Next Issue
Volume 4, June
Previous Issue
Volume 3, December
 
 

Birds, Volume 4, Issue 1 (March 2023) – 12 articles

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Reader to open them.
Order results
Result details
Select all
Export citation of selected articles as:
11 pages, 721 KiB  
Brief Report
Concentrations of Manganese in Tufted Titmouse Feathers near Metal Processing Plants
by Rachael Sarnowski and James S. Kellam
Birds 2023, 4(1), 148-158; https://doi.org/10.3390/birds4010012 - 22 Mar 2023
Viewed by 3226
Abstract
Human industry and land use has led to the anthropogenic release of manganese (Mn) into the air and soil near manufacturing centers. Overexposure to Mn can cause considerable health problems in birds. We studied whether the concentration of Mn in bird feathers correlates [...] Read more.
Human industry and land use has led to the anthropogenic release of manganese (Mn) into the air and soil near manufacturing centers. Overexposure to Mn can cause considerable health problems in birds. We studied whether the concentration of Mn in bird feathers correlates with the distance to point sources of Mn air emissions. Feathers were collected from Tufted Titmice (Baeolophus bicolor) at two sites in western Pennsylvania, USA. One site was in proximity (0.3 km) to a steel plant with documented Mn releases, and the other site was in a different town about 4.0 km away from other steel plants with documented Mn releases. Using the microwave plasma–atomic emission spectrometer (MP–AES), we found that tail feathers collected from nearest to a steel plant had a significantly higher concentration of Mn compared to the samples from the site further from the emission source. A body mass index was calculated for each set of birds; however, the indices did not vary significantly. This is the first published study of Mn sequestration in Tufted Titmouse feathers. This study develops our general understanding of the potential use of bird feathers as non-invasive bioindicators of environmental metal exposure. Full article
(This article belongs to the Special Issue Feature Papers of Birds 2022–2023)
Show Figures

Figure 1

10 pages, 396 KiB  
Article
Acoustic Classification of Bird Species Using an Early Fusion of Deep Features
by Jie Xie and Mingying Zhu
Birds 2023, 4(1), 138-147; https://doi.org/10.3390/birds4010011 - 01 Mar 2023
Cited by 2 | Viewed by 2661
Abstract
Bird sound classification plays an important role in large-scale temporal and spatial environmental monitoring. In this paper, we investigate both transfer learning and training from scratch for bird sound classification, where pre-trained models are used as feature extractors. Specifically, deep cascade features are [...] Read more.
Bird sound classification plays an important role in large-scale temporal and spatial environmental monitoring. In this paper, we investigate both transfer learning and training from scratch for bird sound classification, where pre-trained models are used as feature extractors. Specifically, deep cascade features are extracted from various layers of different pre-trained models, which are then fused to classify bird sounds. A multi-view spectrogram is constructed to characterize bird sounds by simply repeating the spectrogram to make it suitable for pre-trained models. Furthermore, both mixup and pitch shift are applied for augmenting bird sounds to improve the classification performance. Experimental classification on 43 bird species using linear SVM indicates that deep cascade features can achieve the highest balanced accuracy of 90.94% ± 1.53%. To further improve the classification performance, an early fusion method is used by combining deep cascaded features extracted from different pre-trained models. The final best classification balanced accuracy is 94.89% ± 1.35%. Full article
(This article belongs to the Special Issue Feature Papers of Birds 2022–2023)
Show Figures

