Search results for "Biological dispersal"
showing 10 items of 326 documents
Phylogeography of a Habitat Specialist with High Dispersal Capability: The Savi’s Warbler Locustella luscinioides
2012
In order to describe the influence of Pleistocene glaciations on the genetic structure and demography of a highly mobile, but specialized, passerine, the Savi's Warbler (Locustella luscinioides), mitochondrial DNA sequences (ND2) and microsatellites were analysed in c.330 individuals of 17 breeding and two wintering populations. Phylogenetic, population genetics and coalescent methods were used to describe the genetic structure, determine the timing of the major splits and model the demography of populations. Savi's Warblers split from its sister species c.8 million years ago and have two major haplotype groups that diverged in the early/middle Pleistocene. One of these clades originated in…
Disturbance-induced emigration: an overlooked mechanism that reduces metapopulation extinction risk.
2021
Emigration propensity (i.e., the tendency to leave undisturbed patches) is a key life-history trait of organisms in metapopulations with local extinctions and colonizations. Metapopulation models of dispersal evolution typically assume that patch disturbance kills all individuals within the patch, thus causing local extinction. However, individuals may instead be able to leave a patch when it is disturbed, either by fleeing before being killed or simply because the disturbance destroys the patch without causing mortality. This scenario may pertain to a wide range of organisms from horizontally transmitted symbionts, to aquatic insects inhabiting temporary ponds, to vertebrates living in fra…
Late Miocene turnover in the Spanish mammal record in relation to palaeoclimate and the Messinian Salinity Crisis
2006
Abstract The latest Miocene and earliest Pliocene is a period of marked changes in geography and climate in the circum-Mediterranean area. Its geographical situation gives Spain a key position, and its fossil mammal record reflects these important geographical and climatic changes particularly well. The Spanish mammal record shows a gradual change of composition towards the typical Pleistocene and recent fauna, marked by several extinction and dispersal events. These events have the effect that northern Eurasian elements increase, while taxa that locally go extinct may live on in tropical areas. Superposed on this large scale trend, there are some events of short lived incursions of animals…
Land invertebrates of Columbretes Islands : new species
2020
Este artículo se encuentra disponible en la siguiente URL: https://www.mdpi.com/2071-1050/13/4/1776 La fauna terrestre de invertebrados del archipiélago protegido de Columbretes es poco conocida. Además, los pocos estudios existentes se centran en su isla principal, Illa Grossa. Aquí presentamos el listado de espe-cies de invertebrados no registradas, hasta el momento, en el archipiélago, resultados obtenidos mediante una combinación de capturas con trampas de caída, avistamientos y recolecciones aleatorias realizadas tanto en Illa Grossa como en otros tres islotes de este archipiélago. Mediante el primer método se recolectaron un total de 14.830 especímenes entre 2008-2011. La mayor cantid…
Estimating the onset of dispersal in endangered Bonelli's Eagles Hieraaetus fasciatus tracked by satellite telemetry: a comparison between methods
2007
This project was funded by the Terra Natura Foundation. L.C. and P.L.-L. are supported by FPU grants of the Spanish Ministerio de Educacion y Ciencia (references AP2001-1444 and AP2005-0874, respectively).
Fluctuating asymmetry in bank vole populations (Rodentia, Arvicolinae) reflects stress caused by landscape fragmentation in the Mont-Saint-Michel Bay
2003
In intensively farmed, reclaimed areas (polders) of Mont-St-Michel Bay, France, bank voles (Clethrionomys glareolus) live in fragmented hedgerows, where populations are small and dispersal rates and genetic diversity are low. These small populations are likely to have been exposed to potential environmental and/or genetic stress. The sensitivity of development to stress can be measured by fluctuating asymmetry (FA). FA was calculated for three samples from a disturbed area and one sample from an adjacent, more connected and undisturbed landscape. Size FA was estimated from 16 measurements of the skull and teeth whilst shape asymmetry was estimated from the skull alone. Bank voles in fragmen…
PHENOLOGICAL ADAPTATION OF ANT-DISPERSED PLANTS TO SEASONAL VARIATION IN ANT ACTIVITY
2002
We studied a temperate plant community to examine whether the reproductive phenology of ant-dispersed plants is correlated with seasonal variation in seed dispersal activity of ants. We documented flowering and fruiting peak of 24 ant-dispersed and 251 non-ant-dispersed plant species. To characterize the activity of ants, we quantified the seasonal removal rates of greater celandine (Chelidonium majus) seeds. Ant-dispersed plants flowered on average 5.6 wk and fruited 7.1 wk earlier than those with other dispersal modes. This difference was not caused by variation in growth form or habitat. Mean fruiting peak of ant-dispersed plants was early July. Ant activity was especially high between M…
Linking seed dispersal and genetic structure of trees: a biogeographical approach
2009
Aim Natural and human-induced differences in frugivore assemblages can influence the seed dispersal distances of trees. An important issue in seed dispersal systems is to understand whether differences in seed dispersal distances also affect the genetic structure of mature trees. One possible approach to test for a relationship between seed dispersal and the genetic structure of mature trees is to compare the genetic structure of two closely related tree species between two biogeographical regions that differ in frugivore assemblages and seed dispersal distances. Previous studies on two Commiphora species revealed that Commiphora guillauminii in Madagascar has a much lower seed dispersal d…
Is the population genetic structure of complex life cycle parasites determined by the geographic range of the most motile host?
2010
Due to their particular way of life, dispersal of parasites is often mediated by their host's biology. Dispersal distance is relevant for parasites because high degree of dispersal leads to high gene flow, which counters the rate of parasite local adaptation in the host populations. Parasites with complex life cycles need to exploit sequentially more than one host species to complete their life cycle. Most trematode parasites have such complex life cycles involving invertebrate and vertebrate hosts. The spatial scales of invertebrate and vertebrate host populations are often different, which may decrease the probability that the parasite cycles locally in the intermediate host population. W…
Morphology and genetics reveal an intriguing pattern of differentiation at a very small geographic scale in a bird species, the forest thrush Turdus …
2014
12 pages; International audience; Mobile organisms are expected to show population differentiation only over fairly large geographical distances. However, there is growing evidence of discrepancy between dispersal potential and realized gene flow. Here we report an intriguing pattern of differentiation at a very small spatial scale in the forest thrush (Turdus lherminieri), a bird species endemic to the Lesser Antilles. Analysis of 331 individuals from 17 sampling sites distributed over three islands revealed a clear morphological and genetic differentiation between these islands isolated by 40-50 km. More surprisingly, we found that the phenotypic divergence between the two geographic zone…