeding Density and Male Removal on Extrapair Paternity in the Pied Flycatcher
Authors: Rätti Osmo , Lundberg Arne , Tegelström Håkan , Alatalo Rauno V. 
Published: September 2019

Abstract
Molecular methods have brought new insight to the study of mating patterns. Extrapair fertilizations (EPF) have proven to be widespread among bird species irrespective of social relationships. Ecological factors, such as breeding density and synchrony, have been suggested as contributors to variation in EPF rates. Absence of a male during the female fertile period may also increase the probability of EPFs. In this study, we examined experimentally whether breeding density and male absence before egg-laying influence the EPF rate in Pied Flycatchers (Ficedula hypoleuca). DNA fingerprinting revealed that 4.4% (10/225) of nestlings were the result of EPFs and 7.0% (3/43) of broods included at least one offspring sired by a male other than that attending the nest. We did not find any evidence of higher EPF rate with higher breeding density as stated by the density hypothesis. Contrary to expectation, EPFs were more frequent, though not quite statistically significantly, at low breeding density: all three EPF nests were found in low-breeding-density areas. There was no evidence that EPF rate was affected by a 4 h male removal. In all cases of EPF, an old female was mated with a yearling male, which suggests that older females mated with browner yearling males may have adjusted their initial mate choice through EPCs to acquire indirect genetic benefits. Pied Flycatcher females may be constrained to accept a mate of lower than preferred quality, especially at low breeding density, due to the cost of searching for alternative males.
Demography of Brown-Headed Cowbirds at Delta Marsh, Manitoba
Authors: Woolfenden Bonnie E. , Gibbs H. Lisle , Sealy Spencer G. 
Published: September 2019

AbstractAvailable estimates of demographic parameters for Brown-headed Cowbirds (Molothrus ater) vary geographically. However, few estimates are based on long-term studies of marked individuals. We conducted a mark–recapture study on the population of cowbirds at Delta Marsh, Manitoba during the 1993–1998 breeding seasons. We estimated annual survival, breeding site fidelity, and sex ratio, and compared those parameter estimates to other populations of Brown-headed Cowbirds. The Delta Marsh population had higher adult survival (male 90.1%; female 69.6%) and breeding site fidelity (males 66.9%, female 59.5%) than reported for other populations, and the sex ratio was significantly different from unity (1.9 males:1 female). We suggest that differences in survival and breeding-site fidelity between the Delta Marsh population and others may be due to differences in methods used to calculate parameter estimates. In contrast, variation in sex ratios is likely real and due to differences in the local ecological conditions. In our population, high survivorship and breeding-site fidelity may lead to low recruitment of new birds into the resident population and intense competition for limited breeding opportunities. The highly male biased sex ratio may result in strong sexual-selection pressure on males competing for the limited breeding opportunities. Those circumstances have implications for the social behavior and mating system of cowbirds.
Linking Breeding and Wintering Grounds of Bicknell's Thrushes Using Stable Isotope Analyses of Feathers
Authors: Hobson Keith A. , McFarland Kent P. , Wassenaar Leonard I. , Rimmer Christopher C. , Goetz James E. 
Published: September 2019

AbstractPrevious studies have shown that natural abundance of deuterium (D), and to a lesser extent 13C, in feathers of migrant songbirds in North America can be used to infer geographic origins of molt. We used that approach to investigate whether Bicknell's Thrush (Catharus bicknelli) populations could be segregated on the breeding grounds at six sites in eastern North America to evaluate contributions from the breeding areas to wintering populations. Further, we tested our isotopic model using feathers from hatching-year migrant Swainson's Thrush (Catharus ustulatus) and Gray-cheeked Thrush (Catharus minimus) moving through southern Manitoba and Ontario and found that δD values were consistent with northerly boreal forest natal sites in northwestern and central Canada. Despite a strong latitudinal gradient in δD of average growing season precipitation over the breeding range, we found considerable overlap in δD values of Bicknell's Thrush among all breeding sites. No strong pattern in δ13C values of feathers with latitude was apparent. Nevertheless, the more negative δD values of feathers from wintering birds in the Dominican Republic compared to breeding area samples suggested that birds from more northerly locations in North America contributed to this population of wintering birds. High variance in feather δD values within breeding populations also suggested high natal dispersal, considerable movement of birds among island habitats on the breeding grounds, or both. Even higher variances in feather δD values from small study areas on the wintering grounds, compared to similar-sized areas in the breeding range, suggest that many different breeding populations mix in winter habitat.
Area Requirements of Grassland Birds: A Regional Perspective
Authors: Johnson Douglas H. , Igl Lawrence D. 
Published: September 2019

