Search results for "Breed"
showing 10 items of 697 documents
40 Years of Breeding Bird Community Dynamics in a Primeval Temperate Forest (Białowieża National Park, Poland)
2015
We documented the composition and structure of the breeding bird assemblage in the primeval temperate forest of the Bialowieza National Park (BNP), during 2010-2014, and used 40 years of data to assess patterns of its diver- sity. We applied an improved version of the mapping technique (a combined mapping method) for forest birds in seven plots located in three old-growth forest types: ash-alder riverine, oak-hornbeam, and mixed coniferous. The composi- tion of the breeding avifauna and species richness remained basically unchanged. Jointly 67 (79% of 40-year total) breeding species were recorded in 2010-2014. Overall 49 (57%) of all species bred in the study plots in more than 35 years, th…
La presencia del nietzscheanismo en la biopolítica contemporánea
2022
La filosofía de Nietzsche anticipó notablemente el umbral de la modernidad biológica al conceptualizar el alcance fisiológico de la moral, la política y la religión, así como su instrumentalización con fines de control social. El objetivo de este artículo es analizar el estímulo que ha representado la filosofía de Nietzsche para algunos de los principales pensadores de la cuestión biopolítica, en concreto, Michel Foucault, Roberto Esposito y Peter Sloterdijk, y desvelar en qué medida sus núcleos conceptuales convergen y divergen. La aportación concreta reside en señalar algunos de los vínculos que articulan el tema de la disciplina y la cría (Zucht und Züchtung) con la configuración de la b…
Sexual advertisement and immune function in an arachnid species (Lycosidae)
2004
A simple version of the immunocompetence handicap hypothesizes that through condition-dependence, the size of the sexual trait may be positively related to immune function at the population level. In the present study, we investigated the relationship between sexual advertisement and immune function in a natural population of male wolf spiders, Hygrolycosa rubrofasciata (Araneae: Lycosidae). Males of H. rubrofasciata have a costly and condition-dependent acoustic signal, courtship drumming. In the mating season, males drum against dry leaves while wandering around the habitat searching for receptive females. Males increase their mating success by increasing their drumming rate and mobility.…
Prediction Models for Age-at-Death Estimates for Calves, Using Unfused Epiphyses and Diaphyses
2013
For cattle (Bos taurus), age estimations using dental criteria before the eruption of the first molar (3-8months) have large error margins. This hampers archaeozoological investigation into perinatal mortality or the putative slaughtering of very young calves for milk exploitation. Previous ageing methods for subjuveniles have focused on the length of unfused bones, but it is rarely possible to use them because they are restricted to foetuses and because of the fragmentation of bones. This paper presents new age prediction models based on length, breadth and depth of post cranial bones produced from a dataset of modern calves (n=27). This reference collection was compiled from material of k…
Corrosion Phenomena of Eurofeer Steel in Pb-17Li Stationary Flow at Magnetic Field
2006
Search of new energy sources draws the increasing attention to use for this purpose of reactors. In the Europe some years the program EUROATOM uniting scientific of the many countries for the decision of constructive problems at designing of fusion reactors operates. One of the main things in this program is the problem of liquid metals breeder blanket behaviour. Structural material of blanket should meet high requirements because of extreme operating conditions. Therefore the knowledge of the effect of metals flow velocity, temperatures and also a neutron irradiation and a magnetic field on the corrosion processes are necessary. At the moment the eutectic lead -lithium (Pb-17Li) is conside…
Evolution of avian clutch size along latitudinal gradients: do seasonality, nest predation or breeding season length matter?
2010
Birds display a latitudinal gradient in clutch size with smaller clutches in the tropics and larger in the temperate region. Three factors have been proposed to affect this pattern: seasonality of resources (SR), nest predation and length of the breeding season (LBS). Here, we test the importance of these factors by modelling clutch size evolution within bird populations under different environmental settings. We use an individual-based ecogenetic simulation model that combines principles from population ecology and life history theory. Results suggest that increasing SR from the tropics to the poles by itself or in combination with a decreasing predation rate and LBS can generate the latit…
Aspects of the breeding ecology of Rufous Bush RobinsCercotrichas galactotesin southeast Spain
1988
The breeding ecology of Rufous Bush Robin Cercotrichas galactotes was studied over 4 years in southeast Spain. The vegetation of the study area was made up mainly of Olives, Almonds and small shrubs. The density of this species decreased from 0.36 pairs 10 ha-1 in 1980 to 0.7 pairs 10 ha-1 in 1984, a decrease similar to one observed in other parts of Spain. The breeding season lasted from late May or early June to late August. About two-thirds of the pairs laid 2 clutches. Mean clutch size was 3.6 eggs. The incubation period lasted about 13 days and nestlings left the nest after 10 days. Mortality was greater in first clutches, mainly because of predation, which did not occur in second clut…
Nestling growth and mortality of Pied Flycatchers Ficedula hypoleuca in relation to weather and breeding effort
1996
The growth pattern and mortality of young Pied Flycatchers Ficedula hypoleuca were studied to focus on the mechanisms and constraints behind the widely studied optimization of clutch size. The clutch sizes were modified, and the growth and survival of chicks from different clutch sizes were monitored along with the prevailing weather during the nestling period to detect the effect of weather on reproductive success. The weather conditions during the feeding period of the nestlings varied within a season as well as between breeding seasons. The prevailing weather markedly affected both the growth rate and the survival of chicks, yet, the effects of weather on growth were not greater in enlar…
Limitation of Reproductive Success by Food Availability and Breeding Time in Pied Flycatchers
1998
Seasonal variation in reproductive success is a common phenomenon in many taxa. In birds, the costs and benefits associated with alternative breeding dates cause variation in clutch size, which is a main cause of seasonal decline in reproductive success. An immediate cause for this might be seasonal variation in the environment, or alternatively, but not mutually exclusively, date-independent differences in the parental/territory quality of early and late parents. The predictions of these hypotheses on seasonal reduction of reproductive success were tested by manipulating the hatching date and the amount of food during the nestling period of Pied Flycatchers (Ficedula hypoleuca). Delay in t…
Seasonal clutch size variation of multi-brooded bird species: comparisons between breeding season and latitudes
2004
Single- and multi-brooded species of birds differ in their seasonal patterns of clutch size. Single-brooded species start with a maximum clutch size that declines continuously as the season progresses, whereas the clutch sizes of multi-brooded species usually increase to a mid-season maximum peak and then decrease progressively until the end of the breeding season. Previous studies have shown that multi-brooded migrant species present seasonal patterns that are similar to single-brooded species at high latitudes but similar to multi-brooded non-migratory species at lower latitudes. We studied the Greenfinch Carduelis chloris and Goldfinch C. carduelis populations in eastern Spain (Sagunto, …