Monday, January 31, 2011


For the last four years we have conducted our Owl-night-out field trip for the Snow Goose Festival, a fine birding event held in Chico, CA. We hold the event at either of CSU Chico's reserves, the BCCER or BCEP. It corresponds to our "winter sampling" to see if the NSWO are wintering in the area. This year we held it at our OWL3 site at the BCCER. The nine participants were fortunate to meet two darling owls, both caught in the same net run.

They were both females hatched in 2010. One was a recapture from October 15th, which indicates she has been spending the winter (over 3 months) on the Reserve. Both owls were adopted (thank you Rich and Tess!), which helps support our fall monitoring project. Thank you to fine volunteers Raina and Steve King, Nancy Nelson, and Julie Shaw for the great night! All photos are Steve King's.

Saturday, January 22, 2011

NSWO nestlings, a MUST SEE VIDEO!

Check out the Cool Links tab. I have included a darling youtube video by Marcel Holyoak of NSWO nestlings looking out of their nest cavity. Careful, you will fall in love! This "teaser" photo is used with permission of Don Roberson (copyrighted).

Friday, January 21, 2011

Winter Sampling at the Dye Creek Preserve

On January 20, 2011, Julie Shaw and I met with Preserve Associate Jackson Shedd, at the Dye Creek Preserve in Tehama County. The Dye Creek Preserve is managed by The Nature Conservancy (TNC) and is almost 38,000 acres in area. Our ongoing study to understand winter roost selection of saw-whet owls in the area led us to sample the Preserve. The habitat is quite different than our current sampling locations near Chico. The majority of the site consists of Blue Oak woodland and grassland, however Dye Creek is lined with dense riparian vegetation, similar to the Butte Creek Ecological Preserve (see post A Winter Sampling...). The big difference is the lack of winter over-story vegetation from conifers and Live Oaks. Although Live Oaks are scattered in the uplands lining the creek, most of the vegetation is deciduous (the image below shows full leaf out- not winter). But, due to our telemetry study with Julie, we know NSWO select low dense shrubs and Live Oak trees to roost; both components of the Dye Creek Preserve habitats. We figured they just might be roosting along the creek. In these two images you can see the Dye Creek site (upper) and an expanded view of the three sampling sites, Dye Creek, BCCER (higher elevation), and BCEP (lower).

We set up for two hours under a clear sky dotted with stars. An almost full moon came up near the end of our monitoring session. During this time we never detected or captured a saw-whet owl. Based on my experience if NSWO are in the area they will likely respond. I interpret the nights lack of response to mean there were no saw-whet owls using the area during the sampling period. We will try again! We did have a night full of sound, coyotes singing, and many flocks of Tundra Swans and Snow Geese flying overhead. Plus, we captured a Western Screech Owl, released by Jackson Shedd (photo by Julie Shaw).

Wednesday, January 19, 2011

New Post under "What's in a Name" tab

What does birdbling mean? Look at this owls leg for a hint.
Where did the name "Saw-whet Owl" come from?
go to the NSWO - What is in a Name? tab for the answers!

Monday, January 17, 2011

A Winter Sampling of Owls

One of our monitoring goals is to sample the NSWO use of CSU Chico's reserves (equate similar habitats in our area) during the winter. This past weekend, four of us went to the Butte Creek Ecological Preserve (BCEP), located off of Honey Run Road- of off the Skyway. The preserve habitat is very disturbed because the creek was heavily mined. Mine tailings comprise the uplands but on those grow chaparral and mixed hardwood/conifer (oak/grey pine) species. Riparian scrub and forest line Butte Creek. The elevation only about 330' elevation, all and all quite different than the BCCER site. But, we know owls use this preserve based on my previous banding efforts as well as an actual visual. Click the photo above left to see an aerial view of our net array.
This picture below shows the actual lane where we erect our mist nets at the BCEP
On Friday January 14, 2010, we set up just after sunset to the trilling call of a Western Screech Owl. We began to hear many saw-whet vocalizations; toots, twitters, wails and chirps, and knew it would be a good night. Indeed! In just 2.5 hours we captured and banded 5 NSWO, more than we had in any previous winter. The were all owls hatched last year, and all female. The high number of wintering owls does make sense because we had such a great fall season (92 owls!) in 2010. So, the BCEP and proximate area, is providing good prey and winter habitat for the young owls. To see more about the Preserve, hiking trails and birding, click here.