AbstractArea requirements of grassland birds have not been studied except in tallgrass prairie. We studied the relation between both species-occurrence and density and patch size by conducting 699 fixed-radius point counts of 15 bird species on 303 restored grassland areas in nine counties in four northern Great Plains states. Northern Harrier (Circus cyaneus), Sedge Wren (Cistothorus platensis), Clay-colored Sparrow (Spizella pallida), Grasshopper Sparrow (Ammodramus savannarum), Baird's Sparrow (Ammodramus bairdii), Le Conte's Sparrow (Ammodramus leconteii), and Bobolink (Dolichonyx oryzivorus) were shown to favor larger grassland patches in one or more counties. Evidence of area sensitivity was weak or ambivalent for Eastern Kingbird (Tyrannus tyrannus), Common Yellowthroat (Geothlypis trichas), Savannah Sparrow (Passerculus sandwichensis), and Western Meadowlark (Sturnella neglecta). Red-winged Blackbirds (Agelaius phoeniceus) preferred larger patches in some counties, and smaller patches in others. Mourning Doves (Zenaida macroura) and Brown- headed Cowbirds (Molothrus ater) tended to favor smaller grassland patches. Three species showed greater area sensitivity in counties where each species was more common. Five species demonstrated some spatial pattern of area sensitivity, either north to south or east to west. This study demonstrates the importance of replication in space; results from one area may not apply to others because of differences in study design, analytical methods, location relative to range of the species, and surrounding landscapes.
Molecular Systematics and Biogeography of Antillean Thrashers, Tremblers, and Mockingbirds (Aves: Mimidae)
Authors: Hunt Jeffrey S. , Bermingham Eldredge , E. Ricklefs Robert 
Published: September 2019

AbstractWe constructed phylogenetic hypotheses for Greater and Lesser Antillean Mimidae, including five endemic species of tremblers and thrashers that represent the best plausible example of an avian radiation within the Lesser Antilles. Phylogenetic relationships were inferred from analysis of 3,491 base pairs (bp) of mitochondrial DNA (mtDNA) and roughly 780 bp of the nuclear-encoded myoglobin gene. We used a subset of mtDNA gene sequences and pcrRFLP analysis to evaluate the phylogeographic relationships among individuals representing island populations of the Brown and Gray tremblers (Cinclocerthia ruficauda and C. gutturalis), Pearly-eyed Thrasher (Margarops fuscatus), Scaly-breasted Thrasher (Margarops fuscus), and Antillean and continental populations of the Tropical (Mimus gilvus) and Northern mockingbirds (Mimus polyglottos). Phylogeographic analysis distinguished three strongly differentiated mtDNA clades among tremblers, as well as distinct southern (St. Lucia and Martinique) and northern (Dominica to Montserrat) mtDNA lineages of the Scaly-breasted Thrasher. Minor geographic subdivision was also observed between continental and Antillean populations of the Tropical Mockingbird. Phylogenetic analyses of species-level Mimidae relationships that are based on mtDNA and nuclear sequences provide strong support for the monophyly and Antillean origin of a clade that consists of the tremblers, Pearly-eyed Thrasher, and Scaly-breasted Thrasher, but reject the monophyly of the genus Margarops. Phylogenetic analysis cannot confirm the monophyly of all endemic Antillean mimids because of the apparently contemporaneous diversification of the Antillean White-breasted Thrasher (Ramphocinclus brachyurus) with the continental Gray Catbird (Dumetella carolinensis) and Black Catbird (Melanoptila glabrirostris). However, an insertion and a deletion in the myoglobin intron 2 sequence support grouping the West Indian thrashers and tremblers, from which we infer that the endemic Lesser Antillean mimids are an indigenous radiation. Assuming a constant mtDNA clock for the Mimidae, the splitting of the Northern and Tropical mockingbird lineages is roughly contemporaneous with the separation of the three trembler clades, as well as the two Scaly-breasted Thrasher clades. Application of a mitochondrial DNA clock ticking at 2% sequence divergence per million years (Ma), suggests that the history of the endemic thrasher and trembler lineage in the West Indies extends back about 4 Ma, and the three distinct clades of tremblers split about 2 Ma ago.
A Cryptic New Species of Flycatcher (Tyrannidae: Suiriri) From the Cerrado Region of Central South America
Authors: Zimmer Kevin J. , Whittaker Andrew , Oren David C. 
Published: September 2019

AbstractA new species of tyrant flycatcher (Suiriri islerorum) is described from the cerrado region of Brazil and adjacent eastern Bolivia. The species previously had been confused with Suiriri suiriri affinis, with which it is syntopic at multiple sites. The new species was first identified by voice. Although cryptically similar to S. s. affinis in many respects, the new species is readily identified by all vocalizations, bill size, color pattern of the tail, and shape of the central rectrices. Most distinctive are the male–female duets, which are accompanied by dramatic wing-lifting displays not performed by any congeners. Reciprocal playback experiments of tape-recorded vocalizations demonstrated that the new species and S. s. affinis do not respond to one another's vocalizations. We provide information on the natural history of the new flycatcher, along with spectrograms of its various vocalizations. We also provide vocal analysis of all other named taxa in Suiriri, and discuss the various intrageneric relationships. In particular, S. s. affinis and S. s. bahiae, although distinct morphologically, are vocally and behaviorally similar, and respond to one another's vocalizations in playback experiments.