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This article discusses a study on the lifespans of Neotropical forest landbirds, which has been a topic of interest for scientists for a long time. The study used a 45-year dataset from central Panama to determine the longevity of 47 species. The oldest recorded individual was an 18-year-old Rufous Motmot, and most species had a lifespan of at least 7 years. The study also explored the relationship between longevity and factors such as body mass, diet, and sociality. Surprisingly, there was no correlation between body mass and longevity, and some of the smallest species actually lived the longest. The study suggests that future research should involve larger-scale studies to obtain more accurate estimates of lifespan. [Extracted from the article]

Context: Slash-and-burn agriculture generates landscape mosaics composed of different land uses. Ecological theory postulates that in these mosaics, the structure of species assemblages depends on both local- and landscape-scale factors, but their relative role remains poorly known. Objectives: Understanding the relative importance of local and landscape variables for bird assemblages in landscape mosaics of the Mayan tropical forest, Mexico. Methods: We evaluated the effect of two local variables (land use type and tree basal area) and two landscape variables (old-growth forest cover and human proximity) on bird abundance and diversity, separately assessing forest and non-forest birds. As species extirpation may accelerate when forest loss exceeds certain limits (extinction thresholds), we assessed forest loss effects with linear and nonlinear models. Results: We recorded 1867 birds from 118 species in four land-use types (old-growth forest, secondary forest, burned lands, and agricultural lands). Land-use type and surrounding old-growth forest cover better predicted bird abundance and diversity than tree basal area and human proximity. Agricultural lands showed the lowest abundance and diversity of forest species, but the highest abundance and diversity of non-forest species. We found no support for the extinction threshold hypothesis. Yet, independently of the land use, old-growth forest loss decreased the diversity of forest species and increased the abundance and diversity of non-forest species. Human proximity also decreased total bird abundance, especially because of the loss of forest species. Conclusions: Our findings highlight the key role played by old-growth forests for preserving bird assemblages in landscape mosaics exposed to slash-and-burn agriculture. [ABSTRACT FROM AUTHOR]

The mosaic landscape of small-scale cropping, agroforests, and secondary forests common to steep-sloped, volcanic islands in the Caribbean provide habitats and food sources for many terrestrial bird species. Information on the diets of species living in these agroecosystems can inform conservation management and land-use decisions, and reveal the ecosystem services performed by these unique island bird communities. We obtained fecal samples from 356 individuals of 14 bird species, including 3 Lesser Antilles endemics, that occur in various agroforests, pasture, and cropping habitats on the island of Grenada, May–September 2018 and January–March 2019, and determined diet items using DNA meta-barcoding analysis. Identified food items included 14 orders and 259 genera of arthropods, and 25 orders and 98 genera of plants. We found a wide mix of arthropod and plant genera across an annual cycle in every bird species studied, including those believed to be nominally nectarivorous, frugivorous, or granivorous, supporting predictions that small-island bird populations exhibit generalist foraging. Similarly, diet composition varied among species within each study site to a similar degree that diets varied among study sites within each species further indicating opportunistic/generalist foraging. In addition, we found 26 arthropod genera and 34 plant genera that were frequently shared by 3 or more bird species, suggesting the importance of specific food resources for sustaining bird communities in these heterogeneous agricultural landscapes. We also found 4 known invertebrate crop pathogens amongst 5 bird species. Together, this study reveals the various roles that these generalist species play in agroforest habitats (e.g., crop-plant pest control, pollination, seed dispersal), and the results can be used to further explore land-use practices that best provide food resources to support this unique island bird community and the ecosystem functions they carry out. [ABSTRACT FROM AUTHOR]

Of the myriad responses to climate change, an emerging trend is the widespread decrease in animal body size with warming temperatures. Birds, in particular, have been shown to be decreasing in body size in several areas – most notably the Amazon Basin and temperate North America – but trends in much of the world remain unexplored. Here, we analyze temporal trends and climatic associations of body mass for 42 resident bird species over 36 years in the Usambara Mountains of Tanzania, a tropical montane global biodiversity hotspot. In addition, we assess trends in wing length and mass:wing ratio over 21 years. Finally, we examine whether species‐specific trends in body mass are related to average body size or to trends in apparent survival. Overall, species' average body mass in the Usambara Mountains increased by 0.023 g decade‐1, amounting to increases of 4.1% over 36 years. These long‐term shifts in body mass were strongly and positively associated with annual mean temperature but showed no relationship with precipitation. Wing length increased on average by 2.0% over a 21‐year period, yet there was mixed evidence for trends in mass:wing ratio, suggesting that body size in general is increasing. While percentage trends in body mass were not related to trends in apparent annual survival, smaller species did display greater proportional increases in body mass. Although the drivers of increased body size remain unclear – and climate change cannot be ruled out – such increases among Afrotropical montane birds provide an intriguing counterpoint to observed declines in body mass elsewhere and suggest that trends in body mass in tropical birds may be mediated by biogeography or other abiotic or biotic drivers. [ABSTRACT FROM AUTHOR]

The timing of breeding is a key component of the life history of birds. In the tropics, where avian diversity is higher and environmental variability is less predictable than in temperate latitudes, breeding phenology patterns are poorly understood, and many other life-history traits remain largely unstudied. We describe the nest, egg, juvenile plumage, and breeding phenology of a population of the grey-browed brushfinch (Arremon assimilis assimilis, Passerellidae) from the Eastern Andes of Colombia. We found a single bluish-white unmarked egg in a cup-shaped nest. We also examined the relationship between photoperiod and precipitation with breeding phenology by monitoring 44 territorial pairs between 2017 and 2018. Arremon assimilis has two breeding peaks associated with the onset of rainfall in prior months: the first peak extends from mid-May to September, and the second from November and December to January. We also update a recent review of breeding biology data in Arremon and discuss how life-history traits may have evolved in light of the relationships among sparrows in this genus. Our study, one of few analyses of the breeding biology of a population in a montane species from the Andes, highlights the importance of such studies to further comprehend the general mechanisms that shape the breeding biology of tropical birds. [ABSTRACT FROM AUTHOR]

