Burrowing Owl (Speotyto cunicularia - recently revised from Athene cunicularia)

Status: Endangered

Description: The Burrowing Owl, also known as the Ground Owl, is about 23 centimeters tall and weighs between 125 to 185 grams, or 150 grams on average. It is slightly larger than a robin. These owls have a round head with large yellow eyes and no ear tufts. They have long, slim legs and a short tail. The body feathers are light to dark brown with white spots and the under parts are pale brown to white. The young have a rusty coloured chest. The males’ plumage is often lighter due to sun bleaching while foraging: the female remains underground longer, laying and incubating the eggs. Burrowing Owls are most often seen perching on the mound outside their burrow.

Status: Listed as an endangered species in Saskatchewan, in the Wild Species at Risk Regulations, Burrowing Owls are protected on private, provincial and federal lands under Part V of The Wildlife Act.

The Committee on the Status of Endangered Wildlife In Canada (COSEWIC) listed Burrowing Owls as threatened in 1979 and up listed them to endangered in 1995. Canada, is the northern limit of their range in North America. Burrowing Owls were originally found in British Colombia, Alberta, Saskatchewan and Manitoba. In 1977, there were estimates of 2000 breeding pairs of owls in Canada. By 1995, the Canadian population had dropped to less than 1000 breeding pairs.

Burrowing Owls were extirpated in British Columbia, but they are currently being reintroduced at two sites through a captive breeding program. Only one breeding pair was observed in Manitoba in 1998 and none in 2000. They are now likely extirpated in that province. The current rate of decline in Canada is approximately 20 per cent per year. Burrowing Owls may become extirpated in all of Canada in less than 20 years unless the causes of population decline are discovered and conservation actions are taken. Loss of suitable habitat is the most pressing concern and land stewardship must be addressed.

The current range of Burrowing Owls in Canada could be described by a large triangle beginning at Estevan, northwest through Regina to south of Saskatoon, west to Calgary and south to the Montana border through Lethbridge. Burrowing Owl range continues south into the United States and Mexico. There are also separate eastern populations of Burrowing Owls in Florida and in the northern Carribean islands.

Range Maps

Saskatchewan has the largest remaining population of Burrowing Owls in Canada. Considerable research has been undertaken on factors affecting the reproduction and survival of Burrowing Owls in the Regina Plain. In 1987, researcher Paul James observed 78 breeding pairs on a small portion of the current Regina Plain study area east of Regina encompassing Regina, Kronau and Sedley. In the same area in 2000, there was only a single owl observed.

The current Regina Plain study area is the 12,200 square kilometre area between Moose Jaw, Regina and south to Weyburn. Research has been conducted in this larger study area from 1992 to the present. Last summer, researcher Danielle Todd observed 68 owls in that area, a 12 per cent decline from the previous year.

Research on owls returning to the study area each spring suggests a high mortality of owls on their winter range. Approximately 5 per cent of young owls and only one out of every three adult owls return to the Regina Plain area each spring. From a few observations of banded owls and tracking of radio transmitter signals over the winter of 1997-98, it is believed that the Saskatchewan Burrowing Owl population migrates to southern Texas and northern Mexico along the coastal lowlands of the Gulf of Mexico. Causes of mortality over winter are not known, but it has been suggested that the young owls may not have enough food prior to migration to be in prime condition to make the trip successfully.

On December 6, 2000, Canadian Wildlife Service researchers found a radio-tagged Saskatchewan Burrowing Owl in Texas near Galveston Bay. The owl had been banded near Milestone, Saskatchewan in July, 2000 by researchers from the University of Regina. The owl’s roost was found in a recently burned cattle pasture under a clump of bunch grass. It was located after sunset close to oil well sites and a surface dump site for drilling mud. Predators, such as a Great Horned Owl, a short-eared owl and a coyote, were also spotted in the vicinity of the owl’s roost site.

On December 9, 2000, another Saskatchewan Burrowing Owl was located in Texas, near the McAllen International Airport and very close to the shore of the Rio Grande River, the border with Mexico. This male owl had been banded by researchers near Lang, Saskatchewan, south of Regina. It’s signal was last heard in the Regina Plain study area on October 1, 2000. The owl was found in a dense patch of thorn trees and prickly pear cactus, about a quarter section in size. This wood was beside a cultivated field and near a housing development. It is hoped that finding more of the Canadian owls will explain what factors are affecting their over winter survival with a view toward increasing their survival rates.

Life Cycle: Burrowing Owls live approximately five to eight years in the wild. They are able to reproduce at 10 months but usually breed between one and two years of age. Adult Burrowing Owls return to the breeding grounds in Saskatchewan between the second week of April and the third week of May. The average arrival date is the last week of April. The males arrive first, establishing a territory around a vacant burrow. Males often return to the same nesting area that they used the year before.

