Search

Aerial insectivorous birds breeding in North America have experienced decades of population declines for reasons hypothesized to be related to changes in their insect prey. In agricultural landscapes, land management practices can affect insect communities, leading to concerns that ongoing trends toward more intensive cultivation could affect the ability of farmland-breeding aerial insectivores to forage and provision their offspring with aerial insect prey. To understand how differences in agricultural intensity may affect the foraging behavior of different aerial insectivore species, we used GPS tags to compare the movements and habitat use of 2 species with different foraging ecologies, Hirundo rustica (Barn Swallow) and Tachycineta bicolor (Tree Swallow), breeding at 17 sites in agricultural landscapes in Saskatchewan, Canada. Although we identified differences in foraging behavior consistent with each species' reported ecological traits, including T. bicolor foraging farther and over larger areas than H. rustica , overall foraging behavior was similar between species. Resource selection function analyses indicated that both species used wetlands disproportionately often relative to local wetland availability, especially when detected farther from their nests. Hirundo rustica and T. bicolor both also avoided cropped foraging habitat, using it proportionally less than it was locally available. In landscapes with greater wetland cover, both species selected for wetland habitat more strongly, and among T. bicolor , higher wetland density decreased maximum foraging distance and home range area. In contrast, we found no effect of crop cover on foraging habitat selection or foraging movements. These findings suggest that H. rustica and T. bicolor breeding in Saskatchewan agroecosystems share similar foraging strategies, with wetland habitats appearing to be highly important despite comprising only a small proportion of landscape area. Overall, these results indicate that protecting wetland habitats should be a priority for aerial insectivore conservation in the intensive agricultural landscapes such as the Canadian prairies. [ABSTRACT FROM AUTHOR]

Swallows (Hirundo spp.) inhabit a variety of habitats in both tropical and temperate zones. Barn Swallows (Hirundo rustica), in particular, frequently roost in large numbers and construct mud nests on buildings, causing nuisance to humans. At the Glami Lemi Biotechnology Research Centre (GLBRC), which is located in Peninsular Malaysia, there are certain structures that are frequently utilised by a large number of swallows for perching and resting. This results in the defacement of the exterior walls caused by their droppings. Hence, the analysis presented in this paper delves into the factors influencing their presence and numbers. The objective of this study was to examine the fluctuations in the number of perched Barn Swallows and their relationship with three environmental parameters: temperature, relative humidity, and light intensity. Three hours of observation were conducted in two different sessions (i.e., morning and afternoon) three times per week for one year. The results showed that the number of Barn Swallows perched appeared to be stable throughout the year, except for November and December, when it increased tremendously and reached its peak. A Spearman rank analysis was conducted to investigate the correlation between the number of swallows perched and the environmental parameters. The analysis was restricted to only periods when the birds were present. A significant effect of relative humidity and temperature was observed for the morning session, promoting the relationship between the environmental parameters and the perching/resting behaviour of this species. This situation is parallel with the afternoon session, where all three environmental parameters showed a significant effect on swallows’ numbers. This study not only provides valuable information to the GLBRC’s management to effectively anticipate appropriate steps to mitigate the influx of Barn Swallows but also enhances our knowledge of the perching/ resting behaviour of this species. [ABSTRACT FROM AUTHOR]

Copyright of Acta Zoologica Lilloana is the property of Fundacion Miguel Lillo 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.)

Abstract, author, keywords, institution, and cited literature, and used CiteSpace (version 6.1.R3) to visualize the data through the knowledge map, burst keyword analysis, cluster analysis, and collaborative network analysis. Results: A total of 979 articles and reviews were retrieved. Regarding productivity, the top 2 countries were the United States (n =239) and Japan (n =236). Hidetaka Wakabayashi (n =26) was one of the most prolific writers. The first paper in the frequency ranking of references cited was a white paper: European Society for Swallowing Disorders and European Union Geriatric Medicine Society white paper: oropharyngeal dysphagia as a geriatric syndrome (n =53). "Prevalence" (n =173), "risk factor" (n =119), and "aspiration pneumonia" (n =108) were the most frequently occurring keywords (excluding defining nouns). The study identified reliability, tongue pressure, home discharge, and swallowing function as research hotspots from 2020 to 2022. Conclusion: Prevalence, risk factors, and pneumonia are significant areas of study. Tongue pressure and sarcopenia are research hotspots and potential targets. In the future, research on dysphagia needs to refine strategies for prevention and control, as well as provide tertiary preventative services. [ABSTRACT FROM AUTHOR]