Tropical birds are usually placed in the "slow" end of the life-history continuum, and much of their physiology matches the trade-off between lifespan and reproduction. For example, they demonstrate lower whole-animal basal metabolic rates (BMR) and peak metabolic rates (PMR) compared with temperate birds, and at the cell level, tropical birds also have lower rates of oxygen consumption. Oxidative stress, a by-product of aerobic respiration, has yet to be fully elucidated to be linked to life-history theory. However, previous work suggests that tropical birds may have superior antioxidant capacity to birds that live in temperate areas. In the current study, we used muscle tissue from 35 species of tropical birds to measure total antioxidant capacity (hydroxyl scavenging capacity and peroxyl scavenging capacity), the activity of antioxidant enzyme catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx), and lipid damage (LPO). We correlated these measurements to body mass and found a significantly negative correlation between body mass and LPO and a marginally significant negative correlation with hydroxyl scavenging capacity. Interestingly, we also correlated our measurements to literature reported BMR measurements from 22 species included in our study and found no correlations. A negative correlation between body mass and LPO damage may be due to cellular muscle structure and mitochondrial content and structure within the muscle. Las aves tropicales generalmente se ubican en el extremo "lento" del continuo de la historia de vida, y gran parte de su fisiología coincide con el equilibrio entre la vida útil y la reproducción. Por ejemplo, las aves demuestran tasas metabólicas basales (BMR) y tasas metabólicas máximas (PMR) de animal completo más bajas en comparación con las aves de clima templado y, a nivel celular, las aves tropicales también tienen tasas más bajas de consumo de oxígeno. El estrés oxidativo, un subproducto de la respiración aeróbica, aún no se ha dilucidado por completo para vincularlo a la teoría de la historia de vida. Sin embargo, trabajos previos sugieren que las aves tropicales pueden tener una capacidad antioxidante superior a las aves que viven en áreas templadas. En este estudio, utilizamos tejido muscular de 35 especies de aves tropicales para medir su capacidad antioxidante total (capacidad de captación de hidroxilo y capacidad de captación de peroxilo), la actividad de la enzima antioxidante catalasa (CAT), la superóxido dismutasa (SOD), la glutatión peroxidasa (GPx) y el daño de lípidos (LPO). Correlacionamos estas mediciones con la masa corporal y encontramos una correlación significativamente negativa entre la masa corporal y la LPO, y una correlación negativa marginalmente significativa con la capacidad de captación de hidroxilo. Curiosamente, también correlacionamos nuestras mediciones con mediciones de BMR encontradas en la literatura para 22 especies incluidas en nuestro estudio y no encontramos correlaciones. Una correlación negativa entre la masa corporal y el daño por LPO puede deberse a la estructura muscular celular, y al contenido y estructura mitocondrial dentro del músculo. Palabras clave: aves tropicales, estrés oxidativo, historia de vida, metabolismo basal, musculo. [ABSTRACT FROM AUTHOR]

Much of our knowledge on the patterns and timing of breeding and molting come from studies of temperate region birds, yet tropical birds can have markedly different phenologies. The Hawaiian Islands support multiple endemic bird species that have evolved for millions of years in isolation to a tropical environment with minimal seasonality. We examined data from multiple studies (1994–2020) conducted across the avian annual cycle, from multiple locations, to evaluate molt patterns and establish criteria for assignment of age and sex based on the WRP, or molt-cycle age classification system designed specifically for tropical species. In addition, we describe the phenologies of molt and breeding and quantify the differences in males and females based on plumage coloration and morphometrics for 8 native species. We were able to validate the WRP tropical bird aging system as an appropriate method for aging forest birds from the Island of Hawai'i and separate all 8 species examined into juvenile, formative, and definitive plumages based on feather patterns and molt limits. Additionally, 2 species had distinctive second basic plumages. All 8 species examined also had extended periods of breeding and molting unlike their familial temperate counterparts, but these high-energy activities are largely partitioned into separate time periods. Each species had some degree of overlap in breeding and molting, but the frequency of individuals that were simultaneously in breeding condition and molting was low with only 2 species displaying a proportion of overlap greater than 10% among all captures. Accurate aging and sexing techniques improve the quality of data from banding studies and provide important information on how species adapt to their environments. 'O ka nui o ka 'ikepili no ke 'ano a me ka manawa o ka hānau keiki 'ana a me ka māunu 'ana o nā manu, ua loa'a mai ke kālailai 'ana i nā manu o nā 'āina kemepale. 'O nā manu kopikala, he 'oko'a loa ko lākou pō'aiapuni ola. Ma ka hala 'ana o nā makahiki he mau miliona, ua liliuewe mai he mau lāhulu manu 'āpa'akuma ma Hawai'i pae 'āina nei, he 'āina kopikala i loa'a 'ole nā kau kemepale. Ua kālailai māua i ka 'ikepili mai nā atikala he nui ma waena o ka makahiki 1994 a i ka makahiki 2020. He mau 'atikala kālailai ia i nā pō'aiapuni ola o nā manu o kekahi mau 'āina 'oko'a i mea e kālai ai i ke 'ano o ka māunu 'ana o nā manu, a i mea ho'i e ho'okahua ai i nā kūlana pa'a e maopopo i ke keka a me ka nui makahiki o nā manu ma ke 'ano kūmau o ka 'ōnaehana WRP. He 'ōnaehana ka WRP e hō'oia ai i ke 'ano o ka wā māunu a me ke kūlana makahiki o nā manu kopikala. Eia ho'i, ua wehewehe māua i ka pō'aiapuni o ka wā māunu, a me ka pō'aiapuni o ka hānau keiki 'ana o nā manu i kālai 'ia. Ua helu ho'i māua i ka 'oko'a o nā manu kāne a me nā manu wahine o 'ewalu mau lāhulu manu Hawai'i ma ke 'ano o ka waiho'olu'u o ka hulu a me nā 'oko'a 'ē a'e o ke kino. Ua hō'oia māua i ke kūpono o ka WRP i 'ōnaehana hō'oia kūlana makahiki ma kona 'ano he ki'ina hana e hō'oia ai i ke kūlana makahiki o nā manu nahele o ka mokupuni 'o Hawai'i. Ua wae'ano nō māua i nā manu a pau o nā lāhulu 'ewalu i kālai 'ia ma ke 'ano o ka hulu a me ke 'ano o ka māunu 'ana; 'o ia mau 'ano o ka hulu, he hulu kuapo'i, hulu 'ōpiopio, a he hulu makua. Eia ho'i, he 'elua mau 'ano hulu makua 'ana ko 'elua o nā lāhulu manu. Ua 'oko'a nā lāhulu manu 'ewalu a pau mai ke 'ano o nā manu kemepale i ka 'oi lō'ihi o ko lākou mau wā hānau keiki a me ko lākou mau wā māunu. He ka'awale na'e ia mau wā kekahi mai kekahi, no ka ho'oluhi nui paha i ke kino o ka manu. Kaulapa iki nā wā hānau keiki a me nā wā māunu o kekahi mau manu o ia mau lāhulu, 'a'ole na'e i nui loa nā manu e hana pēlā. He 'elua wale ho'i mau lāhulu i 'oi nui ia kaulapa 'ana ma 'umi pakeneka a 'oi o nā manu i hopu 'ia. He kōkua nui ka 'oi maika'i o nā ki'ina hana hō'oia keka a me nā ki'ina hana hō'oia kūlana makahiki i ka hō'oia'i'o i ka 'ikepili i 'ohi'ohi 'ia ma nā kālailai ho'okolo manu. He ko'iko'i ia 'ikepili e maopopo ai kākou i ka liliuwelo o nā lāhulu manu i ko lākou mau wahi pono'ī. [ABSTRACT FROM AUTHOR]