Ideal habitat is a nest burrow in short grass, such as a grazed pasture, surrounded by tall grass and riparian areas suitable for foraging. These burrows may have belonged to Richardson’s ground squirrels, badgers, black-tailed prairie dogs or foxes. If necessary, Burrowing Owls may enlarge the nest burrow by digging if there is not too much clay in the soil.

As breeding season begins, males start hooting, a "coo coooo" call. They also start hunting for deer mice and voles which they cache in the burrow. In good food years, prey caches may exceed 100 small mammals. Females actively search for a mate upon arrival on the breeding grounds.

The nest burrow will often be lined with dried cow or horse manure which is thought to keep the nest dry during wet weather. Fur and hair is also used as nesting material. Shortly after pairing with a male, the female owl will lay between 6 to12 eggs, laying one egg every 36 hours. The average clutch size is nine eggs; the earlier the laying begins, the larger the clutch size. Egg laying may occur between the last week of April and the second week of June. Hatching begins 26 to 30 days after the first egg is laid.

Newly hatched chicks are totally dependent on their parents for warmth and food for the first two to three weeks. Females tend the young while the male hunts. The chicks do not hatch all at the same time. During food shortages, the youngest chicks may die or be killed and eaten by the older chicks. Badgers are the key predators on young chicks during the nesting period.

About three weeks after hatching, the young owls may be seen at the entrances to the burrows. Some will be enticed to nearby burrows by their parents. It is thought that this is a survival strategy so that if a predator attacks one burrow, not all the young will be killed. Major predators during the fledgling period include Great Horned Owls, Ferruginous Hawks, Red-tailed and Swainson’s Hawks.

The young owl’s fledge, or begin to fly and hunt on their own, about five to six weeks after hatching. While they will hunt just about anything that they can catch, their major prey includes small mammals and birds, amphibians and insects. If enough food is available, the owls will eat up to half their own body weight every day. By eight to 10 weeks, the young owls are independent of their parents.

Migration south begins in the third week of September. Most of the owls have left Saskatchewan by the second week of October. Efforts at tracking radio collared Burrowing Owls have found that they can migrate 100 to 300 kilometers per night. Ham radio operators are actively involved in helping Canadian researchers track radio-tagged burrowing owls on their migration. For more information about this interesting project go to the Burrowing Owl Project web page at http://members.aol.com/joemoell/owl.html.

Limiting Factors and Recovery Needs: There are many factors, natural and related to human activity, that are likely contributing to the decline of Burrowing Owl populations across North America. Considerable research efforts in Saskatchewan, across Canada and internationally, are identifying what actions can be taken to ensure the continued survival of these owls.

Loss of habitat on the breeding grounds is considered a major factor in the decline of Burrowing Owl populations. In the Regina Plain study area, which extends from Moose Jaw and Regina in the north to Weyburn in the south, over 90 per cent of the land has been converted from native grasslands to crop land and urban development.

Owls in Saskatchewan are typically found nesting in small patches of heavily grazed pasture land, usually smaller than a quarter section. These remnant grassland patches are often surrounded by several kilometers of cultivated land. Burrowing Owls need grass and other wild plants (forbs) areas close to the nest site for hunting and there is little natural food found on cropland. Research has shown that providing extra food can significantly increase the number of owls that survive to fledging, which may suggest that the males are not able to find enough food close to the nest sites.

Agricultural practices most likely account for this lack of prey. Ground squirrels and other burrowing animals have been actively destroyed as pests. The shortage of burrowing animals also means fewer burrows are available for use by Burrowing Owls as nest sites, roosts and for escape cover.

Grasshoppers feed on planted crops; insecticide spraying usually occurs on fields about the same time that the owls need grasshoppers as a basic food source. Research in the Regina area in 1987 found a relationship between Carbofuran use and a decline in the number of owls fledged. Also, only half as many nests were successful in raising at least one young owl. It may be that the owls were directly affected by the spray, by eating the poisoned grasshoppers or by the general lack of food after spraying.

Successful lobbying by conservation organizations resulted in Carbofuran being deregistered as a grasshopper control in 1995 because of its toxic effects on owls and other wildlife. In 1998, granular Carbofuran, used on canola, was also deregistered as it was considered to present a very high risk of harm to songbirds, small mammals and a wide variety of avian scavengers in the Canadian prairies. Research has also been initiated in Saskatchewan to determine the effects of other pesticides on Burrowing Owls.

Predation is another major factor affecting the survival of young owls. Avian predators include Red-tailed Hawks, Swainson’s and Ferruginous Hawks, Northern Harriers, Prairie Falcons, Short-earred Owls and the Great-horned Owl. Other predators include red fox kits weasels, badgers, striped skunks, raccoons, rattlesnakes, bull snakes, domestic cats and dogs.

