Hellgate Ospreys

Location: Missoula, MT

Camera Host: Montana Osprey Project on Facebook

Find more about Weather in Missoula, MT

July 17, 2018

Louis Delivers Second Fish of the Morning to Hellgate Nest

Ospreys are the original fly fishermen! Over several studies, Ospreys caught fish on at least 1 in every 4 dives, with success rates sometimes as high as 70 percent. The average time they spent hunting before making a catch was about 12 minutes—something to think about next time you throw your line in the water. 

July 13, 2018

Louis Swoops In From Afar With Half-eaten Fish

Watch Louis make a grand delivery from a faraway power pole (with an Eastern Kingbird in tow) as Iris calls him in.  

July 12, 2018

Live Chat Q&A With Dr. Erick Greene and Rob Domenech

Join our experts from the Montana Osprey Project as they discuss the Osprey breeding season so far, answer questions from viewers, and provide insights on everything from Osprey migration to anatomy!  

July 17, 2018

Louis Delivers Second Fish of the Morning to Hellgate Nest

Ospreys are the original fly fishermen! Over several studies, Ospreys caught fish on at least 1 in every 4 dives, with success rates sometimes as high as 70 percent. The average time they spent hunting before making a catch was about 12 minutes—something to think about next time you throw your line in the water. 

July 13, 2018

Louis Swoops In From Afar With Half-eaten Fish

Watch Louis make a grand delivery from a faraway power pole (with an Eastern Kingbird in tow) as Iris calls him in.  

July 12, 2018

Iris Brings In Large Strip of Bark, Builds Up Rim Of Hellgate Nest

Watch Iris bring in a large piece of bark and spend several minutes finding the perfect placement for it in the nest.  

June 27

Iris Removes Deceased Nestling From Hellgate Osprey Nest

Iris removed the body of chick #2 from the nest this morning at around 6:28 AM. According to several observations by researchers, Ospreys are thought to typically leave deceased young in the nest to become part of the natural substrate. However, across various breeding seasons at different on-cam nesting sites, we have also observed adults removing the bodies of their deceased nestlings on several occasions.  

June 25

Youngest Remaining Osprey Chick Dies

We are sad to report that after several hours of inactivity in the nest the younger of the two Osprey chicks in the Hellgate nest has died, likely of starvation, after failing to recover from a roughly 24-hour absence of food at the nest between June 24 and June 25. High water levels and high turbidity in the Clark Fork River and surrounding waterways have proven difficult for fishing, and the Ospreys have not been able to provide enough food to support more than one chick at this point in the breeding season. Despite this sad news, multiple fish have since been brought to the nest, and the remaining chick looks strong and healthy.  

June 11

Youngest Osprey Chick Dies

We are sad to report that the youngest Osprey nestling appears to have perished from starvation after becoming too weak to recover from a 36-hour period without food over the weekend. While it is hard to watch, nestling mortality is not uncommon in wild bird nests. In Ospreys, older siblings have a higher survival rate than younger siblings, and nestling mortality is higher for the first 2-3 weeks after hatch during the peak period of growth. We all had hoped that all of the chicks would survive to fledge, but after after harsh fishing conditions left the nest without food for a day and a half, it is fortunate that the eldest two chicks have survived and been fed well since the hiatus. Thankfully, Louis and Iris still have a chance at a successful breeding season, and we hope that you continue to watch and learn along with us. 

Osprey

Tree

Nest Placement

Ospreys require nest sites in open surroundings for easy approach, with a wide, sturdy base and safety from ground predators (such as raccoons). Nests are usually built on snags, treetops, or crotches between large branches and trunks; on cliffs or human-built platforms. Usually the male finds the site before the female arrives.

Nest Description

Osprey nests are built of sticks and lined with bark, sod, grasses, vines, algae, or flotsam and jetsam. The male usually fetches most of the nesting material—sometimes breaking dead sticks off nearby trees as he flies past—and the female arranges it. Nests on artificial platforms, especially in a pair’s first season, are relatively small—less than 2.5 feet in diameter and 3–6 inches deep. After generations of adding to the nest year after year, Ospreys can end up with nests 10–13 feet deep and 3–6 feet in diameter—easily big enough for a human to sit in.

Clutch Size

1-4 eggs

Incubation Period

36-42 days

Nestling Period

50-55 days

Egg Description

Cream to pinkish cinnamon; wreathed and spotted with reddish brown.

Condition at Hatching

Capable of limited motion. Covered with down and with eyes open.

Fish

Food

The Osprey is the only hawk on the continent that eats almost exclusively live fish. In North America, more than 80 species of live fresh- and saltwater fish account for 99 percent of the Osprey’s diet. Captured fish usually measure about 6–13 inches in length and weigh one-third to two-thirds of a pound. The largest catch on record weighed about 2.5 pounds. On very rare occasions, Ospreys have been observed feeding on fish carcasses or on birds, snakes, voles, squirrels, muskrats, and salamanders. Ospreys probably get most of the water they need from the flesh of their prey, although there are reports of adults drinking on hot days.