Understanding how and why animals use the environments where they occur is both foundational to behavioral ecology and essential to identify critical habitats for species conservation. However, some behaviors are more difficult to observe than others, which can bias analyses of raw observational data. To our knowledge, no method currently exists to model how animals use different environments while accounting for imperfect behavior‐specific detection probability. We developed an extension of a binomial N‐mixture model (hereafter the behavior N‐mixture model) to estimate the probability of a given behavior occurring in a particular environment while accounting for imperfect detection. We then conducted a simulation to validate the model's ability to estimate the effects of environmental covariates on the probabilities of individuals performing different behaviors. We compared our model to a naïve model that does not account for imperfect detection, as well as a traditional N‐mixture model. Finally, we applied the model to a bird observation data set in northwest Costa Rica to quantify how three species behave in forests and farms. Simulations and sensitivity analyses demonstrated that the behavior N‐mixture model produced unbiased estimates of behaviors and their relationships with predictor variables (e.g., forest cover, habitat type). Importantly, the behavior N‐mixture model accurately characterized uncertainty, unlike the naïve model, which often suggested erroneous effects of covariates on behaviors. When applied to field data, the behavior N‐mixture model suggested that Hoffmann's woodpecker (Melanerpes hoffmanii) and Inca dove (Columbina inca) behaved differently in forested versus agricultural habitats, while turquoise‐browed motmot (Eumomota superciliosa) did not. Thus, the behavior N‐mixture model can help identify habitats that are essential to a species' life cycle (e.g., where individuals nest, forage) that nonbehavioral models would miss. Our model can greatly improve the appropriate use of behavioral survey data and conclusions drawn from them. In doing so, it provides a valuable path forward for assessing the conservation value of alternative habitat types. [ABSTRACT FROM AUTHOR]

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Knowledge on species distributions and seasonal movement patterns within landscapes is important for understanding their ecology and roles in agroecosystems, and is critical for enabling their effective conservation and monitoring, particularly in small-island states where conservation resources are limited. We undertook bird surveys to examine species distributions across a range of agricultural land-use intensities and elevations on the Caribbean island of Grenada by collecting data over 6 repeated monthly surveys (3 wet season, 3 dry season) at sites located in a variety of habitats spread over 6–300 m elevation. We observed a gradual upslope increase in bird species diversity and abundance from the mid-wet season to the late-dry season, as well as a movement from reduced-canopy habitats to closed-canopy habitats in the dry season. The mid-elevation hillsides of Grenada consist of a diverse mosaic of closed canopy secondary forest patches, interspersed among more open agroforests and small-scale cropping and grazed areas. These agroecosystems appear to provide important habitats to birds throughout the year, especially open canopy agroforests in the wet season. We also found that open mixed agroforests contained a greater diversity of fruit, flower, and seed resources than closed canopy habitats such as secondary forest, cacao agroforests, young secondary forests, or dry forest scrub; and that plant food diversity was highest in the wet season. However, bird abundance significantly increased in closed canopy forest habitats during the dry season, suggesting that intact canopy forests provide important dry season habitat for many Grenadian birds, which may be particularly important for species in drier lowland areas experiencing more intensive agricultural land use and urban and resort development. Overall, this research demonstrates the importance of maintaining the functional connectivity of treed habitats at local and landscape scales for species conservation, as well as the contribution of diverse, small-scale agriculture to maintaining small-island bird communities. [ABSTRACT FROM AUTHOR]

Long-term studies on the population dynamics of tropical resident birds are few, and it remains poorly understood how their populations have fared in recent decades. Here, we analyzed a 44-y population study of a Neotropical understory bird assemblage from a protected forest reserve in central Panama to determine if and how populations have changed from 1977 to 2020. Using the number of birds captured in mist nets as an index of local abundance, we estimated trends over time for a diverse suite of 57 resident species that comprised a broad range of ecological and behavioral traits. Estimated abundances of 40 (~70%) species declined over the sampling period, whereas only 2 increased. Furthermore, declines were severe: 35 of the 40 declining species exhibited large proportional losses in estimated abundance, amounting to =50% of their initial estimated abundances. Declines were largely independent of ecology (i.e., body mass, foraging guild, or initial abundance) or phylogenetic affiliation. These widespread, severe declines are particularly alarming, given that they occurred in a relatively large (~22,000-ha) forested area in the absence of local fragmentation or recent land-use change. Our findings provide robust evidence of tropical bird declines in intact forests and bolster a large body of literature from temperate regions suggesting that bird populations may be declining at a global scale. Identifying the ecological mechanisms underlying these declines should be an urgent conservation priority. [ABSTRACT FROM AUTHOR]

