Birds, Volume 4, Issue 4 (December 2023) – 5 articles

Using satellite telemetry, it is possible to track long-distance migrant birds with high accuracy and greater spatial coverage. However, prior to 2014, less than 1% of bird species in India had been monitored using this technology. Between January and February 2022, we deployed leg-mounted solar GPS/GSM satellite transmitters to Common Cranes and Demoiselle Cranes (two each) to study home ranges, movement, migration patterns, and habitat use. We used 95% kernels to define the total home range size and 50% kernels to delimit the core areas. The winter habitat use was assessed using Generalized Linear Models (GLM). The average home range of Common Cranes and Demoiselle Cranes was estimated as 161.22 ± 172.08 km² and 971.40 ± 1023.57 km², respectively. During migration, Common Crane-1 and Common Crane-2 traveled an average of 471.19 ± 442.42 and 176.97 ± 24.82 km per day, and Demoiselle Crane-1 and Demoiselle Crane-2 covered an average daily distance of 168.10 ± 203.77 and 192.97 ± 250.72 km, respectively. Water bodies and croplands were the most important habitat variables influencing crane presence positively. In recent years, the share of food grain crops within the study area has declined from 43% in 1994–1995 to 36% in 2014–2015, while the share of cotton crops has doubled from 11% to 20%, indicating a probable cause of concern in the near future. Full article

In previous studies using eBird citizen data, bird abundance rankings followed a power law distribution. Our research delves into the “granular size” concept within these power laws, likening birds to firms. We identified 13 bird species as being the granular size, representing species with significant ecosystem impact, akin to major corporations in an economy. In particular, these species are urban, raising concerns about the eBird database’s sampling bias. Using the economic concept of granular size, we argue that the eBird database may be inherently unreliable. Full article

Lesser Flamingos Phoeniconaias minor regularly collide with power lines in South Africa. Attaching light-emitting markers to overhead wires seems to be an effective mitigation measure; however, the cost of these devices is prohibitive of large-scale installation. Spatial predictions about flamingo collision risk are thus important for achieving efficient and effective proactive mitigation. In this study, collision risk was defined as a combination of factors related to threat exposure. A habitat suitability index was developed according to changes in surface water occurrence and Chlorophyll-a concentrations, which proved accurate in predicting Lesser Flamingo occurrence. Habitat suitability, and three other species and threat exposure variables, were then used in logistic regression models predicting the occurrence of historic collisions. The most parsimonious model included habitat suitability and flight height. Flamingos were only at risk of collision with power lines when flying lower than 50 m and within 3 km from the water’s edge. High-risk power line sections were thus identified from 3 km buffers around waterbodies ranked according to habitat suitability, which significantly reduced the number of power line spans predicted for proactive marking. While our models indicated that aspects related to exposure were important for predicting flamingo power line collisions, aspects related to sensitivity (e.g., nocturnal behavior) must also guide the choice of mitigation. Full article

Although the ornithological history of southern Brazil has been amassed over the last 200 years, few attempts have been made to describe how species have accumulated. Furthermore, the collaboration of citizen scientists has considerably changed the way researchers analyze empirical data. Caprimulgidae (Nightjars and Nighthawks) species were used to illustrate how species have been recorded since the 1800s in Paraná State by comparing traditional and citizen science data. In addition, reports from both researchers and citizen scientists on the breeding biology of these caprimulgids have been verified. A literature review was conducted searching for the Caprimulgid species within the territory of Paraná. Regarding citizen science, records were obtained from four ornithological platforms. Overall, 14 species were detected within the state, 13 of which have been described in the literature, including 1 endemic to the Atlantic Forest and 3 threatened species. Citizen scientists detected all 13 taxa, in addition to one undocumented species that has never been recorded by researchers. There were 12 times more records on ornithological platforms in half of the sampling effort accumulated in studies, but most of them date from the last five years. Citizen scientists also visited 4.5 times more locations than researchers. Citizen scientists accumulated more records around September and November, and most (59%) records were from 2020–2022. Researchers mentioned species as early as 1820, while continuous studies only began during the 1980s; they concentrated their fieldwork mostly in September. Only one (2%) study sought to describe the breeding biology of a caprimulgid species, but there were 84 observations on ornithological platforms between 2004–2022 on their reproduction. Because of the evident mismatch between traditional and citizen science data due to a lack of congruence between their actions, it is suggested that ornithology in Paraná, as well as other Brazilian regions, would benefit the most if traditional and citizen scientists improved their networking communication to focus on common purposes instead of acting independently. Full article

Wildlife–aircraft collisions represent a safety and financial challenge, necessitating site-specific hazard assessments, which are generally based on species’ attributes and collision frequencies. However, for many bird species, collision probability and risk may not be distributed equally among individuals, with sex and age differences possible but rarely examined. We examine Australian Magpies, a resident, grassland species of bird in southeastern Australia frequently involved in collisions with aircraft at airports, and which can be sexed (adults) and aged. We compared collision rates recorded at Melbourne Airport, Victoria, Australia, with airside counts of magpies, recording, when observable, the sex and age of the birds. Adult females and males were similarly abundant at the airport (46.6% female), but females were struck relatively more frequently than males (78.1% female). Juvenile (first-year) magpies were struck more frequently than expected based on their representation in bird counts. We show an example of where some demographic groups within species represent higher hazard potential to aircraft than others, and management which manipulates demography of magpies at and near the airport (such as discouraging local breeding and targeted harassment/dispersal) may be fruitful. Full article