Understanding the diets of predators, prey selection and their impact on prey populations is pivotal to investigations on the ecology of predator and prey species. In this study, we observed a hand-reared European otter (Lutra lutra) foraging in the wild, in order to identify the type of prey captured by the predator. The study was carried out between March and June 2001 in a diverse range of natural otter habitats in Białowieża Forest (NE Poland). We found that tadpoles represented an important part of the otter's diet in June, when their frequency of occurrence and biomass reached 38% and 11%, respectively. During spring, tadpoles were less common than other types of prey, such as adult amphibians, fish, or aquatic Coleoptera. Otter diet varied among months and there were differences in the main prey type captured among water body types. Our results highlight the need to develop methods that enable the identification of tadpoles and other cryptic seasonal food items in riparian predator diets.
We studied the responses of gas exchange, leaf morphology, and growth to irradiance in Taihangia rupestris, a naturally rare herb inhabiting only vertical cliff faces. In low irradiance (LI, 10 % of full sun) T. rupestris had lower net photosynthetic rate (PN) and produced much less leaves, total leaf area, and biomass than in high (HI, full sun) or medium irradiance (MI, 50 % of full sun). PN of T. rupestris was higher in HI than in MI on August 8, but lower in HI than in MI on September 22. T. rupestris had shorter petioles and lower leaf area ratio, and produced more but smaller and thicker leaves in HI than in MI. In HI the fast production of new leaves may guarantee T. rupestris to maintain higher PN at the whole plant level and thus accumulate more biomass at harvest, although the single-leaf PN may become lower as found on September 22. Hence T. rupestris possesses a latent capacity to acclimate and adapt to full sun. Irradiance, therefore, may not be a responsible factor for the restricted distribution of T. rupestris on vertical cliffs. and Min Tang ... [et al.].
Unilateral deafferentation induced by transection of the C4-C8 dorsal roots of spinal cord, followed by a complex of abnormal self-mutilating behavior, is interpreted as an animal model of chronic nociception. The objective of our study was to test the differences in tail-flick latency between intact control and unilaterally deafferented animals and to assess the changes in their acute nociceptive sensation. The initial hypothesis was that deafferentation-induced painful sensation might cause stress-induced analgesia that should be manifested as prolonged tail-flick latency. The experiment was carried out on 11 male and 10 female adult Wistar rats. The tail-flick latency was repeatedly measured over a period of 10 consecutive weeks both in the preoperative baseline period and following multiple cervical dorsal rhizotomy. Contrary to our hypothesis, unilateral deafferentation was followed by a significant shortening of the tail-flick latency both in males and females. In deafferented animals, compared to the controls, variations of tail-flick latency were reduced. In individual animals after deafferentation, concurrent dynamic changes were observed in self-mutilating behavior, in a loss and regaining of body weight, and in tail-flick latency. Our data suggest that changes in tail-flick latency may be interpreted in terms of central sensitization and that tail-flick latency might be considered as a useful marker of chronic nociception.
Čeleď kabarovitých představuje pro většinu lidí nejméně zajímavou čeleď kopytníků. Zahrnuje 7 málo známých druhů žijících ve východní Asii (od východního Afghánistánu přes Himálaj, Tibet a Čínu po střední a východní Sibiř). Tento článek obsahuje hlavní charakteristiky jednotlivých druhů včetně jejich fylogeneze a shrnuje dosavadní znalostí o životě kabarů. Vzhledem k tomu, že kabaři představují významný zdroj pro tradiční čínskou medicínu, stávají se v poslední době i jednou z nejvíce ohrožených čeledí kopytníků., The family Moschidae involves 7 species of musk deer, inhabiting forests and mountains of East Asia (from Afghanistan to the Himalayas, from Tibet and China to Siberia). This article summarizes current knowledge of individual species characteristics, including their phylogeny and natural history. Since these animals are a valuable source for the traditional Chinese medicine, they are the most endangered ungulate species in the world., and Jan Pluháček.