A - date of count. B - season of count. C - species. D - month of count. E - number of days with 100% ice cover 15 days prior to count. F - mean daily temp. 15 days prior to count. G - mean max. temp. 15 days prior to count. H - mean min.temp.15 days prior to count. I - feeding group: B-benthivorous, P-piscivorous. J - count method: A - aerial, L - terrrestrial. K - maximum ice cover in the Baltic in thousand km². L - [=(Mx/Nx)*100]. M - Count results. N - Size of population in a given season.
Ranking of generalized linear mixed models showing the influence of ice cover, maximum ice extent [km2] in the Baltic Sea (max ice) and season on the percentages of the population of the target species in the Odra River Estuary
The models were ranked using the Akaike information criterion (AIC). ΔAIC represents the difference between each model and the best-fit model. wi – Akaike weight (indicating model probabilities); df, – degrees of freedom. The terms in the models are represented by numbers: 1 –feed, 2 – ice cover, 3 – max ice, 4 – season, 5 – ice cover*feed, 6 – max ice*feed, 7 – season*feed.
Results of generalized linear mixed models showing the influence of ice cover, maximum ice extent [km2] in the Baltic Sea (max ice) and season on the percentages of the population of the target species in the Odra River Estuary
The parameters show the interaction between season and species, ice cover and species, max ice and species. The interaction parameters species*season, species*ice cover, species*max ice were used to predict the values presented in Figures 1-3.
Trend of biogeographic population (2) and impact of covariates (3-5) on the dependent variable – the ratio of the percentage of the numbers of a given species in the study area to the estimated total biogeographic population in a given year
(1) Target species, (2) trend of biogeographic population after Nagy et al. 2014; (3) direction of population index change in the ORE; (4) impact of ice cover in the ORE on the dependent variable; (5) impact of ice cover in the whole Baltic on the dependent variable.