[cobirds] Great Egret and fledged White-faced Ibis in heronry at Walden Res (Jackson Co)

I visited Walden Reservoir this morning to check the heronry on a large island. Many White-faced Ibis, which Paul Slingsby and I confirmed nesting August 1, had fledged young. Some could still be heard on the nest. The ibis nested on an island of inundated willows and on the large island that has a large population of California Gulls. About 120 adults and fledged young ibis were present. (Probably a low number).

The large island, which is best observed from the east side of the lake, hosted only California Gulls when Paul, the late Jim Duggan, and I began monitoring the lake for RMBO'sColonyWatch. In 2006, American White Pelicans and Double-crested Cormorants also established highly visible colonies on the island. About that time, we also began seeing 3-5 pair of Snowy Egrets nesting in brush at the south end of the island. Shortly thereafter a few pair of Black-crowned Night Herons established nests in a couple of large willows on the island.

Last year, the gull, pelican and cormorant colonies all but disappeared probably due at least in part to low water levels.

This year, abundant water has brought an efflorescence of the heronry.There were at least 10 Snowy Egret nests. One or possibly two pair of Great Egret nested there. Cattle Egret have been reported by several observers, and on Aug. 1, Paul and I saw an adult in the heronry. Unfortunately, we couldn't tie it to a nest. 

Interestingly, perhaps due to undetected events last year, the pelicans and cormorants developed a strategy of nesting in brush on the island out of sight from shore. Today, about 240 were present, mostly young. 

As a final treat today, I caught a short look at about 20 juvenile Black Terns.

More people deserve credit for North Park ColonyWatch over the years, but that's for another venue.

Chuck Hundertmark

2546 Lake Meadow Drive

Lafayette, CO 80026

303-604-0531

Cell: 720-771-8659

chundertmark8@gmail.com

--
You received this message because you are subscribed to the Google Groups "Colorado Birds" group.
To unsubscribe from this group and stop receiving emails from it, send an email to cobirds+unsubscribe@googlegroups.com.
To post to this group, send email to cobirds@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/cobirds/CACZCCxe5%3DE5Cx2shtOJJ0aXVnUAEMSuV7AjKRJaX-dr_%2BV535g%40mail.gmail.com.
For more options, visit https://groups.google.com/d/optout.