Diana Székely

Diversity and distribution of reptiles in Romania

Abstract The reptile fauna of Romania comprises 23 species, out of which 12 species reach here the limit of their geographic range. We compiled and updated a national database of the reptile species occurrences from a variety of sources including our own field surveys, personal communication from specialists, museum collections and the scientific literature. The occurrence records were georeferenced and stored in a geodatabase for additional analysis of their spatial patterns. The spatial analysis revealed a biased sampling effort concentrated in various protected areas, and deficient in the vast agricultural areas of the southern part of Romania. The patterns of species richness showed a higher number of species in the warmer and drier regions, and a relatively low number of species in the rest of the country. Our database provides a starting point for further analyses, and represents a reliable tool for drafting conservation plans.

Age and Body Size in Populations of Two Syntopic Spadefoot Toads (Genus Pelobates) at the Limit of Their Ranges

Abstract Age and size at sexual maturity are major life-history traits that affect growth rate and reproductive output. The differences in these life-history traits can be better assessed in syntopic populations of related species, where environmental variability in time and space is removed. The Spadefoot Toads (Pelobates spp.) are highly specialized burrowing and nocturnal species with a narrow ecological niche. We tested if age-related parameters are responsible for sexual size dimorphism and size differences in two syntopic populations from the Danube Delta Biosphere Reserve (Romania). The two populations differed significantly in size and body mass, and showed distinct sexual dimorphism, with females significantly larger in P. fuscus, and males slightly larger in P. syriacus. We also found differences in age structure: P. fuscus was on average 5.0 yr old, whereas P. syriacus was on average 7.4 yr old. Both species reached sexual maturity at a similar age. Different growth rates before sexual maturity and differences in energy allocation between growth and reproduction after sexual maturity are responsible for the differences in adult size between these syntopic populations. Our results suggest that growth allocation between species and sexes cannot be explained solely on the basis of age-related parameters.

SALINITY TOLERANCE IN PELOBATES FUSCUS (LAURENTI, 1768) TADPOLES (AMPHIBIA: PELOBATIDAE)

Abstract We investigated the effect of salinity on larval development and survival rate to metamorphosis in the common spadefoot toad Pelobates fuscus (Laurenti, 1768). Our hypothesis was that higher salinity would decrease tadpole survival rate and body size at metamorphosis, and delay metamorphosis. The response of the tadpoles was evaluated through an experimental design with three salinity treatments of 2, 4, and 8‰ compared to a control (deionized water). Survival varied across the treatments: neither of the tadpoles in 8‰ salinity treatment survived the experiment, nor achieved metamorphosis. Salinity levels of 2 and 4‰ had no significant influence on the mean time to metamorphosis, body mass and SVL at metamorphosis. Our results suggest that P. fuscus tadpoles have a tolerance threshold for brackish water up to 4‰, above which survival is impaired. Résumé Nous avons étudié l’effet de la salinité sur le développement larvaire et la survie à la métamorphose du Pélobate brun Pelobates fuscus (Laurenti, 1768). Notre hypothèse a été que en augmentant la salinité, le taux de survie des têtards et leurs dimensions à la métamorphose diminueraient et le temps nécessaire pour la métamorphose serait plus long. La réponse des têtards a été évaluée par un model expérimental avec trois traitements de salinité de 2, 4, et 8‰ par rapport à un témoin (eau déminéralisée). La survie des têtards a été différente à travers les traitements: aucun des têtards soumis au traitement de 8‰ de salinité n’a survit à l’expérience ou accompli sa métamorphose. Les niveaux de salinité de 2 et 4‰ n’ont pas influencé significativement le temps moyen à la métamorphose ou le poids corporel et les dimensions à la métamorphose. Nos résultats suggèrent que les têtards de P. fuscus ont un seuil de tolérance pour l’eau saumâtre jusqu’à 4‰, au dessus duquel la survie est compromise. REZUMAT În acest studiu am investigat efectul salinităţii asupra dezvoltării larvare şi a ratei de supravieţuire a larvelor până la metamorfoză la broasca de pământ brună Pelobates fuscus (Laurenti, 1768). Ipoteza testată a fost că, odată cu creşterea nivelului de salinitate, rata de supravieţuire a larvelor şi dimensiunile acestora la momentul metamorfozei vor descreşte, iar timpul necesar pentru metamorfoză va creşte. Reacţia mormolocilor a fost evaluată experimental în trei tratamente cu salinitate de 2, 4, şi 8 ‰ raportat la un control (apă deionizată). Supravieţuirea larvelor de P. fuscus a variat în cele trei tratamente faţă de control: nici unul dintre mormolocii din tratamentul de 8 ‰ nu a supravieţuit experimentului şi nici nu a ajuns la metamorfoză. Tratamentele de salinitate până la 4 ‰ nu au avut o influenţă semnificativă asupra timpului mediu până la metamorfoză, a greutăţii sau a dimensiunilor la momentul metamorfozei. Rezultatele noastre sugerează că larvele de P. fuscus tolerează ape salmastre cu salinitate de până la 4 ‰, neputând însă supravieţui dincolo de acest prag.

