Early March is a good time to get ready for the coming Osprey season by reviewing what we have seen in prior seasons. In this article, we will summarize the observations from the 2020 through the 2023 seasons, and then list things to look for this season.

2020 Osprey Season

There is an Osprey nest on a platform consisting of a warehouse pallet secured to the top of a utility pole here in my Eugene, Oregon, neighborhood that is conveniently located for observation from ground level. I refer to this as the Boulders nest.

During the COVID-19 pandemic, I began taking photos and writing my observations in articles I self-published on the internet. Here are the links to the articles I wrote about the 2020 season.¹

• Article 1
• Article 2
• Article 3

Below are key points I noted in the 2020 season.

• Three Osprey juveniles successfully fledged
• I observed the adult pair of Ospreys cooperating to handle a large fish on a rock in the river (see the photo above), documented in article 1.
• We spotted an Osprey on the second nest platform about one mile downstream from the Boulders nest (described in article 2), but no nest was established in 2020.
• Also in article 2 (on page 3), I described the rough calendar of dates for Osprey nesting, using published durations counting forward from the observed arrival date window of mid-March.
• I watched the juveniles practicing their flight technique by briefly hovering above the nest in the days before their first successful flight from the nest in article 2.
• I noticed the juvenile Ospreys perching on utility poles and utility cables in their first few weeks of flight, something we have not seen the adults do (see article 2 and article 3).
• I observed the juveniles waiting near the nest for an adult to deliver a fish, then fly to the nest to claim their share, and fly off to eat in peace nearby (described in article 3).

2021 Osprey Season

I wrote eight articles about the 2021 season; below are the links.

• Article 1
• Article 2
• Article 3
• Article 4
• Article 5
• Article 6
• Article 7
• Article 8

The main observations from the 2021 season are listed below.

• Three juveniles fledged from the Boulders nest again this year
• Ospreys add sticks to their nests throughout the season.
• We observed an adult catch a large fish, then call to one of the nearby juveniles and pass the fish to the juvenile (documented in article 7). This appears to be a form of training on how to handle a large fish in the river, though not on the more difficult survival skill of targeting, diving, and catching a fish.
• We noticed Turkey Vultures successfully confronting Ospreys and stealing fish from them (documented in article 8); I haven’t read references to this aggressive behavior by Turkey Vultures, but I assume it isn’t unique to the Willamette Valley.

2022 Osprey Season

In 2022, I wrote four articles on the Ospreys, as listed below.

• Article 1
• Article 2
• Article 3
• Article 4

The summary of my observations from the 2022 season are as follows.

• We observed an Osprey repeatedly diving at a perched juvenile Bald Eagle (see article 2); we had seen Ospreys chase off Bald Eagles in flight before but had not seen them diving on them. Bald eagles are well-known for stealing fish from Ospreys (kleptoparasitism).
• I observed the male and female taking turns incubating eggs at the nest, which confirms that males share in incubation duty.
• Only one juvenile Osprey fledged from the Boulders nest in the 2022 season, compared to three in all the other years observed. I don’t know the reason, but offered some theories in article 3, including 1) the possibility that only one egg was laid, 2) fish scarcity, and 3) predation. In article 4, I mentioned a fourth possibility, heat stress.
• I noted that in both 2021 and 2022, the last date that the Ospreys occupied the nest was around the 23rd or 24th of August.

2023 Osprey Season

For the 2023 season, I wrote eleven articles, the first three using the standalone Adobe InDesign Publish Online method of all my previous articles, and the remaining seven in this WordPress blog.

• Article 1
• Article 2
• Article 3
• Article 4
• Article 5
• Article 6
• Article 7
• Article 8
• Article 9
• Article 10
• Article 11

Here is the summary of what I observed in the 2023 season.

• The sides of the Boulders nest have become taller due to the continual addition of sticks by the Ospreys such that it was difficult to see when the female had begun incubating eggs in 2023.
• The pair in the Boulders nest produced three hatchlings this year, and all three fledged successfully.
• One of the three Boulders nestlings was significantly smaller than the other two; this was the first time we had seen such a clear size difference among the Osprey hatchlings, and we were worried that it might not survive. It was both a relief and a pleasure to see the adult female feed the runt enabling him to thrive and fledge.
• For the first time in many years, a pair of Ospreys occupied the Owosso nest, about one mile downstream from the Boulders nest. The Owosso pair had one hatchling and it also successfully fledged.
• The nesting schedule at the Boulders nest was about one month later than previous years (it was an especially cold and wet spring), exemplified by fledging of the juveniles in the second half of August, as observed in article 9.
• When observing wildlife, it is easy to form emotionally satisfying conclusions that don’t hold up upon closer examination (noted in article 9).
• We observed one of the Owosso adult Ospreys scream at then aggressively dive at a group of Turkey Vultures that had apparently stolen a fish.
• The fish that Ospreys catch attract pesky flying insects which I initially thought were hoverflies, but I now think are stinging yellowjackets. These yellowjackets are readily apparent in photos in article 10.
• Over the years, we have observed the Boulders Ospreys using a particular shallow spot upstream from a gravel bar opposite the nest for bathing.
• The last Boulders Osprey to leave on migration was one of the juvenile females, last sighted on October 1, as noted in article 11.

Looking Ahead to the 2024 Season

The Boulders nest platform survived another winter and stands empty before the arrival of the Osprey pair.

Below are a list of things I will be paying attention to this season.

• The observed arrival times in our neighborhood along the Willamette River range between March 15 and 20, dating back to 2018. When will we see the first Osprey this year?
• Will the Owosso nest be occupied again this season?
• Unfortunately, there is no webcam above the nest, so we won’t know for sure what is going on inside the nest, and we may not be able to see the female when she is hunched down to incubate the eggs this season.
• How many hatchlings will be produced in each nest?
• Will all the hatchlings successfully fledge?
• What interactions will we observe between Ospreys and Turkey Vultures this season? We spotted the Turkey Vultures near the Owosso nest a few days ago, so we know they are already here, looking for fish to claim.
• What interactions will we see between Ospreys and Bald Eagles?
• Will we note any Osprey behaviors we haven’t seen before?
• When will all the Ospreys leave the area on migration?

1. The articles from 2020 through the third article in 2023 were all published individually on the internet using the Adobe InDesign Publish Online feature; from article 4 in 2023, all the pieces are published on this WordPress blog. ↩︎