Search results for "Parus"
showing 10 items of 134 documents
Disappearance rates of old nest material from tree cavities : an experimental study
2013
Numerous forest organisms critically depend on availability of tree cavities. Some birds and rodents fill their cavities with bulky nests, which – if not removed – could accumulate and render cavities unusable, as recorded in nest-box studies. Data from earlier studies indicate that old nests can disappear from tree cavities so fast that practically no remnants are detectable the following spring. Rapid decomposition of nests in situ, augmented by physical removal of nest material by the cavity-users have been proposed as possible causative mechanisms. We tested these hypotheses in cavities used by tits (Parus major L., Poecile palustris L.) in the Białowieża National Park (E Poland). To mi…
Avian Clock gene polymorphism: evidence for a latitudinal cline in allele frequencies
2007
In comparison with most animal behaviours, circadian rhythms have a well-characterized molecular genetic basis. Detailed studies of circadian clock genes in 'model' organisms provide a foundation for interpreting the functional and evolutionary significance of polymorphic circadian clock genes found within free-living animal populations. Here, we describe allelic variation in a region of the avian Clock orthologue which encodes a functionally significant polyglutamine repeat (ClkpolyQcds), within free-living populations of two passerine birds, the migratory bluethroat (Luscinia svecica) and the predominantly nonmigratory blue tit (Cyanistes caeruleus). Multiple ClkpolyQcds alleles were foun…
Isolation and characterization of a fish F-type lectin from gilt head bream (Sparus aurata) serum.
2007
A novel fucose-binding lectin, designated SauFBP32, was purified by affinity chromatography on fucose-agarose, from the serum of the gilt head bream Sparus aurata. Electrophoretic mobility of the subunit revealed apparent molecular weights of 35 and 30 kDa under reducing and non-reducing conditions, respectively. Size exclusion analysis suggests that the native lectin is a monomer under the selected experimental conditions. Agglutinating activity towards rabbit erythrocytes was not significantly modified by addition of calcium or EDTA; activity was optimal at 37 degrees C, retained partial activity by treatment at 70 degrees C, and was fully inactivated at 90 degrees C. On western blot anal…
Response of captive seabass and seabream as behavioural indicator in aquaculture
2010
Welfare of cultivate fish at high-density represents an important concern for modern aquaculture. The behaviour of European seabass (Dicentrarchus labrax) and seabream (Sparus aurata) reared in cages was studied in a fish farm of northern Sardinia (Italy) in autumn 2006 to test whether captive condition had an effect on the movement patterns of these two species.Video images recorded before, during and after the manual feeding distribution allowed us to collect data on different behaviours of captive fish. Thus, behaviours indicating the position of fish in the water column, swimming direction and possible aggressive behaviours (aggression, direction change and collision) showed juveniles a…
Deconstructing incubation behaviour in response to ambient temperature over different timescales
2021
Avian embryos need a stable thermal environment to develop optimally, while incubat-ing females need to allocate time to self-maintenance off the nest. In species with female-only incubation, eggs are exposed to ambient temperatures that usually cool them down during female absences. The lower the ambient temperature the sooner females should return to re-warm the eggs. When incubation constraints ease at increasing ambient temperatures, females respond by increasing either incubation effort or self-maintenance time. These responses are population-dependent even within the same species; but it is uncertain whether they are caused by local environmental conditions or they are an artefact fro…
Fish welfare in aquaculture: From physiology to molecular activities and new tools for study innovative diets, social and spatial stress
2022
Guaranteeing a high quality of life for animals has recently become a matter of increasing concern. Welfare assessment has been well-developed for terrestrial species, mainly for those kept in captivity, but the current state of the art is less well-characterized for aquatic animals. The classical methodologies utilised to date, such as the kind of behavioural observation widely used for terrestrial animals, are not appropriate for improving our knowledge of the well-being of aquatic animals if used alone, mainly due to the large number of species and the difficulty of obtaining comparative results among the different taxa of interest. Among different approaches, the evaluation of internal …
“The tale of the three little tits”: Different nest building solutions under the same environmental pressures
2020
Evolutionary selection pressures, and species-specific ecology and behavior, promote a great variability in the size and composition of nests. However, it would be expected that phylogenetically close species, with similar ecological needs, breeding at the same time in the same place, would also build similar nests. In contrast with this, previous studies have found differences in nest mass and composition among closely related sympatric species. These differences have been attributed to small differences in body size (smaller species building larger and/or more insulated nests), or to the different ways in which species perceive the environment (e.g. perceived predation risk). In this stud…
Carriage of potentially fish-pathogenic bacteria in Sparus aurata cultured in Mediterranean fish farms.
2003
A bacteriological survey of gilthead sea bream Sparus aurata from different fish farms and culture systems on the Spanish Mediterranean coast was conducted. Three different studies were performed. Study A included hatchery-reared larvae; Study B, periodic examination of randomly sampled growing fish; and Study C, growing fish sampled only during mortality/morbidity events. In Studies B and C, sea cages, earth ponds and indoor tanks were surveyed, and in both cases diseased (showing clinical signs) and non-diseased fish were included. In Study A, a shift from Vibrio spp. (30 d after hatching) to oxidative species (60 d after hatching) was detected, and no mortality events were registered. Th…
Alarm calling by individual willow tits, Parus montanus
1990
Abstract Alarm responses of wild-captured individual willow tits to model sparrowhawks, Accipiter nisus, flying over a test chamber were studied. Tits did not usually give alarm calls if the apparent predator was passing nearby (at a height of 10 m), while over half of the individuals responded by alarm calling for a more distant predator (40 m). This suggests that alarm calling involves a risk to the caller. Second, there was individual variation in the responses, with older males giving the call more frequently than females or young males. The greater responsiveness of adult males may indicate that different individuals in a flock gain different benefits by warning the others. The tendenc…
Food Caching By Willow and Crested Tits: A Test of Scatterhoarding Models
1995
In coniferous forests of Central Finland, Willow (Parus montanus) and Crest- ed Tits (P. cristatus) store seeds in a scattered distribution within their territory during the autumn. Individuals cache and recover food items while moving together as members of mixed-species flocks. The purpose of this study was to test certain predictions of scatter- hoarding models (Stapanian and Smith 1978, Clarkson et al. 1986), which predict how the animal should hoard food items from a superabundant source to maximize the number of caches recovered. Our field experiments gave support to most of the predictions of the models. Individual tits stored seeds closer to the food source when food had been availa…