The red-billed leiothrix (Leiothrix lutea): a new invasive species for Britain?

Invasive non-native species (INNS) are one of the major threats to global biodiversity. Climate change and garden bird-feeding may facilitate the establishment of INNS. The Red-billed Leiothrix Leiothrix lutea is a small woodland passerine, native to subtropical Asia, that is an INNS in several parts of the world, including Europe, following escapes from the aviculture trade. Recently, populations of Red-billed Leiothrix have established in Spain, Portugal, Italy and France. Previous studies have shown that much of Europe is suitable for the species, including southern Britain. The Red-billed Leiothrix has not previously been considered as at high risk of establishment in Britain, but we document recent records, including a cluster in southern England, suggesting that establishment may already be underway. We discuss the potential negative impacts of this invasive species on local ecosystems, and how a warming climate and garden bird-feeding might assist their establishment in temperate Europe. We also highlight the importance of improved recording to monitor the potential establishment of INNS, such as the Red-billed Leiothrix, in Britain

Conserving steppe-land birds under climate change: a gap analysis for the Eurasian Stone-curlew (Burhinus oedicnemus) in the Western Palearctic

Climate change is having dramatic impacts on the distribution of animals. Birds, and especially steppe-land birds, are particularly sensitive to climate change and identifying areas that are critical for their conservation is pivotal, as well as estimating the expected impact on these areas under different climate and land use change scenarios. In-situ climate refugia (areas suitable under both current and future climates) are especially valuable for the conservation of climate-sensitive species, and is therefore important to identify them and evaluate their coverage by protected areas. Via species distribution modelling, we aimed to identify in-situ climate refugia in the Western Palearctic for the Eurasian Stone-curlew Burhinus oedicnemus, an umbrella steppic species of conservation concern. We used a comprehensive dataset of occurrences in the breeding period to fine-tune a Maxent species distribution model and project it under three carbon emission scenarios of increasing severity for the year 2050. We then identified in-situ climate refugia and performed a gap analysis estimating the percentage of refugia falling within the network of currently protected areas. In all modelled future scenarios a northward expansion of suitable breeding habitats was predicted, and suitable areas had similar extents, with a slight increase of the overall suitability under more severe scenarios. According to our results, the Eurasian Stone-curlew has the potential to maintain viable populations in the Western Palearctic, even though dispersal limitations might hinder the colonization of newly suitable breeding areas. In-situ climate refugia were mainly identified outside protected areas, particularly in Northern Africa and the Middle East. Therefore, we advocate targeted actions in climate refugia to promote the conservation of this and other steppe-land species under global environmental change

Experimental nest cooling reveals dramatic effects of heatwaves on reproduction in a Mediterranean bird of prey

Future climatic scenarios forecast increases in average temperatures as well as in the frequency, duration, and intensity of extreme events, such as heatwaves. Whereas behavioral adjustments can buffer direct physiological and fitness costs of exposure to excessive temperature in wild animals, these may prove more difficult during specific life stages when vagility is reduced (e.g., early developmental stages). By means of a nest cooling experiment, we tested the effects of extreme temperatures on different stages of reproduction in a cavity-nesting Mediterranean bird of prey, the lesser kestrel (Falco naumanni), facing a recent increase in the frequency of heatwaves during its breeding season. Nest temperature in a group of nest boxes placed on roof terraces was reduced by shading them from direct sunlight in 2 consecutive years (2021 and 2022). We then compared hatching failure, mortality, and nestling morphology between shaded and non-shaded (control) nest boxes. Nest temperature in control nest boxes was on average 3.9 degrees C higher than in shaded ones during heatwaves, that is, spells of extreme air temperature (>37 degrees C for =2 consecutive days) which hit the study area during the nestling-rearing phase in both years. Hatching failure markedly increased with increasing nest temperature, rising above 50% when maximum nest temperatures exceeded 44 degrees C. Nestlings from control nest boxes showed higher mortality during heatwaves (55% vs. 10% in shaded nest boxes) and those that survived further showed impaired morphological growth (body mass and skeletal size). Hence, heatwaves occurring during the breeding period can have both strong lethal and sublethal impacts on different components of avian reproduction, from egg hatching to nestling growth. More broadly, these findings suggest that the projected future increases of summer temperatures and heatwave frequency in the Mediterranean basin and elsewhere in temperate areas may threaten the local persistence of even relatively warm-adapted species

Habitat use during post-pre-breeding period in a Rock Sparrow <em>Petronia petronia</em> population

