Our data allow hypothesizing that the Iberian Peninsula might harbor the ancestral population of CMTVs that could have spread into the rest of Europe. In addition, we found that climate warming could be triggering the CMTV outbreaks, supporting its endemic status in the Iberian Peninsula. Leer más.
Phillips, J.B., Diego-Rasilla, F.J. The amphibian magnetic sense(s). J Comp Physiol A (2022). https://doi.org/10.1007/s00359-022-01584-9
La percepción del campo magnético terrestre es el menos conocido de los principales sistemas sensoriales, a pesar de ser prácticamente omnipresente en los animales y de gran interés para los investigadores en diferentes campos, desde la ecología del comportamiento hasta la física cuántica.
El uso de estímulos magnéticos es más conocido en aves migratorias, peces y tortugas marinas, pero gran parte de nuestra comprensión actual de las propiedades funcionales de la magnetoreception en vertebrados proviene de las investigaciones realizadas con anfibios.
En los anfibios se ha demostrado la presencia de una brújula magnética dependiente de la luz, un segundo mecanismo no dependiente de la luz, que involucra partículas de magnetita y/o maghemita, y una interacción entre estos dos mecanismos de magnetorrecepción que sustenta su capacidad para utilizar un mapa magnético en la orientación hacia los medios acuáticos donde se reproducen. Además, el uso de mapas magnéticos en los desplazamientos de corta distancia llevados a cabo por los anfibios supone para estos animales mayores demandas en los mecanismos subyacentes de detección, procesamiento y memoria sensorial que los mecanismos comparables utilizados por animales que se desplazan largas distancias como aves migratorias y tortugas marinas.
En este artículo se analizan pormenorizadamente todos estos aspectos, destacando que el papel de los estímulos magnéticos en el comportamiento espacial y la percepción sensorial de los anfibios tiene importantes implicaciones en la comprensión del comportamiento, la ecología y la neurofisiología, así como en la gestión de las poblaciones de este importante grupo de vertebrados.
Our results show a strong climatic niche overlap between D. pictus and targeted species in the Iberian Peninsula, including endemic Discoglossus species. Future projections of climatic change suggest that climatic suitability will increase for all species, both inside and outside the Natura 2000 network, with the only exception being a moderate and widespread decrease for Pelodytes punctatus. However, these positive trends are reversed within Natura 2000 sites where most species are explicitly targeted, jeopardizing the effectiveness of protected areas in a long-distance dispersal scenario. Leer más.
The new Namibian material is recovered as a sister species to A. donveae, from which it differs mostly by the colour of the iris (copper versus black) and dorsal colouration. Material from the first elevational gradient of the escarpment in Benguela Province, Angola was found to be more closely related to A. bogerti than A. wulfhaackei. The differences between these two species are more subtle, although the new species exhibits higher mid-body scale rows (79.5 versus 74.8), different dorsal colouration and supranasal scales always in contact (versus 57% in contact). Leer más.
Caballero-Díaz, C., Sánchez-Montes, G., Gómez, I., Díaz-Zúñiga, A., & Martínez-Solano, Í. (2022). Artificialwater bodies as amphibian breeding sites: the case of the common midwife toad (Alytes obstetricans) in central Spain, Amphibia-Reptilia (published online ahead of print 2022). doi: https://doi.org/10.1163/15685381-bja10115
Natural breeding sites for amphibians are decreasing in quantity and quality in temperate regions, resulting in local extinctions and increasing population fragmentation. Artificial water bodies (e.g., water tanks or cattle troughs) can represent suitable reproductive habitats for some amphibians, but demographic data are required to assess this assumption. We evaluated the role of artificial water bodies in the persistence of a species of population concern, the common midwife toad, Alytes obstetricans (Laurenti, 1768), at local and regional scales. We surveyed 275 water bodies to characterize the distribution of the species and detected 63 breeding populations of A. obstetricans where we estimated larval abundance. In addition, we monitored two populations for three consecutive breeding seasons using capture-mark-recapture methods based on photo-identification, assessing abundance, breeding success and the use of space of adult individuals captured on multiple occasions. Our results show that artificial sites are preferentially used as breeding sites in the region compared to natural aquatic habitats, providing key habitat for the species and hosting much larger numbers and densities of larvae than natural sites. At local scale, populations of A. obstetricans in artificial sites were abundant and characterized by high male breeding success. However, adults are spatially aggregated around breeding sites, with small home ranges, implying high vulnerability to population fragmentation. Our results suggest artificial breeding sites can sustain viable populations of A. obstetricans, provided measures promoting connectivity among breeding nuclei are considered.