Out of the ground: two coexisting fossorial toad species differ in their emergence and movement patterns

Understanding the way species with similar niches can coexist is a challenge in ecology. The niche partitioning hypothesis has received much support, positing that species can exploit available resources in different ways. In the case of secretive species, behavioural mechanisms of partitioning are still poorly understood. This is especially true for fossorial frogs because individuals hide underground by day and are active only during the night. We investigated the nocturnal activity and tested the niche partitioning hypothesis in two syntopic fossorial spadefoot toads (Pelobates fuscus and Pelobates syriacus) by examining interspecific variation in emergence from the soil. We employed a night vision recording system combined with video tracking analyses in a replicated laboratory setting to quantify individual movement patterns, a procedure that has not been used until now to observe terrestrial amphibians. Most individuals appeared on the surface every night and returned to their original burrow (about 60% of the times), or dug a new one around morning. There was a large temporal overlap between the two species. However, P. syriacus was significantly more active than P. fuscus in terms of total distance covered and time spent moving, while P. fuscus individuals left their underground burrow more frequently than P. syriacus. Consequently, P. fuscus adopted more of a sit-and-wait behaviour compared to P. syriacus, and this could facilitate their coexistence. The use of night video tracking technologies offered the advantage of individually tracking these secretive organisms during their nocturnal activity period and getting fine-grained data to understand their movement patterns.

A new minute Pristimantis (Amphibia: Anura: Strabomantidae) from the Andes of southern Ecuador

We describe a new rainfrog species (Pristimantis), from the wetland complex Oña, Nabón, Saraguro and Yacuambi, in the Andes of southern Ecuador, at altitudes ranging between 3000–3400 m a.s.l. Pristimantis tiktik sp. nov. is a small frog, displaying sexual dimorphism (the males with dorsum of various shades of gray, brown, orange or green and a whitish or pinkish yellow venter; females with brownish gray or gray dorsum and a reticulated white and black venter), with SVL ranging between 19.7–20.4 mm in females (n = 3) and 16.1–18.4 mm in males (n = 6). The skin on dorsum is tuberculated, that on venter is coarsely areolate, dorsolateral folds are absent, tympanic membrane is absent but the tympanic annulus is evident, cranial crests are absent, discs on fingers just slightly expanded, heel is lacking enlarged tubercles, inner edge of tarsus is bearing a long fold, Toe V is slightly longer than Toe III and the iris coloration is bronze with fine black reticulations. The males have a large subgular vocal sac that extends onto the chest and vocal slits but lack nuptial pads. The unique advertisement call consists of long duration series of periodically repeated clicks: “tik”. Molecular analyses place the new species in the recently resurrected P. orestes group, as the sister species of the assemblage that contains P. bambu, P. mazar, P. simonbolivari and an undescribed species.

The impact of salinity on early developmental stages in two sympatric spadefoot toads and implications for amphibian conservation in coastal areas

Salinity tolerance is critical during the early ontogeny of amphibians, shaping future population size, health and dispersal in a certain area. We focused our research on two related anurans with similar ecological niches—Pelobates fuscus and P. syriacus—inhabiting the western Black Sea coast, at the limits of their ranges. We hypothesize that their differences in salinity tolerance are shaping the actual range limits in coastal areas, within the sympatry zone. We quantified experimentally the impact of salinity (range 0–9‰) during early ontogeny to ask if salinity can modulate their coexistence, by affecting differently reproductive success and fitness. Exposure to salinity from egg to developmental stage Gosner 25 caused mild to severe malformations and affected survival and size in both species, but the impact was lower in P. syriacus compared to P. fuscus when exposed to salt concentrations of 6‰. Embryos of either species did not survive the 9‰ salinity concentration. We expect that increases in salinization up to 6‰ could severely reduce the range of P. fuscus, but not P. syriacus, in coastal areas. These results are highly relevant for the conservation of P. fuscus, which is already declining across Europe.

