In Batesian mimicry, a species lacking defences against predators benefits from mimicking the aposematic signal of a defended species, while the model may incur the costs of reduced defensive efficacy. Similar reciprocal indirect effects may emerge even when the signal is not mimicked; termed associational effects, such interactions are well known in plants sharing herbivores but have received little attention in animal studies. We investigated associational interactions in a system where unequally defended prey (chemically defended Bufo bufo and undefended Rana temporaria tadpoles), sharing general morphology but not an aposematic signal, were exposed to predation by the carp Cyprinus carpio along a gradient of relative prey abundance. In the absence of fish, the assemblage composition had no effect on the survival of Rana, while that of Bufo decreased with increasing abundance of Rana. Fish reduced the survival of tadpoles from both species. However, increased relative abundance of Bufo in the community led to enhanced survival in both Bufo and Rana. Increasing relative proportions of heterospecifics reduced metamorph mass only in Bufo, indicating greater sensitivity to interspecific competition compared to Rana; the effect was reduced in the presence of fish. Our results show that undefended non-mimetic prey enjoy reduced predation with increasing relative abundance of chemically defended prey, which in turn suffer greater mortality with an increasing proportion of the undefended species. Associational resistance/susceptibility, driven by current assemblage composition, not by selection for resemblance, can shape the dynamics of mixed communities of defended and undefended prey in the absence of mimicry.

The study makes use of yields of winter wheat (Triticum aestivum L.) cultivars obtained in a series of PostRegistration Variety Testing System, experiments conducted in 2006-2008 at 12 locations of diverse edaphic and climatic conditions of Western Poland. The experiments were carried out at two intensity levels in two replications. The paper presents an analysis pertaining to the intensive level of cultivation, which differed from the standard cultivation in nitrogen fertilization higher by 40 kg ha -1 , full chemical protection against fungal diseases, application of growth regulator and in foliar spray of the plants with multi-nutrient preparation. The experiments were set out in a split-block design. The trials involved the following 23 cultivars of winter

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Some new cases of anomalies in wild Bufotes viridis from Western Poland are presented together with a discussion of their potential causes and a comparison with similar cases from the literature. The anomalies in question are color aberrations (pre- and post-metamorphic) and developmental pathologies (pre–metamorphic). The color anomalies include an ochre patch in a juvenile, leucism and albinism in both tadpoles and juvenile individuals. Developmental pathologies described in this paper include gigantism, edema, curvature of tail, and asymmetric bodies.

The global biodiversity crisis is becoming one of the key challenges for the global community. At the same time, hands-on knowledge of local biodiversity is decreasing among young people, replaced by information about global issues and/or artificial products provided by the media. While information and computer technologies (ICT) are blamed for the alienation of people from the natural world surrounding them, they may also be used for education about wildlife. The article describes a case study of the use of ICT for education about local biodiversity. A progressive web app (PWA) as a universal software solution for all types of devices was used for creating a virtual educational path within the biodiversity-rich urban park. The PWA complements and expands existing educational facilities, provides a multimedia experience when learning about local biodiversity, and introduces elements of gamification to increase the motivation of users.