Dr. Thomas Hertach

The current distribution patterns of many Mediterranean species are often a consequence of large and impactful past geoclimatic events, such as the Messinian Salinity Crisis (MSC) and the Quaternary glacial cycles. Cicadas are flying insects with poor dispersal ability, which have experienced intense local differentiation in the Mediterranean, where the genus Tettigettalna has surfaced as a biogeographic model. The genus includes 10 species with species-specific calling songs but identical morphology. All Tettigettalna species are restricted to Southern Iberia, with the exception of T. estrellae (northwest Iberia), the widespread T. argentata (mainly Iberia, France and Italy), and T. afroamissa (Morocco). With an expanded genetic dataset involving nuclear (EF1α) and mitochondrial (5′ and 3′ COI and ATP) loci, we reconstructed the phylogeny of the genus and estimated divergence dates for Tettigettalna species under a Bayesian framework. Phylogeny with the new mitochondrial dataset was in agreement with previous studies, whereas the nuclear EF1α supported T. josei and T. afroamissa as monophyletic clades but lacked resolution to resolve the remaining taxa. Some sister taxa share mitochondrial haplotypes, hinting for incomplete lineage sorting. Estimates of divergence time settled T. josei as the earliest diverging lineage, likely as a pre- or early-MSC event. As for the origin of T. afroamissa in Morocco, though time estimates could not entirely rule out post-MSC dispersal, the most likely scenario points to isolation of African Tettigettalna after the reopening of the strait of Gibraltar. The Pleistocene glaciations that followed likely impacted on the diversification of the remaining species of the genus in southern Iberia refugia.

Habitat anthropization is a major driver of global biodiversity decline. Although most species are negatively affected, some benefit from anthropogenic habitat modifications by showing intriguing life-history responses. For instance, increased recruitment through higher allocation to reproduction or improved performance during early-life stages could compensate for reduced adult survival, corresponding to "compensatory recruitment". To date, evidence of compensatory recruitment in response to habitat modification is restricted to plants, limiting understanding of its importance as a response to global change. We used the yellow-bellied toad (Bombina variegata), an amphibian occupying a broad range of natural and anthropogenic habitats, as a model species to test for and to quantify compensatory recruitment. Using an exceptional capture–recapture dataset composed of 21,714 individuals from 67 populations across Europe, we showed that adult survival was lower, lifespan was shorter, and actuarial senescence was higher in anthropogenic habitats, especially those affected by intense human activities. Increased recruitment in anthropogenic habitats fully offset reductions in adult survival, with the consequence that population growth rate in both habitat types was similar. Our findings indicate that compensatory recruitment allows toad populations to remain viable in human-dominated habitats and might facilitate the persistence of other animal populations in such environments.

Der Goldauer Bergsturz von 1806 gilt als zweitgrösste Naturkatastrophe auf Schweizer Boden in historischer Zeit. Er hinterliess eine Sukzessionslandschaft von 6.5 km² Fläche mit zahlreichen Pionierlebensräumen. Diese wertvollen Lebensräume wurden aber über die Jahrzehnte und Jahrhunderte kontinuierlich seltener. Mit ihnen geht eine einzigartige Pflanzen- und Tierwelt verloren, die das Bergsturzgebiet besiedeln konnte. Zum Schutz der Habitate wurden neben Naturwaldreservaten auch Sonderwaldreservate eingerichtet. Auf diesen Flächen werden die Lebensräume seit 2010 durch forstliche Eingriffe wieder offener und lichtdurchfluteter. Davon profitieren sollen Orchideenarten, aber auch Insekten und Vögel. Nach elf Jahren mit Eingriffen zeigen sich bei den Zielarten wie dem Frauenschuh positive Reaktionen.

Parmi les dix espèces de cigales indigènes, huit figurent dans la Liste rouge suisse selon les critères proposés par l’UICN. Cette famille de grands insectes, essentiellement constituée d'espèces rares et sténoèces vivant dans les zones de transition entre forêts et milieux ouverts à climat chaud et sec, est évaluée pour la première fois. Les cigales sont principalement menacées par la disparition des milieux de transition due soit à la déprise agricole, soit à l’exploitation intensive des herbages et à la suppression des structures.

According to the IUCN criteria, eight of the ten native species of cicada are on the Swiss Red List. It is the first time that this family of large, predominantly rare and stenoecious insects living in climatically favoured transition areas between forest and open land has been evaluated. They are especially threatened by the disappearance of transitional environments due either to agricultural abandonment, or to the intensive exploitation of grasslands and the removal of structures.

Integrative taxonomy combines different data sources as a way to detect separately evolving metapopulation lineages or species. This method is applied to cicada populations found in northern Sardinia, based on acoustic, morphological and ecological data. Thereby, the genus Tibicina turned out to be more diverse than previously expected. Besides the anticipated Tibicina corsica corsica and T. nigronervosa, both scientifically described from the neighbouring island of Corsica, two poorly or previously unknown species have been discovered. Tibicina longisyllaba sp. nov. is here described as new. Tibicina corsica s.l. forms a small species complex where syllable periods of the song – the movement cycle of the acoustic organs – are specific without overlaps. Some coloration and hair cover characters, as well as the shape of the song apparatus, are not diagnostic on their own, but highly significant between species. Species occur sympatrically, parapatrically or allopatrically and prefer specific habitats from grassland to closed forests. All four Tibicina taxa are endemic to parts of Sardinia or to the Corso-Sardinian archipelago. The new findings are important for biodiversity conservation and public awareness. The loud, strident calling songs dominate the summer sounds of the islands. The group could form a showcase with respect to biogeography, phylogeny, speciation and sound production.

Von den zehn einheimischen Singzikadenarten stehen gemäss IUCN-Kriterien acht auf der Roten Liste der Schweiz. Damit wird diese Grossinsektenfamilie aus vorwiegend seltenen und stenöken Bewohnern von klimatisch begünstigten Übergangsbereichen zwischen Wald und Offenland erstmals bewertet. Besonders bedroht sind sie durch das Verschwinden von Übergangslebensräumen, entweder durch Rückzug der Landwirtschaft oder durch intensive Grünlandnutzung und Strukturbereinigung.

According to the IUCN criteria, eight of the ten native species of cicada are on the Swiss Red List. It is the first time that this family of large, predominantly rare and stenoecious insects living in climatically favoured transition areas between forest and open land has been evaluated. They are especially threatened by the disappearance of transitional environments due either to agricultural abandonment, or to the intensive exploitation of grasslands and the removal of structures.