Description of New American Carduelis/Spinus Bird Species in La Paz (Bolivia): C./S. lapazensis.

Introduction: South American siskins (Genus Carduelis/Spinus) are the outcome of regional evolutionary radiation from an extant (or other extinct) species: C. notata, a North America siskin, which thrives in Mexico subtropical areas and is parental of one of the three described North American siskin radiations. Methods: Speciation and/or subspeciation of this South American siskin radiation have probably occurred during Pleistocene Epoch. In the present paper, a new species/subspecies akin to C./S. atrata is described by genetic and phenotypic parameters: this new species/subspecies was previously considered a subspecies of C./S. xanthogastra, which thrives further North and is separated about 1,762 km, 1,094 miles, from this described subspecies, Carduelis/ Spinus xanthogastra stejnegeri. Results: Our genetic study using mt cyt b, phenotypic and behavior observations show that this putative C./S. xanthogastra subspecies is either a different species or a C./S. atrata subspecies; we have proposed a provisional name for this finch, C./S. lapazensis, instead of C./S. x. stejnegeri. Conclusion: Species definition is movable and controversial, and it is uncertain in South American siskins, which all show a close genetic and phenotypical relationship, which may be still immersed in speciation processes since Pleistocene Epoch.

Glucose Concentrations in Closely Related Titmice (Baeolophus) Species Linked to Regional Habitat Differences Across an Avian Hybrid Zone

Aims: We used physiological data, in conjunction with habitat information, to elucidate the interactions between two hybridizing songbirds within a hybrid zone. Background: Hybrid zones are ideal regions to examine a variety of ecological, behavior, and evolutionary processes. In addition to genetics, behavior, and morphology, physiological differences may impact hybrid fitness, genetic introgression, and even the stability of a hybrid zone. Objective: To assess physiological differences in hybridizing species, we investigated selected venous blood analytes in two species of songbirds hybridizing along the Balcones Escarpment in central Texas. Methods: Using a portable blood analyzer, we assayed blood samples from Black-crested Titmouse (Baeolophus atricristatus) and Tufted Titmouse (B. bicolor) individuals along a longitudinal transect that included the contact zone. Ecologically, this transect varies from higher elevation semi-arid regions on the Balcones Escarpment (and west across the Edwards Plateau) to lower elevation mesic forests east of the escarpment. Results: As expected, several blood analytes differed with age, sex, and sedative administration; however, we observed relatively increased blood glucose concentrations in Black-crested Titmice, which occupy the semi-arid habitats of west Texas. Furthermore, glucose concentrations were further elevated following rainfall events. Blood glucose concentrations often increase during stressful conditions and or related to changes in diet. Conclusion: We suspect that Black-crested Titmice have relatively increased blood glucose concentrations as a product of living in a semi-arid environment that causes chronic stress from unpredictable food and water resources. The link between rainfall and glucose may be a result of the increased and greater diversity of food availability after rainfall. Although further research is needed, we suspect that habitat differences and associated lack of physiological adaptations may be a limiting factor in westward range expansion in the more aggressive Tufted Titmice.

Bird Diversity in Nensebo Moist Afromontane Forest Fragment, South Eastern Ethiopia.

Background: Birds are one component of biodiversity. Ethiopia is rich in biodiversity resources. The avian diversity record is far from complete. There is no scientifically documented information on bird species composition and abundance at Nensebo forest. The objective of the study was to assess species composition, relative abundance and distribution of birds at Nensebo forest in southern Ethiopia. Methods: We employed a stratified random sampling technique with our study area stratified into two dominant habitat types: moist Afromontane forest and modified habitat. Within strata, we established 20 transect lines of 1km length and 0.25km width to sample 27.75% of the study area. We used line transect count methods aided by binoculars to estimate avian species diversity and distribution. We employed quantitative biodiversity indices, such as Shannon wiener diversity indexes to compare species diversity among habitat types and two way ANOVA to analyze the effect of season and habitat on bird species richness and abundance. Results: A total of 105 bird species consisting of 1 endemic, 8 near endemic, 1 globally threatened and 9 Palearctic migrants were recorded in Nensebo forest. Species richness and abundance varied between habitat types in Nensebo forest with mean species richness greater in modified habitat (mean= 4.70 ±1.65) as compared to moist Afromontane forest habitat (mean= 3.95 ±4.12, F=94.66 P<0.001). Additionally, modified habitat (Shannon diversity index= 4.131) harbored higher diversity of birds as opposed to Afromontane forest habitat (Shannon diversity index=3.79). Conclusion: The Nensebo forest has high avian species diversity including several endemic and endangered species revealing the importance of this site for bird conservation. Although we found that habitat heterogeneity favored bird species diversity, moist Afromontane habitat is critical for forest obligate species. Hence, sustainable bird conservation strategies including land use planning should be initiated for this area.

