Asterocampa celtis
In 3 days ~10% in a week ~20%
Asterocampa celtis, the hackberry emperor, is a North American butterfly that belongs to the brushfooted butterfly family, Nymphalidae. It gets its name from the hackberry tree (Celtis occidentalis and others in the genus Celtis) upon which it lays its eggs. The hackberry tree is the only host plant for A. celtis and is the food source for larvae.
The hackberry emperor is known for being a quick, mercurial butterfly. It often is found along water sources and lowlands, although it lives in a broad range of habitats. Another notable characteristic is that it rarely is spotted visiting a flower, which is considered unusual for a butterfly.
Species in the genus Asterocampa are regarded as being "cheater" organisms, since these butterflies do not pollinate flowers when they feed from them. This species can more accurately be described as parasitizing their hosts and plant food sources since they extract nutrients without providing any benefits to the host.
As a member of the family Nymphalidae, the hackberry emperor oviposits its eggs in clutches, or clusters, upon hackberry leaves. There are a few plausible evolutionary reasons for this behavior, but the exact cause for this species' behavior is in contention. Possible explanations include higher fecundity that may be aided by aposematic coloration. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Point Pelee National Park | 🇨🇦 Canada | |
| 2 | Congaree National Park | 🇺🇸 United States | |
| 3 | Shenandoah National Park | 🇺🇸 United States | |
| 4 | Zion National Park | 🇺🇸 United States | |
| 5 | Great Smoky Mountains National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Dallas | 🇺🇸 United States | |
| 2 | Austin | 🇺🇸 United States | |
| 3 | Chicago | 🇺🇸 United States | |
| 4 | San Antonio | 🇺🇸 United States | |
| 5 | Minneapolis [Saint Paul] | 🇺🇸 United States | |
| 6 | Houston | 🇺🇸 United States | |
| 7 | Montreal | 🇨🇦 Canada | |
| 8 | New York City | 🇺🇸 United States | |
| 9 | Washington | 🇺🇸 United States | |
| 10 | Philadelphia | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report a Hackberry Emperor sighting in Philadelphia on a given day, based on 5 verified sightings from GBIF citizen-science data. It is the 557th most-seen of the 632 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.
Any time of year
In every month with enough records, under 5% of wildlife watchers report a Hackberry Emperor in Philadelphia on a given day, so our monthly data shows no clear season.
Between 10 am and 1 pm
Across all the parks we cover, that three-hour window holds the most Hackberry Emperor sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
10th of 10
Of the 10 cities where we can rate Hackberry Emperor sightings, Philadelphia ranks 10th at under 5%. The best odds are in Dallas (United States, about 20%), Austin (United States, about 10%) and Chicago (United States, about 10%).
Same family: Nymphalidae
The closest relatives of the Hackberry Emperor that you can see in Philadelphia (family Nymphalidae, Brush-footed Butterflies) are Monarch (about 30%), Red Admiral (about 20%) and Variegated Fritillary (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Hackberry Emperor is recorded against all the insects logged in Philadelphia (5 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.
