Subject: Ospreys fishing, Pied-billed Grebes nesting at Green Lake, Seattle
Date: Jul 18 23:01:32 1998
From: "Martin J. Muller" - martinmuller at email.msn.com
Saturday, Seattle.
Went to Green Lake to check on hatching of Pied-billed Grebe eggs. When I
arrived my attention was drawn to an Osprey (Pandion haliaetus) circling
over the lake. The following are my transcribed notes as dictated to a small
cassette recorder at the time:
17:30 Green Lake.
Adult male flying over lake, after 3-4 min circling hits the water, comes up
with a carp (25 cm), gains altitude with it over Aurora Avenue, heads off to
W.
17:35 look back at lake and spot an adult female with signs of primaries
molt in left wing circling to S, she hits the water at 17:38, 17:40, 17:43,
17:46 and finally catches a carp (25 cm) at 17:50, is heading E, a subadult
Bald Eagle (Haliaeetus leucocephalus) comes off the island, starts chasing
her, heading SE, some real close calls with the eagle within feet, but every
time that happens she starts banking and making very tight circles, forcing
the eagle to turn, increasing the distance. Eventually, the eagle gives up
when they are well S of the lake (over Freeway) the Osprey heading straight
S, the eagle returning to Woodland Park.
First time I've seen an Osprey carrying a fish get the better of an eagle
Notes:
Sex of the Ospreys was based on the absence (male) or presence (female) of a
"necklace"; well aware that Bill Clark says this is not a reliable way to
determine sex in this species.
Fish size estimate based on comparison of length Osprey 55-70 cm.
The light was great, sun in my back, no trees in the way, followed the birds
in the scope (at 25x) all the time, at distances from 50-500 m.
I love their body (and wing) shake shortly after getting airborne from a
dive into the water.
Checked on Pied-billed Grebe (Podilymbus podiceps) nests.
Currently there are 8 nests on the lake, all located in lily patches:
1) 3 half-grown young, their parents on 6 eggs
2) 2 independent young, their parents on 5 eggs
3) nest with 2 young and 3 eggs; hatching
4) nest with 5 young remaining of 6 that hatched over past 3 days
5) nest with 5 eggs
6) nest with six eggs
7) nest with 7 eggs
8) nest with 6 eggs.
#3 should finish hatching tomorrow or the day after at the latest.
Most others have another 4-10 days of incubation to go. Those that do not
have young are on their first successful clutch, all having lost previous
clutches to spawning carp accidentally destroying the grebes' floating
nests. Thus far Pied-billed Grebes have lost 25 eggs to carp-induced nest
destruction (that I know of). Grebe revenge: during feeding bouts 15-20
small (1-3 cm) carp can be delivered to hungry grebes in as little as 25
minutes. Towards the end the young are so completely stuffed they peer from
underneath the brooding adult's wings but do not come out for more food,
despite the food-proffering adult's encouraging vocalizations. The adult
ends up eating the fish him/her self, then turns attention to more mundane
task like nest or body maintenance.
Martin Muller, Seattle
MartinMuller at email.msn.com