Continuous variation rather than specialization in the egg phenotypes of Cuckoos (Cuculus canorus) parasitizing two sympatric reed warbler species

The evolution of brood parasitism has long attracted considerable attention among behavioural ecologists, especially in the common cuckoo system. Common cuckoos (Cuculus canorus) are obligatory brood parasites, laying eggs in nests of passerines and specializing on specific host species. Specialized races of cuckoos are genetically distinct. Often in a given area, cuckoos encounter multiple hosts showing substantial variation in egg morphology. Exploiting different hosts should lead to egg-phenotype specialization in cuckoos to match egg phenotypes of the hosts. Here we test this assumption using a wild population of two sympatrically occurring host species: the great reed warbler (Acrocephalus arundinaceus) and reed warbler (A. scirpaceus). Using colour spectrophotometry, egg shell dynamometry and egg size measurements, we studied egg morphologies of cuckoos parasitizing these two hosts. In spite of observing clear differences between host egg phenotypes, we found no clear differences in cuckoo egg morphologies. Interestingly, although chromatically cuckoo eggs were more similar to reed warbler eggs, after taking into account achromatic differences, cuckoo eggs seemed to be equally similar to both host species. We hypothesize that such pattern may represent an initial stage of an averaging strategy of cuckoos, that – instead of specializing for specific hosts or exploiting only one host – adapt to multiple hosts

Jakość życia osób starszych uczestniczących w zajęciach uniwersytetu trzeciego wieku

Quality of life of older people participating in the activities of the university of the third age. In connection with the phenomenon of population aging and the creation of a new social policy, a new direction in pedagogics called andragogy, or sub-discipline dealing with adult education, was created. The task of adult education has taken over Universities of the Third Age, pursuing such goals as: continuing education, socio-cultural activation, physical mobilization and dissemination of gerontological proficiency among participants. The aim of this study is to compare the quality of life of people over 60 years old, studying at the University of the Third Age, with people who do not participate in any seniors’ occupations and live exclusively in their own home environment. The study used the diagnostic survey method. As a research tool, a questionnaire was used for the own questionnaire containing 22 questions, the Oswestry Questionnaire and The World Health Organization (WHOQOL) – BREFF.Jakość życia osób starszych uczestniczących w zajęciach uniwersytetu trzeciego wieku. W związku z zjawiskiem starzenia się społeczeństwa i tworzeniem nowej polityki społecznej powstał nowy kierunek w pedagogice zwany andragogiką, czyli subdyscyplina zajmującą się kształceniem dorosłych. Zadanie kształcenia dorosłych przejęły uniwersytety trzeciego wieku, realizując takie cele jak: edukacja ustawiczna, aktywizacja społeczno-kulturowa, aktywizacja ruchowa oraz szerzenie wśród uczestników gerontologicznej profilaktyki. Celem niniejszej pracy jest porównanie jakości życia osób po 60. roku życia, studiujących na uniwersytecie trzeciego wieku, z osobami nieuczestniczącymi w żadnych zajęciach dla seniorów i bytujących wyłącznie we własnym środowisku domowym. W badaniu zastosowano metodę sondażu diagnostycznego. Jako narzędzie badawcze posłużył kwestionariusz ankiety własnego autorstwa zawierający 22 pytania, Kwestionariusz Oswestry oraz The World Health Organization Quality of Life (WHOQOL) – BREFF

Habitat use by Siberian warbler species at a stopover site in Far Eastern Russia

Knowledge of the routes and habitat use of Siberian songbird species during migration is very limited. The goal of our study was to describe the autumnal habitat use of seven Siberian warbler species in the genera Phylloscopus, Acrocephalus, Iduna and Locustella in Far Eastern Russia. A total of 2283 individuals were trapped in mist nets placed within different habitat types between 2012 and 2014 as part of the Amur Bird Project at Muraviovka Park in Far Eastern Russia. We studied the effect of habitat type and vegetation height on the occurrence of each species, and compared our results to published information on habitat use on the breeding grounds. Our results demonstrate that most species exhibit species-specific preferences for habitat type, and that these stopover habitats were similar to habitats used on the breeding grounds. © 2018 British Trust for Ornitholog

