The burrowing owl young in the Manitoba Burrowing Owl Recovery Program are nearly grown. A total of 28 young from five conservation-release nests were banded, weighed and had a small blood sample taken on July 22. The blood samples are taken to determine sex as burrowing owls are not sexually dimorphic, meaning you can’t distinguish individuals by morphology, or just by looking at them. The results of the blood sex results all us to remove select individuals for a balanced breeding group for the next season’s pairing and release. We removed ten young from the 28, five female and five male, to overwinter at the Assiniboine Park Zoo (APZ). The remaining young owls left in the wild will migrate from the Canadian Prairies mid-September into October.
Watching the owl young navigate the outside world has been entertaining and rewarding. Young burrowing owl are easily distinguishable from adults because they lack barring on their chests and have a solid chest and head coloration. Through the use of 24 hour trail cameras, we are able to observe the activities of the young owls as they continue to grow. We see the young pouncing on mice and insects, testing out their wings flying to nearby burrows, preening one another and even jumping on top of their unsuspecting siblings.
Now that all the protective enclosures are removed, the owls who will be released have been able to explore and mingle. We have noticed that many of the owl young seemed to prefer burrows other than the ones they were raised in. While it is common for burrowing owl young to move to surrounding burrows (i.e., satellite burrows) we often are recording the most owl young at two specific burrows. The adults at these burrows didn’t seem to mind the additional mouths to feed, sharing prey items with the adopted young. Why the majority of the young have decided to congregate at these particular burrows is a bit of a mystery to us.
Burrowing owl young leave their nesting burrow (fledge) at roughly six weeks of age and are typically able to fly short distances by five weeks of age. The young at our release site are roughly eight weeks old and can be seen perching on nearby fences and flying from burrow to burrow with ease.
Supplemented mice provided to nests was tapered off and completely stopped on August 9. We want to ensure that the owls are not relying on supplemented mice as they need to be able to secure their own food and prepare for migration. The young owls appear to be getting the hang of foraging for food on their own. We have seen several of them returning to the burrows with grasshoppers, one of their favourite foods. This season has been very hot and dry which has increased availability of insects like grasshoppers in the mixed-grass prairie of southwestern Manitoba. Burrowing owls are opportunistic, meaning they will eat what is available to them, but generally their diet is composed of 80% insect and 20% other small mammals, birds, amphibians, reptiles, etc.
Released owls will begin their long migration journey in the next four to six weeks. When the temperatures begin to drop the owls will leave the prairie and travel thousands of kilometres south in search of a warm spot for the winter months with lots of food. Some burrowing owls travel as far south as the Gulf of Mexico. These little owls face several challenges along their migration path, but we hope to see some of them return to southwestern Manitoba next spring.
The field season is coming to a close. It has been very rewarding being a part of the Manitoba Burrowing Owl Recovery Program. I am proud of the hard work and effort we have put in toward reintroducing these burrowing owls to the prairies. Currently, all released owls are still present and accounted for at our release site, with no issues of post-fledging mortality which has been noted in all other seasons. We can only hope that they all make it to migration.
One of the goals of this program is to increase the population of burrowing owls in Manitoba. We hope that some of these owls return to Manitoba, but if they do not, we hope they are contributing to the overall population in North America as the species is struggling in the majority of their range due to habitat loss and the effects of climate change. Here’s to 2021 being a fantastic season with hopes that next season is just as successful!