The intestinal microbiota plays an important role in the digestion of food provided by parents to their hatchlings. Non-pathogenic bacteria in the digestive tract can be significantly beneficial to the host species, while pathogenic bacteria can reduce hatchling survival and lead to a decline in the number of new generation. Microbiological analysis of cloacal microflora of hatchlings revealed a highly diverse microbial load present from hatching until fledging (at 15 days) in Barn Swallow (Hirundo rustica). The intestinal microflora of 15-day-olds was the most diverse, and two groups are dependent on age: CPG and Lactobacilli are mostly present in hatchlings of the second and third ages (10 and 15 days). Our research was conducted to identify certain bacterial species, such as E. coli, Salmonella, Pseudomonas, Lactobacillus, Streptococcus, and Staphylococcus. The presence of most species was related to age, while the presence of Salmonella was accidental. [ABSTRACT FROM AUTHOR]

Insectivorous birds are key suppliers of crucial ecosystem services, especially important for pest control in agricultural systems, and are globally decreasing at a fast rate. Among them, the declining barn swallow Hirundo rustica is particularly linked to cattle farms, where it is impacted by changes in livestock husbandry practices.The presence of swallows in cattle sheds might contribute to control insect pests, but such an effect had never been explored. With this work, we evaluated the potential control effect exerted by barn swallow on economically relevant pest insects, filth flies.To assess whether swallows inside the cattle sheds influence the activity rate of pest flies (especially Musca domestica and Stomoxys calcitrans), we assessed the relative abundance of swallows and flies over 16 weeks in nine different cattle farms in Non valley (Trentino, North‐east Italy), either occupied or not by nesting swallows. From April 2022 to August 2022, we collected weekly data on the activity rate of flies by placing eight white spot cards inside each of nine cattle sheds and counting the deposition of faecal and regurgitation spots by flies. Simultaneously, we collected weekly data regarding swallow occurrence, brood size, number and age of chicks.We applied generalised linear mixed effect models on the activity rate of flies, with spot card and farm as nested random effects, to account for potential random variability between cards and farms. We then assessed through model selection the effect of number of cows, number of swallows, and temperature or week alternatively. Temperature and week were modelled also in interaction with the number of swallows.Fly activity rate followed a seasonal trend with a peak in July, which was markedly lower where swallows were present. Moreover, the positive relationship between flies and temperature was lessened when swallows were abundant.Synthesis and applications. Barn swallows are effective biological control agents for lowering pest fly activity in livestock farms. Farmers were actively involved in swallow conservation within their sheds, also with a shared memorandum‐of‐intent. Harnessing the ecosystem services supplied by farmland birds could bring positive outcomes for people and biodiversity. [ABSTRACT FROM AUTHOR]

The presence of feathers is a vital characteristic among birds, yet most modern birds had no feather on their feet. The discoveries of feathers on the hind limbs of basal birds and dinosaurs have sparked an interest in the evolutionary origin and genetic mechanism of feathered feet. However, the majority of studies investigating the genes associated with this trait focused on domestic populations. Understanding the genetic mechanism underpinned feathered-foot development in wild birds is still in its infancy. Here, we assembled a chromosome-level genome of the Asian house martin (Delichon dasypus) using the long-read High Fidelity sequencing approach to initiate the search for genes associated with its feathered feet. We employed the whole-genome alignment of D. dasypus with other swallow species to identify high-SNP regions and chromosomal inversions in the D. dasypus genome. After filtering out variations unrelated to D. dasypus evolution, we found six genes related to feather development near the high-SNP regions. We also detected three feather development genes in chromosomal inversions between the Asian house martin and the barn swallow genomes. We discussed their association with the wingless/integrated (WNT), bone morphogenetic protein, and fibroblast growth factor pathways and their potential roles in feathered-foot development. Future studies are encouraged to utilize the D. dasypus genome to explore the evolutionary process of the feathered-foot trait in avian species. This endeavor will shed light on the evolutionary path of feathers in birds. [ABSTRACT FROM AUTHOR]

Anthropogenic noise can affect a number of behavioral, physiological, and ecological aspects of animals from major taxonomic groups, raising serious conservation concerns. For example, noise pollution impacts communicative behavior and perception of signals, movements and distribution, as well as predator–prey interactions, such as hunting success or predator detection and predation risk assessment. We have carried out an experimental playback study, in which we investigated whether exposure to anthropogenic noise (sound of a tractor) distracts free-ranging barn swallows Hirundo rustica from paying attention to an approaching human "predator" (the "cognitive distraction" hypothesis), or whether noise leads to increased responsiveness to this "predator" (the "increased threat" hypothesis). The subjects were male barn swallows attending their breeding territories during the time when the females were incubating. We found that barn swallow males initiated flight at significantly greater distances to the approaching human "predator" in the noise treatment than during the quiet control trials. These results suggest that anthropogenic noise causes increased vigilance and reactivity rather than a distraction, enabling birds to avoid the "predator" more quickly. We further discuss the mechanism behind the increased alertness in response to noise and contrast the "increased threat" mechanism, usually tested in previous studies, with an alternative "cognitive sensitization" mechanism. [ABSTRACT FROM AUTHOR]

