Bird Visitation Research Articles

Characterizing the domestic-wild bird interface through camera traps in an area at risk for avian influenza introduction in Northern Italy

Direct or indirect interactions between sympatric wildlife and poultry can lead to interspecies disease transmission. Particularly, avian influenza (AI) is a viral epidemic disease for which the poultry-wild bird interface shapes the risks of new viral introductions into poultry holdings. Given this background, the study hereby presented aimed to identify wild bird species in poultry house surroundings and characterize the spatiotemporal patterns of these visits. Eight camera traps were deployed for a year (January to December 2021) in three commercial chicken layer farms, including free-range and barn-type setups, located in a densely populated poultry area in Northern Italy at high risk for AI introduction via wild birds. Camera traps’ positions were chosen based on wildlife signs identified during preliminary visits to the establishments studied. Various methods, including time series analysis, correspondence analysis, and generalized linear models, were employed to analyze the daily wild bird visits. A total of 1,958 camera trap days yielded 5,978 videos of wild birds from 27 different species and 16 taxonomic families. The animals were predominantly engaged in foraging activities nearby poultry houses. Eurasian magpies (Pica pica), ring-necked pheasants (Phasianus colchicus) and Eurasian collared doves (Streptopelia decaocto) were the most frequent visitors. Mallards (Anas platyrhynchos), an AI reservoir species, were observed only in a farm located next to a fishing sport lake. Time series analysis indicated that wild bird visits increased during spring and winter. Farm and camera trap location also influenced visit frequencies. Overall, the results highlighted specific species that could be prioritized for future AI epidemiological surveys. However, further research is required to assess their susceptibility and infectivity to currently circulating AI viruses, essential for identifying novel bridge hosts.

Metallic light-based bird-repellent prototype to reduce paddy yield loss in Jatinangor, Sumedang Regency

Munia birds (Lonchura spp.) are pests that attack paddy plants during the reproductive phase. The traditional methods of controlling birds are considered less effective because birds can adapt to the tools used. This study aimed to determine the effectiveness of a metallic light-based bird-repellent prototype to reduce paddy yield loss. The experiment was conducted in Cileles Village paddy fields, Jatinangor Subdistrict, Sumedang Regency, West Java Province, Indonesia. The effectivity of the prototype was tested by measuring the effective distance (m2), counting the frequency of bird visits (number of visits), bird populations, and the level of paddy damage (%), and paddy yield (kg/64 m2). The result of the experiment showed that 3 m was an effectual deterrent factor for the prototype, thus the tool can protect paddy plants with an area of 28.26 m2. The frequency of bird arrivals in the treatment was 22.25 times, compared to 61.25 times in the control; the bird population in the treatment was 48.25 birds, while the control was 108.75 birds; the level of damage to paddy panicles in the treatment was 10.11%, compared to 37.79% in the control; and the production of paddy yield with the repellent was higher (33.37 kg/64 m2) than the control (23.09 kg/64 m2). This innovative prototype was potentially able to deter bird pests in the paddy fields.

The influence of plant scents on nest box inspection by Eastern Rosella (Platycercus eximius)

ABSTRACT Many cavity nesters add volatile plants with medicinal properties to their nests. In Australia, eucalyptus and tea-trees are highly volatile plants, which have antiparasitic and antimicrobial properties. Here, we tested whether scents of eucalypt (Eucalyptus polybractea) and tea tree (Melaleuca alternifolia) essential oils can attract birds to newly installed nest boxes. Twenty-four nest boxes received three scent treatments (eucalypt, tea tree, control) for 10 days each using a Latin-square design. Bird visitation was recorded using camera traps. Eastern Rosellas (Platycercus eximius) visited the nest boxes the most (1,454 visits) and were therefore the focus of the study. Eastern Rosellas did not change their behaviours in response to the eucalypt scent in nest boxes: there was no difference in visitation, duration of visits or nest box inspection behaviour between nest boxes with eucalypt scent and those with the control scent. However, Eastern Rosellas visited nest boxes with tea tree scent less frequently and spent less time at these boxes than those with the control scent. The mean time that Eastern Rosellas spent inspecting boxes slightly increased over the 10-day period following scent placement at boxes with control and eucalypt scents, while it sharply decreased at boxes with tea tree scent. This is the first study demonstrating that an Australian bird detected and behaved differently in response to plant volatiles. The use of scents may offer opportunities to not only attract, but potentially also deter certain birds from using particular hollows.

