Natural History Journal

Category Archives for // Natural History Journal


Besides being home to horses and cattle, the Chico Basin Ranch also hosts an incredible diversity of native plants, animals, and insects. A closer look at the land will reveal micro-habitats varying from sandhills to sand sage habitat, shortgrass prairies and cholla cactus grasslands. These various ecosystems provide a home for a dizzying array of birds, grasshoppers, swift foxes, pronghorn, badgers, prairie dogs and more.

Birding Checklist

Birding Map

Dragonfly &  Damselfly Checklist

February 9, 2016

Chico’s Earliest Nesting Bird

In December, Great Horned Owls, the most common owl on the Chico, are already paired and both males and females are calling, their distinctive low hoots heard throughout the nighttime.  By February, females are incubating eggs, sitting on nests, this one in a stick nest, others found in the cavities of large cottonwoods.  By early May, young owls are almost full grown and poking their heads out of cavity nests, or falling out of stick nests as the siblings fight

Continue Reading

February 9, 2016

What’s A Falcon?

Until recently, all falcons were thought to be closely related to hawks.  They all have hooked beaks and talons for tearing prey.  However, recent DNA analysis has shown falcons and somewhat surprisingly, parrots, both share a common ancestor, songbirds. A bit baffling at first thought. Falcons do not build their own nests but use cliffs or on the Chico, tree cavities.  In winter, our smallest falcon, American Kestrel, is common in prairie habitat where they use power line perches awaiting

Continue Reading

February 4, 2016

Throwback Thursday – 16 May 2008

A picture is supposed to be worth 1000 words.  Tex, charged with aiding in heifer birthing when needed, administers medicine to a newborn and notches its ear to show it has had medication.  The heifer, Tex’s horse, and I look on.  The grove of Russian olives in the background was hydroaxed and treated during later years.

Continue Reading

January 24, 2016

Prairie Falcons

Cliff nesting Prairie Falcons move to the plains in the winter.  Although this western species is most thought to feed on small ground squirrels, in winter their diet shifts to small birds.  The two most common bird species hunted by Prairie Falcons are Horned Larks and Western Meadowlarks, both fairly common on Chico in the winter.  Prairie Falcons hunt using different methods. Research in Colorado shows that perching on a pole, watch and wait, is the most energy conserving hunting

Continue Reading

January 24, 2016

Winter Sparrows

American Tree Sparrows are poorly named because they aren’t found in trees, more often the weeds next to trees, and they breed on arctic tundra far from trees and winter mostly on the plains in weedy habitats.  Beginning birders are often intimidated by sparrows, they all look  the same, but American Tree Sparrow has a distinctive bicolored bill, a rufous crown, wings, and back, and the clear breast with a central spot or “stick pin” makes I.D. fairly easy.  They

Continue Reading

January 15, 2016

Throwback Thursday

17 May 2008 A typical group of birders looking for migrant and resident bird species when the northern area of the Chico was a large colony of Russian olive trees.  Russian olive is a non-native, state listed noxious plant.  The state of Colorado requires its removal from areas where its abundant fruits have caused a rapid colonization at the expense of native trees and shrubs.  Because Russian olives produce a bounty of fruits most years, birds and wildlife feast on

Continue Reading

November 23, 2015

Wintering Marsh Wrens

Marsh Wrens are found on the Chico during spring migration and also during winter.  They prefer to winter in cattails and there were two today in the small headquarters pond.  For an unknown reason, Marsh Wrens breed in the Boulder, Denver, Ft. Collins area but not on the Chico.  Most birds sing in spring, but when Marsh Wrens first arrive in fall, they sing short parts of their songs in addition to the common chip notes.  This is a bird

Continue Reading

April 30, 2014

Glossy vs. White-faced Ibis

Ibis must be ancient flying dinosaurs.  They look out of place wherever I see them.  Two look alike species often occur together in migration and they hybridize with increasing frequency.  To separate the eastern Glossy Ibis from the western species, White-faced Ibis, first look at the feathering around the eyes.  If you see narrow bluish or blue-white narrow feathers around the eye but not encircling it, you spotted the rare Glossy Ibis.  Check the eyes, they should be brown, not red,

Continue Reading

April 29, 2014

White-eyed Vireo – a rarity

My nemisis Chico bird, White-eyed Vireo, is an aptly named eastern species that prefers dense woodland scrub. Finally, I caught up to the one found this morning at the headquarters willows below the small pond where lots of visiting birders were able to see it actively foraging. Although this bird was not singing, their song is very distinctive. In the U.S. there are 15 vireo species all in the same genus, Vireo, so the common name and the genus name is the

Continue Reading

April 18, 2014

The Subtleties of Field Identification

Finally, a few sparrow species are on the move.  Here are two different sparrow species out in the cholla grassland.  The upper species was singing a very distinctive song so if heard it is easy to I.D.  This one has a  lookalike relative that is also found at the Chico, so the thin crown stripes without a wider white central streak, longish tail, shortish bill, thin eyering, and basically colorless face help to separate this Brewer’s Sparrow from the more colorfull, tan-breasted Clay-colored

Continue Reading