Field Notes Journal

Seasonal Analysis and Species Classification

Blackbird

Model Family : Resident detectability

Blackbird (Turdus merula), Abingdon, UK
Blackbird (Turdus merula), Abingdon, UK David Walker, Field Notes Journal ( CC BY 4.0 )
Blackbird (Turdus merula), Abingdon, UK
Blackbird (Turdus merula), Abingdon, UK David Walker, Field Notes Journal ( CC BY 4.0 )
Blackbird (Turdus merula), Abingdon, UK
Blackbird (Turdus merula), Abingdon, UK David Walker, Field Notes Journal ( CC BY 4.0 )
Blackbird (Turdus merula), Abingdon, UK
Blackbird (Turdus merula), Abingdon, UK David Walker, Field Notes Journal ( CC BY 4.0 )

Summary

Blackbird

Resident with spring persistence and summer suppression

Blackbird is classified as resident with spring persistence and summer suppression. The fitted resident detectability target peaks around March and reaches its lowest point around September. The model indicates strong baseline presence, strong spring carry-over, strong pre-summer retention, strong summer suppression, and strong summer decay acceleration.

Confidence
Medium
Fit score
0.227
Peak detectability
March
Lowest detectability
September

Seasonal wheel

Seasonal wheel for Blackbird Blackbird Peak: March

Calendar strip

Jan 0.66
Feb 0.76
Mar 0.96
Apr 0.83
May 0.67
Jun 0.65
Jul 0.63
Aug 0.36
Sep 0.19
Oct 0.3
Nov 0.38
Dec 0.52

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
3
Target peak label
March
Target trough month
9
Target trough label
September
Target peak value
0.963
Target trough value
0.187
Target mean value
0.576
Target amplitude
0.776
Baseline to peak ratio
0.383
Autumn to winter weight ratio
0.063
Year end to winter weight ratio
0.576
Decay to growth ratio
1.214

Observed and Simulated Seasonal Patterns

Blackbird Observed Presence, Abingdon
Blackbird Observed Presence, Abingdon
Blackbird Observed Totals, Abingdon
Blackbird Observed Totals, Abingdon
Blackbird Simulated Presence, Abingdon
Blackbird Simulated Presence, Abingdon

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. Blackbird. Field Notes Journal. ID FN-WL-SEASONAL. Version 2026.05.21. https://fieldnotesjournal.uk/wildlife/seasonal/abingdon/blackbird.html

Dataset FN-WL-SEASONAL Author David Walker Publisher Field Notes Journal Version 2026.05.21
Reference: Walker, David. Blackbird. Field Notes Journal. ID FN-WL-SEASONAL. Version 2026.05.21.

BibTeX 
@dataset{fn_wl_seasonal,
  author = {Walker, David},
  title = {Blackbird},
  year = {2026},
  publisher = {Field Notes Journal},
  version = {2026.05.21},
  url = {https://fieldnotesjournal.uk/wildlife/seasonal/abingdon/blackbird.html}
}