Seasonal changes in bird communities on poultry farms and house sparrow-wild bird contacts revealed by camera trapping.

Wild birds are considered reservoirs of poultry pathogens although transmission routes have not been conclusively established. Here we use camera trapping to study wild bird communities on commercial layer and red-legged partridge farms over a one-year timeframe. We also analyze direct and indirect interactions of other bird species with the house sparrow (Passer domesticus), a potential bridge host. We conducted camera trapping events between January 2018 and October 2019, in two caged layer farms, one free-range layer farm, and two red-legged partridge farms in South-Central Spain. We observed wild bird visits on all types of farms, with the significantly highest occurrence on red-legged partridge farms where food and water are more easily accessible, followed by commercial caged layer farms, and free-range chicken farms. The house sparrow (Passer domesticus) followed by spotless starlings (Sturnus unicolor) was the most encountered species on all farms, with the highest frequency in caged layer farms. On partridge farms, the house sparrow accounted for 58% of the wild bird detections, while on the free-range chicken farm, it made up 11% of the detections. Notably, the breeding season, when food and water are scarce in Mediterranean climates, saw the highest number of wild bird visits to the farms. Our findings confirm that the house sparrow, is in direct and indirect contact with layers and red-legged partridges and other wild birds independent of the type of farm. Contacts between house sparrows and other bird species were most frequent during the breeding season followed by the spring migration period. The species most frequently involved in interactions with the house sparrow belonged to the order Passeriformes. The study provides a comparative description of the composition and seasonal variations of bird communities in different types of layer/ poultry farms in Southern Spain i.e. a Mediterranean climate. It confirms the effectiveness of biosecurity measures that restrict access to feed and water. Additionally, it underscores the importance of synanthropic species, particularly the house sparrow, as potential bridge vector of avian pathogens.

Decoding the black essence of Melianthus nectar.

This article is a Commentary on Magner et al. (2023), 239: 2026–2040.

Using environmental DNA to investigate avian interactions with flowering plants

AbstractAnimal pollination is an important and highly valued ecosystem function and the role of birds as pollinators is increasingly acknowledged. However, such interactions can be challenging to document and often require extensive field programs. Over the last decade, environmental DNA (eDNA) has been analyzed from several different contemporary sample types, such as water, soil, flowers, and air. The applications of these studies include biodiversity monitoring, detection of endangered species, community compositions, and more recently, flower–arthropod interactions. However, it remains unknown whether flower eDNA is applicable to other taxonomic groups interacting with plants, as well as the deposition and degradation of eDNA on flowers. Here, we test whether eDNA from flowers can be used for detecting bird pollinators. In a controlled environment (an aviary with great tits [Parus major]), we show that birds leave significant traces of DNA on the flowers without observed visits (airborne eDNA). We further show that when birds had been in contact with the flowers, DNA concentrations increased to levels significantly higher than airborne background DNA. Subsequently, we sampled five clusters of wild flowers in Papua New Guinea and detected four species of birds, two of which are nectar‐feeders, and one that is an insectivorous species known to visit flowers. These four bird species were regularly seen in the area and caught in mist‐nets in the days prior to sampling of the flowers. In total, 29 bird species were recorded (18 mist‐netted) in the area and of these, eight are nectarivorous. Our quantitative approach suggests that it is possible to distinguish airborne background bird DNA deposited on flowers from actual flower visits of birds in the wild, although this might be highly context‐specific. Our findings are of broad interest within research on ecosystem functioning, biotic interactions, and plant–animal mutualism.

