Saturday, February 24, 2018

A note on Boreal Owls

There have been at least seven Boreal Owls seen in southern Manitoba recently so we thought it worth a note to the group.  We wanted to ask people to be extra cautious with a Boreal Owl in a seemingly “exposed” roosting  position and not to intervene (these owls need to conserve energy and they sit tight until nightfall, which people sometimes misinterpret as a sign of illness). A longer version of this message is provided below (for those who would like more detail):

Some of the seven Boreal Owls found recently were hunting at feeders (one managed to take a Eurasian Collared-Dove), and a few were injured or deceased (perhaps roadkill).  All that were measured were males. The general area of sightings has ranged from Carman to Ashern but, for obvious reasons, we are not posting the locations in any public forum (remember Manitobabirds is viewable by anyone including non-members). The great popularity of owls these days can be to their detriment.

These Boreal Owl records are not unexpected near the end of a harsh winter. This is presumably a product of this species’ unique “partially migratory” strategy, i.e. females typically move away from the breeding grounds but males try to hold onto their territories as long as reasonably possible (gives them a spring head-start). When the food supply in the boreal forest gets thin, some of these males are forced to leave their territories and they can end up in cities and towns, especially those reasonably close to the southern edge of the boreal forest.  Many such visits are short and the owl moves on in a day or two looking for a new food source.

Some of these owls find themselves in proximity to people, pets and roads (vehicles) and hence at risk. They may appear to roost or perch in “ridiculous” places but these are chosen for reasons such as for sunning, mild heat sources (light, vent or other), wind breaks, and/or proximity to a food source or cached prey. Sadly too often the greatest risk to these owls is people’s good intentions, i.e. people wrongly assume they are ill and try to catch them and bring them in. An owl on or near the ground is one of the most common reasons people try to intervene but there are many good reasons for owls to be on or near the ground (mantling prey or sometimes even “defrosting” prey is one reason and the thermoregulatory reasons discussed above may also bring them low down). Some owls allow close approach but people do not understand the stress such approach causes or the huge risks to small owls if they take flight in the daytime and why they are so reluctant to do so (see: http://artusobirds.blogspot.ca/2014/12/signs-of-stress-in-owls.html). If you do find an owl that you feel is behaving oddly, please don’t intervene but call first. An experienced and trained eye can judge the best course of action. In the vast majority of cases, the very best thing is to leave the owl its space (obvious exceptions would include an owl recently struck by a vehicle).

We welcome details on such records for ongoing research. Thanks for appreciating and caring for our winged wonders!

Christian Artuso (Winnipeg) and Jim Duncan (Balmoral) 

The photo below shows a perfectly healthy Boreal Owl that was perched very low to the ground, which aroused some concern until it became active near dusk:

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