Extrapair mating behaviors in the field sparrow: nocturnal singing and extraterritorial forays

While there has been much research on the mating behaviors of birds, most attention has focused on elaborate and/or conspicuous mating displays, such as diurnal songs, ornaments, or mating dances. Much less attention has been devoted to investigating the role of more subtle behaviors, particularly nocturnal signing by diurnal birds and extra-territorial forays (movements off territory). My research explored the function of nocturnal singing and extra-territorial forays in the Field Sparrow (Spizella pusilla). I determined that nocturnal complex song serves to announce the presence of extra-pair males to females and that extra-territorial forays serve primarily in prospecting and soliciting extra-pair matings. While forays are common among both male and female Field Sparrows, a higher foraying rate did not result in greater extra-pair paternity (EPP). Rather, my data provide strong evidence that extra-pair matings are determined by current and previous relationships; females chose extra-pair sires that were current neighbors or neighbors or social mates during previous breeding seasons. Given female preference for extra-pair matings with neighbors, males who have information on the fertility status of neighboring females and coordinate their nocturnal vocalizations in relation to the fertility stage of neighboring females may be able to increase their EPP. Contrary to other studies, I did not find a relationship between the traits of males, females, or females’ social mates (age and tarsus length) and EPP. Thus, proximity to females, rather than male characteristics, appears to be key for a male’s success at acquiring extra-pair paternity. Finally, my findings are consistent with the hypothesis that female choice for extra-pair mates coupled with female foray behavior are driving patterns of extra-pair paternity and nocturnal singing behavior. By integrating research on nocturnal singing, extra-territorial foray behavior, and extra-pair paternity, my work has led to a more comprehensive understanding of extra-pair mating behavior in birds

Effectiveness and utility of acoustic recordings for surveying tropical birds

Although acoustic recordings have recently gained popularity as an alternative to point counts for surveying birds, little is known about the relative performance of the two methods for detecting tropical bird species across multiple vegetation types. During June and July 2008, we collected species detection/nondetection data to compare the performance of a quadraphonic acoustic recording system and point counts for estimating species richness and composition and detection probabilities of 15 rare, moderately common, and common tropical bird species across six structurally distinct vegetation types (coastal dune scrub, mangrove, low-stature deciduous thorn forest, early and late successional medium-stature semievergreen forest, and grazed pastures) in the northern Yucatan Peninsula.We selected five rare species endemic to the Yucatan Peninsula and 10 moderately common and common species that also occur in other tropical regions. Species richness and composition did not differ between survey methods in any of the vegetation types. At the population level, however, we found support for an effect of method on detection probability for most species. For 13 species, regardless of their abundance, acoustic recordings yielded detection probabilities as high as or higher than those for point counts across all vegetation types. The remaining two species were better detected by point counts in pastures and coastal scrub, where greater visibility likely improved sightings of these species. However, these species were detected as well as or better by acoustic recordings in forests and mangroves where detections were primarily auditory. In tropical regions where experienced field observersmay not be available and funding for field surveys may be limited, acoustic recordings offer a practical solution for determining species richness and composition and the occupancy patterns of most species. However, for some species, a combination of methods will provide the most reliable data. Regardless of the method selected, analyses that account for variation in detection probability among vegetation types will be necessary because most species in our study demonstrated vegetation-dependent detection probabilities

Integrating data types to estimate spatial patterns of avian migration across the Western Hemisphere

