Field Notes Journal

Seasonal Analysis and Species Classification

Brimstone Butterfly

Model Family : Seasonal presence

Summary

Brimstone Butterfly

Extended spring seasonal presence

Brimstone Butterfly is classified as extended spring seasonal presence. The fitted seasonal window runs from about February to September, with a spring peak around April. The season is very_broad, with a moderate active window, strong post-peak decline, and strong off-season suppression.

Confidence
Medium
Peak
April
Season
February–September

Seasonal wheel

Seasonal wheel for Brimstone Butterfly Brimstone Butterfly Peak: April

Calendar strip

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

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

Classification evidence

Season start month
2.295
Season end month
9.265
Forcing peak month
4.065
Season width months
6.97
Season midpoint month
5.78
Season start label
February
Season end label
September
Forcing peak label
April

Observed and Simulated Seasonal Patterns

Brimstone Butterfly Observed Presence, Abingdon
Brimstone Butterfly Observed Presence, Abingdon
Brimstone Butterfly Observed Totals, Abingdon
Brimstone Butterfly Observed Totals, Abingdon
Brimstone Butterfly Simulated Presence, Abingdon
Brimstone Butterfly 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. Brimstone Butterfly. Field Notes Journal. ID FN-WL-SEASONAL. Version 2026.05.21. https://fieldnotesjournal.uk/wildlife/seasonal/abingdon/brimstone_butterfly.html

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

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