Figure 1

21 pages, 8718 KiB  
Article
Activity Patterns, Sex Ratio, and Social Organization of the Bare-Faced Curassow (Crax fasciolata) in the Northern Pantanal, Brazil
by Martin Senič, Karl-L. Schuchmann, Kathrin Burs, Ana Silvia Tissiani, Filipe de Deus and Marinez I. Marques
Birds 2023, 4(1), 117-137; https://doi.org/10.3390/birds4010010 - 20 Feb 2023
Cited by 1 | Viewed by 2171
Abstract
Among Neotropical cracids (Galliformes), many taxa are declining rapidly in population size and facing local extinction. However, in the Brazilian Pantanal, several species occur sympatrically and in abundant numbers to allow for long-term studies. Therefore, the study was intended to collect data and [...] Read more.
Among Neotropical cracids (Galliformes), many taxa are declining rapidly in population size and facing local extinction. However, in the Brazilian Pantanal, several species occur sympatrically and in abundant numbers to allow for long-term studies. Therefore, the study was intended to collect data and statistically evaluate the life history patterns of Bare-faced Curassow (Crax fasciolata), a high-conservation-priority species. Additionally, the effect of applying commonly used independence filters on camera trap data was evaluated. The study was conducted in the SESC Pantanal, Baía das Pedras, Mato Grosso, Brazil, a private protected area of approximately 4200 ha. Between July 2015 and December 2017 (4768 sampling days), 37 sampling locations were monitored with camera traps placed in a regular grid with a spacing of 1 km. Crax fasciolata was detected at 26 (70.27%) of them, with 357 independent captures (554 individuals). Capture success differed among the four seasonal periods, being highest during the receding and lowest during the high-water period. The seasonal difference was more pronounced in the savanna, with significantly lower activity during the rising period and higher activity during the receding period, while it was more uniform in forest-dominated areas. Groups with offspring were more active during the period of receding water, indicating the peak of reproductive activity in the months before. The daily activity of the species followed a bimodal pattern, with peaks between 06:00 and 07:00 and 16:00 and 17:00. Daily activity rhythms were similar when compared between seasonal periods, sexes, and adults with or without offspring and differed between two habitats (more homogeneous in the forest). The mean detected group size was 1.55 ± 0.81 SD, with four animals exhibiting the largest observed aggregation. Larger unisexual aggregations of adults were not observed. The offspring sex ratio was significantly female-skewed at 0.51:1.00, while the adult sex ratio was considered equal at 1.05:1.00 (male:female). The use of different independence filters did not alter the BFC general activity pattern estimates. Cracids can be considered important bioindicators of habitat quality. The results of this study outline the importance of the Pantanal as a stronghold for this species and the privately protected areas with low anthropogenic activity as highly beneficial to its populations. Full article
(This article belongs to the Special Issue Feature Papers of Birds 2022–2023)
Show Figures

Figure 1

14 pages, 2425 KiB  
Article
Avifaunal Diversity and Abundance in the Proposed Sarasalai Mangrove Reserve, Jaffna, Sri Lanka
by Nitharsan Aloysius, Shashi Madhushanka and Chathuri Chandrika
Birds 2023, 4(1), 103-116; https://doi.org/10.3390/birds4010009 - 17 Feb 2023
Cited by 1 | Viewed by 4024
Abstract
Mangrove ecosystems are excellent habitats for migrating and resident birds. The proposed Sarasalai mangrove reserve is located in one of the richest waterbird zones in Sri Lanka. This site has never been properly studied as a single site for its avifaunal diversity. Hence, [...] Read more.
Mangrove ecosystems are excellent habitats for migrating and resident birds. The proposed Sarasalai mangrove reserve is located in one of the richest waterbird zones in Sri Lanka. This site has never been properly studied as a single site for its avifaunal diversity. Hence, the present study aims to find avifaunal diversity in the Sarasalai mangrove. Data collection was performed from April to December 2021. Eight permanent sampling stations were demarcated along the existing roads and were visited twice a month to collect bird abundance data. A total of 107 bird species belonging to 45 families including 58 waterbird species were recorded in the present study. Bird abundance did not significantly differ among the eight studied sites. Studied sites with the availability of water and good tree cover had the highest Shannon Diversity Index. The mangrove vegetation, with tall grasses, and the high water level were significant factors for bird abundance in some sites. Monthly bird abundance showed a notable increase during the migratory months. Among the recorded bird species, Greater Flamingos showed the highest abundance. Moreover, some rare waterbirds including Indian Spot-billed Duck and Glossy Ibis were commonly recorded. Several putative threats have been recorded during this study, namely unplanned land encroachments, bird hunting, and clearing of mangroves. Although this site has a high value in providing a healthy habitat for many wetland birds, it is yet to be declared a protected area. The lack of a clear boundary and a governing body to protect this area exacerbates its protection issues. Hence, it is proposed that immediate legal actions must be taken to declare this important migratory bird area a mangrove forest reserve. Full article
(This article belongs to the Special Issue Feature Papers of Birds 2022–2023)
Show Figures

