Montana's wild wildlife!

Taking Wing:
Montana's Osprey

Hunting on the wing, an osprey appears to glide effortlessly over the water. Ospreys have narrow wings, which they bend when soaring and scanning for fish beneath the surface. They have dark brown feathers on their back and a white belly, with a mostly white head marked by a dark brown eye stripe extending from the eye to the neck and shoulders; the undersides of the wings are white except for dark ?wrist? patches and brown?barred flight feathers. Though smaller than an eagle, ospreys are still big, ranging in length from about 21 to 24 inches with wingspans of roughly 54 to 72 inches.

An osprey may nest in any location that is near a body of water and provides safety and an abundance of fish. Osprey nests are generally found close to a lake, reservoir, river, or large wetland, and even during migration they stay near water, often following river valleys when they depart from Montana in fall for wintering areas that can extend into Mexico, Central America, and South America. Many birds that nest in Montana leave by October, but some juveniles migrate even earlier, following established flyways south.

Since ospreys are so particular about living close to the water, it is not surprising that they are fish?eating specialists. Nearly their entire diet consists of fish, and it is extremely rare for them to eat anything else. Along the upper Missouri River in Montana, studies show that ?rough fish? such as suckers (catostomids) are the most common prey, with trout and other salmonids and cyprinids (minnows) eaten in similar amounts, and perch also taken. Barbed footpads on the soles of an osprey?s feet and long, sharp, curved claws help it grip slippery fish so its lunch does not get away, and dense, oily plumage plus nasal valves that close during dives help keep water out when they plunge feet?first into a river or lake.

Unlike eagles, which usually build nests in live trees below the tree canopy, ospreys prefer to build their nests at the tops of stout dead tree trunks or snags. In the absence of a natural site, an osprey will make its nest on man?made structures such as power poles, channel markers, and especially nest platforms designed for them, and these platforms have become an important tool for maintaining and re?establishing ospreys in areas where tall shoreline trees are scarce.

Ospreys arrive in much of Montana in March and April to build or refurbish their nests. Male and female ospreys share the work of collecting sticks and other materials, but the female does most of the arranging at the nest, which they line with softer materials such as grasses, moss, or cardboard and other light debris. In April or May the ospreys lay their eggs, and the average clutch consists of about three; the eggs do not hatch all at once, so the first chick may hatch up to five days before the last one. The older chick often bullies its younger siblings and grabs most of the food brought to the nest, while bald eagles, great horned owls, raccoons and other predators sometimes take eggs or nestlings, though the speckled appearance of osprey chicks helps camouflage them in the nest. If they receive enough food and remain safe from predators and severe storms, the young typically leave the nest in July and August when they are about two months old.

With the introduction and widespread use of the pesticide DDT, osprey populations in many areas declined sharply in the 1950s and 1960s. DDT was banned in the United States in 1972, and since then osprey populations have rebounded across much of North America, including Montana. In western Montana, however, ospreys that nest along the Clark Fork River and its tributaries continue to help scientists track pollution from historic mining and smelting, because the fish they eat can carry high levels of heavy metals such as arsenic, cadmium, copper, lead, zinc, and especially mercury. Long?term studies of blood from osprey chicks on the Clark Fork have shown mercury concentrations many times higher than thresholds considered safe for humans, making these birds important indicators of lingering contamination and the success of ongoing river cleanup work at one of the nation?s largest Superfund sites.

Today, ospreys are considered a valuable indicator species for monitoring the long?term health of large rivers such as the Missouri and Clark Fork because of their fish?based diet and sensitivity to pollutants that build up in aquatic food webs. They are also such beautiful, impressive animals that they attract bird?watchers and other visitors to rivers, lakes, and nest?camera sites throughout Montana and beyond, supporting local tourism and outdoor education programs. For two decades Missoula?s minor league baseball team honored this swift, graceful bird by playing as the Missoula Osprey before rebranding in 2019 as the Missoula PaddleHeads, a name that now highlights river recreation while still connecting fans to local waterways that ospreys depend on.

You can listen to an osprey’s loud whistled call here.

Updated: February 2, 2026