Roadways also present a danger. As Burrowing Owls tend to fly low when foraging, they may be hit by vehicles. Also, the owls may be hit when foraging for insects living alongside the roads or when scavenging for small mammals killed on the roads.

Research suggests that a lack of small mammals, such as voles, has caused avian predators to turn to Burrowing Owls in recent years for food to raise their own young during nesting. There was reduced avian predation on young owls in 1997, likely due to the very large increase in the vole population that spring and summer, which provided an abundant food source for other birds of prey.

Owls are sometimes affected by human development. In Moose Jaw, some traditional Burrowing Owl nesting habitat is within the city limits. As development has occurred over the past few years, the birds have still attempted to nest in their traditional sites. In some instances, Burrowing Owls have abandoned traditional areas as they have been developed.

The Moose Jaw Exhibition Grounds is now the site of the Saskatchewan Burrowing Owl Interpretive Centre where fragile nesting habitat is being protected. Education programs about the plight of the Burrowing Owls in Saskatchewan are being expanded every year. More information about this program is available by calling the Interpretive Centre office at 1-306-692-8710.

Recovery Actions:

In 1999, Saskatchewan provided legal protection to Burrowing Owls on private, provincial and federal lands through the Wild Species at Risk Regulations under Part V of The Wildlife Act.

In 1995, a national recovery plan for the Burrowing Owl was approved. The goal of the plan was to increase the population of Burrowing Owls in Canada to self-sustaining levels so that the species would no longer be considered officially endangered or threatened.

Saskatchewan leads North America in research efforts to find ways to help the Burrowing Owl population recover. Some of the key research and monitoring work that have been accomplished in Saskatchewan are as follows:

• 1987: Operation Burrowing Owl (OBO) began monitoring Burrowing Owl populations in Saskatchewan. This on-going, voluntary stewardship program, has enlisted over 500 farmers, ranchers and other landowners in the conservation of Burrowing Owl nesting habitat. It has resulted more than 50,000 acres of habitat on private land being voluntarily protected and more than 100,000 acres of public land being protected.
• 1987: Dr. Paul James began surveying a portion of the Regina Plains study area and reported significant declines in Burrowing Owl populations.
• 1994 to present: The Saskatchewan Burrowing Owl Recovery Project (researchers T.I. Wellicome, R. G. Poulin and L.D. Todd) has investigated factors affecting the Regina Plain Burrowing Owl population.
  • 1992 to 1993 research showed that supplemental feeding during the nesting period significantly increased the number of fledglings produced.
  • 1994 study revealed the number of nests lost to predation was too high.
  • 1994 productivity study showed that the number of young per nest could be increased by supplemental feeding and installing artificial nest boxes (ANBs) the prevented badgers and other digging animals from getting into the nests.
  • 1998 post fledging ecology project showed that almost half the young owls died prior to migration, mostly through avian predation and partly due to vehicle collisions.
• 1997 Migration Tracking Project studied the migration behaviour of the owls. Information about leg band colours and radio transmitter frequencies were passed on to the Canadian Wildlife Service researchers who were working on locating the wintering grounds in Texas and Mexico. (See Life Cycle section above for more information on this project).
• 1997 and 1998 captive bred adult owls were released to test and determine appropriate techniques should captive-release become necessary in the future recovery of the species. It was found that the offspring of captive born adults did not survive as well as wild owls and some owls failed to migrate in the fall. They were also very vulnerable to predation. This strategy was decided to be ineffective as a potential recovery strategy. Research on other release strategies is being investigated.
• 1996 The Saskatchewan Burrowing Owl Interpretive Centre opened to the public at Moose Jaw, near the TransCanada Highway, to provide an opportunity for visitors to view the owls in their natural habitat and to raise awareness about the reasons for the decline of the owls.
• 2000 to 2001 Gap analysis of Saskatchewan habitat lands protection status project. The Saskatchewan Environment Species at Risk Unit is reviewing current protection on essential habitat for listed wild species. Where habitat on crown land is unprotected, efforts will be made to include the land in The Wildlife Habitat Protection Act. Where habitat is on private land, voluntary stewardship agreements will be encouraged. These may include participation in Operation Burrowing Owl (OBO), conservation easements and willing-buyer willing-seller arrangements through the Fish and Wildlife Development Fund.

British Columbia continues with its captive bred reintroduction program and is focusing on enhancing habitat for the Burrowing Owls.

The Canadian Wildlife Service is involved in monitoring populations in and near Grasslands National Park in Saskatchewan and in Alberta. Winter monitoring in Texas and Mexico is continuing.

The various research projects have been possible because of the partnerships between government agencies, non-government organizations, universities, industry and landowners. Recovery efforts will only be successful through voluntary participation of these stakeholders in the future.

