Search results for "evolutionary"
showing 10 items of 4392 documents
Pigmentation polymorphism in the invasive amphipod Dikerogammarus villosus : some insights into its maintenance
2004
Dikerogammarus villosus, a freshwater invasive amphipod, exhibits conspicuous pigmentation polymorphism. This polymorphism is documented in two recently colonized areas, the Saand Moselle rivers (north-eastern France), and some of the mechanisms by which pigmentation polymorphism can arise and be maintained are addressed. Body size, reproductive status, fecundity and mate choice are compared among morphs of D. villosus in field samples collected in summer 2001. Body size and female gonad developmental stage were comparable among the different morphs, suggesting that polymorphism is not the result of changes in pigmentation with age or moult- cycle. Fecundity and reproductive status (paired …
Elaboración de modelos de la distribución de la tórtola europea (Streptopelia turtur L. 1758) en el sureste de la península ibérica
2021
The European turtle dove population and breeding range has declined sharply in Spain. This study reanalyses data from the Atlas of Breeding Birds in Alicante (SE Spain), aiming to identify the main variables related to its occurrence and abundance. We used hierarchical partitioning analysis to identify important environmental variables associated with natural vegetation, farming, hydrological web, anthropic presence, climate, and topography. Analysis combining the most explicative variables of each group identified the mixture of pines and scrubland in the semiarid areas and the length of unpaved roads as the most important variables with a positive effect on occurrence, while herbaceous cr…
Disturbance-grazer-vegetation interactions maintain habitat diversity in mountain pasture-woodlands
2017
Low-intensity livestock grazing is a widespread management tool in order to maintain habitat diversity in mountain pasture-woodlands for nature conservation purposes. Historical photographs indicate that forest disturbance significantly contributed to forest-grassland mosaic pattern formation. Disturbance grazer interactions are however poorly understood and the effects of logging or windthrow are rarely considered in management plans. Moreover, disturbance-grazer interactions are crucial for the maintenance of open habitats in the upcoming "rewilding" approach of nature conservation. We aimed to understand the effects of forest gap creation by the breakdown of senile trees or by single-tre…
Emigration speed and the production of sexuals in colonies of the ant Temnothorax crassispinus under high and low levels of disturbance
2015
A nest relocation is costly for social insects, and involves hazards. Emigrations were studied in Temnothorax crassispinus ant colonies, which inhabit ephemeral nest sites, and which frequently change their nests. In a laboratory experiment, ant colonies from one group were forced to change their nest sites 10 times over a ca. 3-month period, whilst colonies from the second group were forced to adopt this practice twice (on the beginning of May, and in the second half of July). Colonies of the ant from both the groups reduced their total emigration duration. However, the duration of the transport phase remained unchanged. In the case of colonies with higher level of disturbance, there was n…
Sandbar shark aggregation in the central Mediterranean Sea and potential effects of tourism
2021
An aggregation of sandbar sharks Carcharhinus plumbeus occurs every summer around the remote uninhabited islet of Lampione (Pelagie Islands Marine Protected Area, south-western Mediterranean Sea), attracting an increasing number of tourists for a shark watching experience. Despite the ecological and socio-economic importance of this rare occurrence in Mediterranean waters, there is a lack of scientific data and lack of information as to the potential impact of tourist activities on the presence and behaviour of this shark species. Using baited underwater videos, this study provides the first assessment of this shark aggregation, as well as a preliminary evaluation of the potential effects t…
Psallus thomashenryi sp. n. and Psallus lucanicus from Turkey (Hemiptera, Heteroptera, Miridae)
2018
Psallus (Psallus) thomashenryisp. n.(Hemiptera: Heteroptera: Miridae: Phylinae: Phylini: Phylina) is described from southern Anatolia, Turkey. Illustrations of the dorsal habitus and male genitalia are provided. Its habitus is similar to other uniformly orange species of the subgenus Psallus Fieber, 1858, particularlyP.asthenicusSeidenstücker, 1966 from which it can be easily distinguished by the combination of extremely small size (2.3 mm in both sexes) and different morphology of the vesica. Psallus (Psallus) lucanicus Wagner, 1968 is recorded for the first time from Turkey. Psallus (Psallus) aurora (Mulsant & Rey, 1852) is removed from the list of Turkish fauna based on a reevalu…
A new genus and nine new species of Eugnomini (Coleoptera, Curculionidae) from New Caledonia
2016
Abstract The genus Rasilinus gen. n. is described (type species Rasilinus tchambicus sp. n.). Nine new species: Rasilinus bicolor sp. n., Rasilinus bifurcatus sp. n., Rasilinus bimaculatus sp. n., Rasilinus grandidens sp. n., Rasilinus longulus sp. n., Rasilinus subgemellus sp. n., Rasilinus subnodulus sp. n., Rasilinus tchambicus sp. n., Rasilinus virgatus sp. n. are described from New Caledonia. Illustrations of the external morphology, male and female terminalia, dorsal habitus colour photographs of the adults, key to species and distribution map of the new genus Rasilinus are provided.
Iridescent (angle-dependent reflectance) properties of dorsal coloration in Podarcis muralis (Laurenti, 1768)
2016
Iridescence is a visual property of those surfaces that change in colour with viewing angle. Iridescence has been rarely reported in reptiles, but some snakes and lizards show this type of coloration. Here we study the effect of different angles of light incidence and observation on the spectrophotometrically assessed reflectance of dorsal coloration in the lizard Podarcis muralis. The results demonstrate clear angle dependence of several colour parameters. In particular, different angles of light incidence and observation result in changes in hue of more than 30 nm. This suggests that lizard dorsal coloration may be perceived, depending on viewing geometry, as being of different colours by…
A new genus and species of Cylapinae from Namibia (Hemiptera: Heteroptera: Miridae)
2016
Abstract A new genus and species, Linnavuorifulvius cheroti gen. et sp. nov., is described on the basis of specimens collected in Namibia. A dorsal habitus picture, pretarsal structure and genitalia illustrations of the new species are presented. The key to Afrotropical genera of the tribe Fulviini is given.
A new species of the Genus Hemiophthalmocoris from the Oriental Region (Hemiptera: Heteroptera: Miridae: Cylapinae).
2016
Abstract This paper provides the second report of the Cylapinae genus Hemiophthalmocoris Poppius, 1912—H. raunoi sp. nov. outside the Afrotropical Region (Malaysia: Sabah). Scanning electron micrographs of selected structures of Hemiophthalmocoris lugubris Poppius, 1912 are presented. A photograph of the adult of H. raunoi sp. nov. and H. sulawesicus Gorczyca & Cherot, 2002 are given. Illustrations of the male genitalia and dorsal habitus drawing of H. raunoi sp. nov. are provided.