Typical Voice

Ospreys have high-pitched, whistling voices. Their calls can be given as a slow succession of chirps during flight or as an alarm call—or strung together into a series that rises in intensity and then falls away, similar to the sound of a whistling kettle taken rapidly off a stove. This second type of call is most often given as an unfamiliar Osprey approaches the nest. As the perceived threat increases, the call can build in intensity to a wavering squeal.
more sounds

See full Species Info at All About Birds

About the Hellgate Canyon Ospreys

This Osprey nest is at the mouth of the spectacular Hellgate Canyon at the edge of Missoula, Montana. It’s in a very busy location, right outside the Riverside Health Care Center and next to busy parking lots, a construction site, a busy highway, and a railroad. However, it’s also an ideal location in many ways, since these Ospreys have riverfront property only about 50 feet from the Clark Fork River. Being so close to people does not bother them, and hundreds of people enjoy watching them every day.

The female Osprey at this nest is called Iris because she has very distinctive spots on her iris, especially in her left eye. These iris patterns serve as individual barcodes and allow us to identify her. She has nested at this site for many years. Her mate of many years, Stanley, did not return in 2016, and she attempted to breed with a new male dubbed “Louis”, named after an influential local Salish elder named Louis Adams

Ospreys are consummate fishing birds, and this pair fishes primarily from the Clark Fork River and nearby Rattlesnake Creek. They use their 6–7 foot wingspans to soar above the water, looking for fish, then diving as deep as 3 feet for shallow-swimming prey. Adult Ospreys usually weigh 3–4 pounds, and they can carry prey up to 50 percent of their own weight. Ospreys can live up to 25 years, and they typically lay 1–4 eggs in a clutch.

Most Osprey pairs are monogamous, staying paired across seasons and beginning nesting soon after each returns from a long migration. Both sexes incubate the eggs. The female sits for the majority of the time (including throughout the night) while the male provisions her with fish. After the eggs hatch, the male continues to bring fish to the nest; the female exclusively broods the young and dissects their meals for about a month after hatching. Later on, when the chicks no longer require her protection and their appetite for fish increases, she will leave the nest and go fishing.

The nest used to be on a power pole about 200 feet west of where it is now. This was dangerous, since the Ospreys could have been electrocuted, causing fires and power blackouts. In 2007, the current nest platform was erected to provide a safer place for the Ospreys to nest. They took to it immediately. Getting the new nest platform set up, and installing and running to high resolution camera for this feed for you to enjoy has been a large effort involving many groups: Riverside Health Care Center, Karen Wagner, Kate Davis and Raptors of the Rockies, Northwestern Energy, Dave Taylor Roofing Company, and Drs. Heiko Langner and Erick Greene of the University of Montana.

About Project Osprey

These Ospreys are an important part of a much larger project focusing on the health of aquatic systems and Osprey populations in western Montana. In collaboration with Rob Domenech (Director of the Raptor View Research Institute), Dr. Heiko Langner and Dr. Erick Greene started Project Osprey in 2007. They have been monitoring about 200 Osprey nests in western Montana.

Because of their top position in the food web, Ospreys are useful indicators of local environmental conditions. Young Ospreys eat only fish their parents catch within a few miles of the nest, so these young birds reflect the condition of the local fish population. And although many hawk species can be touchy—even dangerous—to work with, Ospreys make good subjects: they tolerate human activity well and they actually seek out human-made structures to use as nest platforms.

Osprey populations declined to near-extinction in the Lower 48 states after World War II as a consequence of exposure to DDT-based pesticides. The dwindling Osprey population helped trigger research into problems with DDT, resulting in its ban in the United States in 1972. Since then, Ospreys have returned to many large water bodies. Studies such as this one help scientists keep a watchful eye on how Ospreys—and the water bodies they depend on—are doing.

Since young Ospreys eat fish that their parents catch usually within a few miles of the nest, the young birds reflect the condition of the local water quality and fish. When the chicks are large enough to band, the researchers use a large bucket truck to get up to the nests. They take very small blood and feather samples from the chicks and put them quickly back in their nest. These samples are analyzed in Dr. Langner’s state-of-the-art environmental chemistry lab. The good news is that levels of some of the heavy metals of particular concern in western Montana (arsenic, lead, cadmium, zinc, and copper) occur at very low levels in the Osprey chicks. The bad news is that levels of mercury, a powerful neurotoxin, occurs in very high levels in Osprey chicks in some places. Project Osprey is now focusing on this serious environmental problem.