Boulder County \ Weld County arrivals

[JohnT]

Cobirders:

               I've been doing my normal great horned owl tours and surveys.  This is my 21st year doing this amateur project, and I think this year has been one of the best.   Of the 17 owl nest sites monitored, the average clutch size appears to be three (but if you want to get technical, then 2.7).  Of course while canvassing for owl nests, I bump into lots of other things.

Of note for Saturday April 20th:

For Boulder County:

Great horned owl:  51 individuals at nest sites

Bald eagle:  16 - average clutch size 2, chicks of different sizes being fed

Osprey: 14 - virtually every "hack platform" has a pair now.  The interesting one is at Nelson and 75th, where the developers or the county knocked down the hack box, and put up a tornado siren tower.  Guess what happened?   Poetic justice I say.   The sidewalk is covered with sticks falling from 150 up on top of the tower where they built their nest.  The ospreys got the last laugh. 

Coopers hawk - 8 - actively building nests.  Its interesting to watch how they select the most pliable braches to weave the nest

Red tailed hawk - dozens, all on nests now

Prairie falcon - 1 - Louisville

Myrtle warbler - 4 - Sawhills \ Walden

Audubon's warbler - 6 - Sawhills \ Walden

Wren species:  WINTER or PACIFIC -  I'm not good at differentiating the two (east from west) unless I hear the song.  Along the Lobo trail, from Twin Lakes Gunbarrel, just west of 63rd near the owl nest site in a brush pile by the ditch.  Foraging actively on the ground, but staying in the shadows.

Marsh wren - 3 - at Cottonwood Marsh, and at Jim Hamm Park.  The two at Jim Hamm were actively chasing and singing.

Vesper sparrow - 1 - at McCall Lake

White crowned sparrow - 12 - Sawhills \ Walden, Louisville Open Space, and Boulder County Open Space

American white pelican - two at McCall Lake

White throated swift - 6 - Meadow Park, Lyons

Broad tailed hummingbird - 1 - Meadow Park, Lyons

Yellow headed blackbird - 7 - Jim Hamm Park

Mountain bluebird - 12 - in various locations;  already at higher elevations like Myers Gulch in Boulder Mt Park

Bushtits - 30+  - throughout Louisville and Boulder Mt Park - numbers increasing yearly.  And they are staying in neighborhoods all year long. 

Bull snake - 1st one this year - Sawhills \ Walden - note:  bull snakes prey on baby birds and birds eggs.

(for Boulder County records:  coyote, cottontail, mule deer, fox squirrel, black-tailed prairie dog, Abert's squirrel)

Weld County:

Great horned owl - 8 individuals at nest sites

Bald eagle - 8 individuals at nest sites

American avocet - 4 - Union Reservoir

Brown headed cowbird - 6 -  S. Platte River bridge, Platteville

Barn swallow - dozens - S. Platte River bridge, Platteville

Cliff swallow - hundreds - S. Platte River bridge, Platteville

Wild turkey - 1 - male displaying - St Vrain River flood plain overlook - Road 17 and Hwy 66

Western grebe - 12 - Union Reservoir

Flower note:  blooming: cranesbill, dandelion, and pasque flower:  Signal the nesting of prairie and peregrine falcons, and black bears coming out of hibernation

John T (Tumasonis)  Louisville CO