The life‐history theory of evolution posits that organisms are maximized for reproductive success through the processes of natural selection. Though believed to impact nearly every aspect of an organism, the life‐history theory of evolution shines little attention on the cellular aspects of organismal physiology. Tropical bird species, compared with temperate birds, are typically placed on the 'slow' pace‐of‐life spectrum, and demonstrate a 'slow' pace of life across every level of organization. Previously, we demonstrated that phylogenetically paired tropical birds have significantly smaller muscle fiber diameters than their temperate counterparts. No other muscle‐related properties have been addressed and correlated to life‐histories in the literature. Myonuclear domain (MND), the cytoplasmic volume that each myonucleus serves, is an under‐appreciated skeletal muscle property that has been largely ignored in bird muscle literature. Here, we measured MND in muscle cross‐sections in phylogenetically paired species of tropical and temperate birds. We found that tropical bird species had significantly higher numbers of nuclei per mm of fiber as compared with temperate bird species. This may be due to the fact that tropical birds could have a higher population of slow‐ oxidative fiber and/or due to developing in warmer climates, as compared with temperate birds. In both tropical and temperate birds, we found significantly positive associations between muscle fiber diameter and MND and between muscle cross‐sectional areas and number of nuclei per mm of fiber in tropical birds and temperate birds, as previously noted in other bird species. [ABSTRACT FROM AUTHOR]

Abstract Background Information pertaining to nest-site fidelity and breeding dispersal over successive years can help to better our understanding of how birds respond to nest predation. Methods By using mist nets and tracking the color banded individuals, we investigated nest-site fidelity and breeding dispersal by Common Tailorbirds (Orthotomus sutorius) throughout a year and between successive years in 2017–2018. Results The present study showed that Common Tailorbirds could produce up to four clutches per breeding season. When multiple broods were produced within a year, breeding pairs remained together, and the nest rebuilding rate was up to 92.2%, with only four cases (7.8%) in which birds reused their old nests. The dispersal distance between the nests during multiple breeding was found to be 10.0 ± 10.5 m, and nest-site fidelity within the same year was 90.0%. By the second year of breeding, 76.2% of individuals remained in the original breeding pairs, while for those that did switch partners, the females remained in the nest from the previous year and paired with new males. The dispersal distance between years was 26.5 ± 41.9 m, and nest-site fidelity between different years was 80.1%. There was no significant difference between within-year and between-year dispersal distances. Moreover, there was no significant difference in the dispersal distance of rebuilt nests between birds that had experienced nest predation and those that had not. Conclusions Our findings suggest that Common Tailorbirds maintain a high degree of fidelity to mates and nest-sites, and nest predation had no significant effect on territorial changes or breeding dispersal distance between each breeding attempt.

Tropical birds live longer, have smaller clutches and invest more resources into self‐maintenance than temperate species. These "slow" life‐histories in tropical birds are accompanied by low basal metabolic rate (BMR). It has recently been suggested that the low BMR of tropical species may be related not to their slow "pace of life" or high ambient temperatures (Ta) in tropical latitudes, but to the stability of environmental conditions in tropics. Since the repeatability of metabolic traits is higher in stable environments, such as laboratory conditions, we predicted that long‐term repeatability of BMR in a tropical climate should be higher than in a temperate one. Contrary to our predictions, the repeatability of mass‐independent BMR in 64 individuals of free‐living tropical birds from Vietnam was low and insignificant after the species affiliation was taken into account. It indicates that BMR cannot be used as an individual long‐term characteristic of tropical birds. On the other hand, tropical birds showed consistent differences in their mass‐independent BMR at the interspecific level. Using BMR measurements from 1543 individuals of 134 species, we also found that different characteristics of Ta within the week preceding BMR measurements had a significant impact on the mass‐independent BMR of tropical birds. The most significant effect was the difference between the absolute maximum and minimum Ta within a single week. Our results indicate that the physiology of tropical birds is more subject to changes than would be expected based on the notion of the stability of climatic conditions in the tropics. Research Highlights: The individual repeatability of BMR in free‐living tropical birds did not differ significantly from zero.BMR of tropical birds was dependent on ambient temperature in the period preceding metabolic measurements. [ABSTRACT FROM AUTHOR]

Background: The gut microbiome of animals is an important component that has strong influence on the health, fitness, and behavior of its host. Most research in the microbiome field has focused on human populations and commercially important species. However, researchers are now considering the link between endangered species conservation and the microbiome. In Hawaii, several threats (e.g., avian malaria and habitat loss) have caused widespread population declines of Hawaiian honeycreepers (subfamily: Carduelinae). These threats can have a significant effect on the avian gut microbiome and may even lead to disruption of microbial function. However, the gut microbiome of honeycreeper in the wild has yet to be explored. Methods: We collected 13 and 42 fecal samples, respectively, from two critically endangered honeycreeper species, the akikiki (Oreomystis bairdi) and the akekee (Loxops caeruleirostris). The 16S rRNA gene was sequenced and processed though a MOTHUR-based bioinformatics pipeline. Bacterial ASVs were identified using the DADA2 program and bacterial community analyses, including alpha and beta diversity measures, were conducted using R packages Phyloseq and vegan. Results: A total of 8,958 bacterial ASVs were identified from the fecal samples. Intraspecific differences in the gut microbiome among individual birds explained most of the variation present in the dataset, however differences between species did exist. Both species had distinct microbiomes with minimal overlap in beta diversity. 'Akikiki had a more diverse microbiome compared to 'akekee. Additionally, small but stastically significant differences in beta diversity also exist between sampling location and sexes in akikiki. Conclusion: Akikiki and akekee are currently the focus of captive breeding efforts and plans to translocate the two species to other islands are underway. This baseline knowledge will help inform management decisions for these honeycreeper species in their native habitats, on other islands, and in captivity. [ABSTRACT FROM AUTHOR]

The article discusses aging criteria for 7 species of manakins (Pipridae) from the Manu Biosphere Reserve, Peru, based on patterns of plumage maturation and wing-feather replacement. It mentions Cerulean-capped Manakin (Lepidothrix coeruleocapilla), and Yungas Manakin (Chiroxiphia boliviana) showed evidence of delayed plumage maturation, allowing for age classification up to the third annual cycle.

