Explanations for the ecological integration of migratory and non-migratory (resident) insectivorous birds in the tropics have been complicated by the paradox that arthropod abundances are low when bird abundances reach their annual peak. The breeding currency hypothesis and the nest predation hypothesis both account for this paradox by postulating that residents are held below the non-breeding ...

Wild passerine birds (Passeriformes) from the northeastern part of the Czech Republic were examined for ectoparasites during the pre-breeding period in 2007. Two species of fleas of the genera Ceratophyllus and Dasypsyllus (Siphonaptera: Ceratophyllidae), and 23 species of chewing lice belonging to the genera Ricinus, Myrsidea, Menacanthus (Phthiraptera: Menoponidae), Brueelia, Penenirmus, and ...

Current studies argue that through building the virtual organization breeding environment one can quickly find partners and create a virtual enterprise. The creation of the virtual organization breeding environment requires its own social capital to satisfy some social requirements, but such researches are few This paper, based on complex network theory, proposes a new method to identify the vi...

Plant breeding is considered one of the longest ongoing activities undertaken by humans, who select plants more productive and useful to themselves and the animals for at least 10,000 years ago. The evolution of civilizations paralleled the success of plant breeding, although this has not been recognized by the public. The reason may be lack of understanding of what plant breeding encompasses. ...

Badgers were sampled once during the sexually inactive season (July-November) and during the breeding season (February-April) and testosterone and dihydrotestosterone (DHT) concentrations were measured by radioimmunoassay after separation by chromatography. Concentrations of both hormones were higher in the breeding than non-breeding season, but the mean ratio of testosterone to DHT was greater...

Hemivertebrae are the most frequent vertebral malformations in dogs and particularly common in chondrodystrophic dog breeds like the French bulldog, English bulldog, Pug and Boston terrier. Clinical signs caused by hemivertebrae are pelvic limb ataxia and paresis, loss of reflexes, kyphosis, lordosis and scoliosis, incontinence, atrophy and atony of the pelvic limbs due to a compression of the ...

Frog breeding phenology in temperate zones is usually compared to progress of spring temperatures at a regional scale. However, local populations may differ substantially in phenology. To understand this, local climate and other aspects must be studied. In this study, breeding phenology of the common frog, Rana temporaria, in a set of ponds in southern Sweden is analyzed. There was within year ...

BACKGROUND Humpback whales are known to undertake long-distance migration between feeding and breeding sites, but their movement behavior within their breeding range is still poorly known. Satellite telemetry was used to investigate movement of humpback whales during the breeding season and provide further understanding of the breeding ecology and sub-population connectivity within the southwes...

Genetics is responsible for approximately half the observed changes in animal performance in well structured breeding programs. Key characteristics of the dairy cow of the future include (1) production of a large quantity of high-value output (i.e. milk andmeat), (2) good reproductive performance, (3) good health status, (4) good longevity, (5) no requirement for a large quantity of feed, yet b...

Following over 20 years of research on the climatic effects on biodiversity we now have strong evidence that climate change affects phenology, fitness, and distribution ranges of different taxa, including birds. Bird phenology likely responds to changes in local weather. It is also affected by climatic year-to-year variations on larger scales. Although such scale-related effects are common in e...