273 research outputs found
Diferencias sexuales en jóvenes de Gorrión común (Passer domesticus)
Es van examinar 99 pardals juvenils postmortem. Els ocells es van agrupar segons el color de la gola: ocells amb una mica de gris, i ocells amb la gola blanca sense gens de gris. Una anàlisi anatòmica va revelar que el 2% dels mascles i el 5% de les femelles juvenils s'haurien sexat erròniament si s'haguessin sexat només d'acord amb l'absència/presència de gris a la gola. Es discuteix la vàlua d'aquest i altres caràcters de coloració per a la determinació del sexe en juvenils
Nuevos datos sobre el “grillo cascabel de plata” (Orthoptera, Gryllidae), un grillo olvidado y sometido a un alto riesgo de extinción en Europa occidental
10 pages, 1 figure, 1 table.[EN] Gryllodinus kerkennensis (Finot, 1893) presents a disjunct distribution in the Southern
part of the Western Palearctic from North Africa up to Central Asia inhabiting arid, semidesert
or desert land mostly associated with saline soils near water sources of lagoons or
river beds depressions. The species was not recorded in Western Europe (Iberian
Peninsula) since 1936 and up to now it is currently excluded from all red list books for
Orthopteran conservation. In this paper we report a few and localised populations of this
cricket in Castilla-La Mancha inhabiting sandy shores of hiper-saline lagoons. We also
provide information on its biometrics, phenology, ecology and behaviour including data
of all collection specimens of the Museo Nacional de Ciencias Naturales (MNCN).
Because of its audible and particular song, we propose campaigns of night listening points
to search for this species in other potential sites where it could be present. We believe that
this species may be subject to a high risk of extinction in the Iberian Peninsula, and thus
in the whole Western Europe. This is because of their restricted populations and the
fragility of its specific habitat. We propose an urgent integral protection and the inclusion
of the species in the lists of highly endangered invertebrate species.[ES] Gryllodinus kerkennensis (Finot, 1893) presenta una distribución disjunta a lo largo
de la franja meridional y occidental del Paleártico, desde África del Norte hasta Asia
Central, habitando zonas áridas, desiertos o semi-desiertos, principalmente asociado a
suelos salinos próximos a masas de agua de lagunas o depresiones de cuencas fluviales.
Esta especie no se registraba en Europa occidental (Península Ibérica) desde 1936 y en
la actualidad está excluida de todas las listas de libros rojos para la conservación de
Ortópteros. En este trabajo describimos varias poblaciones aisladas de este grillo en
Castilla-La Mancha en orillas arenosas de lagunas hipersalinas. También proporcionamos información sobre su biometría, fenología, ecología y conducta incluyendo datos
sobre la colección entera de especímenes depositados en el Museo Nacional de Ciencias
Naturales (MNCN). Debido a su canto audible y muy particular, proponemos campañas
de puntos nocturnos de escucha para rastrear la presencia de esta especie en otros posibles
lugares donde aún pudiera estar presente. Creemos que esta especie pudiera estar en
alto riesgo de extinción en la Península Ibérica, y por tanto en toda Europa Occidental
debido a lo localizado de sus poblaciones y a la fragilidad de su hábitat específico. Por
todo ello proponemos su protección integral y urgente debiéndose incluir en las listas de
especies de invertebrados altamente amenazados.This study has been funded thanks to projects: PAI-05-053
and PCI08-0130 from La Junta de Comunidades de Castilla-La
Mancha (JCCLM) and project CGL2005-05611-C02-02/BOS
from the Ministerio de Educación y Ciencia.Peer reviewe
Hierarchical genetic structure shaped by topography in a narrow-endemic montane grasshopper
[Background]: Understanding the underlying processes shaping spatial patterns of genetic structure in free-ranging
organisms is a central topic in evolutionary biology. Here, we aim to disentangle the relative importance of neutral
(i.e. genetic drift) and local adaptation (i.e. ecological divergence) processes in the evolution of spatial genetic structure of
the Morales grasshopper (Chorthippus saulcyi moralesi), a narrow-endemic taxon restricted to the Central Pyrenees. More
specifically, we analysed range-wide patterns of genetic structure and tested whether they were shaped by geography
(isolation-by-distance, IBD), topographic complexity and present and past habitat suitability models (isolation-byresistance,
IBR), and environmental dissimilarity (isolation-by-environment, IBE).[Results]: Different clustering analyses revealed a deep genetic structure that was best explained by IBR based on
topographic complexity. Our analyses did not reveal a significant role of IBE, a fact that may be due to low environmental
variation among populations and/or consequence of other ecological factors not considered in this study are involved in
local adaptation processes. IBR scenarios informed by current and past climate distribution models did not show either a
significant impact on genetic differentiation after controlling for the effects of topographic complexity, which
may indicate that they are not capturing well microhabitat structure in the present or the genetic signal left by