Influence of Disturbance on Avian Communities in Agricultural Conservation Buffers in Mississippi, USA

Introduction: Periodic disturbance of agricultural conservation buffers is required to maintain early successional plant communities for grassland birds. However, a disturbance may temporarily reduce the availability of vegetation cover, food, and nesting sites in a buffer. Objective: Our objective was to determine how the type of disturbance (i.e., prescribed burning, light disking) and time since the last disturbance event in agricultural conservation buffers influence the grassland bird community. Methods: Data collected during line-transect surveys conducted in 46 agricultural conservation buffers in northeast Mississippi during the 2007-2009 breeding seasons (May-early August) demonstrate periodic disturbance through prescribed burning and light disking does not influence breeding bird diversity or density in the buffers. Results: Density of Dickcissels (Spiza americana), Red-winged Blackbirds (Agelaius phoeniceus), and Indigo Buntings (Passerina cyanea) did not differ in the buffers regardless of the type of or time since disturbance. Conclusion: Large effect sizes, however, indicate a potential type two error resulting from this conclusion. Thus, based on relative effect sizes, avian density in undisturbed buffers may be greater than in buffers during their first growing season post-disturbance. Relative effect sizes among estimates also indicate disturbance, namely prescribed burning, may lead to greater densities of breeding birds in agricultural conservation buffers. Though disturbance may initially reduce avian density, it is necessary to maintain long-term early-successional herbaceous habitat in agricultural conservation buffers.

Threats and Vision for the Conservation of Galápagos Birds

Introduction:Threats that affect the avian diversity on the Galápagos Islands are increasing. We evaluated threats such as climate change and severe weather, human intrusions and disturbance, biological resource use, invasive and other problematic species, genes and diseases, pollution, geological events and loss of genetic diversity in relation with avian species enlisted in both the international and national (Ecuador) IUCN Red List, which can be used as sentinel species of the ecosystem. Here, the status of the threatened species for the next ten years (present time up to 2028), under two scenarios, including thestatus quoand theavian diversity visionfor the species’ conservation, was assessed.Methods:The conceptual framework of the assessment was envisioned within the existing knowledge and projections of present and future threats to revisit current conservation efforts. Based on this evaluation, a set of management actions coupled with mitigation strategies to address new anthropogenic threats affecting the long-term survival of species in the face of global and regional environmental changes are recommended. Alternative strategies for species conservation, mainly when declining avian populations are susceptible to demographic bottlenecks or risk of extinction and when natural disasters affect ecosystem stability, are also considered.Results:These results should be envisioned as a guide for the evaluation and management of the avian species in the future to be replicated every decade.

Different Messages are Transmitted by Individual Duet Contributions and Complete Duets in a Species with Highly Overlapped Duets

Background: Duet function hypotheses have been mostly studied in bird species that produce duets with male and female solo songs. However, in order to understand if patterns of duet function are similar across all duetting species, it is highly necessary to test the duet function hypotheses in species that produce duets with vocalizations other than solo songs. Objective: We studied the responses of territorial pairs to each sex’s individual duet contribution and complete duets in a species that produces duets with a vocalization other than male and female solo songs. Methods: We conducted a playback experiment where we presented duet contributions of each sex to three populations of White-eared Ground-sparrows (Melozone leucotis) in Costa Rica, during this species’ breeding season in 2016. Results: The responses to complete duets were stronger than those to each sex’s duet contribution, suggesting that complete duets and each sex’s duet contribution have different functions. Complete duets are used to protect resources from intruders (supporting the resource defense hypothesis), and to prevent the partner from being usurped by intruders (supporting the mate-guarding hypothesis). Males used solo songs in response to female duet contributions, and this may work to attract intruder females (increasing the probability of extra-pair copulation). Males also use solo songs in response to male duet contributions, which may work as a signal to repel intruder males and guard their female. In this case, where mate attraction occurs with a completely different type of vocalization than used for duetting, we found a clear pattern of a double agenda for males when a territorial intrusion occurs. Conclusions: This study provides strong support for the dual function hypothesis in duets and reveals conflicting selective pressures between pair members relative to each hypothesis.