1. Superior physical competence is vital to the adaptive behavioral routines of many animals, particularly those that engage in elaborate socio-sexual displays. How such traits evolve across species remains unclear. 2. Recent work suggests that activation of sex steroid receptors in neuromuscular systems is necessary for the fine motor skills needed to execute physically elaborate displays. Thus, using passerine birds as models, we test whether interspecific variation in display complexity predicts species differences in the abundance of androgen and estrogen receptors (AR and ERα) expressed in the forelimb musculature and spinal cord. 3. We find that small-scale evolutionary patterns in physical display complexity positively predict expression of the AR in the main muscles that lift and retract the wings. No such relationship is detected in the spinal cord, and we do not find a correlation between display behavior and neuromuscular expression of ERα. Also, we find that AR expression levels in different androgen targets throughout the body - namely the wing muscles, spinal cord, and testes - are not necessarily correlated, providing evidence that evolutionary forces may drive AR expression in a tissue-specific manner. 4. These results suggest co-evolution between the physical prowess necessary for display performance and levels of AR expression in avian forelimb muscles. Moreover, this relationship appears to be specific to muscle and AR-mediated, but not ERα-mediated, signaling. 5. Given that prior work suggests that activation of muscular AR is a necessary component of physical display performance, our current data support the hypothesis that sexual selection shapes levels of AR expressed in the forelimb skeletal muscles to help drive the evolution of adaptive motor abilities.

Background The gut microbiome of animals is an important component that has strong influence on the health, fitness, and behavior of its host. Most research in the microbiome field has focused on human populations and commercially important species. However, researchers are now considering the link between endangered species conservation and the microbiome. In Hawaiʻi, several threats (e.g., avian malaria and habitat loss) have caused widespread population declines of Hawaiian honeycreepers (subfamily: Carduelinae). These threats can have a significant effect on the avian gut microbiome and may even lead to disruption of microbial function. However, the gut microbiome of honeycreeper in the wild has yet to be explored. Methods We collected 13 and 42 fecal samples, respectively, from two critically endangered honeycreeper species, the ʻakikiki (Oreomystis bairdi) and the ʻakekeʻe (Loxops caeruleirostris). The 16S rRNA gene was sequenced and processed though a MOTHUR-based bioinformatics pipeline. Bacterial ASVs were identified using the DADA2 program and bacterial community analyses, including alpha and beta diversity measures, were conducted using R packages Phyloseq and vegan. Results A total of 8,958 bacterial ASVs were identified from the fecal samples. Intraspecific differences in the gut microbiome among individual birds explained most of the variation present in the dataset, however differences between species did exist. Both species had distinct microbiomes with minimal overlap in beta diversity. ‘Akikiki had a more diverse microbiome compared to ‘akekeʻe. Additionally, small but stastically significant differences in beta diversity also exist between sampling location and sexes in ʻakikiki. Conclusion ʻAkikiki and ʻakekeʻe are currently the focus of captive breeding efforts and plans to translocate the two species to other islands are underway. This baseline knowledge will help inform management decisions for these honeycreeper species in their native habitats, on other islands, and in captivity.

The feathers of tropical birds were one of the most significant symbols of economic, social, and sacred status in the pre- Columbian Americas. In the Andes, finely produced clothing and textiles containing multicolored feathers of tropical parrots materialized power, prestige, and distinction and were particularly prized by political and religious elites. Here we report 27 complete or partial remains of macaws and amazon parrots from five archaeological sites in the Atacama Desert of northern Chile to improve our understanding of their taxonomic identity, chronology, cultural context, and mechanisms of acquisition. We conducted a multiproxy archaeometric study that included zooarchaeological analysis, isotopic dietary reconstruction, accelerated mass spectrometry radiocarbon dating, and paleogenomic analysis. The results reveal that during the Late Intermediate Period (1100 to 1450 CE), Atacama oasis communities acquired scarlet macaws (Ara macao) and at least five additional translocated parrot species through vast exchange networks that extended more than 500 km toward the eastern Amazonian tropics. Carbon and nitrogen stable isotopes indicate that Atacama aviculturalists sustained these birds on diets rich in marine bird guano-fertilized maizebased foods. The captive rearing of these colorful, exotic, and charismatic birds served to unambiguously signal relational wealth in a context of emergent intercommunity competition. [ABSTRACT FROM AUTHOR]

The capacity for flight varies widely among bird species and influences their ecology, evolution, and conservation. Variation in vagility is influenced by behavioral responses to the nature of gaps between habitat elements as well as intrinsic characteristics of the species, particularly physiological traits influencing the physical capacity for sustained flight. Here, we briefly summarize the current state of knowledge revealing the wide variety of movement capacities of Neotropical birds. We then review current knowledge of avian muscle physiology and the role that muscle characteristics may play in influencing movement behavior. We argue that fundamental shifts in our understanding of avian muscle physiology and the influence of physiology on movement behavior remain to be elucidated, in part because knowledge from other vertebrates is being inappropriately applied to birds. In particular, critical evaluation of assumptions applied to birds from detailed studies of mammals is needed. Moving away from simple binary categorizations of avian flight muscles as "red vs. white" or "fast vs. slow" to characterize the cellular mechanisms and specific isoforms active at various life stages or seasons is also needed. An increasingly large number of avian species with a wide array of flight styles from hummingbirds to soaring raptors are appearing in GenBank, facilitating detailed physiological and evolutionary comparisons among species. Properly assessing the muscle physiological characteristics of Neotropical bird species with a wide array of movement capacities may improve our abilities to predict which species are most sensitive to landscape fragmentation and other factors that influence dispersal and migration. [ABSTRACT FROM AUTHOR]

The slow-paced life history of many Neotropical birds (e.g., high survival and low fecundity) is hypothesized to increase lifetime fitness through investments in self-maintenance over reproduction relative to their temperate counterparts. Molt is a key investment in self-maintenance and is readily shaped by environmental conditions. As such, variation in molt strategies may be a key mechanism underlying life-history trade-offs and adaptation to new environments. Here, we review molt strategies from a diversity of lowland Neotropical landbirds and examine how variation in molt strategies, characterized by differences in molt insertions, timing, extent, and duration contribute to life-history variation and adaptation to diverse ecological conditions. In addition to our synthesis, we present a case study to examine the relationship between home range size and duration of the definitive prebasic molt of a well-studied subset of Amazonian landbirds. Our results suggest a connection between prolonged molt duration and larger home range size of small-tomedium-sized Amazonian landbirds. Our aims were to identify key gaps in our knowledge of Neotropical bird molt, to stimulate further comparative studies into the evolution of molt strategies, and to highlight how variation in molt strategies may be a key mechanism underlying life-history variation across latitudes. [ABSTRACT FROM AUTHOR]

