62 research outputs found

    Avifauna of the Mache Chindul ecological reserve, northwest Ecuador

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    We report on the avifauna of the 120,000 ha Mache Chindul Ecological Reserve (REMACH), northwest Ecuador. The study area is located in a poorly studied transition zone between three major Neotropical biogeographic regions-the Chocó, Tumbesian, and Tropical Andes-each of which contains exceptional diversity and endemism in birds and other organisms. We collected data from 1998–99 and 2004–11 from the Bilsa Biological Station (a 3500 ha private reserve) and several farms, forest fragments, and communities distributed across the central portion of REMACH using observations (aural and visual), audio recordings, mist netting, point counts and photographs. We recorded 360 species of bird (263 genera, 51 families), including 57 threatened species on the Red List of Ecuador, 14 of which are also globally threatened; 23 ‘restricted range’endemic species (15 Chocó and 8 Tumbesian); and 16 migratory species. We recorded breeding activity for 130 species, and documented two distinctive peaks of reproduction, corresponding to the wet and dry seasons, respectively. Our results suggest that REMACH represents a transition zone between Chocó and Tumbesian biogeographic zones, and as such should be considered a priority for conservation of avifauna and other taxa. Accepted 7 November - Reportamos la avifauna de la Reserva Ecológica Mache Chindul (REMACH) de 120.000 ha al noroeste de Ecuador. El área de estudio se encuentra en una zona de transición poco estudiada entre tres grandes regiones biogeográficas neotropicales – el Chocó, Tumbes y los Andes Tropicales – cada una de las cuales contiene una excepcional diversidad y endemismo de aves y otros organismos. Reunimos datos desde 1998–99 y 2004–11 en la Estación Biológica Bilsa (una reserva privada de 3500 hectáreas), en varias fincas, fragmentos forestales y comunidades distribuidas a través de la parte central de REMACH. En estos sitios utilizamos observaciones (registros auditivos y visuales), grabaciones de audio, redes de niebla, puntos de conteo y fotografías. Se registraron 360 especies de aves (263 géneros, 51 familias), incluyendo 57 especies amenazadas de la Lista Roja de Ecuador, 14 de las cuales también se encuentran amenazadas a nivel mundial; 23 especies endémicas ‘rango restringido’ (15 y 8 Tumbes y Chocó ), y 16 especies migratorias. Se registró evidencia reproductiva en 130 especies, y documentamos dos picos bien definidos de reproducción, los que corresponden a las estaciones seca y lluviosa. Nuestros resultados proponen que REMACH representa una zona importante de transición entre las zonas biogeográficas del Chocó y Tumbes, por lo tal debe ser considerada una prioridad para la conservación de la avifauna y otros taxones

    ARTICLE Factors influencing Brown Pelican (Pelecanus occidentalis) foraging movement patterns during the breeding season

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    Abstract: During the breeding season, seabird foraging behaviors are driven by a combination of individual-and external-based factors. This study evaluated how two individual-based factors (body condition and sex) and two external factors (nest stage and colony size), and their interactions, were related to movement. To do so, we used movement data obtained from 22 GPS-tagequipped Brown Pelicans (Pelecanus occidentalis L., 1766) breeding in the northern Gulf of Mexico. In Brown Pelicans, the postegg-hatching phase imposes increased foraging demands on breeding adults relative to the prehatching phase. This study demonstrates that the progression of the breeding period affects the nature and intensity of the relationship between individualbased factors and movement patterns. In particular, birds in relatively lower condition traveled greater distances during foraging trips during the energetically demanding posthatching phase, but not during the incubation stage. Contrary to many seabird species studied to date, neither colony size nor sex appeared to affect Brown Pelican movement patterns. Our results suggest that nest stage is the most important factor influencing foraging movements, and that it may modulate relationships between condition and movement. More refined measures of body condition and foraging behavior will allow further insights into the movement ecology of this seabird

    Sex role similarity and sexual selection predict male and female song elaboration and dimorphism in fairy-wrens

