Assessing rates of parasite coinfection and spatiotemporal strain variation via metabarcoding: insights for the conservation of European Turtle Doves Streptopelia turtur

Understanding the frequency, spatiotemporal dynamics and impacts of parasite coinfections is fundamental to developing control measures and predicting disease impacts. The European turtle dove (Streptopelia turtur) is one of Europe’s most threatened bird species. High prevalence of infection by the protozoan parasite Trichomonas gallinae has previously been identified, but the role of this and other coinfecting parasites in turtle dove declines remains unclear. Using a high-throughput sequencing approach, we identified seven strains of T. gallinae, including two novel strains, from ITS1/5.8S/ITS2 ribosomal sequences in turtle doves on breeding and wintering grounds, with further intra-strain variation and four novel sub-types revealed by the iron-hydrogenase gene. High spatiotemporal turnover was observed in T. gallinae strain composition, and infection was prevalent in all populations (89–100%). Coinfection by multiple Trichomonas strains was rarer than expected (1% observed compared to 38.6% expected), suggesting either within-host competition, or high mortality of coinfected individuals. In contrast, coinfection by multiple haemosporidians was common (43%), as was coinfection by haemosporidians and T. gallinae (90%), with positive associations between strains of T. gallinae and Leucocytozoon suggesting a mechanism such as parasite-induced immune modulation. We found no evidence for negative associations between coinfections and host body condition. We suggest that longitudinal studies involving the recapture and investigation of infection status of individuals over their lifespan are crucial to understand the epidemiology of coinfections in natural populations.

The European Turtle Dove in the ecotone between woodland and farmland: multi-scale habitat associations and implications for the design of management interventions

The European Turtle Dove (turtle dove) is globally threatened after undergoing a sustained and generalised decline across its breeding range, with habitat loss suggested as the main driver. Here, we reviewed the scientific literature on habitat associations across its European breeding range, in relation to distribution, breeding numbers, nesting substrates, food and foraging habitats, to identify optimal habitat management measures. Large-scale distribution seemed related to the availability, but not dominance, of woodland landscapes; abundance was generally higher in woodland than on farmland. However, abundance in woodland increased with additional structural diversity and proximity to farmland, and abundance on farmland increased with greater availability of non-farmland features. Nesting occurred most frequently on trees (secondarily on bushes) but we found geographical differences in the type of nesting substrate, with thorny bushes being used more frequently in the north, and open canopy trees in the south. Turtle doves fed on a wide spectrum of seeds with a predominance of wild, particularly early-flowering, plants; but we could not identify a single plant species whose abundance determined turtle dove numbers. Across the distribution range, a shift from wild to cultivated seeds occurred as the season progressed. However, interventions should favour the availability and access to wild seeds. Efficient management interventions depend on the dominant habitat; overall, interventions should seek to augment landscape heterogeneity by increasing the mixing of farmland and woodland. Combined forestry and agricultural policies must provide the right conditions for ecotone species like the Turtle dove.

Prevalence of Antibodies to Toxoplasma gondii in Different Wild Bird Species Admitted to Rehabilitation Centres in Portugal

Toxoplasma gondii is a worldwide zoonotic parasite. According to the “One Health” approach, studies on toxoplasmosis are essential since it affects humans and domestic and wild animals. In the present study, antibodies to T. gondii were determined in serum samples from 263 wild birds located in five wildlife rehabilitation centres in mainland Portugal by using the modified agglutination test (MAT) with a cut-off titre of 20. An overall seroprevalence of 36.5% (95% confidence interval [CI]: 30.7–42.6) was observed. For the first time, antibodies to T. gondii were detected in some avian species, including pallid swift (Apus pallidus) (33.3%), black-backed gull (Larus fuscus) (39.3%), European turtle-dove (Streptopelia turtur) (100%), bee-eater (Merops apiaster) (50.0%), carrion crow (Corvus corone) (33.3%), and Egyptian vulture (Neophron percnopterus) (100%), which expands the list of intermediate hosts of T. gondii. A lower seroprevalence was found in juvenile birds (31.9%) compared to adults (48.7%) (p = 0.016). The central region of Portugal was considered a risk factor for T. gondii infection in wild birds (odds ratio: 3.61; 95% CI: 1.09–11.91). This pioneer study calls attention to the need for further studies, to provide a clearer understanding of T. gondii epidemiology in Portugal, because it reflects wide dispersion of T. gondii oocysts in the environment.

Modelling European turtle dove (Streptopelia turtur L. 1758) distribution in the south eastern Iberian Peninsula

The European turtle dove population and breeding range has declined sharply in Spain. This study reanalyses data from the Atlas of Breeding Birds in Alicante (SE Spain), aiming to identify the main variables related to its occurrence and abundance. We used hierarchical partitioning analysis to identify important environmental variables associated with natural vegetation, farming, hydrological web, anthropic presence, climate, and topography. Analysis combining the most explicative variables of each group identified the mixture of pines and scrubland in the semiarid areas and the length of unpaved roads as the most important variables with a positive effect on occurrence, while herbaceous crops and scrublands in dry ombrotype climate areas had the most important negative effect. Abundance was related only to the availability of water points. We discuss the implications of these findings for habitat management in conservation of this species.

The genome sequence of the European turtle dove, Streptopelia turtur Linnaeus 1758

We present a genome assembly from an individual female Streptopelia turtur (the European turtle dove; Chordata; Aves; Columbidae). The genome sequence is 1.18 gigabases in span. The majority of the assembly is scaffolded into 35 chromosomal pseudomolecules, with the W and Z sex chromosomes assembled.

Tree characteristics, microhabitat and edge effect in plantations govern European Turtle-dove Streptopelia turtur nest habitat selection at the edge of Sahara: implications for conservation of a vulnerable species

Summary Tree characteristics, microhabitat, and human presence were measured around nest trees (n = 92) and non-nest trees (n = 92) to identify the best predictors of the European Turtle-dove Streptopelia turtur nest occurrence in date palm plantations of the Biskra region (Algeria). Nest occurrence was (i) positively influenced by the height of trees and that of the herbaceous layer, and (ii) quadratically affected by diameter at breast height (DBH), the cover of trees, the cover of the herbaceous vegetation, and the distance to the edge of date palm plantation. Variation partitioning analysis revealed that the pure effect of tree physical characteristics (tree height and DBH) was robust in explaining the occurrence of Turtle Dove nests (adj. R2 = 0.52, P = 0.001). For an efficient management of this Saharan population, special attention should be paid in the short term to keeping high date palm trees while ensuring, in the medium and long term, the presence of different-sized palm tree classes at each exploitation. There is no doubt that date palm plantations of Biskra are of paramount importance because they offer good opportunities for consolidating and improving the knowledge on this threatened species and other species at the Sahara edge.