Search results for "Habit"
showing 10 items of 1816 documents
Habitat Differences and Variability in the Lek Mating System of Black Grouse
1996
Spatially fixed territoriality has been regarded to be a general feature in lek mating systems. In the absence of territories, however, the nature of leks may change remarkably. We compared leks of black grouse in areas, where territoriality was governed by habitat characteristics. On ice-covered lakes, where the lekking ground was homogeneous and offered no landmarks by which the displaying males would be able to recognize territory boundaries, the male aggregations were mobile. 'Classical' leks on bogs, however, were stable. It also appeared that on mobile leks, as compared to stable leks, the opportunities for females to choose their mates were reduced. The distribution of mating success…
Behavioural responses of Eurasian treecreepers, Certhia familiaris, to competition with ants
1997
Competition for a specific resource that is essential for the survival of both the competitors may be intense even between very dissimilar taxa. However, the importance of the effects caused by such interspecific competition has seldom been emphasized. These effects can appear as differences in individual foraging behaviour during the breeding season, which can result in critical variation in fitness. In this study we examined the effects of wood ants (Formica rufa group) on the abundance of other invertebrates on tree trunks and on the foraging site selection of breeding Eurasian treecreepers, which use the same habitat as wood ants. Arthropods were scarcer on the trunks with ants present;…
Diversity and Community Structure of Opiinae (Hymenoptera: Braconidae) in the Forest Estate of Artikutza (Spain)
2011
ABSTRACT The present work analyses the diversity of Opiinae (Hymenoptera: Braconidae) in the forest of the Artikutza Estate, within the Natural Park, Penas de Aya, in the western Pyrenees. Specimens belonging to this subfamily were collected throughout two cycles and in two different habitats: mixed forest and beech forest. A total of 105 specimens, including 20 different species, were collected. Diversity and structure analysis indicated higher diversity for the beech forest habitat, although the community is composed of a few abundant species and many rare species. A relationship between the presence of Opiinae and an increase in temperature was also ascertained.
Exploitation competition between hole‐nesters ( Muscardinus avellanarius , Mammalia and Parus caeruleus , Aves) in Mediterranean woodlands
2005
Data from a long-term study (1993-2003) using artificial nest-boxes, were analysed to examine competition for nesting between blue tit Parus caeruleus and common dormouse Muscardinus avellanarius in Sicily. Occupation rates and the reproductive biology of the blue tit in sample woodlots outside the distribution area of the common dormouse were used as a control in sample areas where the two species were syntopic. A selection test showed that the two species, when living in syntopy, actively chose the small nest-boxes, thus overlapping in the use of the same spatial resource. The experimental exclusion of the common dormouse from nest-boxes caused an increase of blue tit occupation rate. Onc…
Otter Lutra lutra predation on farmed and free‐living salmonids in boreal freshwater habitats
2002
In this paper we aim to define whether fish farms or stocked trout streams substantially contribute to the diet of otters Lutra lutra living in freshwater habitats of Mid-Finland. Diet was assessed using spraint analysis. We especially focused on areas with fish farms and stocked trout Salmo trutta streams (salmonid-rich habitat) and used ‘normal’ (salmonid-poor) habitats as control. Frequency of salmonid remains in spraints was significantly higher in salmonid-rich habitats than elsewhere in all seasons, the difference increasing from summer to winter. In salmonid-rich habitats, however, salmonid consumption was not strongly seasonal. Data from spraint collection indicated a shift in activ…
Effects of ecological flooding on the temporal and spatial dynamics of carabid beetles (Coleoptera, Carabidae) and springtails (Collembola) in a pold…
2011
Within the scope of the Integrated Rhine Program an ecological flood gate and channel was inserted into the polder “Ingelheim” to enhance animal and plant diversity. In 2008, carabid beetles and springtails were collected, using pitfall traps, to measure the effects of ecological flooding and a strong precipitation event at a flood-disturbed and a dry location in this area. At both localities, xerophilic and mesophilic carabid beetle species were dominant throughout the study period. The total number of individuals of hygrophilic species was comparatively constant, while species number increased, partly due to the changed moisture conditions caused by ecological flooding and str…
Feeding ecology of the loggerhead turtle Caretta caretta in the western Mediterranean
2001
We studied the feeding ecology of juvenile loggerhead turtles Caretta caretta in the western Mediterranean based on the contents of the digestive tract of 54 turtles (range of CCL: 34–69 cm) seized in Barcelona (Spain) in 1991. Turtles had been captured in fishing trawls, but specific information about dates and localities is not available. Despite this limitation, we obtained interesting evidences about the foraging strategies of loggerheads, with potentially important conservation implications. We report 33 new taxa in the diet. Results indicated that western Mediterranean loggerheads feed in an opportunistic way. Numerically, fish made up the most important prey group, followed by pelagi…
<p><strong>Typification of the name <em>Galatella sorrentinoi </em>(Asteraceae)</strong></p>
2020
Tripolium sorrentinoi (Todaro 1858: 42) Raimondo & Greuter (2005: 59) (Asteraceae) is a species endemic to Sicily. In this island, it grows on badlands in the Palermo, Enna, Caltanissetta, and Agrigento Provinces, between the coast and the hinterland mountains. Its phytogeographical interest is remarkable because it occurs in selective habitats, where it is often the sole phanerogamic inhabitant. Due to its small population size and to a continuing decline of mature individuals, T. sorrentinoi was assessed as “Vulnerable” (VU) according to the IUCN criteria (Domina & Troia 2016).
A simple model relating habitat features to a diapause egg bank
2006
As a way to escape from adverse conditions, many zooplankton populations produce diapausing eggs that accumulate in the sediments and hatch when suitable environmental conditions are restored. While buried in the sediment, diapausing eggs may be affected by several processes (i.e., production, hatching, deterioration, and loss). We present a simple mathematical model for the dynamics of diapausing eggs in the sediment. We were mainly inspired by the model organism Brachionus plicatilis, a cyclical parthenogen rotifer, but the model is applicable to other zooplankters. Three diapausing egg categories are used as variables in our model: (1) healthy-looking eggs, assumed to represent the fract…
Leptocorticium gloeocystidiatum sp. nov. (Basidiomycota), a new corticioid fungus from Sicily, Italy
2014
A new corticioid species, Leptocorticium gloeocystidiatum is described from Sicily, Italy. It is characterized by a resupinate, buff-coloured basidiome and microscopically by the presence of filiform leptocystidia, gloeocystidia, dendrohyphidia, and small ellipsoid, smooth basidiospores, non-reacting in Melzer's reagent. The species is compared with closest relatives. A key to the accepted species of Leptocorticium is provided.