ACES Morning Birding at Rock Bottom Ranch 09/1/26

September 1, 2026, 7:30am-10:30am

Weather: Sunny, warm

Location: ACES at Rock Bottom Ranch, Basalt, CO

Birds were flocking and moving about in typical ways for this fall migration season: geese flew in formation, a few remaining swallows foraged in a loose flock overhead, mixed sparrows worked over the compost pile for goodies beneath cabbage leaves, and red-winged blackbirds and starlings gathered into their respective flocks in treetops. Partway through the morning, we found ourselves in the pollinator garden looking at the fruits of Russian olive trees: little green olives with a very hard pit inside. Birds love these fruits, and we soon discovered proof of that as about ten robins flew back and forth between an olive tree outside the garden and the cottonwood canopy inside… As we watched the robins, we began to notice that other species of birds were busily feeding inside the tree’s dense foliage. Gray catbirds, a Bullock’s oriole, and red-winged blackbirds. Then we identified a Swainson’s thrush and a western tanager. We spent time comparing the tanager and the oriole, noting their different body proportions, the oriole’s eyeline, and where their yellow markings were on their bodies. Evening grosbeaks and a black-headed grosbeak joined as we stood watching and enjoying the spectacular diversity of birds in front of us. It was a memorable half hour! We wondered why the all of the birds wanted to be in that specific olive tree, while other nearby trees were bridles; perhaps the fruit was ripe and “just right!” Other highlights were the abundance of western wood-pewees and the Clark’s nutcrackers that moved high overhead between the cottonwood forest and the pinyon-juniper woodlands on the lower slopes of the Crown area. Join us next week for special fall migration field trips on the mid valley section of the Rio Grande Trail and at Difficult Campground!

Species List:

~Rebecca Weiss, ACES Birding Guide

Featured Photo: 

Photo credit: Marlene Cashen