Notice of permit

Regional or Local Number: SARA-PNR-2017-0383

Notice is hereby given that pursuant to the provisions of section 73 of the Species at Risk Act permit no. SARA-PNR-2017-0383 is issued.

Scientific research for the conservation of the species

This is a renewal of permit SARA-PNR-2016-0342 (and amendment SARA-PNR-2017-0370). All birds from the 2016 pilot project survived the winter in captivity and the researchers propose to expand the study. Project activities will remain the same except for sample size and refinements to methods (increasing the number of owlets from 6 to 10, modifying the supplemental feeding scheme to only when necessary to limit disturbances, and keeping owlets in temporary holding pens in the field while awaiting sexing results). This permit allows the researchers to disturb the residence of burrowing owls, to capture up to 10 juvenile burrowing owls per year on CFB Suffield, to hold owlets in temporary pens for up to 4 days while awaiting sexing results, and to transport these juvenile owls off of federal lands to a qualified facility (Calgary Zoo) that will over winter the owls and enable the owls to pair based on DNA analysis. The permit also allows the permit holder to undertake supplemental feeding of dead mice to the owls and owlets for the entirety of the permit duration. Upon capture, each owlet will be weighed, and the permit holder or assistant will also measure the tail length, and length of the 9th primary of the wing to get an accurate age of the bird. This permit allows the holder to release paired yearling owls to suitable breeding habitat on non-federal lands adjacent to CFB Suffield the following May and opportunistically back onto CFB Suffield as the opportunity arises. The number of owls to be released shall be at least equal to the number of owls taken from CFB Suffield. This permit allows the holder to band and place radio transmitters on the captive burrowing owls one week prior to release. This permit allows for a soft release, using cages, for up to 14 days. Surveyors will use call playbacks to locate nests. Peeper cameras will be used to monitor the young in the burrows. The smallest (i.e. youngest/lightest weight) 2 chicks of a brood may be captured approximately two weeks post hatching as they emerge from the burrow entrance. Each brood will receive supplemental food to help ensure that the last-hatched chicks will survive until emergence. Capture of nestlings will be done by using one-way walk-in traps. A dark hood will be placed on birds during the marking/banding and blood sampling process. Birds will be placed in a temporary holding pen in the field for up to 4 days while awaiting sexing results. Selected birds will then be placed in brooder boxes (with controlled temperature, light and humidity) and transported off of federal lands to the Calgary Zoo Animal Health Centre and captive-reared in enclosures for approximately 10 months. The owls will be paired and taught survival and hunting skills. The following spring the pairs will be released back into the same general area on lands adjacent to federal lands. The pair will be soft-released (an open wire cage over a burrow) and fed supplemental food and held in the enclosure on the release site for up to two weeks to encourage site fidelity and egg laying). Each owl will be fitted with five-gram solar-powered satellite transmitters to monitor post-release movements, migration, and survival. The transmitters will be attached with a backpack-style Teflon ribbon harness. The satellite transmitters weigh < 5% of the owls’ body mass. Transmitters will be attached to owls while at the Calgary Zoo under supervision and monitoring of zoo staff, approximately one week prior to their soft release. By over-wintering juvenile owls in Canada and soft-releasing them within Canadian nesting grounds to breed as yearlings, the permit holders will assess whether forcing site fidelity (and thus increasing return rates to Canada after migration), concomitant with increasing overwinter survival, will increase the population of burrowing owls in future years. The permit holders will also place radio transmitters on the released owls to study post-release owl migration, to help elucidate whether yearling owls migrating from Canada tend to have high mortality rates on migration or on their wintering grounds, or whether they simply disperse to other locations to breed outside of the Canadian study area.

