Captive Management of the Tropical Screech Owl

Abstract

I have long been captivated by the magnificence and nocturnal adaptation of the owl. The manner in which they have evolved and have been placed in their appropriate niches, is a well studied subject.

Having studied and looked for owls for many years, I was thrilled when a young tropical screech owl (Otus choliba) was brought to me to take care of on a temporary basis. By observing this diminutive owl night and day, I have been able to increase my knowledge about the habits and mannerisms of this curious family.

DESCRIPTION

This species measures between 8 and 9 inches in length, depending on eartufts being erected or lying suppressed. The main color is brownish to grayish in tone, having the facial disks light grey in color, and a black rim enclosing them. A few creamy white feathers are found on the forehead where the cere is located. The wings, upper back and tail feathers are reddish-brown, decorated with distinct black bands, creating a mottled effect. The breast is cream colored with darker streaks, not forming bars, but small vertical markings. The beak is horn colored, feet are grayish and the claws are black.

On various museum specimens, which I have studied, I have noticed some to be more rufous and others quite grayer in tone. The eyes do not reflect back as in Caprimulgids, but their bright yellow irides are quite obvious.

DISTRIBUTION

Robert Ridgely says in his Birds of Panama that it is "fairly common in light second growth woodland and woodland borders, clearings and open areas with scattered trees, and residential areas in lowlands on Pacific slope from Chiriqui (western Panama) to Canal Zone and Panama City.'' There existed no record for this bird in eastern Darien on the Colombian border, but one has since been taken there.

According to Ridgely, the range includes Costa Rica and Panama, south to northern Argentina and southern Brazil. Slud states in his Birds of Costa Rica (1961) that it has been collected almost entirely on the subtropical central plateau and neighboring slopes. Carriker wrote in his Birds of Costa Rica (1910) that very little was known about its distribution or its life. Obviously the life of this bird in its wild haunts merits further study.

VOCALIZATIONS

In the wild this owl utters, from what I have heard, a short trill similar to that of the eastern screech owl Otus asio of North America, but it is followed by one to three "hoooks" in a higher pitch than that of the trill. I have heard this vocalization but once in captivity, and also that of a shallow growl, "awrrrr" and a bill snapping sound made by slamming the lower and upper mandible together. This bill snapping is made when I approach him during the day when he is roosting quietly on a perch situated high in his cage. The growl is emitted at night either when hungry and he has not been fed yet, or while he is near his food and is trying to avoid intrusion.

I am located in an apartment in an urban area. It might be possible that this bird and others of his kind kept in a captive situation would utter their call more frequently if they were kept in an aviary in a rural area where feral owls could be heard.

FEEDING

I do not know with any certainty what comprises the diet of this owl in the wild. It almost certainly consists of small rodents and invertebrates much the same as that of Otus asio.

In captivity this owl has been offered one dead mouse nightly. Every three or four nights the owl is not fed in order to keep its weight down. During periods of rodent scarcity, I fed this bird strips of raw beef smothered in cod liver oil and covered with feathers to provide roughage in the hopeful event that it would cast pellets.

HABITS IN THE WILD

In the wild I have noticed the habits of this species to be nearly identical to that of Otus asio. It frequents the same type of habitat, found more often at clearings and scattered tree savannas, than in heavy rain forests. It responds well to recordings of its voice not by answering, but by flying to a nearby location and fluttering around. Although I never heard this owl call back, the eastern screech owl has perched about ten feet away from me in the state of Maryland, and has begun to call.

Whether or not the birds are defending their territory from an intruder, or merely responding to their mating call, I am not sure, for I have never been divebombed by these birds.

OBSERVATIONS IN CAPTIVITY The tropical screech owl has fascinated me in the period of time that I have kept him. Having been hit by a car, his wing is broken, and has mended in the wrong way, making him an unreleasable subject. Although he can fly for some distance when I release him in a large room, he is not capable of a sustained flight or hunting on his own.

The plumage of owls is incredibly suited for night life, since they are endowed with specialized barbs on their flight feathers, making their flight noiseless. I have noticed this adaptation when releasing the owl for exercise. The plumage is also very soft, and one characteristic that I have noted is that the eyelids are independently maneuvered, being able to open one eye to view its surroundings, while keeping the other one closed. Another interesting aspect about the eyelids is that they are feathered; a very unique feature.

Since owls have binocular vision, like humans, they are able to move their heads in any direction. Much to the surprise of many people, owls can see just as well during the day as during the night.

In one instance, when I had placed the food inside the owl's enclosure, I noticed how similar he appeared to the burrowing owl, Speotyto canicularia, of the drier areas of the United States. With legs extended and eartufts suppressed, he was most reminiscent of this northern bird.

I find owls to be extremely interesting avicultural subjects, and much can be learned about their behavior in the wild by studying them and their habits in captivity. Since breeding most owls in a captive environment is relatively simple, increased effort should be placed in rearing these most fascinating creatures of the night.