Search results for " zoology"
showing 10 items of 2242 documents
Insect oviposition induces volatile emission in herbaceous plants that attracts egg parasitoid
2003
SUMMARYThe egg parasitoid Trissolcus basalis (Wollaston) (Hymenoptera:Scelionidae) responded to synomones emitted by leguminous plants induced by feeding and oviposition activity of the bug Nezara viridula (L.)(Heteroptera: Pentatomidae). This was shown by laboratory bioassays using a Y-tube olfactometer. Broad bean leaves (Vicia faba L.) damaged by feeding activity of N. viridula and on which host egg mass had been laid produced synomones that attracted T. basalis. By contrast,undamaged leaves or feeding-damaged leaves without eggs did not attract wasp females. French bean plants (Phaseolus vulgaris L.) also emitted attractive synomones when they were damaged by host feeding and carrying e…
Effect of weather conditions on somatic cell score in Sicilian Valle del Belice ewes
2010
Mastitis susceptibility of Valle del Belice ewes from the south of Sicily to temperature, humidity, precipitation, solar radiation, sun hours, air pressure, wind-speed and wind-direction measured by a public weather station was investigated using 65,848 test-day somatic cell score (SCS) records of 5,237 ewes. All weather parameters had an effect on SCS in a regression approach. Extreme values of maximum and minimum temperaturehumidity indices resulted in increased SCS. Higher precipitation, solar radiation and sun hours resulted in increased SCS, whereas higher air pressure and wind speed resulted in reduced SCS.
Forehead Patch Size Predicts the Outcome of Male–Male Competition in the Pied Flycatcher
2013
Males of many animal species express ornaments that affect their reproduction opportunities through male–male competition or female mate choice. Such ornaments can, for example, inform conspecifics about the fighting ability, condition or territory ownership of the bearer. Pied flycatcher (Ficedula hypoleuca) males have a conspicuous white forehead patch that varies greatly in size. We examined whether the white forehead patch is an intrasexually selected trait in a Finnish population. We artificially manipulated forehead patch size to represent two naturally occurring extremes and competed males against each other in the presence of a female. Males with a large forehead patch were more agg…
Phenotypic and genetic analysis of udder health using SCC in Valle del Belice dairy sheep
2005
Intramammary infections (IMI) are a complex of inflammatory diseases which are defined as an inflammation of the mammary gland resulting from the introduction and multiplication of pathogenic micro-organisms.
Camouflage in arid environments: the case of Sahara-Sahel desert rodents
2020
Deserts and semi-deserts, such as the Sahara-Sahel region in North Africa, are exposed environments with restricted vegetation coverage. Due to limited physical surface structures, these open areas provide a promising ecosystem to understand selection for crypsis. Here, we review knowledge on camouflage adaptation in the Sahara-Sahel rodent community, which represents one of the best documented cases of phenotype-environment convergence comprising a marked taxonomic diversity. Through their evolutionary history, several rodent species from the Sahara-Sahel have repeatedly evolved an accurate background matching against visually-guided predators. Top-down selection by predators is therefore …
Interpretation of gut microbiota data in the ‘eye of the beholder’: A commentary and re‐evaluation of data from ‘Impacts of radiation exposure on the…
2021
1.Evidence that exposure to environmental pollutants can alter the gut microbiota composition of wildlife includes studies of rodents exposed to radionuclides. 2.Antwis et al. (2021) used amplicon sequencing to characterise the gut microbiota of four species of rodent (Myodes glareolus, Apodemus agrarius, A. flavicollis and A. sylvaticus) inhabiting the Chernobyl Exclusion Zone (CEZ) to examine possible changes in gut bacteria (microbiota) and gut fungi (mycobiota) associated with exposure to radionuclides and whether the sample type (from caecum or faeces) affected the analysis. 3.The conclusions derived from the analyses of gut mycobiota are based on data that represent a mixture of inges…
Return of the Apex Predator : How Brown Trout (Salmo trutta) Re-Establishment Shapes an Ecosystem
2021
Re-establishment of a declined apex predator fish species in a lake ecosystem may have dramatic effects on other fish and plankton community already inhabiting the ecosystem. We studied mechanistically potential impacts of re-establishment of the brown trout (Salmo trutta) in the west-central European Lake Constance focusing on two commercially important fish species: whitefish and Eurasian perch. We compared simulation model outputs from two versions of an allometric trophic network model for Lake Constance, one with and one without the trout as the apex predator. The re-establishment of the declined brown trout reduced the perch population directly by predation and indirectly by increased…
Size-dependent aggression towards kin in a cannibalistic species.
2022
Abstract In juveniles extreme intraspecies aggression can seem counter-intuitive, as it might endanger their developmental goal of surviving until reproductive stage. Ultimately, aggression can be vital for survival, although the factors (e.g., genetic or environmental) leading to the expression and intensity of this behavior vary across taxa. Attacking (and sometimes killing) related individuals may reduce inclusive fitness; as a solution to this problem, some species exhibit kin discrimination and preferentially attack unrelated individuals. Here, we used both experimental and modeling approaches to consider how physical traits (e.g., size in relation to opponent) and genetic relatedness …
Nesting behaviour and description of mature larva of Lindenius albilabris (Fabricius, 1793) (Hymenoptera: Crabronidae)
2022
Nesting habits of the digger wasp Lindenius albilabris (Fabricius, 1793) at two localities in Poland were studied. The female hunts nymphs or adults of plant bugs Lygus rugulipennis Poppius, 1911 and L. pratensis (Linnaeus, 1758), depositing up to 10 individuals per cell, depending on their size. Nests are built in a wide variety of sandy habitats, on dirt roads, and in wastelands. The nest consists of a 10–12 cm long main burrow and one to three cells. Males are usually found on flowers of wild carrots Achillea millefolium, Daucus carota, Peucedanum oreoselinum, Pimpinella sp. and Tanacetum vulgare. The nest kleptoparasite Metopia argyrocephala was recorded in nests of this species. The ma…
Biometric characterisation and taxonomic considerations of european rabbit Oryctolagus cuniculus (Linnaeus 1758) in Sicily (Italy)
2014
In Sicilian Mediterranean ecosystems the European rabbit Oryctolagus cuniculus is a keystone species, very important for popular small game species and for ecological reasons. However, its spread across the island seems to have decreased and fragmented in recent times, but until now no accurate population management has been carried out due to the lack of ethological, ecological and taxonomic knowledge. A biometric analysis of European rabbit specimens from Sicily to widen current taxonomic knowledge was performed. In this paper, 7 body variables and 23 cranial variables of 166 and 120 individuals, respectively, were examined. Thereafter, the results were compared with biometric data from o…