NOT PEER-REVIEWED
"PeerJ Preprints" is a venue for early communication or feedback before peer review. Data may be preliminary.

A peer-reviewed article of this Preprint also exists.

View peer-reviewed version

Supplemental Information

Raw data

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.

DOI: 10.7287/peerj.preprints.2652v3/supp-1

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.

DOI: 10.7287/peerj.preprints.2652v3/supp-2

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.

DOI: 10.7287/peerj.preprints.2652v3/supp-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.

DOI: 10.7287/peerj.preprints.2652v3/supp-4

Additional Information

Competing Interests

The authors declare that they have no competing interests. Łukasz Ławicki is a member of the West-Pomeranian Nature Society, all his work with this article was made a non-profit as a volunteer.

Author Contributions

Dominik Marchowski conceived and designed the experiments, performed the experiments, analyzed the data, contributed reagents/materials/analysis tools, wrote the paper, prepared figures and/or tables, reviewed drafts of the paper.

Łukasz Jankowiak conceived and designed the experiments, performed the experiments, analyzed the data, contributed reagents/materials/analysis tools, wrote the paper, prepared figures and/or tables, reviewed drafts of the paper.

Dariusz Wysocki conceived and designed the experiments, performed the experiments, analyzed the data, contributed reagents/materials/analysis tools, wrote the paper, reviewed drafts of the paper.

Łukasz Ławicki conceived and designed the experiments, performed the experiments, contributed reagents/materials/analysis tools, wrote the paper, reviewed drafts of the paper.

Józef Girjatowicz conceived and designed the experiments, performed the experiments, contributed reagents/materials/analysis tools, wrote the paper, reviewed drafts of the paper.

Animal Ethics

The following information was supplied relating to ethical approvals (i.e., approving body and any reference numbers):

The research consisted of observations of birds from a distance, such studies do not cause disturbance of birds. In Poland, such studies do not need special permission or approval.

Data Deposition

The following information was supplied regarding data availability:

The raw data has been supplied as a supplementary file.

Funding

Counting birds were carried out by volunteer members of the West-Pomeranian Nature Society. Since 2011 mid-winter counts are part of a larger program Monitoring of Birds of Poland, the project is commissioned by the General Inspectorate of Environment Conservation (GIOŚ) and supported by the National Fund for Environmental Protection and Water Management to (NFOŚiGW), coordinating by Polish Society for the Protection of Birds (OTOP). http://monitoringptakow.gios.gov.pl/about-project The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.


Add your feedback

Before adding feedback, consider if it can be asked as a question instead, and if so then use the Question tab. Pointing out typos is fine, but authors are encouraged to accept only substantially helpful feedback.

Some Markdown syntax is allowed: _italic_ **bold** ^superscript^ ~subscript~ %%blockquote%% [link text](link URL)
 
By posting this you agree to PeerJ's commenting policies
  Visitors   Views   Downloads