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    Historically, bird song complexity was thought to evolve primarily through sexual selection on males; yet, in many species, both sexes sing and selection pressure on both sexes may be broader. Previous research suggests competition for mates and resources during short, synchronous breeding seasons leads to more elaborate male songs at high, temperate latitudes. Furthermore, we expect male–female song structure and elaboration to be more similar at lower, tropical latitudes, where longer breeding seasons and year-round territoriality yield similar social selection pressures in both sexes. However, studies seldom take both types of selective pressures and sexes into account. We examined song in both sexes in 15 populations of nine-fairy- wren species (Maluridae), a Southern Hemisphere clade with female song. We compared song elaboration (in both sexes) and sexual song dimorphism to latitude and life-history variables tied to sexual and social selection pressures and sex roles. Our results suggest that song elaboration evolved in part due to sexual competition in males: male songs were longer than female songs in populations with low male survival and less male provisioning. Also, female songs evolved independently of male songs: female songs were slower paced than male songs, although only in less synchronously breeding populations. We also found male and female songs were more similar when parental care was more equal and when male survival was high, which provides strong evidence that sex role similarity correlates with male–female song similarity. Contrary to Northern Hemisphere latitudinal patterns, male and female songs were more similar at higher, temperate latitudes. These results suggest that selection on song can be sex specific, with male song elaboration favored in contexts with stronger sexual selection. At the same time, selection pressures associated with sex role similarity appear to favor sex role similarity in song structure

    How User‐centric Innovation is Affecting Stakeholder Marketing Strategies: Exploratory Findings from the Music Industry

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    This paper empirically explores how user‐centric innovation (UCI) in the music industry is affecting how key stakeholder groups are approaching and developing their marketing (and associated management) strategies. The three‐stage interview‐based research methodology consisted of 52 semi‐structured in‐depth interviews with UCI experts and artist managers, as well as representatives from major record labels. The findings make four substantial contributions to theory and practice in the interrelated fields of UCI, marketing and the music industry. First, they provide practical and pragmatic insights for industry practitioners on how different UCI marketing approaches are affecting their management strategies. Second, they take steps towards answering many of the identified gaps in research and knowledge relating to the concept of UCI. Third, they present theoretical models as a foundation for which new UCI marketing theory can be built upon. Last, they offer directions for future research to advance our empirical findings.</jats:p

    Multiple hypotheses explain variation in extra-pair paternity at different levels in a single bird family

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    Extra‐pair paternity (EPP), where offspring are sired by a male other than the social male, varies enormously both within and among species. Trying to explain this variation has proved difficult because the majority of the interspecific variation is phylogenetically based. Ideally, variation in EPP should be investigated in closely related species, but clades with sufficient variation are rare. We present a comprehensive multifactorial test to explain variation in EPP among individuals in 20 populations of nine species over 89 years from a single bird family (Maluridae). Females had higher EPP in the presence of more helpers, more neighbours or if paired incestuously. Furthermore, higher EPP occurred in years with many incestuous pairs, populations with many helpers and species with high male density or in which males provide less care. Altogether, these variables accounted for 48% of the total and 89% of the interspecific and interpopulation variation in EPP. These findings indicate why consistent patterns in EPP have been so challenging to detect and suggest that a single predictor is unlikely to account for the enormous variation in EPP across levels of analysis. Nevertheless, it also shows that existing hypotheses can explain the variation in EPP well and that the density of males in particular is a good predictor to explain variation in EPP among species when a large part of the confounding effect of phylogeny is excluded

    Age-dependent relationships between multiple sexual pigments and condition in males and females

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    The reliability of sexual signaling may change across age classes due to shifts in resource allocation patterns. Two contrasting hypotheses exist regarding how the condition dependence of ornaments may shift with age, and both have received empirical support. On one hand, ornaments may more reliably reflect condition and quality in older individuals, because younger individuals of high quality invest in survival over signaling effort. On the other hand, the condition dependence of ornaments may decline with age, if older individuals in poor condition terminally invest in ornaments, or if resource constraints decline with age. Further, the expression and condition dependence of different ornaments may shift with age in unique ways, such that multifaceted sexual displays maintain reliable signaling across age classes. In yellow warblers (Setophaga petechia) of both sexes, we assessed how relationships between carotenoid-and phaeomelanin-based sexual pigmentation, prenesting body reserves, and condition at molt (reflected by growth bars and feather quality) vary across age classes. Melanin coverage correlated with condition at molt across age classes in males and showed high repeatability in both sexes. In contrast, carotenoid saturation increased longitudinally with age in males and correlated with condition at molt in different age classes in the 2 sexes. Specifically, carotenoid saturation correlated positively with condition at molt in younger, but not older males, whereas in females, the situation was reversed, with a positive correlation present only in older females. Results suggest that age-dependent signaling may promote maintenance of multifaceted sexual displays and that agedependent signaling dynamics depend on sex. © The Author 2013. Published by Oxford University Press on behalf of the International Society for Behavioral Ecology. All rights reserved