Figure 1

2 pages, 242 KiB  
Editorial
Acknowledgment to the Reviewers of Birds in 2022
by Birds Editorial Office
Birds 2023, 4(1), 101-102; https://doi.org/10.3390/birds4010008 - 14 Feb 2023
Viewed by 817
Abstract
High-quality academic publishing is built on rigorous peer review [...] Full article
16 pages, 1656 KiB  
Article
Flight Type and Seasonal Movements Are Important Predictors for Avian Collisions in Wind Farms
by Alfonso Balmori-de la Puente and Alfonso Balmori
Birds 2023, 4(1), 85-100; https://doi.org/10.3390/birds4010007 - 09 Feb 2023
Cited by 1 | Viewed by 3399
Abstract
Wind farms are an alternative energy source mitigating environmental pollution. However, they can have adverse effects, causing an increase in mortality for wildlife through collision with wind turbines. The aim of this study was to investigate the risks of bird collisions with wind [...] Read more.
Wind farms are an alternative energy source mitigating environmental pollution. However, they can have adverse effects, causing an increase in mortality for wildlife through collision with wind turbines. The aim of this study was to investigate the risks of bird collisions with wind turbines linked to species-specific variables. For this purpose, we have analysed the dead birds involved in wind farm collisions that were admitted to two rescue centres in Spain over a period of 16 years (2001–2016; full dataset: n = 3130). All the birds analysed in this study were killed by turbines in wind farms. We performed two linear models using all species and a reduced dataset (bird of prey and passerine having more than four collisions) that included group, seasonal movements, flight type, length, and the number of pairs for the Spanish and European populations. The coefficients and the percent of variance explained by each relevant variable were determined in the models and the real values were compared with predicted values to visualise the goodness of fit. We found that the flight type was the most important variable explaining 35% of the total variability for the model including all species and 29% for the reduced dataset respectively, followed by seasonal movement type (4%/17% respectively) and the Spanish population (4%/6%). Subsequent analyses suggested that species with hovering, song-flights and active soaring flights are more susceptible to collisions with wind farms, and that species showing partial migration have a significant peak of collisions across spring and autumn. The estimated species-specific collision index can help in modelling the theoretical risk of collision with wind turbines, depending on the species existing in the area and their predicted values of vulnerability, which is linked to flight types and seasonal movements. Full article
(This article belongs to the Special Issue Feature Papers of Birds 2022–2023)
Show Figures

Figure 1

12 pages, 983 KiB  
Article
Susceptibility to Predation Varies with Body Mass, Foraging Niche, and Anti-Predator Responses among Bird Species
by Guy Beauchamp
Birds 2023, 4(1), 73-84; https://doi.org/10.3390/birds4010006 - 05 Feb 2023
Cited by 7 | Viewed by 2291
Abstract
Predation is a major source of mortality for many avian species. Species that face more predators, and those with less effective anti-predator responses, are presumably more likely to die from predation over time. Predation rate, as a measure of susceptibility to predation, is [...] Read more.
Predation is a major source of mortality for many avian species. Species that face more predators, and those with less effective anti-predator responses, are presumably more likely to die from predation over time. Predation rate, as a measure of susceptibility to predation, is difficult to measure in the field. Radio-tracking studies, however, allow researchers to determine the time and cause of death of marked individuals, making it possible to estimate predation rate. I used estimates of predation rates from a large number of published radio-tracking studies in birds to assess in a phylogenetic framework the effect of several potential determinants. I obtained 393 estimates of predation rates from 129 species. Predation rates were lower in areas with fewer predators, such as islands and aquatic habitats, and for species with fewer potential predators, such as larger species. The predation rate was also lower for prey species with effective anti-predator responses, such as those that forage in flocks. Radio-tracking studies provide a unique opportunity to estimate overall predation rate in the field. Broadening the range of species and the range of habitats involved in such studies will help to further elucidate the factors that affect susceptibility to predation. Full article
(This article belongs to the Special Issue Feature Papers of Birds 2022–2023)
Show Figures

Figure 1

12 pages, 1372 KiB  
Article
Using Acoustic Data Repositories to Study Vocal Responses to Playback in a Neotropical Songbird
by Pietra Oliveira Guimarães, Letícia Campos Guimarães, Renato Rodrigues Oliveira, Fernando Almeida and Pedro Diniz
Birds 2023, 4(1), 61-72; https://doi.org/10.3390/birds4010005 - 04 Feb 2023
Viewed by 2096
Abstract
Birds may alter song structure in response to territorial challenges to convey information about aggressive intent or fighting ability. Professional and amateur ornithologists upload daily many birdsong recordings into acoustic data repositories, usually scoring whether songs were recorded in response to a conspecific [...] Read more.
Birds may alter song structure in response to territorial challenges to convey information about aggressive intent or fighting ability. Professional and amateur ornithologists upload daily many birdsong recordings into acoustic data repositories, usually scoring whether songs were recorded in response to a conspecific playback or produced spontaneously. We analyzed recordings from these repositories to evaluate if song traits of Rufous-browed Peppershrikes (Cyclarhis gujanensis) vary between playback-elicited songs and spontaneous songs. For each recording after playback, we chose one spatially closer spontaneous recording to avoid geographic bias. Birds recorded after playback produced slightly longer songs than birds that were singing spontaneously. This result was accounted for by increases in the amount of sound and silence within a song after the playback instead of changes in the mean number or duration of elements. Playback did not alter song frequency parameters (bandwidth, minimum, mean, and maximum frequencies) or song rate. These results indicate that song duration might mediate aggressive interactions in Rufous-browed Peppershrikes. Even considering limitations such as unknown playback stimulus identity and possible pseudoreplication, acoustic data repositories give a unique yet unexplored opportunity to gather insights into the evolution of song flexibility during aggressive encounters. Full article
(This article belongs to the Special Issue Feature Papers of Birds 2022–2023)
Show Figures