Sex Allocation in Relation to Host Races in the Brood-Parasitic Common Cuckoo (Cuculus canorus)

Sex allocation theory and empirical evidence both suggest that natural selection should favour maternal control of offspring sex ratio in relation to their ability to invest in the offspring. Generalist parasites constitute a particularly interesting group to test this theory as different females commonly utilize different host species showing large variation in provisioning ability. The common cuckoo (Cuculus canorus) is a generalist brood parasite that lays its eggs in the nest of many different passerine birds, but each female tends to specialize on one particular host species giving rise to highly specialized host races. The different host species show large variation in their ability to invest in the parasitic offspring, presenting an opportunity for female cuckoos to bias offspring sex ratio in relation to host species quality. Here, we investigate host-race specific sex allocation controlling for maternal identity in the common cuckoo. We found no evidence of any significant relationship between host race and sex ratio in one sympatric population harbouring three different host races, or in a total of five geographically separated populations. There was also no significant association between host quality, as determined by species-specific female host body mass, and cuckoo sex ratio. Finally, we found no significant relationship between individual cuckoo maternal quality, as determined by her egg volume, and sex ratio within each host race. We conclude that the generalist brood-parasitic common cuckoo show no significant sex-ratio bias in relation to host race and discuss this finding in light of gene flow and host adaptations

Detecting non-binomial sex allocation when developmental mortality operates

Optimal sex allocation theory is one of the most intricately developed areas of evolutionary ecology. Under a range of conditions, particularly under population sub-division, selection favours sex being allocated to offspring non-randomly, generating non-binomial variances of offspring group sex ratios. Detecting non-binomial sex allocation is complicated by stochastic developmental mortality, as offspring sex can often only be identified on maturity with the sex of non-maturing offspring remaining unknown. We show that current approaches for detecting non-binomiality have limited ability to detect non-binomial sex allocation when developmental mortality has occurred. We present a new procedure using an explicit model of sex allocation and mortality and develop a Bayesian model selection approach (available as an R package). We use the double and multiplicative binomial distributions to model over- and under-dispersed sex allocation and show how to calculate Bayes factors for comparing these alternative models to the null hypothesis of binomial sex allocation. The ability to detect non-binomial sex allocation is greatly increased, particularly in cases where mortality is common. The use of Bayesian methods allows for the quantification of the evidence in favour of each hypothesis, and our modelling approach provides an improved descriptive capability over existing approaches. We use a simulation study to situations where current methods fail, and we illustrate the approach in real scenarios using empirically obtained datasets on the sexual composition of groups of gregarious parasitoid wasps demonstrate substantial improvements in power for detecting non-binomial sex allocation in situations where current methods fail, and we illustrate the approach in real scenarios using empirically obtained datasets on the sexual composition of groups of gregarious parasitoid wasps

First Record of Slime Molds in Biebrza National Park (NE Poland)

This paper provides the first recorded data of slime molds in Biebrza National Park (NE Poland). In total, 16 species of myxomycetes belonging to nine genera were observed.The study was carried out as part of the tasks financed from the subsidy of the Ministry of Science and Higher Education for the Department of Algology and Mycology, Faculty of Biology and Environmental Protection, University of Lodz

Testing multiple pathways for impacts of the non-native Black-headed Weaver Ploceus melanocephalus on native birds in Iberia in the early phase of invasion

Not all non-native species have strong negative impacts on native species. It is desirable to assess whether a non-native species will have a negative impact at an early stage in the invasion process, when management options such as eradication are still available. Although it may be difficult to detect early impacts of non-native species, it is necessary to ensure that management decisions can be based on case-specific scientific evidence. We assess the impacts of a non-native bird, the Black-headed Weaver Ploceus melanocephalus, at an early stage in its invasion of the Iberian Peninsula. To do this we identify potential pathways by which competition for shared resources by Black-headed Weavers could lead to population declines in two ecologically similar native species, and generate hypotheses to test for evidence of competition along these pathways. Black-headed Weavers could potentially impact native species by displacing them from nesting habitat, or by reducing habitat quality. We found no evidence for either potential competition pathway, suggesting that Black-headed Weavers do not currently compete with the two native species. However, it is possible that mechanisms that currently allow coexistence may not operate once Black-headed Weavers reach higher population densities or different habitats