Avian haemosporidian diversity on Sardinia: a first general assessment for the Insular Mediterranean

The Western Palearctic is one of the most investigated regions for avian haemosporidian parasites (Haemoproteus, Plasmodium and Leucocytozoon), yet geographic gaps in our regional knowledge remain. Here, we report the first haemosporidian screening of the breeding birds from Sardinia (the second-largest Mediterranean Island and a biodiversity hotspot), and the first for the insular Mediterranean in general. We examined the occurrence of haemosporidians by amplifying their mtDNA cytb gene in 217 breeding birds, belonging to 32 species. The total prevalence of infected birds was 55.3%, and of the 116 haplotypes recovered, 84 were novel. Despite the high number of novel lineages, phylogenetic analysis did not highlight Sardinia-specific clades; instead, some Sardinian lineages were more closely related to lineages previously recovered from continental Europe. Host-parasite network analysis indicated a specialized host-parasite community. Binomial generalized linear models (GLMs), performed at the community level, suggested an elevational effect on haemosporidian occurrence probability (negative for Haemoproteus; positive for Leucocytozoon) likely due to differences in the abundance of insect vectors at different elevations. Furthermore, a GLM revealed that sedentary birds showed a higher probability of being infected by novel haplotypes and long-distance migrants showed a lower probability of novel haplotype infection. We hypothesize that the high diversity of haemosporidians is linked to the isolation of breeding bird populations on Sardinia. This study adds to the growing knowledge on haemosporidians lineage diversity and distribution in insular environments and presents new insights on potential host-parasite associations

Combining habitat requirements of endemic bird species and other ecosystem services may synergistically enhance conservation efforts

Biodiversity conservation and the optimisation of other ecosystem service delivery as a contribution to human well-being are often tackled as mutually alternative targets. Modern agriculture is a great challenge for the fulfilment of both. Here, we explore the potential benefits of integrating biodiversity conservation and the preservation of wider ecosystem services, considering the conservation of an endemic species (Moltoni's warbler Sylvia subalpina; Aves: Sylvidae) and soil erosion control (a final ecosystem service) in intensive vineyards in Italy. We modelled factors affecting warbler occurrence and abundance at 71 study plots by means of N-mixture models, and estimated soil erosion at the same plots by means of the Universal Soil Loss Equation. Shrub cover had positive effects on both warbler abundance and soil retention, whereas higher slopes promote warbler abundance as well as soil erosion. Creating shrub patches over sloping sites would be at the same time particularly suited for warblers and for soil retention. We simulated three alternative conservation strategies: exclusive focus on warbler conservation (1), exclusive focus on soil preservation (2), integration of the two targets (3). Strategies assumed the creation of 1.5-ha shrub patches over 5% of the total area covered by plots and targeted either at wildlife or soil conservation. The exclusive strategies would allow an increase of 105 individuals and the preservation of 783 tons ha−1 year−1, respectively. Each individual strategy would ensure benefits for the other target corresponding to 61–64% of the above totals. The integrated strategy would allow for the achievement of 91–93% of the benefits (96 warblers and 729 tons ha−1 year−1) of the individual strategies. The integration of the two approaches could provide important synergies, allowing to broaden the effects of conservation strategies, such as agri-environmental schemes that could be drawn from our results (and which are particularly urgent for intensive permanent crops)

Completing the genetic puzzle of the reed warbler complex: insights from Italy

Capsule: Analysis of mitochondrial DNA from reed warblers sampled in Italy reveals that they are most similar to the nominate race of European Reed Warbler Acrocephalus scirpaceus scirpaceus. Aim: To fill gaps in our knowledge of the distribution of European/African Reed Warblers Acrocephalus scirpaceus/baeticatus in the Mediterranean region through genetic analysis of populations from the key biogeographic areas of Sicily, Sardinia and mainland Italy. Methods: We assessed the genetic placement of Italian reed warbler populations within a comprehensive dataset of this species complex, by sampling these birds from principal peninsular and insular breeding populations (for a total of 17 samples) and by comparing their mitochondrial cyt b sequences with those available in GenBank-NCBI. Results: The final dataset included 171 cyt b sequences (763 base pair long). The analysis showed samples from Italy had a high similarity with the European Reed Warbler A. s. scirpaceus subspecies. This fills an important information gap in the phylogeography of the group. Conclusion: The genetic cohesion shown between Italian and other European populations may denote a structuring in at least three distinct refugia in the Western Palearctic: Iberia for A. baeticatus ambiguus, the Caucasus Mountains for A. s. fuscus, and both Italy and the Balkans for A. s. scirpaceus

