Threatened Colorado
Burrowing owl standing at the entrance to a prairie dog burrow on shortgrass prairie, showing long legs, yellow eyes, and spotted brown plumage
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Burrowing Owl

Athene cunicularia

Federal: None CO State: Threatened NatureServe G4
Class
bird
Population (CO)
No current range-wide estimate for Colorado; last systematic statewide assessment conducted in 2005. Breeds primarily on eastern plains black-tailed prairie dog colonies. Tier 1 Species of Greatest Conservation Need in Colorado State Wildlife Action Plan.
Trend
Decreasing
Critical Habitat
Not designated

Overview

The burrowing owl is one of Colorado’s most distinctive and immediately recognizable birds — small, long-legged, and active during daylight hours, often seen standing upright at burrow entrances on the eastern plains, rotating its head with the alert, deliberate quality that makes owls so compelling to watch. Most owls are creatures of darkness and forest. This one lives underground on open grassland and hunts in full sun. It is genuinely different from every expectation an owl carries.

In Colorado it is state threatened, with no federal Endangered Species Act protection. State law is its primary legal safeguard — a thinner shield than federal listing provides, and one that does not trigger the consultation requirements that can influence development decisions on federally permitted projects. Its conservation depends on what Colorado chooses to do, and on whether the owners of eastern plains land decide that prairie dog colonies are worth keeping.

That last point is not incidental. The burrowing owl’s fate in Colorado is inseparable from the fate of the black-tailed prairie dog — and through that shared dependency, it is part of the same ecological story as the black-footed ferret.

Natural History

The burrowing owl (Athene cunicularia) is a small, compact owl standing 7.5 to 10 inches tall with a wingspan of 21 to 24 inches and a weight of 4.5 to 9 ounces. Unlike most owl species, males are slightly larger than females — a reversal of the usual raptor pattern. The plumage is brown with white and tan spots across the back and barring on the breast; white eyebrow markings above bright yellow eyes give the face an expressive, almost quizzical appearance. The legs are conspicuously long — an adaptation for a life spent running across open ground rather than gripping branches.

It is one of very few diurnal owls, active during daylight and hunting by sight across short vegetation. Prey includes grasshoppers, beetles, and other large insects, as well as rodents, lizards, and occasionally small birds. Adults are year-round opportunists — they will eat almost anything catchable at their scale.

Nesting is underground, almost always in abandoned black-tailed prairie dog burrows in eastern Colorado. Burrowing owls are capable of excavating their own burrows but rarely do so when prairie dog infrastructure is available. Adults line burrow entrances with dried animal dung — a behavior once dismissed as coincidental but now understood to serve two functions: it masks the scent of eggs and young from mammalian predators, and it attracts dung beetles as convenient prey.

Clutch size runs 6 to 12 eggs, incubated for 28 to 30 days, with young fledging in approximately six weeks. Fledglings remain in the parent territory through the summer. The species is migratory in Colorado, arriving on breeding grounds in mid-March to early April and departing in early fall for wintering areas in Mexico and the southwestern United States. Adults in good condition may live 6 to 8 years.

The Prairie Dog Connection

In eastern Colorado, burrowing owls nest almost exclusively on black-tailed prairie dog (Cynomys ludovicianus) colonies, and this relationship is not casual or substitutable. Prairie dog colonies provide the owl with everything it needs to breed successfully: a ready supply of excavated burrows sized appropriately for a small owl, reduced vegetation height that enables the low-flight hunting style the owl depends on, the constant predator alarm calls of hundreds of prairie dogs that extend the owl’s early-warning system across a much larger area than it could monitor alone, and the dilution effect of a dense colony that reduces any individual bird’s probability of predation.

Take the prairie dogs away and the owls leave. The relationship has been documented consistently enough across the range that burrowing owl presence is now used as a reliable proxy for prairie dog colony health.

Black-tailed prairie dog populations have declined an estimated 90 to 98 percent since 1900 — one of the most dramatic reductions of any North American mammal. The causes are familiar: sylvatic plague introduced from Asia in the early 20th century, which moves through prairie dog colonies with lethal efficiency; conversion of native grassland to agriculture and development; and a century of active eradication programs that treated prairie dogs as competitors for cattle forage.

The burrowing owl’s decline maps directly onto that collapse. It is also what connects the burrowing owl directly to the black-footed ferret. Both species are obligate residents of black-tailed prairie dog colonies. Both have experienced parallel, severe declines driven by the same forces. Both depend for recovery on a prairie dog ecosystem that the surrounding culture has spent a century trying to eliminate. The ferret’s story gets more attention — it is a charismatic mammal with a dramatic near-extinction narrative. But the burrowing owl’s story is the same story told from a different vantage point, and its absence from federal ESA protection makes it in some ways more vulnerable, not less.

