The Birders Report

Burrowing Owl (Athene cunicularia) photos by Larry Jordan

Burrowing Owls (Athene cunicularia) are active both day and night but they nest in underground burrows making them sometimes difficult to spot. If you are out looking for these charismatic little owls you may expect to see something like this, just a head sticking above the rim of the burrow entrance (click on photos for full sized images).

This is what it looks like when you are looking out over the grass in the early hours of the dawn with that morning glow lighting up this sleepy raptor. Burrowing Owls tend to spend time sleeping following crepuscular foraging activities in the first few hours after sunrise and in the middle of the night¹.

Luckily for me, whenever I need a Burrowing Owl fix, I can drive about 2 1/2 hours south to Wildhorse Golf Club where there is a resident population of these very special owls.

The city of Davis’ 26 acre greenbelt around Wildhorse Golf Club has one of the densest populations of Burrowing Owls in the state². They began building artificial burrows in 2003 using the turfgrass and soil plugs created during their fairway aerification process to create the owl’s above ground burrows. Now the owls have expanded their colony around the perimeter of the golf course and into the interior of the course proper, wherever there are California Ground Squirrels digging burrows that the owls can use for nesting.

Burrowing Owls most often use burrows dug by animals such as ground squirrels, badgers, prairie dogs, marmots, skunks, armadillos, kangaroo rats, and tortoises¹. In California, it’s primarily the ground squirrel that does the digging for our owls. The squirrels also act as an early warning system, warning the owls when there are predators in the area.

This is a video I shot of the owl shown at the top of the post that was within a few yards of the gravel running path. He flew up to within a few yards of the golf cart path and remained perched as a golf cart drove by and, at the same time on the running path, a kid with a dog on a leash ran by on the other side. You can hear their distinctive alarm chatter call twice in the video.

Back at the artificial habitat site, one of the adults was roosting on a post, sleeping off and on.

You can see from the lack of some of their facial feathers in some of the photos that these adults are going through a molt following a successful breeding season.

Their offspring on the other hand have gone through their preformative molt and their juvenile plumage is barely distinguishable from the adults.

Watching this juvenile in front of one of the burrows giving me their famous, ever so cute, head tilt maneuvers…

and showing off their playfulness and constant curiosity…

sets them apart from the more sedate adults.

You can also see from the video and following photos of the juvenile preening that they still have lighter colored and un-spotted feathers on their heads.

This little one accidentally picked up a piece of straw while preening, keeping it entertained for quite awhile.

Here he or she is, all fluffed up…

and looking up for aerial predators.

The adult female is seen in the lower right corner of the following video and you will see squirrels pop their heads up as they forage near the owls.

If you are ever in Northern California and want to see Burrowing Owls, stop by Wildhorse Golf Club. You won’t be disappointed!

If you are going to be in the area and want more information on the status of the Western Burrowing Owl, the California Burrowing Owl Consortium is holding a meeting, open to the public, on Thursday, September 20, 2012 from 10am to 2pm at 45211 County Road 32B, Davis, CA 95618. It’s just a stones throw from Wildhorse Golf Club. Feel free to email me if you are interested!

References: ¹Birds of North America Online, ²Leith, Wes (2008). Case study: Wildhorse Golf Course creates artificial mounds for burrowing owls. Golf Course Superintendents Association of America

Brown Creeper (Certhia americana) photos by Larry Jordan

Please take a moment to check out my latest West Coast Beat Writer post over at 10000 Birds! You will see some cool photos of the Brown Creeper (Certhia americana) and some video of them going in and out of their nest with tasty morsels for their nestlings!

House Sparrow (Passer domesticus) Male photos by Larry Jordan

Just the mention of the House Sparrow (Passer domesticus) in the world of Bluebird nest monitoring sends shivers down the back of some trail monitors, and rightfully so. There is plenty of documentation of House Sparrows attacking Bluebirds and other cavity nesting species, killing both young and adult birds (see my friend Bet Zimmerman’s page here).

House Sparrow Female

You see, the House Sparrow is a non-native species, introduced in North America from England in 1851. Being a non-native species, it is not protected by the Migratory Bird Treaty Act and yet this bird has become the most widely distributed bird on the planet¹.

Native range in dark green and introduced range in light green

The problem is that House Sparrows are cavity nesters and compete with native cavity nesting birds in North America for breeding sites. Luckily, I have not had a problem with them on my bluebird trails but many monitors have, especially in the mid-west and Eastern U.S. (see the North American Bluebird Society’s page on House Sparrow control).

Crossing a bridge over the Sacramento River recently, I saw a flock of birds on the railing out of the corner of my eye as I drove over the bridge. They didn’t look like the Cliff Swallows that always nest under this bridge.

I pulled off the road and parked below the bridge where I found a rather large colony of House Sparrows nesting under the bridge in Cliff Swallow nests. House Sparrows are known for using and even usurping nests of Bluebirds, Purple Martins, Barn, Bank and Cliff Swallows.

It certainly surprised me to see these Cliff Swallow nests with House Sparrow heads sticking out of them and females feeding their young.

This video shows the females feeding young in several of the Cliff Swallow nests under the bridge and the male claiming nests by sitting in them.

The irony of the whole thing is that now the House Sparrow is declining in it’s native home of Europe and Great Britain¹.

To see more great bird photos from around the world, check out Wild Bird Wednesday and the Bird D’pot.

References: ¹Wikipedia