Phylogeography of Lanius senator in its breeding range: conflicts between alpha taxonomy, subspecies distribution and genetics

Implementing efforts to understand biogeographic distribution patterns and taxonomic limits within animal groups is crucial for addressing several challenges of modern zoology. Although avian phylogeography has been extensively investigated within the Western Palearctic, several families, such as shrikes, still display unresolved or neglected biogeographic patterns both between and within species, thus requiring further investigations. The Woodchat Shrike (Lanius senator) is a long-distance migratory species that exhibits three morphologically well-recognizable subspecies, whose boundaries have never been phylogenetically investigated. Here, we aimed to define the phylogeographic structure of Lanius senator throughout its breeding range and assess the genetic coherence with respect to the phenotypically described subspecies. We assembled a collection of 34 samples mainly from breeding populations of each subspecies and analysed them using four mtDNA and two nuDNA markers. We did not find clear phylogenetic structure in nuclear Ornithine Decarboxylase (ODC) and Myoglobin intron 2 (MYO), but all the four mtDNA loci (i.e., ND2, COI, cytb and CR) highlighted two main haplogroups: one including both the nominate subspecies L. s. senator and L. s. badius and a second one consisting of L. s. niloticus (the easternmost part of its range). Surprisingly, individuals phenotypically assigned to L. s. niloticus from Israel were genetically assigned to the senator/badius haplogroup. Moreover, genetic distances between haplogroups showed intermediate values between inter-intraspecies diversity usually reported for Passerines. We estimated a divergence time at ca. 890 kya (554-1.259 kya HPD). Our findings showed a mismatch in subspecies assignment using morphology and genetic information and a marked differentiation between the eastern L. s. niloticus and all other L. senator populations sampled

No evidence of avian malaria occurrence in two Mediterranean endemic seabirds

In birds, pathogens and diseases, such as avian malaria, can have severe detrimental effects on individual fitness. Pathogen prevalence can vary across species and may differ between populations living in different localities, but screening can aid in our understanding of a disease’s distribution and parasite-host interactions. Although seabirds generally exhibit low avian malaria infection patterns, blood parasites of several species and populations have never been investigated in detail. Using molecular techniques, we screened for blood parasites in two Mediterranean seabirds, the Scopoli’s Shearwater Calonectris diomedea and the Mediterranean Storm Petrel Hydrobates pelagicus melitensis. In addition, we searched for and sampled potential vector insects at each seabird colony. DNA was extracted from blood samples (or whole specimens for vector insect species), and polymerase chain reaction was performed to assess the presence of Plasmodium, Haemoproteus, and Leucocytozoon, the most frequent infective protozoan genera. Our results showed no evidence of haemosporidians, either in the sampled species or in the vector insects. The low prevalence of parasites in these species could reflect the absence or rarity of the vector for transmission. Thus, extreme care must be taken when releasing individuals into the wild to avoid introducing infection into new seabird populations

Species interactions and climate change: How the disruption of species co-occurrence will impact on an avian forest guild

Interspecific interactions are crucial in determining species occurrence and community assembly. Understanding these interactions is thus essential for correctly predicting species' responses to climate change. We focussed on an avian forest guild of four hole-nesting species with differing sensitivities to climate that show a range of well-understood reciprocal interactions, including facilitation, competition and predation. We modelled the potential distributions of black woodpecker and boreal, tawny and Ural owl, and tested whether the spatial patterns of the more widespread species (excluding Ural owl) were shaped by interspecific interactions. We then modelled the potential future distributions of all four species, evaluating how the predicted changes will alter the overlap between the species' ranges, and hence the spatial outcomes of interactions. Forest cover/type and climate were important determinants of habitat suitability for all species. Field data analysed with N-mixture models revealed effects of interspecific interactions on current species abundance, especially in boreal owl (positive effects of black woodpecker, negative effects of tawny owl). Climate change will impact the assemblage both at species and guild levels, as the potential area of range overlap, relevant for species interactions, will change in both proportion and extent in the future. Boreal owl, the most climate-sensitive species in the guild, will retreat, and the range overlap with its main predator, tawny owl, will increase in the remaining suitable area: climate change will thus impact on boreal owl both directly and indirectly. Climate change will cause the geographical alteration or disruption of species interaction networks, with different consequences for the species belonging to the guild and a likely spatial increase of competition and/or intraguild predation. Our work shows significant interactions and important potential changes in the overlap of areas suitable for the interacting species, which reinforce the importance of including relevant biotic interactions in predictive climate change models for increasing forecast accuracy