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Abstract

On the basis of observations and markings of Weddell seals in the region of the Admiralty Bay it was estimated that numbers of this species decreased systematically from about 500 to about 100 individuals from December to February. The sex structure of the local population also changed, showing a growing domination of females. Males were observed more often on coastal snow patches, females prevailed on rocky beaches close to the sea. A thesis of an increased nocturnal activity of Weddell seal was confirmed, indicating also a possibility of a two days activity cycle of this species. Synchronized among the individuals of local populations by atmoshperic conditionds.

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Michał Woyciechowski
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Abstract

Twelve mineral elements and total ash were examined in regard to the possible use as the estimators of digestibility of natural food in Antarctic seals. Four of them: phosphorus, calcium, copper and zinc have proved to give most reliable results. The estimated total dry mass and organic matter digestibilities of fish food in Weddell seals (Leptonychotes weddelli (Lesson)) averaged 82 and 91%, while the corresponding values for krill eaten by crabeaters (Lobodon carcinophagus (Hombron and Jaequinot)) and leopard seals (Hydrourga leptonyx (Blainville)) reached approximately 87 and 91%, respectively.

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Authors and Affiliations

January Weiner
Michał Woyciechowski
Jan Zieliński
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Abstract

Adam Łomnicki, a member of the Polish Academy of Sciences, the Polish Academy of Arts and Sciences and Academia Europaea, passed away on 15th December 2021. Adam Łomnicki was born in Warsaw, as a descendant of famous Łomnicki scholars - naturalists and mathematicians. He spent his childhood and youth in Sokołów Małopolski and Zakopane, where he completed his secondary school. In the years 1952–1957 he studied biology at the Jagiellonian University, where despite the domination of Soviet biology at the time, which denied the existence of scientific genetics and evolutionism, he had the opportunity to learn about these fields. His first job was at the Department of Nature Conservation of the Polish Academy of Sciences; he worked in the Tatra Mountains. Soon after graduating, Adam Łomnicki spent a few months at Oxford with one of the greatest ecologists of the time, Charles Elton. On his advice and under the supervision of prof. Roman Wojtusiak, he conducted his PhD thesis on the factors determining distribution of arachnids and coleopterans in the Tatra Mts. and graduated in 1961. His habilitation, completed in 1971, concerned the population ecology of Roman snails and led to very important conclusions on the effect of differences between individuals in population regulation (published in Nature). At that time, there was a crisis in environmental biology, caused by the contradictions between the principles of evolutionary theory and the existence of altruism and population regulation. An attempt to resolve these contradictions was Wynne Edwards' concept of group selection (1962), which, thanks, among others, to Łomnicki, turned out to be wrong. The concept of kin selection, put forward by W.D. Hamilton in 1964, of reciprocal altruism by Robert Trivers (1971) and models based on game theory by Maynard-Smith and Price (1973) resolved conflicts with behavioural biology, but it was Łomnicki's concept, based on mathematical models and supported by empirical studies showing the importance of individual variation in a population, that finally solved one of the most important problems of modern evolutionary biology and ecology – regulation of population numbers; Łomnicki's concept, presented in several publications, culminated in the book “Population ecology of Individuals” (Princeton University Press, 1988). Adam Łomnicki was not only a researcher, but also a master and teacher of a few generations of Polish evolutionary biologists and ecologists. With great enthusiasm he organized ecological seminars, national Schools of Mathematical Modeling in Biology (1975–1985), Evolutionary Biology Workshops (4 times a year in 1995–2012) later transformed into several-day international Polish Evolutionary Conferences. He was an excellent lecturer, and author or co-author of the most important Polish textbooks in the field of population ecology, evolutionary genetics and mathematical statistics for natural scientists. In 1981–1988 he was director of the Institute of Environmental Biology (now Institute of Environmental Sciences) of Jagiellonian University; during the dramatic change of political system in Poland, Łomnicki contributed to the modern organization of this institution and to the way of conducting university studies in modern Western style. Privately, he was very sociable, had a great sense of humor, was interested in history and skiing.
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Authors and Affiliations

Jan Kozłowski
1
January Weiner
1
Michał Woyciechowski
1

  1. Em. prof. Instytutu Nauk o Środowisku Uniwersytetu Jagiellońskiego

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