Bee diversity in fragmented areas of Volcano Etna (Sicily, Italy) at different degrees of anthropic disturbance (Hymenoptera: Apoidea, Anthophila)

The present three-year study traces the diversity of four bee communities in fragmented pedemontane areas of Volcano Etna (Catania province, Sicily) near the Metropolitan City of Catania, under different land management regimes. The selected areas comprise two different urban parks within Catania (Parco Gioeni and Parco degli Ulivi), a Nature Reserve (Complesso Immacolatelle e Micio Conti, San Gregorio di Catania), and an agroecosystem (a citrus orchard, Aci Catena). Previous data obtained from a well-investigated area (Leucatia, north of Catania) have been used as a control for bee diversity for this study. The results include an outline of bee species richness, data on the composition of bee communities, and seasonal patterns, using several diversity indexes. The study of bee diversity shows a total of 163 species, arranged in five families. The four investigated locations include 104 species arranged in four families: Andrenidae (20 species), Halictidae (15 species), Megachilidae (31 species), and Apidae (38 species); with a similar number of species (102) recorded in the control site (Leucatia). The study highlights strong seasonal variations of bee communities in all investigated sites, with differentiated seasonal patterns, whose compositions are affected mainly by forage sources, suitable nesting sites, as well as human activities. The data obtained provide a rough but basilar framework to assess management strategies to maintain adequate levels of bee diversity, especially for those areas with moderate to high environmental fragmentation. Our findings highlight the importance of season-long sampling of bee population factors if used as indicators in ecological studies.

Breeding record of Black-headed Ibis Threskiornis melanocephalus (Aves: Threskiornithidae) at Mavoor wetland, Kozhikode District, Kerala, India

Black-headed Ibis Threskiornis melanocephalus is a nomadic and medium sized waterbird foraging in shallow water habitats and is listed under Near-Threatened category of IUCN. Though it has a widespread distribution within Kerala, little is known about their breeding sites and their ecology. In Kerala, only three nesting sites were reported so far. Present study found an additional nesting site in Mavoor wetland, which is the first record in Kozhikode district and fourth site for Kerala.

Nest aggregations of wild bees and apoid wasps in urban pavements: a street life to be promoted in urban planning

In the last 10 years, knowledges of wild bees and apoid wasps community dynamics have gained interest in urban ecology focusing on the availability of floral resources in cities. Although understudied, the urban environment impacts the conditions of their nesting sites. Recent observations in the Brussels-Capital Region (Belgium) showed that urban pavements can be a novel nesting opportunity for Hymenoptera ground-nesting species such as wild bees and apoid wasps. Here, using citizen science, we investigated the richness of ground-nesting species living under urban pavements, the preferences of the sidewalk joint size related to ground-nesting species size and for sidewalk type or for soils texture under the pavements on the nesting site selection. A total of 22 species belonging to 10 Hymenoptera families of wild bees and digger wasps with their associated kleptoparasites were identified on 89 sites in Brussels. Sandstone setts or concrete slabs with an unbound joint size around 1 cm were found to be best suitable urban pavements for the ground-nesting species. The soil texture under the pavement was highly sandy among our samples. Finally, we also suggest engineering management guidelines to support bee and wasp species nesting under urban pavement in highly urbanized areas. Such observations pave the way for much research in the field of urban ecology to conceive multifunctional pavement promoting biodiversity.

Causes of the dieback of littoral stands in an overpopulated water-bird reserve: Role of eutrophication, fish and geese

European fishponds can serve as refuges for water birds if the fish stocks are limited, but the effects of other ecological factors on their ecological stability are rarely considered. The aim of this study is to determine the causes of marked dieback of littoral stands dominated by Typha angustifolia L. in a hypertrophic fishpond that is also a valuable water bird reserve. A field study and two experiments were conducted in order to separate the effects of mineral nutrient availability, redox conditions, fish and water birds. The physico-chemical characteristics of the water and sediments confirmed hypertrophic conditions in the fishpond, but a mesocosm experiment did not indicate it had a negative effect on plant growth. On the other hand, a field enclosure experiment showed that in sparse stands, unfenced parts had a significantly smaller shoot density than fenced parts. This was attributed to grazing by greylag geese (Anser anser L.). In addition, damage to belowground parts of plants were ascribed to large individuals of albeit a few large common carp (Cyprinus carpio L.). This study highlights a conservation dilemma as large numbers of geese destroy littoral stands in fishpond nature reserves, which then become unsuitable nesting sites for other species of water birds.

Shift in demographic structure and increased reproductive activity of loggerhead turtles in the French Mediterranean Sea revealed by long-term monitoring

Climate-induced environmental changes are profoundly impacting marine ecosystems and altering species distribution worldwide. Migratory organisms, including sea turtles, are expected to be particularly sensitive to these variations. Here, we studied changes in the size structure and reproductive activity of loggerhead turtles in the French Mediterranean over 30 years. Overall, there was a significant increase in the size of observed loggerheads between 1990 and 2020. However, this increase was only significant during the breeding/nesting season (May to September) and was driven by the increased presence of adults. Furthermore, nesting activity along the French coast was detected in 2002 for the first time in more than 50 years, and has become frequent after 2014, with nests discovered every year. The number of eggs laid as well as incubation duration and success varied among sites but fell within the range reported at established Mediterranean nesting sites. These observations, along with recent reports of breeding activity and evidence of significant sea surface warming, suggest that the north-western Mediterranean basin has become increasingly suitable to loggerhead turtles. We postulate that this range expansion is the result of climate change and propose that emerging nesting activity in France should be closely monitored and guarded against human activities.