Most studies focusing on Rock Sparrow populations concern their breeding biology. With this study, we aim to investigate the wintering habitat and social behaviour outside the breeding period. In the study area the species is present all year long, and, outside the breeding period, birds frequently gather together on flocks of different size (3-150 individuals), which are larger in the coldest months. The habitat types most used by the species were cereal fields with crops in their first stage of development (17.71% ± 4.72 Standard Deviation) and arable stubbles, both of them with bushes and trees on their boundaries (82.4%), which likely provide shelters from predators. The bird species most frequently associated with Rock Sparrow flocks were Tree Sparrow, Starling and Crested Lark. Holes in the roof tiles of the same abandoned buildings used for breeding were also used as night shelters. The average hours of leaving and returning to the shelters was strictly related to the photoperiod (rs = -0.9405; 0.8810).</jats:p

Modelling the potential spread of the Red-billed Leiothrix Leiothrix lutea in Italy

International audienc

Effects of human disturbance on detectability of non-breeding birds in urban green areas

Animals adapted to disturbed habitats have evolved multiple behavioural strategies, spanning from hiding to displacing to less disturbed microhabitats. Urban areas pose new evolutionary challenges since animals often need to deal with novel environmental conditions. In this context, urban parks may constitute biodiversity hotspots within the concrete jungle. Nonetheless, the recent increase in recreational activities in urban parks potentially puzzles the ability of urban-dwelling animals to exploit these environments. In this study, we evaluated the effect of human disturbance and other contextual variables on the activity patterns of four bird species commonly found in European urban parks, covering a wide range of ecological characteristics: the blackbird (Turdus merula), the hooded crow (Corvus cornix), the Eurasian robin (Erithacus rubecula), and the wood pigeon (Columba palumbus). We performed repeated counts of these bird species in six urban parks in northern Italy and we fitted Bayesian N-mixture models to estimate the relationship between detection probability and human disturbance (number of people present in the park), phenology (date and time of the day), and weather conditions (temperature and precipitation). For all the species but the blackbird, we found a negative relationship between the number of people present in the park and the detection probability of the focal species. We also found species-specific effects of both phenology and weather conditions on the detection probability. Our results suggest that urban dwelling species can finely modulate their activity patterns in response to the level of human disturbance, suggesting a possible key role of behavioural phenotypic plasticity. Furthermore, uncovering patterns of detectability of urban fauna can help in planning biodiversity monitoring and conservation, as it provides useful information to carry out surveys when the probability of detecting individuals is highest, optimising resource investments and reliability of biodiversity estimates

Projected dynamics of breeding habitat suitability for a steppe-land bird warrant anticipatory conservation actions

ABSTRACTUnderstanding spatial and temporal variations of habitat suitability is fundamental for species’ conservation under global change. Steppic species are particularly sensitive to anthropogenic change and have undergone large declines in the last decades. We aimed to describe current and future breeding habitat suitability for the Eurasian stone-curlew Burhinus oedicnemus, a steppic species of conservation concern, and to identify critical areas for its conservation. We collected 1628 presence records covering the period 1992-2016. We developed a species distribution model using a dynamic Maxent algorithm and a set of pseudo-absences with a spatial density weighted on a fixed kernel density estimated on the presences, to mitigate the potential sampling bias. We projected this model under a set of carbon emission, socioeconomic and land-use/land-cover scenarios for the years 2030, 2050, 2070 and 2090. Finally, we described the cell-wise and mean change of breeding habitat suitability through consecutive time intervals and identified the areas critical for the species’ conservation.All scenarios predicted a short-term northward shift of suitable areas, followed by a period of stability. We found no consistent trends in the mean change of breeding habitat suitability, and similar extents of suitable areas under current and future scenarios. Critical areas for the conservation of the species are mainly located in Northern Europe, Israel and parts of North Africa, the Iberian Peninsula and Italy. According to our results, the Eurasian stone-curlew has the potential to maintain viable populations in the Western Palearctic, but dispersal limitations might hinder the colonization of shifted suitable areas. Targeted conservation interventions in the critical areas are therefore recommended to secure the future of the species under global change.</jats:p

Data from: Trophic niche segregation in a guild of top predators within the Mediterranean basin.

Diet data used for the analyses of trophic niche partitioning among three species of owls living in sympatry across the Mediterranean Basin.  Location: Mediterranean biodiversity hotspot. Taxon: Northern long-eared owl (Asio otus), Tawny owl (Strix aluco), Eurasian eagle owl (Bubo bubo).</p