Гнездовые группировки орлов на ключевой орнитологической территории «Чинк Донызтау» в 2022 году

Гнездовые группировки орлов на ключевой орнитологической территории «Чинк Донызтау» в 2022 году

Monitoring Wind-Borne Particle Matter Entering Poultry Farms via the Air-Inlet: Highly Pathogenic Avian Influenza Virus and Other Pathogens Risk.

Wind-supported transport of particle matter (PM) contaminated with excreta from highly pathogenic avian influenza virus (HPAIv)-infected wild birds may be a HPAIv-introduction pathway, which may explain infections in indoor-housed poultry. The primary objective of our study was therefore to measure the nature and quantity of PM entering poultry houses via air-inlets. The air-inlets of two recently HPAIv-infected poultry farms (a broiler farm and a layer farm) were equipped with mosquito-net collection bags. PM was harvested every 5 days for 25 days. Video-camera monitoring registered wild bird visits. PM was tested for avian influenza viruses (AIV), Campylobacter and Salmonella with PCR. Insects, predominantly mosquitoes, were tested for AIV, West Nile, Usutu and Schmallenberg virus. A considerable number of mosquitoes and small PM amounts entered the air-inlets, mostly cobweb and plant material, but no wild bird feathers. Substantial variation in PM entering between air-inlets existed. In stormy periods, significantly larger PM amounts may enter wind-directed air-inlets. PM samples were AIV and Salmonella negative and insect samples were negative for all viruses and bacteria, but several broiler and layer farm PM samples tested Campylobacter positive. Regular wild (water) bird visits were observed near to the poultry houses. Air-borne PM and insects-potentially contaminated with HPAIv or other pathogens-can enter poultry air-inlets. Implementation of measures limiting this potential introduction route are recommended.

Micro-scale patterns and drivers of bird visitation on street fig trees in Delhi, India

Street trees have been used as a means of mitigating the negative effects of urbanization on biodiversity, particularly bird fauna. Despite their widely acknowledged benefits for birds, studies so far have been largely limited to relatively coarse scales, with an understanding of the role of local environments and individual tree characters lacking. We studied the patterns of bird visitation at individual street Ficus (fig) trees, providers of keystone resources in tropical landscapes, in Delhi, India, and their drivers at different scales (tree characteristics, local and landscape variables). Three common fig species were surveyed for bird visitors across 3 sites with varying urban patterns. Fig trees were found to be a relatively common street tree choice, and the 106 trees surveyed were visited by 29 bird species, including 7 obligate frugivores. We found that reducing green cover in surrounding landscape and increasing noise did not deter birds from visiting these trees. Instead, variables at finer scales like tree canopy diameter, tree species and local resource density had sizable and significant effects on both species richness and abundance of bird visitors. Our results highlight how bird assemblages, guilds and individual species respond differently to a range of ecological variables, and an understanding of these responses at different scales is useful for maximising the value of street trees for urban birds. Thus, coarse-scale studies can provide insights into bird diversity of city landscapes, but micro-scale studies are important in helping make fine scale management decisions, like selection of street trees.

A Study of Seasonal Abundance of Aquatic Birds including Migratory Birds with a Special Attention on population of Bar-headed Geese at Magadi Kere, Shirahatti Taluk, Gadag District, Karnataka, India

A study of seasonal abundance of aquatic birds including migratory birds with a special attention on population of Bar-headed Geese coming from Siberia and Tibet to Magadi Kere, Shirahatti Taluk, Gadag District Karnataka was conducted over a period of five years spanning from March 2015 to March 2020. A total of 34 aquatic bird species were observed and recorded. The abundance and frequency of visits of migratory birds especially of Barheaded Geese at different time intervals was recorded and inferences were drawn. The Bar-headed geese followed a fixed pattern of migration with the season starting from October-November, reaching the highest count in January-February and finally subsiding in March-April every year. It is also discerned from the study that the feeding pattern of aquatic birds coincides with the local crops grown in the vicinity, which are nearly at harvesting stage during the peak season of migration.

Physical, landscape, and chemical properties of Amazonian interior forest mineral licks.

