Tag Archives | Osprey

Osprey are Awesome!

Osprey Adult with Nestlings Underwing

Osprey Adult with Nestlings Underwing

The Osprey, aka fish hawk, is a bird of prey with some very special adaptations giving them their own taxonomic genus, Pandion and family, Pandionidae. Their outer toes, like those of owls, are reversible, allowing them to grasp their prey with two toes in front and two behind. Osprey toes also have sharp spicules on their lower surface allowing them to grasp slippery fish. They are the only raptor that plunge-dives feet first for live fish, which account for over 99% of their diet.

Osprey Diving For Fish courtesy of Teddy Llovet, Flickr Creative Commons

Like the Bald Eagle, Osprey populations suffered major declines largely due to the use of DDT in the 1950s and 60s. Osprey studies provided key evidence in court to block continued use of persistent pesticides, and Osprey populations recovered rapidly thereafter. Although small pockets of contamination remain, their historic range has greatly expanded and many populations in Canada and the United States now exceed historical numbers, owing to a cleaner environment, increasingly available artificial nest sites, and this bird’s ability to tolerate human activity near its nests. Now Osprey are the second most widely distributed raptor species, after the Peregrine Falcon, found in temperate and tropical regions of all continents, except Antarctica.

Osprey Building Nest at Shasta Dam

Being a predominately fish eating raptor, they nest near fresh or salt water, building large stick nests historically atop trees, rocky cliffs, and promontories. However, predation, loss of trees, and development of shorelines have been driving forces of Osprey shifting their nesting preferences to an array of artificial sites like channel markers in harbors and busy waterways; towers for radio, cell phone, and utility lines; and platforms erected exclusively for the species.

Osprey On Nest Platform

Osprey On Nest Platform

Shasta County is blessed, having many nesting locations for Osprey, several of them being man-made platforms. There was a pair of Osprey that built a nest atop the soccer field lights at Anderson River Park for many years. Unfortunately, the lamps in that light array had to be replaced every so often which usually caused damage to the nest. Wintu Audubon Society and the late Karen Scheuermann, wildlife rehabber of Tehama Wild Care, coordinated with the City of Anderson to install a permanent nesting platform atop that light stand to allow the Osprey to nest there in the future without being disturbed.

Osprey are usually monogamous and mate for life. They also show high fidelity to successful nest sights. We are pleased to announce that a pair of Osprey have indeed accepted our nest platform at the Anderson River Park soccer field and are currently raising two young! In the coming weeks we will be mounting a plague on the light pole to commemorate this coordinated and successful effort to advance the continued breeding success of this beautiful raptor.

Osprey Adult with Nestling at Anderson River Park

Osprey Adult with Nestling at Anderson River Park, June 17, 2021

0

Wintu Audubon Outing to Burney Falls

Join us on a day journey to Burney Falls State Park. We will have opportunities to see Osprey, Bald Eagles, Steller’s Jays, Turkey Vultures, Robins, Crows, Hawks, Mergansers and the Park’s unique annual resident Black Swifts who flit in and around the falls themselves. The falls are full and beautiful in the spring! The walk will last for a couple of hours. Bring a lunch and enjoy the Park after the walk. Meet Wintu guides at the Kutras Lake Parking Area in Redding at 8 a.m., or meet at the Burney Safeway parking lot in Burney at 9:15 a.m. Contact Catherine Camp, 337- 6874 for more information.

0

A Burning Question Beyond a Bird’s-eye View

Osprey Covering Young

Osprey Adult Shading Young

Something’s wrong, and the birds can’t figure it out. Day to day and year to year, it’s hotter. The birds go about their daily lives as they always have, and their days are too few, their minds too scripted, to even see that there’s a change. But they pant more. Vigor wanes, and they sing less. Rather than snuggling down to warm their eggs and chirp gently to the young inside, they stand over the eggs to shade them. Nestlings die from dehydration and heat exhaustion.

And then the fires hit. Most nestlings had already fledged this year, so at least for the mobile songbirds, and probably for most of the quail, turkeys, grouse, and roadrunners, too, escape was possible—a little by foot, and a lot by flight. Of course not all survived the firestorms, but Shasta Wildlife Rescue and Rehabilitation reported a single avian burn victim, a Great-horned Owl with scalded feet.

Carr Fire Burned House

Where did they fly? People who lost their homes might be able to tell you: wherever they could. But housing grows short. Even where humane values are diligently exercised there is upheaval. And birds are not particularly humane. They are birds, after all, not people.

Even with their best quail-like fellowship, they must crowd into smaller areas where there is still water to drink and vegetation to support the insects they feed on. But not all those places are seasonally ready to support them. The berries may not have ripened, and the fall salmon are not yet decaying along the riverbanks. Disease spreads more readily.