Primary Threats

Prairie dog decline is the foundational threat — everything else is secondary to it. When sylvatic plague sweeps through a prairie dog colony, the owl nests on that colony disappear with it. Plague can eliminate a colony within weeks; without intervention in the form of oral vaccine bait distribution or colony treatment with insecticide dust, recovery of both prairie dogs and the owls that depended on them can take years.

Habitat loss and fragmentation through agricultural conversion and urban and suburban development has eliminated prairie dog colonies across the eastern plains. The Front Range has been particularly impacted — historically dense prairie dog country that now runs largely under subdivisions and commerce.

Active eradication continues on both private and public lands, though it has decreased from historic levels. Poisoning and shooting programs targeting prairie dogs remove the substrate on which burrowing owl colonies depend.

Vehicle collisions are a significant source of direct mortality along eastern plains roads, particularly during fall migration when young-of-year birds are dispersing and unfamiliar with road hazards.

Wind turbine collisions have emerged as a measurable threat as wind energy development expands across the eastern plains, in the same landscape that supports the owl’s breeding population.

Pesticide exposure affects owls both directly, through the uptake of rodenticides used for prairie dog control, and indirectly, through reduced insect prey availability in heavily treated agricultural areas.

Predation by feral cats and dogs contributes to adult and juvenile mortality in colonies near developed areas. Feral cat predation is particularly significant near the urban-rural interface on the Front Range.

Climate change adds compounding pressure through increased drought frequency, altered precipitation timing, and spring temperature extremes that can affect insect emergence timing, chick survival, and prey availability.

The absence of federal ESA listing means that none of these pressures — except on federal lands — triggers mandatory consultation under Section 7 of the ESA. Development projects that destroy burrowing owl habitat have no federal legal obligation to mitigate unless federal permits or funding are involved.

Recovery & Conservation

The burrowing owl is designated a Tier 1 Species of Greatest Conservation Need in Colorado’s State Wildlife Action Plan — the plan’s highest priority tier, reserved for species facing the most significant decline and threats. USFWS designates it a Bird of Conservation Concern at the national level. Neither designation carries the force of law.

Colorado Parks and Wildlife maintains recommended survey protocols and a grassland species conservation plan that includes burrowing owls. CPW survey guidelines call for repeated point counts during the breeding season at known and potential colony sites. The last systematic statewide population assessment was conducted in 2005; an updated assessment is needed to establish current baseline numbers and detect population trends across the breeding range.

The most effective single conservation action for burrowing owls in Colorado is the conservation of black-tailed prairie dog colonies — their size, health, and connectivity. Research suggests that burrowing owl reintroduction efforts require approximately 16 prairie dogs per acre of active colony to support nesting pairs. Below that threshold, colony quality degrades rapidly for the owl even if individual prairie dogs remain.

Defenders of Wildlife and other conservation organizations have worked with landowners on voluntary prairie dog and burrowing owl habitat programs. Permanent land protection through conservation easements on properties supporting active prairie dog colonies provides the most durable form of habitat security.

What You Can Do

  • Report sightings to iNaturalist and eBird. Breeding season records from eastern Colorado — particularly from specific prairie dog colonies — are genuinely useful data. Even fall and spring migration observations help document movement corridors.
  • If you find prairie dog colonies with burrowing owls, report the location to CPW. Active nest sites that aren’t in the database can’t be managed or monitored.
  • Respect nesting areas from April through August. Approach burrow entrances slowly and at distance; sustained disturbance at active burrows can cause nest abandonment. If you see adult owls repeatedly alarm-calling or young owls retreating underground, you’re too close.
  • Support conservation of black-tailed prairie dog colonies on both public and private lands. The political context for prairie dog conservation is contested on the eastern plains. Landowners who maintain or restore colonies are performing a real conservation function that deserves recognition.
  • Contact CPW or Defenders of Wildlife about landowner programs that provide technical and financial support for prairie dog and burrowing owl habitat management.

Data Sources

Species status, population data, and recovery information drawn from:

  • USFWS Species Profile: Burrowing Owl (primary source)
  • USFWS Status Assessment and Conservation Plan for the Western Burrowing Owl
  • Colorado Parks and Wildlife State Wildlife Action Plan — Tier 1 designation
  • Population assessment of burrowing owls nesting on black-tailed prairie dog colonies in Colorado (Mountain Scholar repository)
  • Burrowing Owl Conservation Network
  • Defenders of Wildlife: Burrowing Owls
  • Boulder County Open Space species description

Last reviewed: January 2024

Range Map

Phase 2 — Coming Soon

An interactive county-level range map (Leaflet.js + OpenStreetMap) will appear here. Maps show general habitat range only — no precise GPS coordinates are published in accordance with sensitive species protection policy.