Nathalis iole
In 3 days ~20% in a week ~40%
Nathalis iole, the dainty sulphur or dwarf yellow, is a North American butterfly in the family Pieridae. This species is the smallest North American pierid. A rare population, known from Homestead (Smith et al., 1994), is said to have mostly white individuals. Some feel that the dainty sulphur is so unique among pierids, in shape and in several structural features, that it should belong in a separate subfamily. Its appearance is highly variable but a subset of distinctive features aid in identification. The forewings' elongated shape is distinctive. The upperside of the wings is yellow with the tip of the forewing being black. Black bars extend along the trailing edge of the forewing and the leading edge of the hindwing. Male dainty sulphurs have an oval scent patch (called an androconial spot) in each hindwing bar. The androconial spot is reddish orange but fades to pale yellow after death. The underside of the wings varies depending on the season. Summer individuals have yellowish hindwings whereas winter individuals have greenish-gray hindwings. Both forms have black spots near the forewing margin and have a yellowish-orange patch near the base of the... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Big Bend National Park | 🇺🇸 United States | |
| 2 | Saguaro National Park | 🇺🇸 United States | |
| 3 | Bahía de Loreto National Park | 🇲🇽 Mexico | |
| 4 | Guadalupe Mountains National Park | 🇺🇸 United States | |
| 5 | Joshua Tree National Park | 🇺🇸 United States | |
| 6 | Padre Island National Seashore | 🇺🇸 United States | |
| 7 | Merritt Island National Wildlife Refuge | 🇺🇸 United States | |
| 8 | Everglades National Park | 🇺🇸 United States | |
| 9 | Grand Canyon National Park | 🇺🇸 United States | |
| 10 | Zion National Park | 🇺🇸 United States | |
| 11 | Rocky Mountain National Park | 🇺🇸 United States | |
| 12 | Cumbres de Monterrey National Park | 🇲🇽 Mexico |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Miami | 🇺🇸 United States | |
| 2 | Austin | 🇺🇸 United States | |
| 3 | San Antonio | 🇺🇸 United States | |
| 4 | Ciudad Juárez | 🇲🇽 México | |
| 5 | Mexico City | 🇲🇽 México | |
| 6 | Dallas | 🇺🇸 United States | |
| 7 | Puebla | 🇲🇽 México | |
| 8 | Torreón | 🇲🇽 México | |
| 9 | San Luis Potosí | 🇲🇽 México | |
| 10 | Mesa | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Dainty Sulphur sighting in Rocky Mountain National Park on a given day, based on 14 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 93rd most-seen of the 191 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 40%, if each day is a fresh chance.
July to October
In those months about 10% of wildlife watchers report a Dainty Sulphur in Rocky Mountain National Park on a given day, against under 5% in November to June, the lowest months.
Between noon and 3 pm
Across all the parks we cover, that three-hour window holds the most Dainty Sulphur sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
11th of 12
Of the 12 parks where we can rate Dainty Sulphur sightings, Rocky Mountain National Park ranks 11th at about 10%. The best odds are in Big Bend National Park (United States, about 30%), Saguaro National Park (United States, about 30%) and Bahía de Loreto National Park (Mexico, about 20%).
Same family: Pieridae
The closest relatives of the Dainty Sulphur that you can see in Rocky Mountain National Park (family Pieridae, Whites, Yellows, and Sulphurs) are Mead's Sulphur (about 10%), Margined White (about 10%) and Queen Alexandra’s Sulphur (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Dainty Sulphur is recorded against all the insects logged in Rocky Mountain National Park (14 verified sightings from 2019 to 2026), 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.