Recruitment Rates, Natal and Breeding Dispersal of Montagu’s Harriers (Circus Pygargus) by Means of Microsatellite Analysis

Introduction:Adult philopatry as well as juvenile dispersal and recruitment rates are key factors for population development. We investigated these questions for the first time in an increasing German population of Montagu’s harrier in Frankonia using microsatellite markers.Methods:By means of 16 loci, we genotyped 2265 samples from juvenile and adult female Montagu’s harriers. Parentage and identity tests were used to reconstruct life histories of birds for a 10 year period. Most of the birds were breeding in one or two years. The longest life history was eight years.Results:Adult philopatry was quite high and differed significantly between sexes. We found 73.5% of females to breed < 5 km around the previous nest site (80.4% < 10 km, median nesting distance 2.1 km). All investigated males (n=18) were breeding in a distance of < 5 km (median nesting distance 1.3 km) to the previous nest. Juveniles showed a low recruitment rate (females: 2.9%, males: 4.9%, together 4%). Median natal dispersal distance was 19.1 km for females and 12.3 km for males. We found 29.4% of females and 41.2% of males to be philopatric, as the distance between hatching and first breeding site was < 10 km. Philopatry results mostly agree with data from other European countries.Discussion:Due to strict marker and data selection we received high quality life histories of Montagu’s harriers, which demonstrate that microsatellite analyses are valuable tools in ornithology.Conclusion:Nevertheless, comparison of philopatry and recruitment rates depend directly on the scale used and investigation method and therefore remain a challenge.

Painted Redstarts (Myioborus Pictus) Attack Larger Prey when Using Flush-Pursue Strategy

Introduction:Prey escape reaction in insects is an antipredatory adaptation that is mediated by prey neural escape circuits with specific sensory properties.Methods:Certain insectivorous birds, flush-pursuers, exploit this visual sensitivity by employing conspicuous pivoting movements of spread tail and wings to flush the prey into the air where it is available for chase in aerial pursuits. Although it is known that this strategy increases the number of insects attacked, no information has been published on the size distribution of arthropods attacked using flush-pursue strategyvs. traditional gleaning and pecking off substrate strategy.Results:Based on one season of observational data of foraging redstarts (Myioborus pictus) we show that prey items that were flushed and chased were on average larger than prey pecked off of substrates.Conclusion:This may be one of the benefits from flush-pursue foraging – a strategy that is probably costly in terms of energy demands.

Cretaceous Reverie: Review of Birds of Stone: Chinese Avian Fossils from the Age of Dinosaurs by Luis M. Chiappe and Meng Qingjin1

Birds of Stone contains a portfolio of outstanding photographs of the spectacularly preserved Jehol bird fossils, from the Chinese Lower Cretaceous, and other pertinent vertebrate fossils of varying ages, along with comments on each fossil. The book nicely illustrates a range of species of the radiation of enantiornithines (opposite birds), the dominant Mesozoic landbirds, as well as the ornithuromorphs, the Mesozoic antecedents of the modern neornithine birds. Although the first section of the book is fairly straight forward, the second section, on bird origins and their early evolution is one-sided, presenting only the popular paleontological view and omits discussion of controversial subjects. Examples are the highly speculative presence of dinosaur protofeathers and improbable scenarios of flight origins. There are no citations of the numerous credible opposing views in the literature.

Evidence for a Relationship Between the Movements of the Common Redpoll (Acanthis flammea) and the American Goldfinch (Spinus tristis)

Background:Many bird species that breed at high latitudes exhibit irregular southward incursions in response to spatial and temporal variation in winter food availability.Methods:We analyzed Christmas Bird Count records to compare the migratory behavior of the Common Redpoll (Acanthis flammea), an Arctic breeder known to invade southern latitudes every other winter, with that of the American Goldfinch (Spinus tristis), a closely related finch species that breeds broadly in temperate latitudes in North America.Results and Discussion:Historic data indicate that east of the Rocky Mountains, both species overwinter in relatively even numbers across latitudes. In contrast, we found few significant positive correlations between the winter records of each species in different areas along the same longitude. We attribute these patterns to the fact that resource levels and environmental conditions tend to be similar across latitudes. While previous studies of historic data have identified a biennial pattern in the migration of the Common Redpoll, we found evidence that populations of American Goldfinches breeding in the northern parts of the species’ range similarly display significant southward movements every other year. Because these two species breed at different latitudes and show large-scale southward movements during the same years, areas across southern Canada and the northern United States alternate between having high winter abundances of Common Redpolls and American Goldfinches. We propose that these alternations are caused by a shared response to cyclical seed crop failure across the northern regions of North America.