Erannis tiliaria
In 3 days ~10% in a week ~20%
Erannis tiliaria, the linden looper, also known under the rather ambiguous name "winter moth", is a moth of the family Geometridae. The species was first described by Thaddeus William Harris in 1841. It is found in North America from central Alberta east to Nova Scotia, south to Missouri, Georgia, Utah and Texas.
Erannis vancouverensis was considered to be a subspecies of E. tiliaria for some time, but appears to be a separate species. The wingspan is 32–42 mm for males. Females are wingless. Adult males are on wing in late fall.
The larvae feed on various deciduous trees and shrubs, including basswood, apple, ash, beech, birch, elm, maple, oak, poplar, Prunus and Ribes. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Elk Island National Park | 🇨🇦 Canada |
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Edmonton | 🇨🇦 Canada | |
| 2 | Calgary | 🇨🇦 Canada | |
| 3 | Minneapolis [Saint Paul] | 🇺🇸 United States | |
| 4 | Austin | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report a Linden Looper Moth sighting in Calgary on a given day, based on 15 verified sightings from GBIF citizen-science data. It is the 131st most-seen of the 256 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.
June and October
In those months about 10% of wildlife watchers report a Linden Looper Moth in Calgary on a given day, against under 5% in July–September and November–May, the lowest months. Those are among Calgary's wettest months, with about 75 mm of rain a month against 15 mm in January.
Between 8 and 11 am
Across all the parks we cover, that three-hour window holds the most Linden Looper Moth sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
2nd of 4
Of the 4 cities where we can rate Linden Looper Moth sightings, Calgary ranks 2nd at under 5%. The best odds are in Edmonton (Canada, about 10%).
GBIF citizen-science records
It is estimated from how often the Linden Looper Moth is recorded against all the insects logged in Calgary (15 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.
