Smokey’s Corner: In Search of Mexican Spotted Owl

Editor's Note: This is part two of a two part series on the Mexican Spotted Owl.

In this segment on Mexican spotted owls, we will continue our trek with Lincoln National Forest Wildlife Biologist Larry Cordova of the Smokey Bear District.

In our last article of Searching for Mexican spotted owls we looked at a few basic facts about owls... they’re very unique. Owls are nocturnal birds and function extremely well at night. Their ability to see in the dark has elevated owls in some cultures, to manifestations of wisdom.

Perhaps the earliest known link between owls and wisdom is their association with Athena. The Greek goddess of wisdom is often depicted holding an owl. In this article we will look at their breeding habits and habitat.

Larry Cordova carefully removed one of the little mice from his mouse container and gently placed it on a branch. The owl immediately aroused from its mid-morning slumber, opening his large sensitive eyes wide as he positioned himself for flight.

The owl flew towards the branch grasping the mouse with his widely spread, powerful talons. He then flew toward the next tree. Normally, an adult male will take prey to the female while she is sitting on (incubating) the eggs.

Male owls normally communicate with the female to signal the arrival of a meal. Not only do owls hoot, owls also make a wide range of other sounds, such as screeches, whistles, barks, growls, rattles and hisses. During the nesting season, owl calls can often be heard from up to a mile away. Female owls generally have a higher pitched call than their mates.

Males also respond to other male owl calls to protect their territory. Males feed the females until the eggs are hatched. Afterwards, the female will then teach the owlets to hunt and feed until they are able to catch prey on their own.

“The mating season usually begins in March,” says Larry Cordova, “and the gestation period is usually a little over a month.”

All owls are territorial, particularly around active nests. With the Mexican spotted owl species, females are slightly larger than males. This is called sexual dimorphism, a condition where the two sexes of the same species exhibit different characteristics. Dimorphism occurs in many animals. Differences may include size, color, markings, and may also include behavioral differences. Male owls have to look good to attract the female.

A female will brood the eggs from 30-35 days. Once the eggs hatch, the female will stay with the young and will generally leave the nest only to defecate or to release her castings (furry pellets of bones and other indigestible material). She will occasionally get off the nest to take prey items from the male. For 7 to 10 days after the eggs hatch, the male will continue to feed the female and their young. Afterwards, the female takes over and will hunt and bring prey back to the nest, tear up the prey, and stuff it down the nestling’s mouth. The fluffy white balls grow quickly. After 10 to 15 days, they start to hop about. Once the young leave the nest they are called fledglings. After two weeks, the fledglings appear as large as an adult owl due to their fluffy down feathers.

Owls usually live for up to 16–17 years. March is also the month for pair-bonding.

They will have a territory they’ll protect for a long time and will not leave unless there is a fire or loss of habitat. During April or the first part of May they’ll select a nest tree to lay their eggs.

By the middle of June, the adult female will begin to entice the young to leave the nest area, teaching them to hunt and fly. By September she stops feeding them. It is at this point the fledglings hunt alone. If the young owls are not good hunters they perish; usually during the first year, due to starvation and predation. The mortality rate can be as high as 50 percent or greater during the first year.

“In the first year sub-adults are most prone to attack by other raptors in the forest,” Larry Cordova said, “sub-adults usually live along the periphery of suitable habitat and are called satellite-birds because they have not found a territory.”

There is a lot of competition for suitable habitat. If they can make it through the first year, there is a good chance for survival. Mexican spotted owls are considered mature and can breed after 2-3 years.

Mexican spotted owls nest inside broken trees tops with live foliage above the opening for shade and protection. They prefer live trees like Douglas fir or white fir. Mexican spotted owls also utilize cavities, inside live trees or large dead snags.

“Owls are opportunistic. They will use whatever is available for a nest because they do not build their own nests,” Cordova said. “They’ve also been known to use witches brooms; which is a deformity where a dense mass of shoots grow from a single point resembling a broom or a bird's nest, for a nest.”

In the Carlsbad area and Guadalupe Mountains, owl’s nests are in caves or in large crevices in rock.

The relationship between owls and man has always captivated people. When Cordova and I were searching for Mexican spotted owls in the forest, I was intrigued that the owl we fed flew so close to us after collecting its prey. It looked at us like it wanted to thank us. It seemed like the owl could tell we were not a threat to him.

Because owls are normally only active at night, they blend in well with their surroundings. Normally you may only hear them. But, keep your eyes and ears open this time of year in the Lincoln National Forest, you may be rewarded by seeing or hearing this beautiful forest owl.

Read part one of the two part series by clicking on Smokey's Corner.