Roxan Chicalo: Searching for the elusive Western Screech Owl

Roy L Hales/Cortes Currents - A small group of people turned out to hear an overview of FOCI’s Western Screech Owl Project at Mansons Hall on Friday September 27, 2024. Participants listened to different owl calls, examined owl feathers and learned why putting up nest boxes is important. The speakers were the two biologists from Madrone Environmental who wrote FOCI’s final report. Cortes Currents interviewed the lead author, Roxan Chicalo, afterward.  

“What gets me up in the morning, when I'm working at these species at risk, is thinking about balanced ecosystems. Everything is working together to create the ecosystem that supports our lifestyles as humans. In my mind, every animal and plant has a role that they play,” she began.

“Screech owls are a small avian predator. They eat  anything from amphibians to small mammals to fish, insects, slugs,  all sorts  of different small animals in the ecosystem. As a predator, they  keep a check on those prey species populations so that they don't get out of control, and they also support biodiversity. If one of these prey species booms in their populations, they might start to compete against  other populations of other animals. We might see that we're having more extinction events.  That's why we should care to  promote a balanced ecosystem and support that.” 

Cortes Currents: How scarce are Western Screech Owls?  

Roxan Chicalo: “There's not a whole lot of recent data regarding population estimates for Western screech owls. So first I would like to talk about the two subspecies that exist in British Columbia.  There's the Megascops kennicottii kennicottii subspecies, the coastal subspecies.  They go  up to the south coast of Alaska, and  all the way down the coast to northern Oregon.  Then we have an interior subspecies,  the MacFarlane's Western Screech Owl. Their range is just  a little bit into the Kelowna-Okanagan area.  Today I'm mostly talking about the coastal subspecies that we would have on Vancouver Island and the Discovery Islands.  The most recent population estimate from the COSEWIC report is about 2,000 individuals left in the wild and the range is between 1,500 to about 3,000.” 

“This data is heavily skewed from where these surveys have taken place.  There's so many areas along the coast that are inaccessible or really expensive to access. A lot of the surveys were in Metro Vancouver, Vancouver Island around Victoria, a little bit on the Sunshine Coast, but not much further north than that.” 

“There have been some long term studies, specifically from the Christmas bird counts. Where they started documenting their owl counts in 1983, they detected an owl about one hour per hour survey time. I think the most recent estimate, a COSEWIC report from 2012, found about one owl for every 10 hours of survey effort.” 

“So there's been about a 20 to 30% decline in the 15 years prior to 2012 and it's suspected that that decline has continued, maybe have stabilized a little bit. Nobody really knows, but there are recent efforts by the government to conduct an inventory of what is happening now with those populations.” 

Cortes Currents: Has the Screech Owl been driven out of areas like southern Cortes Island by human development and predation from larger owls?