Pat Weber initially found a single Green Heron on 12-Aug-2017. Other observers who saw a Green Heron or more include Zeke Watkins, Cheryl Huizinga, Steve Butterworth, Darren Clark, and Kathy Eklund. Kimberli Conrad was birding with me.
LOCALITY OF OBSERVATION
All 6 individuals were observed within 100 meters on both sides of the Willow Bay Recreational Area pier on American Falls Reservoir in Power County. Specifically 42.807500, -112.836174. Mostly, they all behaved as a group on the east side of the pier.
HABITAT WHERE THE BIRD WAS OBSERVED
The habitat was open, swampy riparian-marsh bordering open water. Muddy ground with lots of willows that had previously been submerged, and blankets of short leafy plants in the shallow water.
SIGHTING DURATION, CONDITIONS, and EQUIPMENT USED
I observed the birds for a little over an hour at a maximum distance of 100 meters. Sunny and warm weather with slight breeze. Great viewing conditions. Optics used include Leuopold Spotting Scope and 10x42 Vortex Binoculars.
DID YOU TAKE NOTES?
Yes, later the same day
DID YOU CONSULT A FIELD GUIDE OR OTHER REFERENCE WORK?
Yes, during the observation
WHICH GUIDE(S) OR REFERENCE(S): DID YOU CONSULT?
I referenced two guides to confirm the ages of the birds. Sibley Guide to Birds of North America 2nd ed. by David Sibley published in 2014 and National Geographic Field Guide 6th ed. by Jon Dunn and Jonathon Alderfer published in 2011.
DESCRIPTION OF THE BIRD(s)
Small herons with classic body structure of Ardeidae family. Long legs relative to body, long neck, medium-length straight and sturdy bill, relatively large and rounded wings.
Adults: Yellow legs, maroon neck, whitish chin and throat, dark green cap and upperparts, grayish belly. Upper wing coverts outlined in a yellowish color. Limited streaking on neck and deep maroon color were expressed by 2 birds, suggesting them as adults.
Juveniles: Green upperparts with lighter brown neck coloration and extensive streaking on underparts.
BEHAVIOR OF THE BIRD(s)
Initially and adult was observed preening on a partly submerged, algae-covered willow for about 30 minutes. Then, it flew over the pier, from west to east, and landed on the other side. Then we noticed 5 other Green Herons ( juveniles and 1 more adult) beside the docks chasing each other and squawking at times, the juveniles were especially energetic for a little bit. One adult moved off and began hunting and the other flew back to the west side of the pier. The juveniles stayed in the same general spot throughout our time there.
The hunting individual would stand motionless for a time and slowly move a foot or so at a time before stopping again. I never saw it catch anything.
HOW AND WHEN DID YOU POSITIVELY IDENTIFY THE BIRD, AND WHAT CLINCHED THE IDENTIFICATION FOR YOU?
The smaller size of the herons and their diagnostic color patterns, especially the extensive green, allowed for quick identification.
HOW DID YOU ELIMINATE SIMILAR SPECIES? WHAT WERE THEY?
The most similar species would be Black-crowned Night Heron, which naturally occurs in this area. It was ruled out quickly by color pattern and habitat. The Night-Herons prefer denser stands of trees along water.
American Bittern is similar but was also quickly ruled out by habitat, color pattern, and behavior.
WHAT IS YOUR EXPERIENCE WITH THIS (AND SIMILAR) SPECIES?
This was my first time observing this species but I am extremely familiar with Black-Crowned Night-Herons and the other Idaho herons, egrets, and bitterns.
DESCRIBE YOUR GENERAL BIRDING EXPERIENCE
Extensive, especially in the intermountain west. I have about 10 years or so of good birding experience.
WERE PHOTO(S), VIDEO, AND/OR AUDIO OBTAINED FROM THIS SIGHTING?
FIRST ROUND VOTING:
Description and photos are enough to confirm identification of Green Heron.
well documented with description and photos - seen by several other birders
Excellent documentation including written notes, discussion, and diagnostic photos.
diagnostic pics and described well
Good descriptions, and clear photos of at least one of the adult birds, plus the decent photo showing all of the individuals discussed, is sufficient for me to accept. While late in the season, and clearly long fledged youngsters, it is interesting to think that this was an Idaho raised family of this unusual bird for the State. Great record!
These were indeed Green Herons, and this report suggests local breeding. That's exciting!