Life History

The life of Megascops kennicottii

Unlike some birds, M. kennicottii doesn’t migrate so it lives in one area for most of its life (Herting and Beltoff 2001; Rodriguez-Estrella and Palaez Careaga 2003). Since they do not migrate, they are typically socially monogamous throughout the entirety of adulthood (Ellsworth and Belthoff 1999; Herting and Belthoff 2001; BirdWeb 2014). This simply means that the Western Screech-owl is devoted to one mate in its life. There are four major phases of life for the Western screech-owl—these include courtship and nesting, fledging, young adult, and adulthood.

The Western Screech-owl’s Nest

Like described in in the Habitat page, the nest is comprised of a simple tree cavity with no added structures. After the male and female mate, the female bird lays around 2-5 eggs and incubates the eggs over a range of 26-34 days (Molina 2010; BirdWeb 2014). Courtship and mating generally takes place during the winter and eggs hatch in mid-March (Herting and Belthoff 2001). After hatching, the female stays with the young while the male protects and hunts for food for the female and offspring (Herting and Belthoff 2001; BirdWeb 2014).


Fledging is a term to describe the point at which a bird’s wings are developed for flight. After the brood, or offspring, have fledged, the owls remain in proximity to the nest for approximately five to six weeks (Ellsworth and Belthoff 1999). However, many do not leave the nesting area until eight to nine weeks after fledging (Ellsworth and Belthoff 1999). The owls who leave the nest first generally described as establishing dominance of the brood by being larger and stronger than the others (Ellsworth and Belthoff 1999). This is important because the individuals to leave the nest first have an advantage of accessing prime nesting locations and resources before those who leave later (Ellsworth and Belthoff 1999). Thus, dominance may be a contributing factor to the survival of the individual.

Young Adult to Adulthood

Megascops kennicottii is considered to be a young adult when it officially leaves the nest (Molina 2010). At one year, the owl is considered an adult as it establishes a nest and family and can live up to twenty years (Molina 2010). As an adult, the male owl protects its nest and its mate year-round (Hertin and Belthoff 2001; Herting and Belthoff 1997). In fact, the male Western Screech-owl is considered to be rather aggressive and studies have showed endocrine and behavioral relationships—levels of testosterone is the main contributor to aggressiveness. M. kennicottii with higher levels of testosterone are observed to be more aggressive than those with lower levels during periods of mating and incubation of the brood (Herting and Belthoff 1997). However, Western Screech-owls are observed to have increased aggressive behavior during non-mating seasons for territorial protection and is believed to be attributed to some other factor (Herting and Belthoff 1997). Overall, it is crucial for M. kennicottii to protect its nest for the future success of the species and is heavily regulated by testosterone levels during mating seasons.

Hoo, hoo: the sound of M. kennicottii

The most generalized sound of the owl animal is not the sound that is vocalized by M. kennicottii. In fact, the noise of the Western Screech-owl isn’t even a screech! The noise made is described as a trill that increases in speed and can be described as two types: bounce and double trill (Herting and Beltoff 2001). Their calls are believed to be important for territorial defense of the nest (Herting and Belthoff 2001). Male and females also have been observed to have different versions of the trill call. These calls that are specific for each sex help the Western Screech-owl respond to different Western Screech-owls that may be potential invaders of the nest (Herting and Belthoff 2001). Overall, the songs that M. kennicottii vocalize are very important songs that are involved with maintenance of their territory and communication. Follow this link to listen to the different calls of the Western Screech Owl!

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