The simultaneous effects of habitat traits and interspecific interactions determine the occurrence and habitat use of wildlife populations. However, little research has been devoted to examining spatial co‐occurrence among closely related species while considering the effect of habitat variation and imperfect detectability of species in the field. In this study, we focused on migratory and resident 'wood‐warblers' that coexist during the winter in a Neotropical working landscape in southern Mexico to understand if habitat occupancy of resident wood‐warblers is influenced by habitat characteristics and by the presence of other species of resident and migratory wood‐warblers. For this purpose, we implemented two‐species occupancy models, which account for the imperfect detectability of these birds in the field. Our results revealed that habitat occupancy of resident wood‐warblers was positively influenced by the presence of other closely related species (both migratory and resident). These positive relationships may be explained by the fact that different species of wood‐warblers frequently participate in mixed‐species flocks. However, these patterns of species co‐occurrence were more evident among resident species than between migratory and resident species, which may be explained by micro‐habitat segregation and differences in behaviours between resident and migratory wood‐warblers. We also found that some habitat characteristics may mediate the observed patterns of species co‐occurrence. Specifically, sites with larger trees were associated with the co‐occurrence of some species of resident wood‐warblers. In addition, we discuss the possibility that species co‐occurrence might be the result of shared preferences for environmental factors that we did not consider. Our study highlights the importance of the interplay between species co‐occurrence and habitat traits in determining the presence and habitat use of resident birds in Neotropical working landscapes. [ABSTRACT FROM AUTHOR]

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Nest success of forest birds is typically low due to high rates of predation, but little is known regarding how different nest predators affect nest-site selection and nesting success, particularly in the tropics. We studied nest-site selection and nest success of the understory-nesting Scaly-crowned Babbler (Malacopteron cinereum) in a seasonal evergreen forest in northeastern Thailand during four breeding seasons. We identified nest predators using video-monitoring and examined relationships between nest site vegetation structure and nest predation by dominant predators. Based on 71 video-monitored nests, 98.5% of failures were due to predation; 59 predation events from nine predator species were documented including Northern Pig-tailed Macaque (Macaca leonina) (47.5%, n = 28), five avian predator species (32.2%, n = 19), and two snake species (18.6%, n = 11). Nest sites had significantly higher concealment and number of lianas than random sites. Higher concealment may represent selection against visually oriented predators which were responsible for approximately 80% of predation events. Vegetation parameters suggested opposing patterns for macaques versus snakes; nests surrounded by higher density of saplings and lower density of taller stems (5–10 m) were depredated by macaques, whereas snake depredated nests were associated with a lower density of saplings, a higher density of taller stems and a higher density of lianas. Nests depredated by avian predators were not associated with any measured variables. Our data suggest that different vegetation structures perhaps facilitate or impede different predators and different predators may generate conflicting selection pressures for nesting birds within a given habitat. Our data also imply that impacts on nesting success from vegetation disturbance (e.g., logging, road edges, etc.) may be difficult to predict, as these effects are likely to vary among sites and regions depending on the foraging behavior of dominant local predators. [ABSTRACT FROM AUTHOR]

Nest predators are responsible for the majority of reproductive failures in birds in multiple habitats globally. Snakes are likely one of the main nest predators, but few studies have focused on snake nest predation patterns in the tropics where the diversity of snakes and nesting birds is highest. Here we examined nest predation patterns of the bridle snake (Lycodon cf. davisonii), a poorly known species, but potentially a major nest predator of understorey nesting birds in Asian tropical evergreen forests. In an ongoing, long-term study of nest survival in a dry evergreen forest in northern Thailand, we monitored 478 natural nests of 23 bird species during breeding seasons of 2013-2019 with video cameras placed near active nests to assess nest predator species and their predation activities. We documented 308 predation events from 15 species of nest predators. Bridle snake was the third most important nest predator accounting for 13% of all predation events; it was exclusively nocturnal and preyed solely on eggs. Bridle snakes, unlike the other four top nest predators in our system, which were likely generalists, appeared to prefer open-cavity nests relative to other nest types, and was responsible for > 45% of nest failures of open-cavity nesting birds. This preference of the bridle snake is likely to influence nest survival rates of open-cavity nesting birds. Thus, further study of the factors influencing its predation behaviours and activity patterns, particularly its response to human disturbance, could be useful for the management of tropical forest birds. [ABSTRACT FROM AUTHOR]

Life‐history theory postulates that physiological traits, such as energy metabolism, can be understood in terms of allocation trade‐offs between self‐maintenance and reproduction over an organism's life span, and data show that metabolic intensity and survival vary inversely with latitude, with tropical birds exhibiting a "slow" pace of life relative to temperature species. However, tropical regions harbour strong environmental gradients of their own, and it remains to be shown whether similar life‐history trade‐offs between metabolism and longevity are reflected among tropical birds of the same latitude.We estimated apparent annual survival in 37 species of tropical passerine birds along an elevational gradient (400–3,000 m) in Peru to test whether variation in survival was influenced by basal metabolic rate (BMR; estimated at the same sites), elevation or both factors. We used path analysis to test our prediction that survival would decline as BMR increased, while accounting for the potential direct effects of elevation on survival due to differences in predation pressure or environmental conditions as well as potential indirect effects of elevation on BMR via temperature and the costs of thermoregulation.Higher BMR in tropical passerine birds predicted lower apparent survival, regardless of the elevation at which species occurred. In addition, elevation had a direct negative effect on apparent survival, perhaps due to harsher abiotic conditions, low site fidelity or both at high elevations.We provide evidence of a link between metabolic rate and longevity previously undescribed in populations of free‐living birds. Our results illustrate that tropical montane species may be characterized by a unique suite of traits in their pace of life, in which BMR does not differ from lowland birds, but survival does. A plain language summary is available for this article. [ABSTRACT FROM AUTHOR]

