Tuesday, November 22, 2016


We had another great season with 57 new NSWO and 8 same season recaptures. The  owls arrived steadily and we only dipped one night, so 17 out of 18 nights of effort, we banded owls. There were two peak migration nights on November 1 (8 owls and 1 recapture) and November 16 (8 new owls!).
A trio of owls could indicate family members flying together.
On these peak nights we typically capture multiple owls in one run and there is current DNA research to determine if these may be siblings or family members migrating together. The eight same season recaps is our record for recaptures in one season. They stayed on the property between 6 days and 26 days and may continue to winter on the Reserve. Their overlapping and continued presence and good body weight indicates a healthy prey base (rodents) for so many owls.This year we had several chunky owls with a good amount of fat and weights over 100 grams! Fat, which can be seen as a yellow layer under the skin, is an important fuel for migration and cold winter nights.
This individual has 3-4 generations of feathers, noted by the different colors in the
blocks of feathers; she is over 3 years old
We have also noted that the older birds tend to migrate later (we capture them later in the season), probably because the young of the year disperse early from their natal area. On our last banding night we banded this older female with several generations of feathers. These birds can be challenging to age, but it is great to see that some owls survive seasons of migration and breeding.

Thank you volunteers Julie Woodruff, Ken Sobon, Julie Newman, Wyatt Hersey, Erika Iacona, Maureen Morales and Kim Armstrong, for another great season of owl monitoring, season 12!!!!

Sunday, November 6, 2016


One of our project's goals is to educate people about Saw-whet owls. On Friday we got to introduce an owl to a group of 8 girl scouts and two moms (Troop 70079). My colleague at the US Forest Service, Maria Cisneros, organized this group so we were representing the USFS, Altacal Audubon Society and the Reserve, a great team! Wyatt, one of the owl banders, entertained the girls with moon, stars and wildlife stories, Maria shared binoculars, headlamps, flashlights, and treats and I even got to tell a spooky ghost story. Perfect under-the-milky way conversation! And then came an owl.......

Troop 70079 at the BCCER with Maria Cisneros (USFS) and Wyatt Hersey (Altacal)
 On our last run, voila! there she was, all feathers and golden eyes. So our conversation went to ooohs and aaaahs and the value of owls in the ecosystem, the importance of forests and snags for their breeding, Reserve habitats for migration refueling and wintering, owls as individuals and their amazing feathered toes, large asymmetric ears and keen vision. The saw-whet cast her spell again and left 8 girls, no doubt dreaming about owls!

Showing the numbered USGS bracelet (band, bling!) that we place
on the owls tarsus to identify them as individuals.
All smiles! Our owl is in the middle of the picture. Next step, RELEASE!

Sunday, October 30, 2016


We had a very interesting night last night netting 7 owls! 3 of those owls were recaptures from 3 different previous nights, the most same season recaptures I have ever caught in one night. The owls were banded 10, 8 and 6 days prior.These owls are using the Reserve as a restful migration stop, or may winter on site if they prey base (mice and voles) are good.  Most owls this year are quite chunky with good fat reserves and high body mass. It is good to know they are eating well!
 Milk Chocolate Owl
The owls are always unique but some individuals really stand out. Last night we banded this very richly plumed brown and buff owl. The juveniles are brown so I was thinking she retained some juvenal plumage but no, she was a second year bird, and just unique in color. A very beautiful owl!

Ken holding the Chocolate Owl before release

Thursday, October 27, 2016


Unpredictable is a synonymous word for Northern Saw-whet Owl! 1-5 owls per night since we started this season, and then, on the most perfect night, in the peak of the season- 0 owls! But here we are with 22 owls almost 1/2 way through the season.We never know what will happen next but this is what the year looks like so far, 22 owls:
Two owls, maybe migrating together? 
October 5- 1 owl
October 12- 1 owl
October 16- cancelled due to rain
October 17- 5 owls
October 19 -3 owls
October  20- 5 owls
October 21- 3 owls
October 23 - 4 owls
October 24- cancelled due to rain
October 25- cancelled due to rain
October 26 - 0 owls!

Friday, October 7, 2016


Yes, year 12! October 5 kicked off our informal banding season to determine early owl arrival. In 2.5 hours we had a mix of weather, clear and cool, with gusts of wind, then quiet. We also had a mix of netted critters; a Western Screech Owl, Northern Flying Squirrel and our first of the season Northern Saw-whet Owl, a male!

Young N. Flying Squirrel. Photo by Julie Woodruff
The flying squirrel was probably just about 3 months old based on size, but very mobile and active. Squirrels bite readily and hard, so caution to the human hand, and holding the loose-skinned flyer (see picture below), takes focus. We released her in the oak she was likely "flying" to, and she scurried away.
Web photo of gliding N. flying Squirrel

First NSWO, a petite but mighty male. Photo by Ken Sobon
Our first of the year saw-whet was a boy! In all years, our male capture is very low, likely because they stay on breeding territory if winter conditions are fair. But this youngster was hatched only this year, so must have left his natal site (unless he was hatched near the Reserve!). Thank you volunteers Ken Sobon, Julie Newman and Julie Shaw for the fun opening night!

Monday, February 29, 2016


Such a fortune to have found this Northern Saw-whet Owl roosting in dense vegetation along the Potter's Ravine trail in Oroville in February. Since assisting Julie with her telemetry study, I have gained a good search image and perspective of where to look for these owls wintering here. From my banding study we know that in fall many NSWO migrate through higher elevations and winter in foothill and valley habitats. With telemetry during the day we found them roosting on the ground, in shrubs, and 80' in the canopy of a tree. But almost always surrounded by dense vegetation during the day, which makes them extremely hard for us, and predators, to see. But, if you don't use telemetry there is still another way to find them. Songbirds dislike this formidable owl predator (even though NSWO primarily feed on rodents), and will make a real ruckus, often bringing in all of their friends, a mob of birds-in-the-hood.  It was only a pair of oak titmouse that alerted me, but I was on the search. Look what I found-you might have to click on the pic and zoom in.

In the center of this photo is a saw-whet peering out of the toyon
Here is a zoomed in view of the roosting saw-whet owl. 
What we also know from banding is that the birds begin to migrate to their breeding grounds in March through April.  From there, we don't know where they go, but I suspect they are moving north and/or upslope to the Sierra Nevada/Cascade ranges.
See more about our wintering study on this blog, an example is here:


Our snow goose festival outing was a huge success with two Northern Saw-whet Owls captured in mist-nets. One bird had previously been banded by our team in October 2015 during fall migration, an indication that the bird was wintering on the Reserve property, and had so far survived the hardships of winter. All good news for this individual.
Happy Snow Goose Festival participants gather around
a saw-whet owl.
Our trip is always a quick sellout every year because many people have never seen these beautiful, common but cryptic owls.  Our team this year was me, Steve King, Sheila Frisk and Ken Sobon. Thanks team!

Saturday, January 16, 2016


With our arrival back to OWL3 this year, we banded 15 nights during fall migration. Even with the reduced banding effort our capture rate was high and we banded 55 Northern Saw-whet Owls, and 3 new Western Screech Owls. Almost 50% of our birds were hatched this summer season, meaning a good nesting and fledgling success for owls. See our annual report- with fun pictures for our successful and productive year. As we say goodbye to our fall season, I end our 2015 postings with this youtube video+ of a sweet saw-whet, just before release. See you in 2016!

Saw-whet owl, caught in a blink