Colourful Puffleg, Munchique NP, Colombia. Photo: Nigel Voaden

Birders have a borderline obsessive tendency to keep records. From big days to life lists, many birders find joy in quantifying their bird-watching experiences. The citizen science project eBird, a collaboration between the Cornell Lab of Ornithology and Audubon that allows birders to track their states in real-time, harnesses this urge—with riveting results.

So here are some numbers for all of the stat-happy birders out there: Since the project was launched in 2002, eBirders have submitted records for a staggering 98 percent of all bird species that exist today. That’s 10,055 out of 10,301 possible species. In July 2014, eBird posted an article highlighting the species that were missing from their records and called for eBirders to fill in the gaps. Within 45 days of posting the article, eBird received accounts chronicling sightings of 92 of the 246 previously missing species.

These numbers are a testament to eBirders’ dedication to contributing to science and conservation. But numbers can’t tell the whole story. They don’t tell of the long journeys to remote locations and grueling hikes that went into collecting data in remote locations, or the ecstatic moments when a rare bird first comes into view.

While eBird’s data is freely available, to hear the tales behind the numbers we had to ask eBirders themselves. Here’s what some of them had to say about their rare sightings.

Colorful Puffleg, spotted in Munchique National Park, Colombia (pictured above)

eBirders: Patty O’Neill and Nigel Voaden

Species: Eriocnemis mirabilis

Dates: February 3, 2010

The sighting: Voaden and O’Neill were on a birding tour high up in the cloud forests of Columbia’s Munchique National Park when they received a whispered message passed down the line from the other birders on the tour. Hours of hiking and a nerve-racking ride on a rickety old bus had paid off: a handsome little male Colorful Puffleg was perched on a snag ahead. This critically endangered species has an extremely tiny range, and this spot—which even the guides had never visited before—was evidently part of it.

As Voaden and O’Neill watched this shimmering little bird through the mountain mist, a nearby Munchique Wood Wren sang along. “There are a couple of birds that I think of as the Mozarts of birds—the Musician Wren and this bird," O’Neill said. “I was just transfixed by the beauty of the puffleg and the beautiful song that was accompanying the view."

Why eBird: "To have one record that's available globally is a powerful tool, and it’s only going to grow as time goes on," says Voaden.

Tonga Megapode, spotted in Niuafo'ou, Tonga

eBirder: Lisle Gwynn

Date: April 12, 2014

The sighting: Gwynn and his fellow voyagers landed on the lava wharf in Tonga on a pitch-black night. His travels, part of Heritage Expeditions’ South Pacific Voyage, brought him to Niuafo’ou, the most remote island of the Tonga archipelago. Once docked, it still took several hours for the group to reach the inner caldera lakes by way of a small, rickety, skidding lorry. When the path became too treacherous for the lorry, Gwynn and the others were left to wade through the chest-high sulfurous waters of Vai Si’i Lake to the tiny island of Motu Lahi.

There they crouched in silence, listening hopefully to the megapodes calling in the distance. After over an hour of waiting, one of the birders managed to flush a megapode out of the thick vegetation and into a small patch of moonlight. The bird stood on a log and called right in front of them, as if it knew that it was the star of the show.

Why eBird: “I submitted my records after I saw the article on species missing from the database. Having seen some rather rarely seen species, I felt I should do my bit and contribute to eBird where perhaps no one else would. I'd used eBird to investigate areas before, so thought I should give something back.”

Kauai Oo. Illustration: Walter Rothschild/Wikimedia Creative Commons

Kauai Oo, spotted in Kauai, Hawaii, United States

eBirder: Paul Sykes

Species: Moho braccatus

Dates: May 24-26, 1983

The sighting: A lifelong birder and wildlife researcher, Sykes was visiting colleagues in Hawaii when he tagged along on a research outing that took him through the soaking rainforests of Kauai. As he made his way through some of the wettest places on Earth, the musical, bell-like calls of the Kauai Oo caught his attention.

Due to habitat destruction—particularly the introduction of pests including mosquitoes and black rats—this endemic bird was extremely rare at the time. Realizing that he was looking at a precious survivor of a dwindling species, Sykes spent several hours watching the bird and came back to find it in the days that followed. What he didn’t realize was just how close the Oo was to extinction—the bird he saw turned out to be the last known individual on the planet.

Why eBird: Sykes describe himself as “computer illiterate”—he even writes out scientific publications longhand and has someone type them up. Fortunately, others have volunteered to submit his books full of valuable data to eBird for him.

Caucasian Grouse. Illustration: John Gould/Wikimedia Creative Commons

Caucasian Grouse, spotted on Hillside East of Stephansminda, Georgia

eBirder: Peter Kaestner

Species: Tetrao mlokosiewiczi

Date: April 16, 2014

The sighting: Spotting a grouse-sized jet-black bird atop a snowy mountain may seem like an easy task, but the male Caucasian Grouse remains elusive despite its stark coloration. Kaestner, a U.S. diplomat and avid birder, went up about 10,000 feet on the mountainside where he heard the grouse lived on the edge of rhododendrons. Along the way, he flushed a female grouse from the bushes and got a nice look at her as she flew away. But Kaestner was really searching for the males, who sport a “fabulous long, lyre-shaped tail that sort of curves underneath."

Several hours of searching revealed no male grouse, but a lone wolf running through the snow kept Kaestner’s spirits up. He continued searching south of where he had seen eBird reports of this species. Suddenly, the bird he spent all day scanning the snow for was glaringly obvious. Perched atop a rock was a stunning male grouse fully displaying his dark, elegant plumes.

Why eBird: "I'm a twitcher. I've seen over 8,500 birds and I'm always looking for ways to contribute."

Rufous-vented Ground Cuckoo, spotted at the Mushu Llacta Forest, Ecuador

eBirder: Rudy Gelis

Species: Neomorphus geoffroyi

Date: April 3, 2005

The sighting: Gelis and several other field biologists had spent the day hiking through Ecuador’s Mushu Llacta Forest. “We knew that we were real explorers here, because no ornithologist had really studied the area before,” he says. By the time Gelis arrived at the campsite he was, “beat, but glowing.”

Too excited to sleep, Gelis set out that evening to scope out the area. To his astonishment, he saw a male Rufous-vented Ground Cuckoo and his mate right there on the trail, not even 10 feet away. When the cuckoos disappeared into the forest, Gelis hurried back to the campsite to show off the photos he snapped, turning everyone’s exhaustion into friendly jealousy.

Why eBird: “It’s a way for me to leave a legacy. This is actually data—long-term data.”