Conservation efforts are needed in the face of the rapid decline in farmland birds over the past decades. While existing conservation strategies have shown limited success, there is a growing recognition of the role of farmers as primary stakeholders in agroecosystems conservation. We applied the ''Human Dimension'' approach, which emphasizes the importance of human perspectives on wildlife conservation, to assess whether a long-term monitoring project of barn swallows Hirundo rustica, ongoing since 1999, has heightened farmers’ awareness regarding biodiversity protection. Indeed, while monitoring serves to track population trends and understand the factors influencing species dynamics, it also provides opportunities for interaction between researchers and farmers. Through in-person administration of the questionnaire, we investigated the impact of the barn swallow monitoring project on farmers’ environmental consciousness in terms of their perceptions of the environment, knowledge about priority habitats for biodiversity, and preferences for environmental awareness strategies. Subsequently, we investigated whether environmental consciousness and the participation in the barn swallow monitoring project translated into their inclination to implement costless actions for barn swallow conservation. Our findings suggest that the barn swallow monitoring project may not have enhanced farmers’ environmental consciousness. However, a higher environmental consciousness and the engagement in the barn swallow monitoring project were associated to a greater willingness to undertake actions in support of barn swallows. This study highlights the potential of long-term projects in fostering the conservation of charismatic species through establishing a mutual trust between farmers and researchers over years of monitoring, with cascading benefits for the barn swallows.

We present two new records of leucism in two bird species from two locations in Mexico. First, we report one leucistic Barn Swallow (Hirundo rustica); the individual was a nestling observed between 15 July and 6 August 2010, in a suburban area of central Jalisco, showing gray-whitish coloration and dark eyes. We also report of one leucistic Turkey Vulture (Cathartes aura) spotted during the afternoon of 4 November 2014, flying overhead while migrating in the city of José Cardel, Veracruz; the individual showed white primary feathers interspersed with dark secondaries, white primary coverts, white neck, and chest feathers. Our records represent the first Mexican report of leucism in the Barn Swallow, and the first published report of a leucistic vulture migrating across central Veracruz, respectively. Our observations also show that both leucistic individuals were accomplishing regular life-cycle activities, enriching the available knowledge of chromatic abnormalities in Mexican birds.

Although extensive research has been carried out on the occurrence of mercury (Hg) in biota, bioaccumulation and tissue distribution of Hg in songbirds have not been well characterized. In the present study, Hg was investigated in insects and barn swallows (Hirundo rustica) to explore the bioaccumulation characteristics of Hg. Hg in swallow feathers and tissues including muscle, liver, and bone was investigated to determine the tissue distribution of Hg. The concentrations of Hg were 1.39 ± 1.01 μg/g, 0.33 ± 0.09 μg/g, 0.47 ± 0.10 μg/g, and 0.23 ± 0.09 μg/g in feather, muscle, liver, and bone samples, respectively. The trophic magnification factor of Hg in swallows and insects was higher than 1. However, the Hg concentrations in swallow feathers were not significantly correlated with stable isotope values of carbon or nitrogen, which implies the complex food sources and exposure processes of Hg for swallows. Feathers had significantly higher concentrations of Hg than liver, muscle, and bone samples (p < 0.01 for all comparisons). Feather, muscle, bone, and other organs had fractions of 64.4 ± 11.9%, 6.07 ± 2.06%, 20.0 ± 8.19%, and 9.56 ± 2.96% in total body burden of Hg in swallows. Hg in feathers contributed more than half of Hg in the whole body for most swallow individuals. Swallows may efficiently eliminate Hg by molting, and the excretion flux of Hg and other contaminants via molting deserves more investigation. [ABSTRACT FROM AUTHOR]

The cost of ornamentation is often measured experimentally to study the relative importance of sexual and viability selection for ornamentation, but these experiments can lead to a misleading conclusion when compensatory trait is ignored. For example, a classic experiment on the outermost tail feathers in the barn swallow Hirundo rustica explains that the concave (or U‐shaped) aerodynamic performance cost of the outermost tail feathers would be the evolutionary outcome through viability selection for optimal tail length, but this conclusion depends on the assumption that compensatory traits do not cause reduced performance. Using a simple "toy model" experiment, I demonstrated that ornamentation evolved purely though sexual selection can produce a concave cost function under the presence of compensatory traits, which was further reinforced by a simple mathematical model. Therefore, concave cost function (and the low performance of individuals with reduced ornaments) cannot be used to infer the evolutionary force favoring ornamentation, due to a previously overlooked concept, "overcompensation," which can worsen the whole body performance. [ABSTRACT FROM AUTHOR]