Satellite Tracking of Post-nesting Green Sea Turtles (Chelonia mydas) From Ras Baridi, Red Sea

Identifying migratory pathways and linking nesting sites to foraging areas is essential for effective conservation management of migratory species, such as marine turtles. Post-nesting marine turtles disperse from their nesting sites to multiple foraging areas located from a few to hundreds of kilometers away. Over a six-year period 16 female green turtles (Chelonia mydas) were equipped with satellite transmitters between October and December of five nesting seasons to determine their migratory routes from their nesting area at five contiguous beaches at Ras Baridi, Saudi Arabia, to their foraging areas. All foraging areas for these turtles were located in shallow coastal areas or in shallow areas around offshore islands within the Red Sea basin. The majority (n = 12) migrated through the shallow (<200 m) water along the coastal margin to reach foraging areas located to the North (n = 4) and South (n = 12) of the nesting site. Four turtles crossed the deep trough of the Red Sea during their journeys. Ten of the 16 turtles migrated to foraging areas within the territorial waters of Saudi Arabia. The other six turtles migrated to foraging areas in Egypt (n = 4) and Eritrea (n = 2). These 16 turtles traveled between 130 and 1749 km from their nesting site to foraging areas located in the northern, middle and southern parts of the Red Sea. Because these turtles utilized foraging areas in at least three countries (Saudi Arabia, Egypt, and Eritrea) and one passed through the territorial waters of Sudan, conservation and management of green turtles in the Red Sea requires multinational cooperation to address anthropogenic threats in the region.

Effectiveness of using nest boxes as a form of bird protection after building modernization

Modernization of urban buildings can decrease the availability of nesting sites in buildings, leading to sudden decreases in the density of avifauna. In this study, we investigated the use of nest boxes as a bird conservation measure after buildings were thermally modernized. In a 10 ha experimental area we mounted five types of nest boxes of different sizes and dimensions (a total of 132). Nest boxes were dedicated to species that lost access to their previous nesting sites. All species associated with the buildings significantly declined or disappeared. In the first year after the modernization, the House Sparrow (Passer domesticus) decreased by 66% compared with the period before the modernization, Eurasian Jackdaw (Corvus monedula) by 68%, Common Starling (Sturnus vulgaris) by 70%, and Common Swift (Apus apus) by 100%. In the first two years after the modernization, the birds nested only in nest boxes. Five years of monitoring showed that using nest boxes as compensation for bird nesting sites lost during the renovation of buildings can cause a population to recover to ca. 50% of its original level. To optimize deployments of nest boxes, wildlife managers should consider target species’ preferences for the dimensions and placement of boxes and limit the time boxes are used if a species prefers nesting outside nest-boxes, but in buildings (e. g. the House Sparrow) and does not require additional support.

We are what we eat, plus some per mill: Using stable isotopes to estimate diet composition in Gyps vultures over space and time.

1. Dietary studies in birds of prey involve direct observation and examination of food remains at resting and nesting sites. Although these methods accurately identify diet in raptors, they are time-consuming, resource-intensive, and associated with biases from the feeding ecology of raptors like Gyps vultures. Our study set out to estimate diet composition in Gyps vultures informed by stable isotopes that provide a good representation of assimilated diet from local systems. 2. We hypothesized that differences in Gyps vulture diet composition is a function of sampling location, and that these vultures move between Serengeti National Park and Selous Game Reserve protected areas to forage. We also, theorised that grazing ungulates are the principal items in Gyps vulture diet. 3. Through combined linear and Bayesian modelling, diet-derived from 13C in Gyps vultures consisted of grazing herbivores across sites, with those in Serengeti National Park consuming higher proportions of grazing herbivores (> 87%). 13C differences in vulture feather subsets did not indicate shifts in vulture diet and combined with blood 13C, vultures fed largely on grazers for ~159 days before they were sampled. Similarly, 15N values indicated Gyps vultures fed largely on herbivores. 34S ratios separated where vultures fed when the two sites were compared. 34S variation in vultures across sites resulted from baseline differences in plant 34S values, though it is not possible to match 34S to specific locations. 4. Our findings highlight the relevance of repeated sampling that considers tissues with varying isotopic turnover and emerging Bayesian techniques for dietary studies using stable isotopes. Findings also suggested limited vulture movement between the two local systems. However, more sampling coupled with telemetry is required to fully comprehend this observation and its implications to Gyps vulture ecology and conservation.

INFLUENCE OF RECREATIONAL LOAD ON ORNITOFAUNA OF THE CITY OF VORONEZH

In this work, we determined the number and systematic affiliation of the most common bird species of the Voronezh upland oak forest in the territories exposed to anthropogenic impact. Field studies were carried out from 2019 to 2020 on the territory of the Voronezh upland oak forest. At the sites selected for the survey, a route counting of birds by voices was carried out. The species composition of the avifauna was supplemented by an analysis of information about the habitat of birds and their nesting sites in areas with constant recreational impact. At the selected sites, birds were counted by voices (mating song). From the results of counts in the studied areas, one can see the diversity of the species composition of the avifauna during the reproductive period. Analysis of the data obtained makes it possible to determine the ecological belonging of the species and compare the quantitative indicators of the birds encountered.