June 23, 2012: Construction Activity Near Nest

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by Bob Sallinger

kgw.com

Posted on June 23, 2012 at 12:37 PM

Updated Saturday, Jun 23 at 2:07 PM

Many viewers have been asking about the construction activity that is occurring near the osprey nest and are concerned that the activity will disturb the birds. This is definitely a valid concern. We will contact folks on Monday to see if something can be done to provide better protection to the birds. From my limited viewing I have not seen obvious disturbance behaviors---however it is tough to tell on the screen.

Osprey are among our most tolerant birds of prey when it comes to human activity in the vicinity of their nests. They often nest on low pilings with heavy nearby boat activity and in active human use areas. In Portland we have had them build nests on industrial sites, cranes and even on ships that have come into port. A pair has nested on top of the light poles in the middle of the parking lot at the Jantzen Beach Mall.

However that is not to say that they are immune to disturbance. This is especially true when there are sudden and dramatic changes in their nesting area during the nesting season. Disturbance can manifest itself in many ways. Nest abandonment is probably the most extreme example, but it can also be more subtle. For example disturbance can cause parents to leave the nest temporarily leaving eggs or young vulnerable to predation, overheating or over cooling. It can cause disruptions in hunting and feeding patterns and result in young not getting enough food---all the bigger concern if there are many mouths to feed (in this case there is only one). It can spook the young and cause them to fledge prematurely before they can fly.  These birds live their lives on the edge and the difference between nesting success and nesting failure can be a very fine line...and often you don't know you have crossed it until it is too late.

The construction at the South Waterfront Site has been planned for years. The city is restoring the greenway to provide habitat for fish and wildlife and to remove contaminants. It will ultimately benefit the osprey as well by leaving the river healthier and cleaner. The construction will take more than a year and faces significant timing restrictions due to protections for federally listed salmon species. It needs to happen and it will make the river healthier for people and for wildlife---it has been a very long time coming! We are assuming that the activity that is being observed on raptor cam is associated with the greenway restoration, but we will confirm on Monday.

There was consideration given to relocating the osprey nest further from the construction zone prior to the 2012 season. However this option was opposed by some members of the local community who were concerned that the the osprey would not accept a new nest further up the greenway and also because they felt their viewing opportunities would be more limited. For the record, Audubon's position on this issue was that priority should be on locating the nest in a manner that minimized construction disturbance as much as possible while still providing a reasonable likelihood for nesting. For better or worse things didn't go that direction and the nest was left near the construction zone...The birds are there and they are nesting....so it is what it is.

One thing that folks should realize is that the video feed is somewhat distorted. We are filming from far above the nest and a good distance away. This flattens out the picture and makes the foreground and background appear much closer than than they actually area. There is definitely activity close to the nest but it is not as close as it seems on raptor cam. I will try to go down today and take some ground based pictures that will give you a better idea of what things really look like.

Again we will be in contact with folks on Monday to 1) determine whether this is greenway construction or something else and 2) regardless see if greater protection can be carved out for the birds.

 

 

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