Field Notes Journal

Seasonal Analysis and Species Classification

Cormorant

Model Family : Resident detectability

Cormorant (Phalacrocorax carbo), Farmoor Reservoir, UK
Cormorant (Phalacrocorax carbo), Farmoor Reservoir, UK David Walker, Field Notes Journal ( CC BY 4.0 )
Cormorant (Phalacrocorax carbo), Farmoor Reservoir, UK
Cormorant (Phalacrocorax carbo), Farmoor Reservoir, UK David Walker, Field Notes Journal ( CC BY 4.0 )
Cormorant (Phalacrocorax carbo), Radley Lakes, UK
Cormorant (Phalacrocorax carbo), Radley Lakes, UK David Walker, Field Notes Journal ( CC BY 4.0 )

Summary

Cormorant

Resident with summer detectability collapse

Cormorant is classified as resident with summer detectability collapse. The fitted resident detectability target peaks around April and reaches its lowest point around October. The model indicates moderate baseline presence, weak spring carry-over, moderate pre-summer retention, moderate summer suppression, and strong summer decay acceleration.

Confidence
Medium
Fit score
0.206
Peak detectability
April
Lowest detectability
October

Seasonal wheel

Seasonal wheel for Cormorant Cormorant Peak: April

Calendar strip

Jan 0.27
Feb 0.28
Mar 0.45
Apr 0.75
May 0.56
Jun 0.32
Jul 0.26
Aug 0.21
Sep 0.21
Oct 0.11
Nov 0.17
Dec 0.36

Highlighted months indicate stronger modelled presence or detectability. A ring marks the fitted peak; a hollow mark indicates the trough where available.

Classification evidence

Target peak month
4
Target peak label
April
Target trough month
10
Target trough label
October
Target peak value
0.748
Target trough value
0.105
Target mean value
0.329
Target amplitude
0.642
Baseline to peak ratio
0.286
Autumn to winter weight ratio
0.046
Year end to winter weight ratio
0.385
Decay to growth ratio
2.593

Observed and Simulated Seasonal Patterns

Cormorant Observed Presence, Thrupp Lake
Cormorant Observed Presence, Thrupp Lake
Cormorant Observed Totals, Thrupp Lake
Cormorant Observed Totals, Thrupp Lake
Cormorant Simulated Presence, Thrupp Lake
Cormorant Simulated Presence, Thrupp Lake

Cite this dataset

You are welcome to reuse or reproduce this material under the terms of the Creative Commons CC BY 4.0 licence but please cite it using the reference below, include a link to the licence, and indicate if any changes were made.

Walker, David. Cormorant. Field Notes Journal. ID FN-WL-SEASONAL. Version 2026.05.26. https://fieldnotesjournal.uk/wildlife/seasonal/thrupp_lake/cormorant.html

Dataset FN-WL-SEASONAL Author David Walker Publisher Field Notes Journal Version 2026.05.26
Reference: Walker, David. Cormorant. Field Notes Journal. ID FN-WL-SEASONAL. Version 2026.05.26.

BibTeX 
@dataset{fn_wl_seasonal,
  author = {Walker, David},
  title = {Cormorant},
  year = {2026},
  publisher = {Field Notes Journal},
  version = {2026.05.26},
  url = {https://fieldnotesjournal.uk/wildlife/seasonal/thrupp_lake/cormorant.html}
}