For many avian species, spatial migration patterns remain largely undescribed, especially across hemispheric extents. Recent advancements in tracking technologies and high-resolution species distribution models (i.e., eBird Status and Trends products) provide new insights into migratory bird movements and offer a promising opportunity for integrating independent data sources to describe avian migration. Here, we present a three-stage modeling framework for estimating spatial patterns of avian migration. First, we integrate tracking and band re-encounter data to quantify migratory connectivity, defined as the relative proportions of individuals migrating between breeding and nonbreeding regions. Next, we use estimated connectivity proportions along with eBird occurrence probabilities to produce probabilistic least-cost path (LCP) indices. In a final step, we use generalized additive mixed models (GAMMs) both to evaluate the ability of LCP indices to accurately predict (i.e., as a covariate) observed locations derived from tracking and band re-encounter data sets versus pseudo-absence locations during migratory periods and to create a fully integrated (i.e., eBird occurrence, LCP, and tracking/band re-encounter data) spatial prediction index for mapping species-specific seasonal migrations. To illustrate this approach, we apply this framework to describe seasonal migrations of 12 bird species across the Western Hemisphere during pre- and postbreeding migratory periods (i.e., spring and fall, respectively). We found that including LCP indices with eBird occurrence in GAMMs generally improved the ability to accurately predict observed migratory locations compared to models with eBird occurrence alone. Using three performance metrics, the eBird + LCP model demonstrated equivalent or superior fit relative to the eBird-only model for 22 of 24 species–season GAMMs. In particular, the integrated index filled in spatial gaps for species with over-water movements and those that migrated over land where there were few eBird sightings and, thus, low predictive ability of eBird occurrence probabilities (e.g., Amazonian rainforest in South America). This methodology of combining individual-based seasonal movement data with temporally dynamic species distribution models provides a comprehensive approach to integrating multiple data types to describe broad-scale spatial patterns of animal movement. Further development and customization of this approach will continue to advance knowledge about the full annual cycle and conservation of migratory birds

Multicentric study of cervical cancer screening with human papillomavirus testing and assessment of triage methods in Latin America : the ESTAMPA screening study protocol

Q1Q1Introduction Human papillomavirus (HPV) testing is replacing cytology in primary screening. Its limited specificity demands using a second (triage) test to better identify women at high-risk of cervical disease. Cytology represents the immediate triage but its low sensitivity might hamper HPV testing sensitivity, particularly in low-income and middle-income countries (LMICs), where cytology performance has been suboptimal. The ESTAMPA (EStudio multicéntrico de TAMizaje y triaje de cáncer de cuello uterino con pruebas del virus del PApiloma humano; Spanish acronym) study will: (1) evaluate the performance of different triage techniques to detect cervical precancer and (2) inform on how to implement HPV-based screening programmes in LMIC. Methods and analysis Women aged 30–64 years are screened with HPV testing and Pap across 12 study centres in Latin America. Screened positives have colposcopy with biopsy and treatment of lesions. Women with no evident disease are recalled 18 months later for another HPV test; those HPV-positive undergo colposcopy with biopsy and treatment as needed. Biological specimens are collected in different visits for triage testing, which is not used for clinical management. The study outcome is histological high-grade squamous intraepithelial or worse lesions (HSIL+) under the lower anogenital squamous terminology. About 50 000 women will be screened and 500 HSIL+ cases detected (at initial and 18 months screening). Performance measures (sensitivity, specificity and predictive values) of triage techniques to detect HSIL+ will be estimated and compared with adjustment by age and study centre. Ethics and dissemination The study protocol has been approved by the Ethics Committee of the International Agency for Research on Cancer (IARC), of the Pan American Health Organisation (PAHO) and by those in each participating centre. A Data and Safety Monitoring Board (DSMB) has been established to monitor progress of the study, assure participant safety, advice on scientific conduct and analysis and suggest protocol improvements. Study findings will be published in peer-reviewed journals and presented at scientific meetings. Trial registration number NCT01881659Revista Internacional - Indexad