A new species of Pristimantis from southern Ecuador (Anura, Craugastoridae)

Abstract A new species of Pristimantis is described from Reserva Buenaventura, southern Ecuador, at elevations between 878 and 1082 m. A molecular phylogeny based on nuclear and mitochondrial genes shows that the new species is closely related to Pristimantis phoxocephalus, Pristimantis riveti, and Pristimantis versicolor. The new species differs from them and other morphologically similar congeners in having a low W-shaped dermal ridge in the scapular region, a large conical tubercle on the upper eyelid and on the heel, a thin mid dorsal fold, and a longitudinal lateral fold starting behind the tympanic fold and extending along the anterior two thirds of the flank. The new species inhabits cloud forests in the Pacific slopes of the Andes.

Anfibios de un bosque seco tropical: Reserva Ecológica Arenillas, Ecuador

La Gestion Integrada de Plagas (GIP) es un enfoque ecosistemico para la produccion y proteccion de cultivos que combina diferentes estrategias para reducir al minimo el uso de pesticidas sin disminuir la produccion (FAO 2015). Las estrategias de GIP se han convertido en una solucion para la industria citricola espanola, la cual necesita responder a las nuevas legislaciones europeas y a las demandas de un mercado internacional y una sociedad que exigen habitos alimenticios mas sanos y sistemas de produccion con menor impacto en el medio ambiente (Urbaneja et al. 2015). El agroecosistema de citricos alberga un abundante y diverso complejo de enemigos naturales (EN), muchos de los cuales ejercen un control biologico (CB) eficaz sobre las diversas plagas existentes en este cultivo (Urbaneja et al. 2015). No es el caso para el pulgon Aphis spiraecola Patch. (Hemiptera: Aphididae) (Fig. 1A). Este pulgon es plaga clave en el cultivo de clementinos de la cuenca Mediterranea (Tena y Garcia-Mari 2011) donde infesta los brotes tiernos de primavera (Fig. 1B), causando importantes perdidas economicas todos los anos. Actualmente su CB no esta desarrollado y el control quimico no resulta del todo eficaz (Urbaneja et al. 2015). Los esfuerzos realizados en el CB de A. spiraecola en citricos se habian centrado en la introduccion y/o conservacion de parasitoides de pulgones, todos ellos sin exito. Los parasitoides de pulgones son himenopteros que depositan un huevo dentro del huesped, el cual se convertira en momia, y de donde emergera otro parasitoide adulto. Hasta la fecha se desconocian las causas de la baja eficacia de los parasitoides frente a este pulgon. Otro grupo de EN son los depredadores, los cuales pertenecen a grupos tan diversos como los coleopteros, dermapteros, dipteros y neuropteros (Fig. 1C y D). Muchos estudios han abordado el potencial de los depredadores de A. spiraecola en laboratorio pero su impacto directo sobre las colonias de A. spiraecola en campo no se ha documentado. En esta tesis se abordaron diferentes objetivos para disenar una estrategia de control biologico frente a A. spiraecola en clementinos: i) identificar las razones por las que se dan bajos niveles de parasitismo ii) determinar cuando y como los depredadores pueden controlar las poblaciones y finalmente iii) determinar si una cubierta de gramineas puede mejorar el CB de este pulgon en clementinos mediante la mejora en el establecimiento de sus depredadores. Gomez-Marco, F. 2016. Gestion integrada de Aphis spiraecola (Hemiptera: Aphididae) en clementino: mejora de su control biologico. Ecosistemas 25(2):114-118. Doi.: 10.7818/ECOS.2016.25-2.16.

Amphibia, Anura, Bufonidae, Rhaebo ecuadorensis Mueses-Cisneros, Cisneros-Heredia & McDiarmid, 2012, and Anura, Hylidae, Phyllomedusa tarsius (Cope, 1868): range extensions and first records for Zamora-Chinchipe province, Ecuador

We report the first provincial records for Rhaebo ecuadorensis Mueses-Cisneros, Cisneros-Heredia & McDiarmid, 2012, and Phyllomedusa tarsius (Cope, 1868) in Zamora-Chinchipe, southern Ecuador. The new locations are significant because they represent the southernmost records in Ecuador as well as the westernmost limits of the ranges of these two species.