Operophtera occidentalis
In 3 days ~10% in a week ~20%
| # | Park | Country | Daily sighting probability |
|---|
More parks will be added in future updates.
Rare
Under 5% of wildlife watchers report a Western Bruce Spanworm sighting in Portland on a given day, based on 19 verified sightings from GBIF citizen-science data. It is the 249th most-seen of the 507 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 20%, if each day is a fresh chance.
December
In that month about 20% of wildlife watchers report a Western Bruce Spanworm in Portland on a given day, against under 5% in February to October, the lowest months. That is one of Portland's wettest months, with about 250 mm of rain against 10 mm in July.
Yes
Of the 2 cities where we can rate Western Bruce Spanworm sightings, Portland has the highest daily chance: under 5%. Next come Seattle (United States, under 5%).
Same family: Geometridae
The closest relatives of the Western Bruce Spanworm that you can see in Portland (family Geometridae, Geometer Moths) are Brown-Lined Looper (about 10%), Tissue Moth (about 10%) and Small Dusty Wave (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Western Bruce Spanworm is recorded against all the insects logged in Portland (19 verified sightings), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