Evaluating the use of acoustic monitoring for surveying tropical birds

In this study I evaluated the effectiveness of an acoustic recording system (SRS) for surveying tropical bird communities and species relative to traditional point count surveys. To address this goal, I compared species richness, composition and detection probability of 20 species between SRS and point counts across six tropical habitats in the northeastern Yucatan Peninsula. SRS performed in a similar fashion to point counts for estimating species richness and composition, two main features of community structure. Estimates of species richness were not significantly different between methods in any of the habitats. Although similarity in species composition between SRS and point counts was lower in coastal dunes than secondary and mature semi-evergreen forests, at least 92% of the species were shared between the two methods in all habitats. Similarly, the multi-method occupancy models demonstrated that SRS yielded detection probabilities similar to or greater than those of point counts for nearly all species across all habitats, although a few important exceptions occur for species in which SRS performed better than point counts in some habitats. Collectively my results on richness and similarity suggest that, although there are a small number of species detected exclusively by one method or the other, SRS and point counts perform equally well at detecting and identifying the majority of species in the communities I studied. Thus, the choice of a survey technique for characterizing bird communities is more of a logistic question than a monitoring technique question. Because SRS offers a logistically easier method given the lack of experienced point count technicians, SRS stands to help characterize bird communities in tropical habitats

Effectiveness and utility of acoustic recordings for surveying tropical birds

Although acoustic recordings have recently gained popularity as an alternative to point counts for surveying birds, little is known about the relative performance of the two methods for detecting tropical bird species across multiple vegetation types. During June and July 2008, we collected species detection/nondetection data to compare the performance of a quadraphonic acoustic recording system and point counts for estimating species richness and composition and detection probabilities of 15 rare, moderately common, and common tropical bird species across six structurally distinct vegetation types (coastal dune scrub, mangrove, low-stature deciduous thorn forest, early and late successional medium-stature semievergreen forest, and grazed pastures) in the northern Yucatan Peninsula.We selected five rare species endemic to the Yucatan Peninsula and 10 moderately common and common species that also occur in other tropical regions. Species richness and composition did not differ between survey methods in any of the vegetation types. At the population level, however, we found support for an effect of method on detection probability for most species. For 13 species, regardless of their abundance, acoustic recordings yielded detection probabilities as high as or higher than those for point counts across all vegetation types. The remaining two species were better detected by point counts in pastures and coastal scrub, where greater visibility likely improved sightings of these species. However, these species were detected as well as or better by acoustic recordings in forests and mangroves where detections were primarily auditory. In tropical regions where experienced field observersmay not be available and funding for field surveys may be limited, acoustic recordings offer a practical solution for determining species richness and composition and the occupancy patterns of most species. However, for some species, a combination of methods will provide the most reliable data. Regardless of the method selected, analyses that account for variation in detection probability among vegetation types will be necessary because most species in our study demonstrated vegetation-dependent detection probabilities

Effectiveness and utility of acoustic recordings for surveying tropical birds

Although acoustic recordings have recently gained popularity as an alternative to point counts for surveying birds, little is known about the relative performance of the two methods for detecting tropical bird species across multiple vegetation types. During June and July 2008, we collected species detection/nondetection data to compare the performance of a quadraphonic acoustic recording system and point counts for estimating species richness and composition and detection probabilities of 15 rare, moderately common, and common tropical bird species across six structurally distinct vegetation types (coastal dune scrub, mangrove, low-stature deciduous thorn forest, early and late successional medium-stature semievergreen forest, and grazed pastures) in the northern Yucatan Peninsula.We selected five rare species endemic to the Yucatan Peninsula and 10 moderately common and common species that also occur in other tropical regions. Species richness and composition did not differ between survey methods in any of the vegetation types. At the population level, however, we found support for an effect of method on detection probability for most species. For 13 species, regardless of their abundance, acoustic recordings yielded detection probabilities as high as or higher than those for point counts across all vegetation types. The remaining two species were better detected by point counts in pastures and coastal scrub, where greater visibility likely improved sightings of these species. However, these species were detected as well as or better by acoustic recordings in forests and mangroves where detections were primarily auditory. In tropical regions where experienced field observersmay not be available and funding for field surveys may be limited, acoustic recordings offer a practical solution for determining species richness and composition and the occupancy patterns of most species. However, for some species, a combination of methods will provide the most reliable data. Regardless of the method selected, analyses that account for variation in detection probability among vegetation types will be necessary because most species in our study demonstrated vegetation-dependent detection probabilities