The White-shouldered Fairywren (Malurus alboscapulatus) is a tropical passerine bird distributed across much of New Guinea. White-shouldered Fairywrens are among few species of fairywren with exclusively tropical distributions and differ from better studied congeners in Australia because subspecies vary by female, but not male, coloration and morphology. As with many bird species in New Guinea, basic demographic, social, morphological, and breeding data are limited. From 2011 to 2018 we documented the basic biology of two subspecies representing extremes of the female ornamentation spectrum. Both subspecies form groups having an even operational sex ratio and appear to breed year-round. Extra-pair paternity occurs in the subspecies with female ornamentation; comparable data are lacking for the subspecies having unornamented females, but the greater scaled cloacal protuberance volume of males suggests similar or higher extra-pair paternity rates. Females of the ornamented subspecies are generally larger than those lacking ornamentation, but exhibit reduced tail lengths, which is thought to serve as a signal of social dominance in other fairywrens. After first achieving adult-like plumage, males and ornamented females retain ornamented plumage year-round; however, only males in the subspecies with unornamented females appear to exhibit delayed plumage maturation. Our discussion highlights similarities and differences between White-shouldered Fairywren life histories and those of better studied Australian Malurus species; we focus on tropical vs. temperate environments and variable female ornamentation, and we identify priorities for future research. [ABSTRACT FROM AUTHOR]

Many species show pronounced differences in life-history traits, from the individual level to divergences between distinct populations. Understanding the variation in these traits provides not only an insight into individual fitness but also essential information for the management of wild populations. Despite their popularity in aviculture and importance for captive research, our knowledge of many Estrildid finches in the wild is limited. Here we detail the breeding behaviour of 12 discrete colonies of Crimson Finch (Neochmia phaeton) in the east Kimberley region of Western Australia over two breeding seasons, and contrast our findings with studies on populations occupying different habitats. We found that many aspects of Crimson Finch breeding biology were consistent across site and studies. However, in our populations, adult survival was lower and group sizes were larger than has been reported elsewhere. We also examined age and sex differences in nestling care and found weak support for age or sex differences in feeding rates. We briefly discuss these findings in relation to theories of colony formation. These findings may help explain the evolution of colonial breeding in this species, as well as having implications for long-term ecosystem management. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Field Ornithology is the property of Resilience Alliance and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Lovely Fairy-Wren (Malurus amabilis) is endemic to the wet tropics of Australia and is one of 11 species in the genus Malurus. Despite the large number of studies on fairy-wrens, little is known about the Lovely Fairy-Wren. This study provides the first detailed description of its ecology, behaviour, and breeding biology. Lovely Fairy-Wrens displayed breeding behaviour characteristic of tropical birds, with groups maintaining territories and breeding year-round, small clutch size (two to three eggs), long juvenile dependence (2 months) and high adult breeder survival (86%). They breed cooperatively, and groups formed when male (but not female) offspring delayed dispersal and remained in their natal group as subordinates. Groups were typically small (2.5 ± 0.8 individuals), possibly because productivity was low: 29% of the monitored groups produced at least one fledgling per year. Males provided high levels of parental care and this, together with low extra-pair courtship and petal displays, suggests that this species may not be as promiscuous as other fairy-wrens. Unlike other Australian fairy-wrens, males maintained their brightly coloured adult plumage year-round after initial acquisition. This lack of seasonal moult into dull plumage, coupled with the unusually colourful plumage of females in this species, suggests that the impact of natural selection on the plumage colour of both sexes may be lower in this species than in their congeners. We discuss similarities and differences in life-history and morphological traits between the Lovely Fairy-Wren and other Malurus species. [ABSTRACT FROM AUTHOR]

Despite Hispaniola’s high rates of avian endemism and its importance to supporting global biodiversity, relatively little information is available on the basic biology and ecology of its resident birds, particularly the 31 species endemic to the island. Here we describe the nesting ecology and nesting success (n = 643 nests) of species of resident and endemic birds occurring in southwestern Dominican Republic, spanning 4 major habitat types over an elevational gradient from sea level to ~1,750 m: desert thorn scrub, dry broadleaf forest, pine forest, and montane cloud forest. We quantify nesting success in terms of daily nest survival and cumulative survival probabilities for 14 resident species (3 endemic) and describe life history metrics for these species, including clutch size and length of incubation and brooding. We compare nest success among habitats and highlight the large impact of introduced mammalian predators in all habitats studied. Nesting success was generally lower than in temperate areas, but comparable to other studies of nesting success in the Neotropics, with a mean cumulative survival probability for all open-cup nesting species of 33.6%. Nest failure due to predation varied by species but was overall notably high, ranging from 73% to 100% of all failed nests. Predation was primarily attributable to nonnative mammals introduced via European colonization. [ABSTRACT FROM AUTHOR]

ABSTRACT Flight initiation distance (FID), defined as the distance at which an individual flees from an approaching predator, might depend on how the individual perceives the risk of being predated. Using a standardized walking approach method on focal bird individuals, we investigated whether different levels of vegetation cover (habitat) influence the perception of predation risk. To do this, we worked in an area of tropical dry forest in central Mexico that is currently part of a restoration ecology experiment. We hypothesized that restoration decreases individual’s predation risk perception by increasing the complexity of the vegetation cover. The escape responses of three tropical birds with different diets and foraging strategies were also contrasted. There was no effect of habitat on FID, suggesting that birds in both habitats perceived predation risk in a similar manner. There was, however, a difference in FID among species: the Golden-cheeked Woodpecker tolerated closer human presence before flight than the Inca Dove and Streak-backed Oriole. This difference is likely due to the use of an alternative avoidance strategy of this species, which uses trunks for hiding. To decrease birds’ perceived predation risk, restoration intervention plans should include a mosaic of larger excluded plots located near relatively well-conserved sites to increase the area covered by vegetation.

Relatively little is known about the longevity of free-living landbirds, especially in the tropics. We used mark-recapture data for birds originally banded in 2005 and 2006, and later recaptured between 2011 and 2016, to estimate minimum longevity for 20 species from southeastern Peru. The oldest recorded longevity was 10 years, 6 months for a Black-billed Treehunter (Thripadectes melanorhynchus). Another notable record was for a Russet-crowned Warbler (Myiothlypis coronata; 9 years, 2 months). Our estimated minimum longevity records generally reflect the findings of other researchers, indicating that tropical birds are often markedly site faithful and long-lived. [ABSTRACT FROM AUTHOR]

Females often invest more in parental care than males, but in socially monogamous systems, males invest as much as females in caring for their offspring, and male contribution is believed essential for reproductive success in these systems. Here we describe the number of visits, the feeding rate to their nestlings, and the time on the nest invested by each sex of the socially monogamous songbird, the Clay-colored Thrush ( Turdus grayi), for 16 nests in San José, Costa Rica. Both males and females fed their nestlings at a similar rate, but females visited the nests more frequently than males. The feeding rate of both females and males was also similar when controlled by age of nestling. The feeding rate was highly variable across males (minimum 1, maximum 15 visits per 2 h), possibly related to the probability of males fathering the offspring of the attended nest. Females spent more time on the nest than males, but males tended to remain near the nest to defend it from predators. Moreover, male contribution during the nestling period correlated with the reproductive success. [ABSTRACT FROM AUTHOR]