Mineral licks, sites where animals go to consume soil, are key resources for herbivorous birds and mammals in the Amazon, providing supplemental dietary nutrients and toxin adsorption functions. However, because they are often difficult to find, the properties of mineral licks are poorly understood. Here, we undertake the largest survey of Amazonian mineral licks to date to determine the landscape, physical, and chemical properties of these critical sites. We used a generalized linear mixed-effects modeling framework to assess how soil samples from 83 mineral licks differ from nearby control soils in a series of physical and chemical characteristics, then used Jaccard's index of similarity and a principal component analysis (PCA) to determine how those samples differed among themselves. We found that mineral licks were generally located in specific ranges of landscape variables. Soils from mineral licks had elevated concentrations of almost all minerals measured. There was very little similarity between consumed and control samples, and within each sample type. We suggest that these mineral licks have the potential to provide multiple services to visiting species, demonstrating their ecological importance. The high levels of dissimilarity between samples indicate that a large sample of mineral licks is needed to draw conclusions in studies pertaining to geophagy. We emphasize that studying mammal and bird visitation at these sites could provide critical conservation and physiological information on cryptic and understudied species of Amazonian herbivores.

Tree visitation and potential seed dispersal of keystone Ficus species by vertebrates in an urban mosaic landscape in eastern South Africa

Globally with the human population increase, urban expansion has increased, impacting biodiversity and ecosystem functions. Visitation of fruiting trees by vertebrate frugivores can influence the persistence of fleshy fruited trees and so further maintain frugivore communities in transformed landscapes. Figs (Ficus spp.) have been recognised as keystone plant resources that support diverse frugivorous vertebrate communities. Our main objective was to identify the frugivorous vertebrates visiting fruiting Ficus trees in an urban mosaic landscape of Durban, Ethekwini Municipality, KwaZulu-Natal, South Africa, using camera traps focused on focal fig trees. We quantified the diurnal and nocturnal frugivore visitation rates and levels of interactions. We analysed frugivore visits to 12 individual trees of five Ficus species between 2019 and 2020. During 3888 h, we recorded a total of 4,071 videos from camera traps with 10,016 visits and levels of interactions of three main vertebrate taxa (8958 fruit bat visits, 808 bird visits and 250 monkey visits). These were in five Ficus species (F. burkei, F. lutea, F. natalensis, F. sur and F. sycomorus). Of the bird species visiting, we identified a total of 34 species, but some species were unidentified. We recorded a total of 8958 visits by Wahlberg's epauletted fruit bats Epomophorus wahlbergi, and 250 visits by vervet monkeys Chlorocebus pygerythrus. The latter tended to stay for prolonged periods in the trees feeding. Our data showed the importance of fruiting fig trees for vertebrate frugivores in the urban mosaic landscape. This highlights the conservation implications of figs as keystone resources in the urban mosaic landscape. Our findings support the planting and conservation of native Ficus tree species in transformed urban mosaic landscapes for the persistence of forest species biodiversity.

Effect of bird scaring methods on crop productivity and avian diversity conservation in agroecosystems of Benin

Farmers are developing methods to scare off and reduce bird damages. The aim of this study is to explore the effect of these methods through a simple form of evaluation that allowed to highlight relationship between these methods and productivity on the one hand, and the relationship between these methods and conservation of birds in the agricultural environment according to different vegetative stages on the other hand. 713 farmers were interviewed in the agro-ecological zones of Benin. This study reveals the use of four methods. These are auditory method, visual method, exclusion method and mixed method. They are used primarily to reduce "loss and damage" and "reduce the frequency of bird visits". 96.78% of farmers agreed that these methods improve yields. Moreover, effectiveness of the methods varies according to the vegetative stages and the duration of its application. Bird species richness was also significantly and positively influenced by bird control methods (Maize: p= 5767e-3) and (Rice: p=4482e-6). Long-term studies, generalized to different forms of agricultural area, are needed for a better assessment.