Start Date: 2017-06-20   End Date: 2020-05-31

Issuing Authority: Environment Canada

Authority Used:

  • Species at Risk Act

Location of Activity (province, territory or ocean):

  • Alberta

Affected Species:

(a) All reasonable alternatives to the activity that would reduce the impact on the species have been considered and the best solution has been adopted. Burrowing owl populations continue to decline across the prairies and doing nothing would not help the species. A prairie-wide supplemental feeding program for wild burrowing owl broods was tested and shown to be ineffective in increasing the local populations of owls during 8 years of trials in two different projects in Saskatchewan and Manitoba. Because intensive population management may be required to recover the species, a full captive breeding program was considered. However, since a full captive breeding program is much more intensive and would require a large genetic pool of individuals as well as other difficulties, head-starting was considered much more feasible. This new technique of overwintering, pairing and releasing birds on breeding grounds, of the youngest birds in each brood, which would normally perish in the wild, needs to be field tested to determine whether it may increase local Burrowing owl populations. This project is targeted at critical life stages with minimal negative impact to the species and habitat while increasing the likelihood of survival and recovery for this species. Some modifications were made from the pilot study to increase the chances of survival of the owlets, and decrease the disturbance on the nests and individuals. (b) All feasible measures will be taken to minimize the impact of the activity on the species or the residences of its individuals. This activity will not impact the critical habitat of this endangered species. By working collaboratively with the Canadian Wildlife Service we have minimized the field personnel and research projects needed in the wild. Residences will have minimal disturbance since nest visits are kept as short as possible to reduce the time that adults are away from the nest and to reduce stress on the adults. After trapping, one or two dead mice are left in the nest burrow to compensate for any lost hunting time. Stress is decreased by placing a dark hood on birds during any marking/banding process. Only 10 owlets will be captured. Also, only the youngest owlets in each brood, which have the highest likelihood of mortality, will be taken. In the wild, because burrowing owls have asynchronous hatching (Wellicome 2005), there is a high probability (>75%) that the youngest chick(s) in each brood will likely die from starvation through competition with nest mates over food, in years or during weather conditions when food resources are not highly available (Wellicome 2000; Fisher et al. 2015). Furthermore, if only 6% of fledging owls return to study areas in Canada, then last-hatched owlets have an extremely low probability of surviving and returning (1.5%) to breed in Canada under natural circumstances. All procedures for holding owlets in temporary enclosures (for sexing) follow the same high standards of husbandry and welfare as when owls are in captivity at the zoo, and will have animal care approval. The Zoo has extensive experience and has housed burrowing owls in captivity from 1978-2011. Owls will be housed in enclosures with both indoor and outdoor access areas and will have artificial burrows and perches which would mimic, to the best extent possible, natural conditions. We have designed protocols to minimize any environmental stress (e.g., light, temperature, and noise) during transport to and from the Calgary Zoo. While in human-care, owls will undergo a veterinary examination, including blood sampling and fecal parasite screening. These measures will ensure individual health is good which will increase the owl’s chances of survival in the wild once it is released. Pre-release training techniques (such as live prey capture or flight in wind tunnels) will help prepare owls for release into the wild. We will use published (Mitchell et al. 2011) soft-release methods for placing the owls back in the wild the following spring. This method ensures that the owls are prepared to survive in the wild after being captive and trained to hunt. Researchers will supplementally feed the released owls while within the soft-release enclosure and monitor their pellets and prey caches after enclosures are removed to ensure they are eating wild prey. Satellite transmitter techniques have been refined over many years and are less than 5 percent of body weight. The Teflon harness attachment technique has been used on greater than 100 owls with no sign of injury from the harness upon examination when the owls were recaptured. (c) The activity will not jeopardize the survival or recovery of the species. This activity is designed to aid in the survival and recovery of this species. The youngest owlets have an extremely low probability of surviving and returning (1.5%) to breed in Canada under natural circumstances. This project predicts that by increasing the first-year survival and site fidelity of this critical age class it will slow the population decline in Canada.

Contact Person(s)
Canadian Wildlife Service
Edmonton, Alberta
Phone: (867) 975-4633
Fax: (867) 975-4645