Some theoretical models predict that nestling begging must be a costly activity to transmit reliable information to parents about offspring hunger. One candidate cost is oxidative stress, which could impair growth or immune function. This hypothesis predicts that nestlings in a poor oxidative status should pay higher costs for a given amount of begging, hence beg at lower rates for a similar degree of hunger. To test this prediction, we experimentally induced a transient alteration of the oxidative status of Barn Swallow (Hirundo rustica) nestlings by administering them either a single dose of a pro-oxidant substance (BSO) or an antioxidant (vitamin E), and recorded their begging behaviour. Chicks treated with vitamin E increased their begging rates in the hours following treatment. However, and contrary to prediction, BSO nestlings did not decrease begging compared to controls. These inconsistent results are difficult to explain by the hypothesis that begging performance is mediated by the oxidative status of nestlings because chicks with an impaired oxidative status (the BSO group) begged the same as controls. Alternatively, vitamin E may alleviate the inhibitory effects on begging of stress responses mediated by glucocorticoids. This study suggests that oxidative costs of begging are minor or absent in this species. Future studies should consider alternative explanations for an association between oxidative status, antioxidant supplementation and begging behaviour, particularly those involving glucocorticoids. [ABSTRACT FROM AUTHOR]

"Nestwork: New Material Rhetorics for Precarious Species" by Jennifer Clary-Lemon explores the concept of ecological care in the face of species extinction. The author challenges anthropocentric and human exceptionalist perspectives on rhetoric, drawing on posthumanism, new materialism, and Indigenous ways of knowing. The book examines efforts to support Canada's barn swallows, chimney swifts, and bobolinks, highlighting the complexities of coexistence in the Anthropocene. Clary-Lemon argues for the importance of reimagining and remaking our relationships with both human and more-than-human others in order to thrive in the future. [Extracted from the article]

Brood parasitic birds lay eggs in the nests of other birds, and the parasitized hosts can reduce the cost of raising unrelated offspring through the recognition of parasitic eggs. Hosts can adopt vision-based cognitive mechanisms to recognize foreign eggs by comparing the colors of foreign and host eggs. However, there is currently no uniform conclusion as to whether this comparison involves the single or multiple threshold decision rules. In this study, we tested both hypotheses by adding model eggs of different colors to the nests of Barn Swallows (Hirundo rustica) of two geographical populations breeding in Hainan and Heilongjiang Provinces in China. Results showed that Barn Swallows rejected more white model eggs (moderate mimetic to their own eggs) and blue model eggs (highly non-mimetic eggs with shorter reflectance spectrum) than red model eggs (highly non-mimetic eggs with longer reflectance spectrum). There was no difference in the rejection rate of model eggs between the two populations of Barn Swallows, and clutch size was not a factor affecting egg recognition. Our results are consistent with the single rejection threshold model. This study provides strong experimental evidence that the color of model eggs can has an important effect on egg recognition in Barn Swallows, opening up new avenues to uncover the evolution of cuckoo egg mimicry and explore the cognitive mechanisms underlying the visual recognition of foreign eggs by hosts.

Many animals breed colonially, often in dense clusters, representing a complex social environment with cognitive demands that could ultimately impact individual fitness. However, the effects of social breeding on the evolution of cognitive processes remain largely unknown. We tested the hypothesis that facultative colonial breeding influences attention and decision-making. Barn swallows (Hirundo rustica) breed in solitary pairs or in a range of colony sizes, up to dozens of pairs. We tested for selective attention to social information with playbacks of conspecific alarm calls and for decision-making with simulated predator intrusions, across a range of colony sizes from 1 to 33 pairs. We also evaluated the adaptive value of both processes by measuring seasonal reproductive success. Swallows breeding in larger colonies were more selective in their attention to social information. Birds breeding in larger colonies were also less risk averse, deciding to return more quickly to their nests after a predator approach paradigm. Finally, birds that showed higher selective attention hatched more eggs and birds that returned to their nests more quickly after a predator intrusion had more nestlings. Although we cannot fully attribute these fitness outcomes to the cognitive measures considered in this study, our results suggest that social breeding plays a role in adaptively shaping both the acquisition of social information and decision-making., (© 2024. The Author(s).)