Why is the Shaw's Agave (Agave shawii subsp. Shawii) Not Reproducing? Investigating a Rare Species' Pollination and Germination in a Fragmented Urban Park

Shaw's Agave (Agave shawii subsp. shawii) is a rare plant found in only a handful of occurrences within the extreme southwestern corner of the USA in a highly urbanized region. Seedling recruitment of Shaw's Agave in California is visibly low, and viable seed production appears to have been very low in recent years, and has been identified as a primary threat to the persistence of these populations. We performed pollination trials, seed germination studies, and inventoried floral visitors and potential pollinators (including the collection of invertebrates) to determine if pollination and/or germination failure is limiting reproduction. We placed bat detectors and camera traps near blooming agaves, and observed bird and insect visitation to the flowers. Pollination treatments included hand pollination with cross-individual and selfing trials. Our results found a low amount of seed produced per fruit across the pollination trials. Seedling herbivory was also very high (85% and 100%) in the two treatments. The combination of low seed set and high herbivory may help explain the lack of recruitment observed at multiple sites in recent years. No nectar feeding bats utilized the Shaw's agave in our study area. The only significant insect visiting flowers was the honey bee (Apis mellifera), which gathered nectar without touching the anthers. Hummingbird species were also frequent visitors but generally avoided touching the agave anthers. Only the Hooded Oriole (Icterus cucullatus), a migratory bird, appeared to regularly visit flowers for their nectar, while standing on the flowers and brushing against the anthers, potentially providing some pollination but only for plants blooming during the period the oriole is present in the region. Seedling predation was significant, and poses a considerable threat to this population. Further research into seed set and pollination treatments is recommended.

Filament union provides landing site for birds and increase pollen removal and deposition in an ornithophilous species

Filament union is a widely distributed characteristic in angiosperms where the stamens in a flower are united by filaments in diverse modes. Yet, its adaptive significance has remained empirically unexplored. Bombax ceiba (Malvaceae) has large red flowers with two whorls of stamens differing in degrees of filament union, and therefore provides an opportunity to explore the adaptive significance of filament union. We observed floral visitors in a large wild population of B. ceiba in Hainan Island, south China. We manipulated the filament union and dyed pollen grains for two whorls of its stamens to explore effects of filament union on bird visitation and pollination consequences. We found that the main floral visitor to B. ceiba was Zosterops palpebrosa, which foraged for nectar via landing on stamens, petals, and branches. When filaments were separated, bird forage attempts and visit durations decreased due to weakened support for bird landing. Consequently, pollen removal was also decreased significantly. Filament union may help in generating the landing sites for the visiting birds to drink nectar, and thus, increases the frequency of their contact with the nearby five-branched stigmas, facilitating pollen deposition from other flowers. Therefore, filament union in B. ceiba may function as an efficient mechanism of cross-pollination by low-frequency but high-efficiency pollinators through stabilizing the anther position and by providing the united stamens as landing sites for birds, and increasing both pollen removal and deposition.

The role of fringing vegetation in supporting avian access to arid zone waterholes

ABSTRACT Access to drinking water is essential for many avian species in arid landscapes, especially in hot and dry periods when metabolic requirements for water increase. The role of fringing vegetation in facilitating surface water access by arid zone bird communities was investigated over a 14-month period during which water demand increased. Bird visitation to six long-lasting waterholes in the MacDonnell Ranges Bioregion in central Australia was recorded over two summers and one winter using camera traps. Species were assigned to functional classes based on their size and preferred foraging substrate. Generalised linear mixed models were used to test relationships between fringing vegetation variables and the independent trapping events for each functional class. Fringing vegetation was critical for small and intermediate-sized canopy foragers to access waterhole sites. Their activity declined to almost zero in areas where the nearest tree or shrub cover was greater than 10 m. The strength of this relationship was consistent as weather conditions became drier and hotter. However, activity of small and intermediate-sized canopy foragers was negatively related to the percent canopy cover of the nearest tree or shrub, potentially because sparse vegetative cover offers greater visibility when approaching the water’s edge. In contrast, ground forager and raptor activity at waterhole sites was unrelated to surrounding vegetation, and these groups frequently accessed water from open areas. Under future warming scenarios, small and intermediate canopy foragers may be vulnerable to predation if they are forced to access water at sites away from nearby fringing vegetation.