American and Lesser Goldfinches

Then comes the smoke. Most birds don’t live that long, so they may be protected from longer-term ailments like lung cancer. But like children they breathe quickly, so are probably more prone to asthma and bronchial infections, and may suffer similarly with reduced lung, heart, and brain functions.

People try to cope. We don N95 masks, or pretend we’re too rugged or bully to need them. Homeowners negotiate with insurance companies. The Chamber of Commerce and the EDC advertise business relief loans.

Birdhouse In Burn

The feathered things cope more primitively. They fly. They cannot make complex plans, or contemplate next year, or the likelihood of more heat, or the reality that their homes and livelihoods are gone up in smoke, leaving skeletons of trees and dead ash on the ground that once sustained them; or consider the years and generations following, and how the hundreds of thousands of acres burned and the millions more wilting in heat and drought will change resources for food or housing or the animal joy of singing.

Birds don’t have the capacity to grasp or modify the underlying conditions that cause suffering—to address resources with a deliberate eye to health, wildlife, a sustainable economy, climate change, and general well-being. They can’t discern the world beyond their own visceral and short-term needs. The burning question is, can we?

0

Osprey Nesting Platform Install

Osprey In Flight

The Osprey (Pandion haliaetus) at Anderson River Park in Shasta County have been nesting atop a soccer field light stand for over 17 years. The problem is that they build the nest right on top of the field lights. This becomes an issue when, every four or five years the light bulbs need to be replaced and the nest can be destroyed in the process.

Osprey Nest

One of my wildlife rehabber friends had received a legacy gift and contacted me regarding the prospect of building a nesting platform to place at the top of the utility pole. This would allow the Osprey to safely nest above the bank of lights, thereby keeping their nest intact year after year, with no interference from the maintenance crew.

I, of course said, “what a great idea!” I found an excellent plan for the platform (shown below) from the International Osprey Foundation and built it in less than a day. It is a 40 x 40 inch box which I modified using all 2 x 6 inch pressure treated lumber.

Osprey Nesting Platform

Before building the platform I contacted the Anderson City Public Works department to discuss the possibility of actually putting up the platform and got the OK. We obviously wanted to get it up before the Osprey arrived and were able to install it on January 31st.

Osprey Platform Lift

This is an 86 foot utility pole so a lift was rented and the excellent workers from the City of Anderson Public Works department generously gave their time and expertise to the project.

Having never seen an Osprey nest close up, I asked one of the installers to take some photos of the nest before removing it and placing the nesting material in a bin to be put back into the new platform.

Osprey Nest

The shape of the Osprey nest changes during the breeding cycle. During incubation the nest is distinctly bowl-shaped. After hatching the nest flattens out, but a rim of sticks is maintained, sometimes by the young themselves, while the young are beginning to move clumsily about the nest. In the last weeks of the nestling phase, the nest often becomes completely flat1. Note the large sticks and bark.

Osprey Nest

Here’s a shot of one of the installers placing the nesting material back into the newly installed nesting platform.

Osprey Nesting Material

About four weeks after the install I went back to the park to see if Osprey had shown up. I found one bird perched inside the platform!

Osprey In Nest

However, there were also a pair of very vocal Red-Shouldered Hawks (Buteo lineatusin) in a nearby tree.

Red-shouldered Hawk Pair

Apparently they were interested, for whatever reason, in the nesting platform as well.

Red-shouldered Hawk

A week later when I returned, the platform was now occupied by a pair of Osprey!

Osprey Pair

I observed them for over an hour but never saw them bring in nesting material, although there is obviously new sticks in the nest. The Red-shouldered Hawks were still hanging around but this day, the Osprey pair were involved in mating and the hawks were vigorously chased away by the male Osprey.

Osprey Copulation

Osprey pairs copulate frequently, on average 160 times per clutch, but only 39% of these result in cloacal contact. Pairs average 59 successful copulations per clutch, starting 14 days before, and peaking a few days before, the start of egg-laying1.

Osprey Copulation

Pairs copulate most often in early morning, at the same time as egg-laying1.

Osprey Copulation

As I returned a couple of weeks later, the first thing I noticed is that there has been much more nesting material placed into the platform and the male was bringing in more and arranging the sticks.

Osprey Building Nest

After trimming and arranging these large, long sticks, the male Osprey took off and the female did some rearranging.

The male soon returned to a nearby utility pole on the opposite side of the soccer field with a rather large, what looks like a trout.

Osprey With Fish

He ate about half of the fish, starting at the head, before carrying the remaining portion back to the platform to share with his mate.

Osprey With Fish

References: 1Birds of North America Online

0

Local Weekday Bird Walk at Anderson River Park

The river access, ponds, marsh, riparian and oak woodlands are all accessible by an extensive trail system at Anderson River Park. Meet trip leader Linda Aldrich 223-5341, at the Anderson River Amphitheater parking lot. All varieties of avian life are found here from waterfowl, Osprey, Bald Eagles to Scrub-Jays and Warblers.

0