    Correlation between investment in sexual traits and valve sexual dimorphism in Cyprideis species (Ostracoda)

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    Assessing the long-term macroevolutionary consequences of sexual selection has been hampered by the difficulty of studying this process in the fossil record. Cytheroid ostracodes offer an excellent system to explore sexual selection in the fossil record because their readily fossilized carapaces are sexually dimorphic. Specifically, males are relatively more elongate than females in this superfamily. This sexual shape difference is thought to arise so that males carapaces can accommodate their very large copulatory apparatus, which can account for up to one-third of body volume. Here we test this widely held explanation for sexual dimorphism in cytheroid ostracodes by correlating investment in male genitalia, a trait in which sexual selection is seen as the main evolutionary driver, with sexual dimorphism of carapace in the genus Cyprideis. We analyzed specimens collected in the field (C. salebrosa, USA; C. torosa, UK) and from collections of the National Museum of Natural History, Washington, DC (C. mexicana). We digitized valve outlines in lateral view to obtain measures of size (valve area) and shape (elongation, measured as length to height ratio), and obtained several dimensions from two components of the hemipenis: the muscular basal capsule, which functions as a sperm pump, and the section that includes the intromittent organ (terminal extension). In addition to the assessment of this primary sexual trait, we also quantified two dimensions of the male secondary sexual trait-where the transformed right walking leg functions as a clasping organ during mating. We also measured linear dimensions from four limbs as indicators of overall (soft-part) body size, and assessed allometry of the soft anatomy. We observed significant correlations in males between valve size, but not elongation, and distinct structural parts of the hemipenis, even after accounting for their shared correlation with overall body size. We also found weak but significant positive correlation between valve elongation and the degree of sexual dimorphism of the walking leg, but only in C. torosa. The correlation between the hemipenis parts, especially basal capsule size and male valve size dimorphism suggests that sexual selection on sperm size, quantity, and/or efficiency of transfer may drive sexual size dimorphism in these species, although we cannot exclude other aspects of sexual and natural selection

    Plumage color and reproduction in the red-backed fairy-wren: Why be a dull breeder?

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    Males of many species can breed in distinct alternative phenotypes; for example, in many birds some males breed in dull plumage while others breed in bright plumage. Because females often appear to prefer brighter males, it is unclear why some males breed in dull plumage. Males in dull plumage might enjoy enhanced within-pair reproductive success if they can gain access to better breeding territories, or they might have relatively high extrapair reproductive success if they are better able to intrude on the territories of other males. To test these possibilities, we examined the reproductive consequences of plumage color in the redbacked fairy-wren (Malurus melanocephalus), a species in which males can breed in either bright plumage or dull plumage or serve as nonbreeding auxiliaries. Male plumage color was distributed bimodally and was loosely associated with age, such that some males molted into bright plumage a year or more earlier than others. Both male phenotypes were cuckolded at similar rates, but bright males sired significantly more extrapair young than did dull males, and this effect was independent of age. Thus, 1-year-old males who bred in dull plumage had low seasonal reproductive success compared with same-aged males who bred in bright plumage. These results suggest that males may not reap any fitness benefits by breeding in dull coloration, compared with breeding in bright plumage, but rather may be constrained to breed in suboptimal plumage by the timing of plumage acquisition

    Early-moulting Red-backed Fairywren males acquire ornamented plumage in the absence of elevated androgens

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    Sexual ornaments, including plumage ornamentation, are often studied during breeding periods even though signal development can take place months earlier. This temporal disconnect potentially obscures the proximate mechanisms that underlie signal expression and development. We studied the correlation between androgen levels and expression of ornamented plumage in adult Red-backed Fairywrens (Malurus melanocephalus) 4-6 months before breeding, when signal production occurs in some, usually older, males. We found that, during this period, ornamented males, unornamented males and females all had low plasma androgen levels that did not differ from each other. Variation in androgen levels was unrelated to phenotype or moult. These findings differ from previous research conducted immediately prior to breeding in a different population of this species, which used correlative and experimental work to demonstrate that testosterone induces prenuptial moult and acquisition of ornamented plumage in younger males. Our study demonstrates that mechanisms contributing to signal production may vary within and among populations in relation to temporal, age-dependent, or geographic parameters. These results highlight the complexity of hormonal pathways to signal production, and the importance of studying signal acquisition throughout the entire period when signals are produced, as studies conducted at different time points may have quantitatively different results
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