Osprey
The weather has been a nightmare for Delaware County’s Osprey this spring. While I cannot be absolutely sure about the trials and tribulations of nest life on top of an exposed tower, I can postulate that high winds, low temperatures, relentless rain, and deep, fast flowing water are negative factors affecting fish hawks this year. I offer my interpretations of this year’s bumpy start to the Osprey season.
The Osprey platform at Delaware lake stands just south of the Rt. 229 Bridge. Incubation started between April 19 – 24. Incubation lasts 37 days, so hatching is predicted to occur between May 26 and June 1.
Four platforms stand in the northern most regions of Alum Creek Lake (AC) along Hogback Road just southeast of Kilbourne, a small village along Rt. 521. As many as seven Ospreys have been counted at one time which has been another energy-burning factor as “soap operas” continue when unmated birds invade established territories. Bald Eagles are also common intruders at Alum Creek.
My observations and predictions:
- At Platform One (AC-1), the most northern, incubation started around April 12, but the nest failed by April 21. A second attempt at incubation started on April 28 and eggs should hatch around June 5.
- AC-2 is unoccupied at the present time even though a “floater” claimed it earlier in the season.
- AC-3 is home to a Canada Goose nest with five eggs, thanks to the Osprey on AC-4 that initially added sticks to AC-3 upon their arrival from South America. Once the Osprey moved to AC-4, the geese took over the platform and scooped the sticks into a neat pile that became their nest. The Goose incubates as the gander swims below. He sometimes stands beside his mate on their nest. Incubation started around April 21 and hatching, along with long drops by goslings, is expected on May 18 or 19.
- Incubation on AC-4 started on April 12, and like AC-1, the nest attempt failed by April 21. Incubation had resumed around April 23 and hatching is expected to help observe Memorial Day.
- The most visible nest in Delaware County is at the Hoover Nature Preserve (H) near the end of the boardwalk at Galena. Hoover Number Two, H-2, was installed in October 2008 and is very visible from the very public boardwalk over Hoover Reservoir. H-2’s Ospreys are the county’s earliest to nest and incubation was in progress on April 7, so hatching is predicted by May 15 or earlier.
H-1, the original platform erected on September 11 and 12 in 2002, is hundreds of yards from the boardwalk and spotting scopes are needed to watch its nest that was built by the same pair that now occupies H-2. Eagle activity might have convinced this year’s Osprey to stick with H-2 to avoid encounters with our national bird. H-1 is unoccupied for now.
For those wishing to see Osprey nestlings, it takes ten days to two weeks before “dinosaur heads” can be seen reaching for food above the rim of the nest during feeding events. After hatching, nestlings are fed for eight weeks before they can fly from the nest.
American Kestrels
Kestrels are off to a promising start.
On May 11, the fourth time this season, Dick Phillips and I checked the fifty-mile-long roadside route of 18 nestboxes hanging from utility poles. We recorded sixteen active nests which were one more than counted two weeks earlier. We attached aluminum leg bands to the first family of 2011, a passive family of four females and a male. At other nests, seven adult females and a lone male stayed on their nests, making data counts impossible as they incubated eggs or brooded nestlings. I have considered the notion that veteran hawks know us as harmless annoyances that lift the lid of their abodes and quickly leave without causing harm. Probably not, but it is something to smile about.
After I count eggs and age nestlings, I use thirty days each for the incubation and nestling periods when I calculate, extrapolate and predict kestrel due-dates in my master data books.
Two remaining nestboxes, K-1 and K-16, held seven and eight European Starling eggs, respectively. We always remove the aliens’ eggs while leaving their nests alone since kestrels will use abandoned starling nests for their own attempts. Starlings do not lay first eggs beyond the first week in June.
So far, all of the visible sparrow hawk clutches have shown five eggs. No clutches of four or six have appeared. Standing water has been the norm during many of the days of the kestrel season so far. Earthworms have been abundant, and perhaps meadow voles and other furry prey are more vulnerable to hunting hawks after being flushed from their burrows. Also, I have twice watched kestrels fly by with snakes in their talons. Whatever kestrels are doing to deal with this spring’s high water and adverse weather, their nest chambers show great potential while hanging safely on utility poles that are protected from raccoons by bands of aluminum flashing.
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A Final Note
I would like to add that the best observations on May 11 were farmers starting to work their fields. Hopefully, our own food chain will have a successful outcome after this year’s extremely wet, late start