Positive Hatching Signs At Riverside

Thirty M.P.H. winds made it difficult to observe and photograph the nest Sunday afternoon, but there were positive signs that one or more eggs may have hatched.  The mother ate on the nest and appeared to be sharing food.  It wasn’t conclusive and she may have just been “eating for one”, but it did look like she might be feeding.  We’ll know for sure in a few days.

The father joined the mother on the nest but there wasn’t an exchange.  Another sign one or more eggs may have hatched.

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Bad News And Good News At Riverside

The bad news is the adult male Riverside Park hawk ate a dead rat on Wednesday around the dumpsters where the Bromadiolone was placed.  Reports on Wednesday were that the male seemed lethargic, but he seemed fine on Friday when I was in the park.  Since the poison takes 5-7 days to take effect, we’ve got to keep our fingers crossed.  Hopefully, the secondary dose from the rat was low enough not to cause harm to hawk.

Susan B. Elbin, Ph.D., Director of Conservation and Science, New York City Audubon passed along an article from Environmental Contamination and Toxicology, Anticoagulant Rodenticides in Three Owl Species from Western Canada, 1988–2003,  Courtney A. Albert, Laurie K. Wilson, Pierre Mineau, Suzanne Trudeau, John E. Elliott.  Among the topics the paper discussed was the potential under reporting of deaths caused by non-lethal doses of Anticoagulant Rodenticides.  The authors believed that many non-lethal doses which cause lethargy, resulted in increased predation and “accidental” deaths due to collisions and car accidents. 

I had always thought about poisons from a perspective of instant “Romeo and Juliet” style poisoning, rather then a more nuanced problem where the poisons act slowly and can cause secondary problems such as infertility in lower doses. Could the two highway accidents in 2009 have been a result not of inexperience fledglings misunderstanding traffic, but a result of non-lethal doses of Rodenticides making the hawks lethargic and therefore misjudging their flight paths?   It’s impossible to know, but it does suggest that necropsies should be performed on urban hawks, even if cause of death seems obvious.

Now the excellent news… Both Glenn Phillips, Executive Director, New York City Audubon and Leslie Day, author of the Field Guide to the Natural World of New York City and Boat Basin resident have been having productive discussions with John Herrold, Riverside Park Administrator, Dr. Robert Corrigan, who is in charge of DOH’s rodent control program and Parks Commissioner Adrain Benepe. 

From what I understand the discussions have been positive and both short term and long term results should be forthcoming.   I can’t thank Glenn and Leslie enough for their efforts on behalf of the Riverside hawk pair.  It’s clear that everyone involved is committed to finding a solution to this complicated issue. 

Discussions have uncovered topics that weren’t entirely obvious. For example, while the Parks Department has a conservative approach to applying poisons, restaurants in the park are required by the Department of Health to have a rodent control plan.  This introduces independent exterminators, who then potentially over apply poisons in the park without Parks Department supervision or oversight.  (We saw this a few years ago at the Boat House Restaurant, which mirrored the situation at Riverside. At the Boat House improved sanitation has greatly decreased issues with rodents, and reduced the needs for poisons.)

It’s also been discovered that grass seed is being stored in the open in plastic bags on the lower garage level of the Boat Basin below the café and is attracting rats from the Amtrak train tunnel.  Finding a better storage method should become a priority.

I spent about two hours watching the hawks on Friday afternoon.  There were no signs the eggs had hatched yet.  I saw the father circle overhead, but didn’t see him at the nest.  (This isn’t unusual for this pair in the late afternoon.)

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Riverside Nest

I finally got down to the Riverside Park nest today.  Daylight Saving Time, sure helps make it easier to bird watch after work.

The female is already sitting on the nest, and I got to watch the male arrive and allow her to take a dinner break.  After this pair’s bad luck over the last few years, I hope this year goes smoothly.

The nest is the same as last year’s and is along the river around 81st Street.

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Riverside Update

I’ve been away on weekends, and it’s too dark in the late afternoon to visit Riverside Park after work, so I haven’t been able to visit until this Saturday. 

While I was away I received reports of the youngster being at the ballfields by the dumpsters south of the Boat Basin, and further north in the 90’s and 100’s.  The youngster’s being outside of the parent’s territory is a great sign that it’s growing up!

When I visited Saturday, I only found the two parents.  They were together on a water tower at 81st and Riverside, and both few off towards the south.  I found one, perching on various lamp posts above the highway.

I went looking for the youngster, without any luck.  As I left the park, I saw a bird perched on a building at 90th and Broadway.  I was hoping it was the youngster, but found that it was a Peregrine Falcon, a nice consolation prize.

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Promenade On Monday

When I finally found the juvenile Red-tail at Riverside Park it was on the Soldier and Sailors monument on top of one of the decorative eagles.  By the time I got my equipment out, the hawk had left!  The hawk then when up and down the Promenade a few times before roosting in an Oak tree on the east side of the Hippo playground.

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