A study of seasonal abundance of aquatic birds including migratory birds with a special focus on population of Bar-headed geese at Magadi Kere, Shirahatti Taluk, Gadag district, Karnataka, India

A study of the seasonal abundance of aquatic birds, including migratory birds, focuses on the population of Bar-headed geese coming from Siberia and Tibet to Magadi Kere, Shirahatti Taluk, Gadag District, and Karnataka was conducted over five years spanning from March 2015 to March 2020. A total number of 34 aquatic bird species were observed and recorded. At different time intervals, the abundance and frequency of visits of migvisitsy birds, especially of Bar-headed geese, were recorded and inferences were drawn. The Bar-headed geese followed a fixed migration pattern with the peak season starting from October-November, reaching the highest count in January-February and finally subsiding in March-April every year. The study also discerned that the feeding pattern of aquatic birds coincides with the local crops grown in the vicinity, which are at the harvesting stage during the peak season of migration.

Acute mortality in California tiger salamander (Ambystoma californiense) and Santa Cruz long-toed salamander (Ambystoma macrodactylum croceum) caused by Ribeiroia ondatrae (Class: Trematoda).

In early September 2019, a morbidity and mortality event affecting California tiger salamanders (Ambystoma californiense) and Santa Cruz long-toed salamanders (Ambystoma macrodactylum croceum) in late stages of metamorphosis was reported at a National Wildlife Refuge in Santa Cruz County, California, U.S.A. During the postmortem disease investigation, severe integumentary metacercarial (Class: Trematoda) infection, associated with widespread skin lesions, was observed. Planorbid snails collected from the ponds of the refuge within seven days of the mortality event were infected with Ribeiroia ondatrae, a digenetic trematode that can cause malformation and death in some amphibians. We suggest sustained seasonal high-water levels due to active habitat management along with several years of increased rainfall led to increased bird visitation, increased over-wintering of snails, and prolonged salamander metamorphosis, resulting in a confluence of conditions and cascading of host-parasite dynamics to create a hyper-parasitized state.

Deterring non-target birds from toxic bait sites for wild pigs

Toxic baiting of wild pigs (Sus scrofa) is a potential new tool for population control and damage reduction in the US. Field trials testing a prototype toxic bait (HOGGONE 2 containing 5% sodium nitrite [SN]), though, revealed that wild pigs spilled small particles of toxic bait outside of bait stations which subsequently created hazards for non-target species that consumed those particles, primarily passerine birds. To deter non-target birds from consuming particles of spilled bait, we tested four deterrents at mock bait sites (i.e., baited with bird seed) in north-central Colorado, USA during April–May 2020. We found a programable, inflatable deterrent device (scare dancer) reduced bird visitation by an average of 96%. Then, we evaluated the deterrent devices at SN-toxic bait sites in north-central Texas, USA during July 2020, where the devices were activated the morning following deployment of SN-toxic bait. Overall, we found 139 dead wild pigs at 10 bait sites following one night of toxic baiting, which represented an average of 91% reduction in wild pigs visiting bait sites. We found that deterrent devices were 100% effective at deterring birds from toxic bait sites. We found two dead non-target mice at bait sites without deterrent devices. We noted that deploying toxic bait in mid-summer rather than late-winter/early-spring reduced hazards to migrating birds because they were not present in our study area during July. We recommend using deterrent devices (i.e., novel, programmable, battery operated, continuous and erratic movement, and snapping sounds) to reduce hazards to non-target birds at SN-toxic bait sites. We further recommend deploying SN-toxic bait during seasons when migrating birds are not as abundant until further research demonstrates minimal risks to migrating birds.

Top 10 Raptors of Northern Belize

More than 500 species of birds visit or live in Belize and because of its location, Northern Belize serves as an important stop-over point and attracts a large majority of migratory birds in addition to its year-round residents. This guide showcases the top 10 raptor species (predatory birds) that you are most likely to encounter while in Northern Belize.