Figure 1

15 pages, 5986 KiB  
Article
Status of the Pallas’s Gull Ichthyaetus ichthyaetus during Summer/Autumn in the Fairway Volga–Kama Reservoirs (East European Plain) in Russia
by Sergey Golubev
Birds 2023, 4(1), 46-60; https://doi.org/10.3390/birds4010004 - 31 Jan 2023
Viewed by 1191
Abstract
The Pallas’s Gull Ichthyaetus ichthyaetus is a fish-eating predator listed in the category of recovering species of the Red Book of the Russian Federation. The purpose of the research was to study the state of the Pallasʹs Gull in the fairway (navigable zone) [...] Read more.
The Pallas’s Gull Ichthyaetus ichthyaetus is a fish-eating predator listed in the category of recovering species of the Red Book of the Russian Federation. The purpose of the research was to study the state of the Pallasʹs Gull in the fairway (navigable zone) of the Volga–Kama reservoirs, in Russia and to assess their role in the current distribution of the species. In the summer and autumn of 2020–2022, at 11 reservoirs of the Volga and Kama rivers, counts of Pallasʹs Gulls were carried out from the bow deck of the R/V Akademik Topchiev. The transect length was 4633.5 km; the duration of observations was 364.3 h. A comprehensive bird count was applied in the direction of the vessel’s movement on transects with a fixed counting strip width of 200 m (100 m in each direction from the bow of the vessel). Birds were usually fixed on 30-min transects. The Pallas’s Gulls were found in 7 of the 11 reservoirs studied, and their status varied between common and very rare. The species was more abundant in the Gorky reservoir than in the Cheboksary, Kuibyshev, Saratov, and Nizhnekamsk reservoirs. The smallest abundance was recorded in the Volgograd and Rybinsk reservoirs. The Pallas’s Gull shows a steady annual presence on most reservoirs. The results indicate that in the Volga Basin, the range of Pallas’s Gull has expanded further north by more than 1000 km over the past 30 years from the species’ original areas of sustainable breeding in the North Caspian. Adult individuals of the Pallasʹs Gull (83.4% of the age composition of the population) play the main role in the dispersal. The most favorable clusters of the stable presence of the species were lake-shaped fragments of the Gorky and Kuibyshev reservoirs. On the territory of the East European Plain, the Volga–Kama reservoirs are important, if not decisive, in expanding the range of Pallas’s Gull to the north. Full article
(This article belongs to the Special Issue Feature Papers of Birds 2022–2023)
Show Figures

Figure 1

18 pages, 2759 KiB  
Article
Spatiotemporal Distribution of Photographic Records of Brazilian Birds Available in the WikiAves Citizen Science Database
by Dárius Pukenis Tubelis
Birds 2023, 4(1), 28-45; https://doi.org/10.3390/birds4010003 - 22 Jan 2023
Cited by 6 | Viewed by 1852
Abstract
About four million photographic records of Brazilian birds are deposited in the WikiAves database. The objective of this study was to examine the spatiotemporal distribution of photographic records available in this database. Searches were performed in the database in 2022. Record numbers produced [...] Read more.
About four million photographic records of Brazilian birds are deposited in the WikiAves database. The objective of this study was to examine the spatiotemporal distribution of photographic records available in this database. Searches were performed in the database in 2022. Record numbers produced by citizens were obtained by selecting states and municipalities in different periods. The annual record production in Brazil has increased substantially since 2009, reaching about 400,000 records per year in 2020–2021. Most records were obtained in the Sudeste and Sul geopolitical regions. Seasonal variations in record production in the Cerrado and the Atlantic Forest are comparable, with more records obtained in July–October. In Amazonia, a more substantial decrease in record production occurred between November and April. The monthly record production was more uniform in the Caatinga. When municipalities were compared, similar seasonal variation in record production was observed for four ecosystems (Amazonia, Atlantic Forest, Cerrado and Pampa). However, substantial differences were observed for municipalities in the Pantanal and the Caatinga. The results indicate that high human density, high individual income and the breeding season of birds are potential factors leading to high record production. On the other hand, heavy rainfall, flooding, remoteness and environmental harshness are pointed out as factors potentially leading to relatively fewer records. Further, this article discusses the implications of record availability for ornithological studies that use photographic records deposited in the WikiAves database. Full article
(This article belongs to the Special Issue Birds and People)
Show Figures