The search for explanations of the well-documented positive relationship between latitude and avian clutch size has created the expectation that tropical birds should balance their smaller clutch sizes with relatively high survival probabilities. So far, efforts to detect a latitudinal gradient in survival have found no statistical support, leading to the hypothesis that a gradient may be present in the survival of juveniles alone. Such a gradient could be masked by the data on adults when field records make no distinction between ages. We aimed to (1) assess the effect of age on survival of tropical birds by estimating age-specific annual apparent survival probabilities for a set of 40 passerine understory species from the central Brazilian Amazon and (2) test the hypothesis of a latitudinal gradient in adult survival with a meta-analysis of tropical and temperate-zone forest passerine survival probabilities at study areas from Peru to Alaska. We estimated age-specific survival using a hierarchical, multispecies Cormack-Jolly-Seber (CJS) model that treats species-specific parameters as random effects. To extend our analysis to data on birds of unknown age at the time of banding, we developed a novel CJS model with a mixture component for the survival of birds of unknown age. We found a strong effect of age on survival at our site, with juveniles having lower survival than adults. The meta-analysis of 342 survival estimates from 175 species and a latitude span of >60 degrees revealed a negative effect of latitude on survival, which supports the widely accepted hypothesis that, on average, tropical birds have higher annual survival than their temperate counterparts. We conclude that there is no need for an alternative latitudinal trend in juvenile survival to account for the general trend in clutch size. [ABSTRACT FROM AUTHOR]

The majority of our knowledge of avian energetics is based on studies of birds from temperate and high latitudes. Using the largest existing sample of wild-caught Old World tropical species, we showed that birds from Southern Vietnam had lower basal metabolic rate (BMR) than temperate species. The strongest dissimilarity between tropical and temperate species was the low scaling exponent in the allometric relation between BMR and body mass in tropical birds (the regression slope was 0.573). The passerine migrants to temperate and high latitudes had higher BMR than tropical sedentary passerines. Body mass alone accounted for 93% of the variation in BMR (body mass ranged from 5 to 252 g). Contrary to some other studies, we did not find evidence besides the above mentioned that phylogeny, taxonomy, behavior, or ecology have a significant influence on BMR variation among tropical birds. [ABSTRACT FROM AUTHOR]

Flight initiation distance (FID), defined as the distance at which an individual flees from an approaching predator, might depend on how the individual perceives the risk of being predated. Using a standardized walking approach method on focal bird individuals, we investigated whether different levels of vegetation cover (habitat) influence the perception of predation risk. To do this, we worked in an area of tropical dry forest in central Mexico that is currently part of a restoration ecology experiment. We hypothesized that restoration decreases individual's predation risk perception by increasing the complexity of the vegetation cover. The escape responses of three tropical birds with different diets and foraging strategies were also contrasted. There was no effect of habitat on FID, suggesting that birds in both habitats perceived predation risk in a similar manner. There was, however, a difference in FID among species: the Golden-cheeked Woodpecker tolerated closer human presence before flight than the Inca Dove and Streak-backed Oriole. This difference is likely due to the use of an alternative avoidance strategy of this species, which uses trunks for hiding. To decrease birds' perceived predation risk, restoration intervention plans should include a mosaic of larger excluded plots located near relatively well-conserved sites to increase the area covered by vegetation. [ABSTRACT FROM AUTHOR]

Information on reproductive biology is limited for many tropical birds, despite the importance of these data in areas such as ecology, taxonomy, and conservation. Hafferia zeledoni belongs to the Thamnophilidae family and was only recently elevated to the species level, and consequently little is known about its ecology and natural history. We found and monitored a dome-shaped nest of this species during 30 days. It was located on a steep slope in a sub-Andean forest, and both male and female participated in the incubation and care of nestlings. Night incubation was only performed by the female, and even though she also incubated during day, it was the male who spent more time on the nest during that period. The eggs were white with reddish blotches, and they measured on average 27.8 ± 1.2 x 19.7 ± 0.1 mm and weighed 5.84 ± 0.17 g. The two nestlings were naked with black skin and weighed 5.64 and 5.60 g at hatching, increasing to 28.61 and 31.60 g prior to fledging. We monitored the incubation behavior during 17 days, and the nestling period lasted 14 days. We compared our results with other members of the longipes clade finding similarities that support the newly established phylogenetic relationships. Our study provides the first description of the nest, nestlings, and incubation behavior of Hafferia zeledoni, and it provides new information on nest architecture that supports the dome nest radiation in this clade. [ABSTRACT FROM AUTHOR]

Disturbed forest fragments comprise a substantial proportion of tropical landscapes, and these habitats along with associated ecotones have become important to tropical biodiversity conservation in human-modified landscapes. This study evaluated how tropical avifaunal communities respond to moderate habitat disturbances, such as shifting cultivation, selective logging and restoration from exotic plant species, in the Yagirala Forest Reserve, a fragmented tropical lowland rainforest in south-west Sri Lanka. Thirty circular plots with a 25-m fixed-radius, located to cover four prominent habitat types (secondary forest, Pinus-dominated forest, abandoned paddy lands and home gardens), were studied from March to December 2014. The results suggest that despite being fragmented and disturbed by human actions, the Yagirala Forest Reserve and associated ecotone collectively provide an important refuge for avifauna in the landscape context. The forest-home garden interface supported the highest avifaunal diversity. Edge habitats represented by home gardens and abandoned paddy lands generally supported greater bird richness. However, less disturbed secondary forest and Pinus-dominated forest were be more important for endemic and forest-specialist birds. Our results further highlight the potential value of wooded forest-home garden interfaces and forest stands restored with exotic pines in supporting native forest bird assemblages, especially in fragmented and isolated forest patches. [ABSTRACT FROM AUTHOR]

Copyright of Ornitologia Colombiana is the property of Asociacion Colombiana de Ornitologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Caribbean Ornithology is the property of Society for the Conservation & Study of Caribbean Birds and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)