Effectiveness and utility of acoustic recordings for surveying tropical birds

Although acoustic recordings have recently gained popularity as an alternative to point counts for surveying birds, little is known about the relative performance of the two methods for detecting tropical bird species across multiple vegetation types. During June and July 2008, we collected species detection/nondetection data to compare the performance of a quadraphonic acoustic recording system and point counts for estimating species richness and composition and detection probabilities of 15 rare, moderately common, and common tropical bird species across six structurally distinct vegetation types (coastal dune scrub, mangrove, low-stature deciduous thorn forest, early and late successional medium-stature semievergreen forest, and grazed pastures) in the northern Yucatan Peninsula.We selected five rare species endemic to the Yucatan Peninsula and 10 moderately common and common species that also occur in other tropical regions. Species richness and composition did not differ between survey methods in any of the vegetation types. At the population level, however, we found support for an effect of method on detection probability for most species. For 13 species, regardless of their abundance, acoustic recordings yielded detection probabilities as high as or higher than those for point counts across all vegetation types. The remaining two species were better detected by point counts in pastures and coastal scrub, where greater visibility likely improved sightings of these species. However, these species were detected as well as or better by acoustic recordings in forests and mangroves where detections were primarily auditory. In tropical regions where experienced field observersmay not be available and funding for field surveys may be limited, acoustic recordings offer a practical solution for determining species richness and composition and the occupancy patterns of most species. However, for some species, a combination of methods will provide the most reliable data. Regardless of the method selected, analyses that account for variation in detection probability among vegetation types will be necessary because most species in our study demonstrated vegetation-dependent detection probabilities

Full-service hotels, convenience stores, or fire escapes? Evaluating the functional role of stopover sites for Neotropical migrants following passage across the Gulf of Mexico in autumn

Nearctic Neotropical migratory songbirds incur the highest mortality during migration. En-route, songbirds rely on a network of stopover sites to rest, refuel, and/or seek refuge during poor weather. Conservation strategies prioritize protection of sites that best meet these needs. However, the specific function of a stopover site is expected to vary in relation to factors, such as geographic location, surrounding landscape, and weather. To identify sites with the highest conservation value for migratory songbirds, a conceptual framework was independently developed to classify sites into three functional categories based on their geographic and landscape features: fire escapes, convenience stores, and full-service hotels. The few attempts to empirically validate this framework have focused on temperate stopover sites. We evaluated the framework by testing the hypothesis that a site’s geographic and landscape characteristics can predict its function. We used capture and radio-tracking data at an island and mainland site in the Yucatan Peninsula, Mexico to quantify mean and variance in daily capture rate, body condition, stopover duration, and departure behavior during autumn, with a focus on four species: Swainson’s Thrush ( Catharus ustulatus ), Red-eyed Vireo ( Vireo olivaceus ), Gray Catbird ( Dumetella carolinensis ), and Prothonotary Warbler ( Protonotaria citrea ). Our results supported our predictions that the island functions as a fire escape, providing refuge for very high numbers of birds after encountering crosswinds or headwinds over the Gulf of Mexico, and the mainland forest site serves as a full-service hotel. The framework provides valuable insight for strategic conservation planning and management of stopover sites for songbirds. We suggest future studies evaluate the framework’s application to non-forest bird species. Additionally, we encourage collaborative efforts to consolidate and integrate tracking data, capture data from migration banding stations, and radar-based bird density estimates across a broad geography to test the framework’s ability to inform conservation planning across species’ full migratory range

Nuevos registros de aves para el Estado de México

Se informa por primera vez sobre la presencia en el Estado de México del halcón guaco (Herpetotheres cachinnans), el halcón enano (Falco rufigularis), la guacamaya verde (Ara militaris), el cuclillo manglero (Coccyzus minor), la titira enmascarada (Tityra semifasciata) y la golondrina sinaloense (Progne sinaloae). Estos registros fueron realizados en el Parque Natural Sierra Nanchititla. Ara militaris y P. sinaloae se encuentran clasificadas como especies en riesgo, de acuerdo con criterios nacionales e internacionales