Figure 1

13 pages, 1056 KiB  
Article
Urban Birds Using Insects on Front Panels of Cars
by Jukka Jokimäki and Marja-Liisa Kaisanlahti-Jokimäki
Birds 2023, 4(1), 15-27; https://doi.org/10.3390/birds4010002 - 19 Jan 2023
Cited by 1 | Viewed by 2639
Abstract
Urbanization influences the food availability and quality for birds in many ways. Although a great amount of food for birds is provided incidentally or intentionally in urban areas, the quantity of insect-based food can be reduced in cities. We studied the role of [...] Read more.
Urbanization influences the food availability and quality for birds in many ways. Although a great amount of food for birds is provided incidentally or intentionally in urban areas, the quantity of insect-based food can be reduced in cities. We studied the role of one artificial food source, insects smashed on the front panels of cars, in Finland, and more specifically in the city of Rovaniemi, by conducting questionnaire research, searching for data from databases and performing a field study. Our results indicated that a total of seven bird species have been detected using insects on the front panels of cars in Finland. However, this behavior is not yet common since about 60% of responders to the questionnaire stated that this behavior is currently either rare or very rare. Most of the observations identified House Sparrows, followed by the White Wagtail or the Eurasian Jackdaw. Only a few observations identified the Eurasian Tree Sparrow, the Hooded Crow, the Great Tit and the Eurasian Magpie. The phenomenon was distributed quite widely across Finland, except in the case of the Eurasian Jackdaws, for which observations were restricted only to the southern part of the country. The first observation was made about the House Sparrow in 1971, followed by the White Wagtail (1975), Hooded Crow (1997), Eurasian Jackdaw (2006), Eurasian Tree Sparrow (2011), Eurasian Magpie (2019) and Great Tit (2022). The species using this food source are mainly sedentary urban exploiters, such as corvids and sparrows, that have been previously reported to have several different types of innovative behaviors. Most of the observations were conducted in urban parking sites of hypermarkets, and no observations were made in residential areas. Most of the foraging observations were made during the end phase of the breeding season, partly supporting the extra need for high-quality insect-based food for nestlings and fledglings. Our observations indicate that this behavior is not yet common and widespread among species. Full article
(This article belongs to the Special Issue Feature Papers of Birds 2022–2023)
Show Figures

Figure 1

14 pages, 1814 KiB  
Article
When to Return to Normal? Temporal Dynamics of Vigilance in Four Situations
by Claudia Mettke-Hofmann
Birds 2023, 4(1), 1-14; https://doi.org/10.3390/birds4010001 - 22 Dec 2022
Cited by 1 | Viewed by 1518
Abstract
Vigilance is an important behaviour to monitor the environment from detecting predators to tracking conspecifics. However, little is known about how vigilance changes over time either without disturbance (vigilance decrement) or after a change occurred. The time course of vigilance can indicate how [...] Read more.
Vigilance is an important behaviour to monitor the environment from detecting predators to tracking conspecifics. However, little is known about how vigilance changes over time either without disturbance (vigilance decrement) or after a change occurred. The time course of vigilance can indicate how animals perceive a situation and the potential mechanism used to deal with it. I investigated the time course of vigilance in Gouldian Finches in four situations (familiar environment, two changed environments–novel object at a neutral location (exploration trial) or above the feeder (neophobia trial), novel environment). The frequency of head movements was assessed in four consecutive 15-min blocks in same sex pairs with a high frequency generally seen as indicative of high vigilance. Vigilance decreased over time in the familiar situation indicating vigilance decrement with a similar time course in the exploration trial. Vigilance was consistently high in the neophobia trial and only returned to normal in the last block. Finally, vigilance plummeted in the novel environment and did not return to normal within an hour. Results suggest that perceived threats affected vigilance and that information gathering reduced uncertainty allowing vigilance to return to normal levels but with different time courses depending on the situation. Full article
(This article belongs to the Special Issue Feature Papers of Birds 2022–2023)
Show Figures

Figure 1

Previous Issue
Next Issue
Back to TopTop