Guidelines are in place limiting direct disturbance of active owls’ nests during the nesting period. During the nesting period, April 15^th to July 15^th, a 200 metre buffer distance is recommended for low intensity (passive) activities such as walking past a nest or vehicle surveys. During the nesting and fledging period, April 15 to July 31^st, a 500 metre buffer is recommended for high intensity activities. This would include development activities such as drilling, trenching and seismic work. The timing of development should be co-ordinated with the absence of the owls from the breeding grounds. These guidelines are to help reduce the possibility of the owls abandoning the nest and to increase the possibility of the owls successfully raising their young.

Landowners can play a major role in the recovery of the Burrowing Owl by adopting the following land management practice, based on recommendations by Operation Burrowing Owl:

• Maintain a diversity of grassland conditions, including heavily grazed sites.
• Tolerate badgers, ground squirrels and other burrowing mammals on pasture land.
• Avoid or exercise caution when using pesticides (a minimum 250 metre buffer zone from active nests is suggested).
• Leave ditches and road allowances uncultivated.
• Maintain areas of taller grass adjacent to pastures with Burrowing Owls as this provides foraging habitat.
• Seed pasture, roadsides and right-of-ways with native seed, which results in more diversity of prey.
• Avoid tree planting near pastures with Burrowing Owls.
• Co-ordinate development activity with the absence of the owls.
• Consider entering into a voluntary conservation easement agreement with a recognized conservation agency. More information can be found on the Saskatchewan Environment website at: http://www.se.gov.sk.ca/ecosystem/conservationeasements.htm

Operation Burrowing Owl recommends the following actions that members of the public can take to benefit the Burrowing Owl and the prairie ecosystem:

• Be informed by joining a conservation organization.
• Become actively involved by volunteering your time and skills to conservation programs.
• Support conservation programs through charitable donations.
• Support sustainable agricultural practises. Buy low chemical, locally produced foods and range-fed livestock.
• Acknowledge and commend sponsors and partners of Burrowing Owl and prairie conservation programs.
• Write letters to encourage habitat conservation and support for species at risk programs.
• Practise the 4R’s (reduce, reuse, recycle and recover).
• Help monitor Saskatchewan’s Burrowing Owl population by reporting observations. Please phone the HOOT line at 1-800-667-HOOT (4668).

Selected References: Please contact your local library or visit the Internet sites below for more information on Burrowing Owls.

Blood, D.A. and D. Low, 1998. Burrowing Owl. Ministry of Environment, Lands and Parks, Victoria, BC. 5 pp.

Environment Canada. Species at Risk in Canada. http://www.speciesatrisk.gc.ca/Species/English/SearchDetail.cfm?SpeciesID=20 [Online]. Visited June 2000.

Homing In. The Burrowing Owl Project.

http://members.aol.com/joemoell/owl.html   [online]. Visited November 2000.

Hjertaas, D., S. Brechtal, K. De Smet, O. Dyer, E. Haug, G. Holroyd, P. James, and J. Schmutz, 1995. National Recovery Plan for the Burrowing Owl. RENEW Report No. 13. Recovery of Nationally Endangered Wildlife Committee. Ottawa, ON. 33 pp.

Nature Saskatchewan. Operation Burrowing Owl.

Http://www.unibase.com/~naturesk/obo.htm   [online]. Visited June 2000.

Nature Saskatchewan and Saskatchewan Environment, 2000. Operation Burrowing Owl and Conservation: Fact Sheet 1. Authors. Regina, SK. 4 pp.

Nature Saskatchewan and Saskatchewan Environment, 2000. Burrowing Owl Research/Investigations in the Field: Fact Sheet 2. Authors. Regina, SK. 4 pp.

Nature Saskatchewan and Saskatchewan Environment, 2000. Burrowing Owl Behaviour and Biology: Fact Sheet 3. Authors. Regina, SK. 4 pp.

Poulin, R. G., K. Scalise, and L. D. Todd, Saskatchewan Burrowing Owl Recovery Project: A Synthesis of Research (1994 - 1998). Saskatchewan Environment, Fish and Wildlife Branch, Regina, SK. 18 pp.

RENEW, 1999. Burrowing Owl (Speotyto cunicularia) RENEW Report No. 9. Environment Canada, Canadian Wildlife Service. Ottawa, ON. pg. 13

The Committee on the Recovery of Nationally Endangered Wildlife (RENEW), 1999. RENEW Report No. 9: 1998-99. Environment Canada, Canadian Wildlife Service, Ottawa, ON. 48 pp.

Wellicome, T. I., 1997. Status of the Burrowing Owl (speotyto cunicularia hypugaea) in Alberta. Alberta Environmental Protection, Wildlife Management Division, Wildlife Status Report No. 11, Edmonton, AB. 21 pp.