Rato C, Marques V, Paracuellos M, Tortolero J, Nevado JC, Carretero MA (2021) Alborán Island, a small meeting point for three invasive lizards, whose geographic origin is uncovered by molecular analysis. BioInvasions Records 10(4): 977–990.
https://www.reabic.net/journals/bir/2021/4/BIR_2021_Rato_etal.pdf
Francisco J. Diego-Rasilla, John B. Phillips; Evidence for the use of a high-resolution magnetic map by a short-distance migrant, the Alpine newt (Ichthyosaura alpestris). J Exp Biol 1 July 2021; 224 (13): jeb238345. doi: https://doi.org/10.1242/jeb.238345
Newts can use spatial variation in the magnetic field (MF) to derive geographic position, but it is unclear how they detect the ‘spatial signal’, which, over the distances that newts move in a day, is an order of magnitude lower than temporal variation in the MF. Previous work has shown that newts take map readings using their light-dependent magnetic compass to align a magnetite-based ‘map detector’ relative to the MF. In this study, time of day, location and light exposure (required by the magnetic compass) were varied to determine when newts obtain map information. Newts were displaced from breeding ponds without access to route-based cues to sites where they were held and/or tested under diffuse natural illumination. We found that: (1) newts held overnight at the testing site exhibited accurate homing orientation, but not if transported to the testing site on the day of testing; (2) newts held overnight under diffuse lighting at a ‘false testing site’ and then tested at a site located in a different direction from their home pond oriented in the home direction from the holding site, not from the site where they were tested; and (3) newts held overnight in total darkness (except for light exposure for specific periods) only exhibited homing orientation the following day if exposed to diffuse illumination during the preceding evening twilight in the ambient MF. These findings demonstrate that, to determine the home direction, newts require access to light and the ambient MF during evening twilight when temporal variation in the MF is minimal.
Diego-Rasilla, F.J., Luengo, R.M. Magnetic compass orientation in common midwife toad tadpoles, Alytes obstetricans (Anura, Alytidae). J Ethol (2020). https://doi.org/10.1007/s10164-020-00653-3
We provide the first evidence for y-axis magnetic compass orientation in Alytes obstetricans. Evidence for wavelengthdependent effect of light on magnetic compass orientation is also shown. In the first series of experiments, two groups of tadpoles were tested shortly after being collected from a pond with a natural shoreline and a clearly defined y-axis under two different lighting conditions (full-spectrum and long-wavelength light). Magnetic bearings from tadpoles tested under full-spectrum natural skylight displayed bimodal distribution along an axis that coincided with the magnetic direction of the y-axis in their home pond, while those tested under long-wavelength light failed to exhibit a consistent overall direction of orientation relative to the magnetic field, although a subset of tadpoles exhibited magnetic compass orientation that was rotated about 90° counter-clockwise of the magnetic direction of the y-axis in their home pond. In the second series of experiments, tadpoles were collected from a watering trough without a defined y-axis, trained to learn the direction of the y-axis in tanks with an artificial shore at one end and tested under full-spectrum natural skylight. Tadpoles from the two trained groups showed bimodal magnetic compass orientation along the shore–deep water magnetic axis of their respective training tanks. The present findings widen the number of species with y-axis magnetic compass orientation to include Alytidae, a family of primitive semiterrestrial frogs.
Santos, Joana L.; Žagar, Anamarija; Drašler, Katarina; Rato, Catarina; Ayres, César; Harris, D. James; Carretero, Miguel A.; Salvi, Daniele: ‘Phylogeographic evidence for multiple long-distance introductions of the common wall lizard associated with human trade and transport’, Amphibia-Reptilia, 2018, DOI: https://doi.org/10.1163/15685381-20181040
The common wall lizard has been widely introduced across Europe and overseas. We investigated the origin of putatively introduced Podarcis muralis populations from two southern Europe localities: (i) Ljubljana (Slovenia), where uncommon phenotypes were observed near the railway tracks and (ii) the port of Vigo (Spain), where the species was recently found 150 km far from its previously known range. We compared cytochrome-b mtDNA sequences of lizards from these populations with published sequences across the native range. Our results support the allochthonous status and multiple, long-distance origins in both populations. In Ljubljana, results support two different origins, Serbia and Italy. In Vigo, at least two separate origins are inferred, from western and eastern France. Such results confirm that human-mediated transport is promoting biological invasion and lineage admixture in this species. Solid knowledge of the origin and invasion pathways, as well as population monitoring, is crucial for management strategies to be successful.
Silva-Rocha I. et al. (2018) Herpetological History of the Balearic Islands: When Aliens Conquered These Islands and What to Do Next. In: Queiroz A., Pooley S. (eds) Histories of Bioinvasions in the Mediterranean. Environmental History, vol 8. Springer, Cham. https://doi.org/10.1007/978-3-319-74986-0_5
Balearic herpetofauna represents a paradigmatic case of multiple biological invasions within the Mediterranean Basin, with a much higher number of alien amphibians (i.e. frogs and toads) and reptiles (i.e. lizards, snakes and turtles/tortoises) than native. The paleogeography of the Balearic Islands, located on Western Mediterranean between Spain and Sardinia, is complex, comprehending an ancient split from the continent during the late Miocene and Pleistocene climatic fluctuations connecting and disconnecting islands from one another (but not them to the continent) that eventually re-shaped the archipelago’s biota. The archipelago has been also influenced by humans since the Neolithic, being a cross-road for alien biota between North Africa and Southern Europe, which caused range regressions and extinctions in the native herpetofauna, nowadays restricted to one amphibian and two reptiles. During the last century, tourism development, the pet trade, and cargo transport of ornamental plants have produced a new wave of biological invasions. Recently introduced snakes are of particular concern, since the effect of predation may seriously threaten the remaining native reptiles in the main islands and endemic subspecies in surrounding islets. Balearic people have a negative social perception of such snakes, mainly due to the lack of familiarity with snakes among islanders but also to the herpetophobic attitude of many Mediterranean cultures. Here we review the herpetological invasions in the Balearic Archipelago and their impacts. We further discuss the on-going management actions on alien reptiles in this archipelago, namely the control of invasive snakes in Ibiza involving monitoring, trapping, environmental education and promotion of social participation.