Thursday, January 13, 2011

Updated Post!

Check under the Monitoring tab for updates today: Ageing the Saw-whet owl!

Wednesday, January 5, 2011

Logistics of banding and tracking

Yes, it is very exciting to have a NSWO in the hand and also to see one in the wild, like this one! And it isn't easy. Both federal and state permits are required to capture and band birds, and install telemetry. I have these permits only after a lot of training and a project that has scientific merit. My training consists of 16 years of banding, several banding workshops and meetings, and most recently a training session to install telemetry. I met with NSWO researcher, author and conservationist, Scott Weidensaul who has conducted telemetry and geolocator studies in Pennsylvania supported by the Ned Smith Center for several years. Here I learned a safe and efficient way of making a harness that will "break away," after about 3 months, leaving the owl without its backpack or radio, and giving us about 3 months of information regarding roost locations and movement of our owls. (I took this photo of "Dos," she is one of our radioed owls).

And that is our study of scientific merit. You will note that so little is known about the NSWO in the Pacific States, that our banding and telemetry studies will help us better understand the ecology of the NSWO in this region- new and exciting stuff (and necessary knowledge for conservation measures)! This picture shows two dedicated volunteers (Raina King and Colleen Martin) banding and taking measurements of the a NSWO (photo by Steve King) during our fall monitoring project.

See the previous post for a pic of the harness and radio and a map of one of our owls movements to Bidwell Park. And don't forget to go to the Adopt -an-Owl tab, to become a guardian of one of our banded and released (and adorable) owls!

Tuesday, January 4, 2011

Tracking the Saw-whet

Our fall monitoring project has expanded to have a new component- radio telemetry and tracking. I am helping a CSU graduate student Julie Shaw, with her studies to determine winter roost sites of the saw-whet. One of our questions derived from the fall monitoring was, "where do the birds go in the winter after migrating through the Reserve?" We knew that some stayed

on the Reserve because we recaptured a few, a couple of weeks to
months later.

But now, because we have installed tiny radio transmitters on the owls (3 grams total, less than 3% of the birds body weight-see picture above that includes radio and harness material), we are able to track them to their actual locations! Julie will collect 2 years of data and then publish her results, brand new information for our region- and wonderful to better understand the ecology of our population of owls! So far we have found owls roosting on the ground like this bird,

some a few feet off the ground, and many way up in a tree- up to 85 feet, so all we see is a feathery ball, like in the picture (the bird is within the red circle).

We always like to get a good look if possible to check the condition of them and make sure their harness is fitting well. The harness will come off in about 3 months- the same time as the life of the radio battery. Most of the birds sit in good cover to protect themselves from diurnal predators like Cooper's Hawks. We got a really nice look at this bird who has had her transmitter on for 8 weeks.

Julie has been great about creating maps of the bird's locations, like this one. Here you can see a map with 4 different roost locations of one bird who was banded at the Reserve and then moved
down into Bidwell Park.

Saturday, January 1, 2011

NSWO prey items

Most studies looking at pellets (the fur and bones remaining from eaten prey that an owl will regurgitate, often before flying off to hunt again), show that small rodents make up a high percentage of the NSWO diet. You can imagine how great it is to have a rodent hunter like a saw-whet around! This photo is a pic I took of an actual NSWO pellet.

Julie Shaw (CSU Chico graduate student) and trackers are tracking owls to their roost sites. Roosts are a great place to look for pellets and Julie will collect and analyze these. This is incredibly important because around here, there is no documented or published information about what the NSWO eats during the winter. But personally I have seen a NSWO sitting on a deer mouse (3 times) and a meadow vole. If you look closely at the picture below, of a bird we named "Lucky", you can see she has a large grey blob in front of her- a meadow vole!

Other prey items that saw-whets take include many small mammals like shrews, pocket mice, red tree voles, and even juvenile chipmunks and squirrels! Small birds are taken mostly during their nocturnal migrations and even some insects like beetles and grasshoppers. I took this information from the Birds of North America series for the NSWO, Cannings 1993, but you can go and subscribe online to this excellent resource!
Sometimes these small owls can't eat their whole prey, and eat them in pieces. If their is too much for one meal they will either cache the leftovers somewhere safe, like a crook in branch, or they will roost on top of it. What better way to have a warm dinner?