Pachydiplax longipennis
In 3 days ~40% in a week ~70%
The blue dasher (Pachydiplax longipennis) is an insect of the skimmer family. It is the only species in the genus Pachydiplax. It is widely distributed throughout North America and into the Bahamas. Although the species name longipennis means "long wings", their wings are not substantially longer than those of related species. Females do, however, have a short abdomen that makes the wings appear longer in comparison. The blue dasher grows up to 25–43 millimeters (1.0–1.7 in) long.
The males are easy to recognize with their vibrant blue color, yellow-striped thorax, and metallic green eyes. Females are somewhat less colorful than the male, an example of sexual dimorphism. While they have a matching yellow-striped thorax, their abdomen has a distinct brown and yellow striping that sets them apart from the male, along with contrasting red eyes. Both sexes develop a frosted color with age.
Pachydiplax longipennis exhibits aggression while finding mates and foraging, and they are not under any conservation threats. Pachydiplax longipennis is a commonly spotted dragonfly species in the United States, and this species is found in many types of habitats. These... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Big Cypress National Preserve | 🇺🇸 United States | |
| 2 | Everglades National Park | 🇺🇸 United States | |
| 3 | Point Pelee National Park | 🇨🇦 Canada | |
| 4 | Merritt Island National Wildlife Refuge | 🇺🇸 United States | |
| 5 | Congaree National Park | 🇺🇸 United States | |
| 6 | Big Bend National Park | 🇺🇸 United States | |
| 7 | Padre Island National Seashore | 🇺🇸 United States | |
| 8 | Shenandoah National Park | 🇺🇸 United States | |
| 9 | Death Valley National Park | 🇺🇸 United States | |
| 10 | Acadia National Park | 🇺🇸 United States | |
| 11 | Redwood National Park | 🇺🇸 United States | |
| 12 | Great Smoky Mountains National Park | 🇺🇸 United States | |
| 13 | Saguaro National Park | 🇺🇸 United States | |
| 14 | Yosemite National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Houston | 🇺🇸 United States | |
| 2 | Austin | 🇺🇸 United States | |
| 3 | Boston | 🇺🇸 United States | |
| 4 | Dallas | 🇺🇸 United States | |
| 5 | Miami | 🇺🇸 United States | |
| 6 | Washington | 🇺🇸 United States | |
| 7 | New York City | 🇺🇸 United States | |
| 8 | Mesa | 🇺🇸 United States | |
| 9 | Orlando | 🇺🇸 United States | |
| 10 | Portland | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Blue Dasher sighting in Portland on a given day, based on 381 verified sightings from GBIF citizen-science data. It is the 23rd most-seen of the 507 insects we can rate there. Over three days the chance rises to about 40%, and over a week to about 70%, if each day is a fresh chance.
July
In that month about 30% of wildlife watchers report a Blue Dasher in Portland on a given day, against under 5% in October to April, the lowest months. That is one of Portland's driest months, with about 10 mm of rain against 250 mm in December.
Between 1 and 4 pm
Across all the parks we cover, that three-hour window holds the most Blue Dasher 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 30
Of the 30 cities where we can rate Blue Dasher sightings, Portland ranks 10th at about 10%. The best odds are in Houston (United States, about 30%), Austin (United States, about 20%) and Boston (United States, about 20%).
Same family: Libellulidae
The closest relatives of the Blue Dasher that you can see in Portland (family Libellulidae, Skimmers) are Common Whitetail (about 20%), Flame Skimmer (about 10%) and Western Pondhawk (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Blue Dasher is recorded against all the insects logged in Portland (381 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.