dispersal routes defined by habitat corridors in the past.[Conclusions]: Overall, these results indicate that spatial patterns of genetic variation in our study system are primarily
explained by neutral divergence and migration-drift equilibrium due to limited dispersal across abrupt reliefs, whereas
environmental variation or spatial heterogeneity in habitat suitability associated with the complex topography of the
region had no significant effect on genetic discontinuities after controlling for geography. Our study highlights the
importance of considering a comprehensive suite of potential isolating mechanisms and analytical approaches in order
to get robust inferences on the processes promoting genetic divergence of natural populations.VN was supported by a FPI pre-doctoral scholarship (BES-2012-053741) from Ministerio de Economía y Competitividad. JO was supported by Severo Ochoa (SEV-2012-0262) and Ramón y Cajal (RYC-2013-12501) research fellowships. This work received financial support from research grants CGL2011-25053 (Ministerio de Ciencia e Innovación and European Social Fund), POII10-0197-0167, PEII-2014-023-P (Junta de Comunidades de Castilla-La Mancha and European Social Fund) and UNCM08-1E-018 (European Regional Development Fund).We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI).Peer reviewe
Discordant patterns of genetic and phenotypic differentiation in five grasshopper species codistributed across a microreserve network
Conservation plans can be greatly improved when information on the evolutionary and demographic consequences of habitat fragmentation is available for several codistributed species. Here, we study spatial patterns of phenotypic and genetic variation among five grasshopper species that are codistributed across a network of microreserves but show remarkable differences in dispersal-related morphology (body size and wing length), degree of habitat specialization and extent of fragmentation of their respective habitats in the study region. In particular, we tested the hypothesis that species with preferences for highly fragmented microhabitats show stronger genetic and phenotypic structure than codistributed generalist taxa inhabiting a continuous matrix of suitable habitat. We also hypothesized a higher resemblance of spatial patterns of genetic and phenotypic variability among species that have experienced a higher degree of habitat fragmentation due to their more similar responses to the parallel large-scale destruction of their natural habitats. In partial agreement with our first hypothesis, we found that genetic structure, but not phenotypic differentiation, was higher in species linked to highly fragmented habitats. We did not find support for congruent patterns of phenotypic and genetic variability among any studied species, indicating that they show idiosyncratic evolutionary trajectories and distinctive demographic responses to habitat fragmentation across a common landscape. This suggests that conservation practices in networks of protected areas require detailed ecological and evolutionary information on target species to focus management efforts on those taxa that are more sensitive to the effects of habitat fragmentation.JO was supported by a Ramón y Cajal Fellowship (RYC-2013-12501) and a research contract funded by Severo Ochoa Program (SEV-2012-0262). VGN is supported by a Forschungskredit of the University of Zurich (FK-14-103). VN is supported by a FPI predoctoral fellowship from Ministerio de Economía y Competitividad. This work received financial support from grants CGL2011-25053 (Ministerio de Economía y Competitividad), PCI08-0130-3954 and POII10-0197-0167 (Junta de Comunidades de Castilla-La Mancha and European Social Fund) and UNCM08-1E-018 (European Regional Development Fund).Peer reviewe
Lensing and dynamics of ultracompact bosonic stars
Spherically symmetric bosonic stars are one of the few examples of gravitating solitons that are known to form dynamically, via a classical process of (incomplete) gravitational collapse. As stationary solutions of the Einstein-Klein-Gordon or the Einstein-Proca theory, bosonic stars may also become sufficiently compact to develop light rings and hence mimic, in principle, gravitational-wave observational signatures of black holes (BHs). In this paper, we discuss how these horizonless ultracompact objects (UCOs) are actually distinct from BHs, both phenomenologically and dynamically. In the electromagnetic channel, the light ring associated phenomenology reveals remarkable lensing patterns, quite distinct from a standard BH shadow, with an infinite number of Einstein rings accumulating in the vicinity of the light ring, both inside and outside the latter. The strong lensing region, moreover, can be considerably smaller than the shadow of a BH with a comparable mass. Dynamically, we investigate the fate of such UCOs under perturbations, via fully nonlinear numerical simulations and observe that, in all cases, they decay into a Schwarzschild BH within a time scale of O(M), where M is the mass of the bosonic star. Both these studies reinforce how difficult it is for horizonless UCOs to mimic BH phenomenology and dynamics, in all its aspects
- …