Barn owls are mysterious and captivating birds that have long fascinated humans. One of the most interesting aspects of barn owl behavior is their mating habits and whether they form lifelong pair bonds with their mates.
Barn owls (scientific name: Tyto alba) are medium-sized owls with long legs, a heart-shaped facial disk, and a light-colored body. They are found worldwide and known for their eerie screeching calls.
Like other owl species, barn owls are primarily nocturnal or crepuscular (active at dawn and dusk). They roost in sheltered spots during the day such as barns, abandoned buildings, caves, or nest boxes put up specifically for barn owls.
Barn owls prey on small rodents such as voles, mice, rats, gophers, and chipmunks. They hunt by quartering low over open areas listening for prey with their acute hearing and sight. Once prey is detected, barn owls dive down swiftly to catch the prey in their talons.
Barn owls are cavity nesters and prefer nesting in human-made structures. They lay 4-7 eggs per clutch which are incubated for about 30 days. The female does most of the incubating and brooding early on while the male provides food. The young fledge at around 2 months old.
Do barn owls mate for life?
Whether barn owls stay together as lifelong pairs or frequently find new mates each breeding season has long interested researchers. Studying owl behavior in the wild is inherently challenging given their nocturnal and secretive natures.
Early observations of barn owls in captivity and the wild suggested they may mate for life. Barn owls are often observed roosting and hunting together in male-female pairs. Pairs also work cooperatively to raise young and defend nest sites.
However, more systematic research using banding studies has shown barn owls actually display varying mating patterns, depending on the conditions and owl population:
- In some populations and years, barn owls do exhibit long-term pair bonds, staying with the same mate across multiple breeding seasons.
- In other cases, barn owls will switch mates between breeding attempts or seasons, displaying seasonal monogamy.
- Barn owls may also show polygyny, where one male mates with multiple females. Males have been observed mating with up to 5 females in a season.
There are a few key factors that determine which mating strategy barn owls follow:
Food availability
Food supply has a major influence on barn owl breeding behavior. In years or areas with abundant prey, barn owls are more likely to stay paired with the same mate across seasons. When food is scarce, they are more prone to switching partners.
Nest site availability
Nest sites are limited for barn owls, so competition for good sites is high. Owls with established nests are more likely to maintain long-term bonds. Without a stable nest, they may have a different mate each season.
Age and experience
Older, more experienced barn owls tend to maintain consistent pair bonds while younger owls often switch partners more frequently.
Gender
Some research indicates female barn owls may be more prone to having new mates each season than males. But patterns vary across populations.
Population density
At higher population densities, barn owls have more potential mate options available to them. This leads to an increased tendency to find new partners versus staying paired for life.
Signs barn owls are paired for life
There are several behaviors that suggest a mated pair of barn owls is closely bonded and may stay together long-term:
- Nesting together in the same site across multiple years
- Jointly defending their nest area from intruders
- Roosting near each other regularly outside the breeding season
- Coordinated hunting, with the pair calling and signaling to each other
- Grooming each other
- Sharing food provisioning and brooding duties at a nest
These behaviors reflect the cooperation and familiarity that comes from prolonged bonds between mates.
Why might barn owls stay paired for life?
There are some potential advantages to barn owls remaining with one mate long-term:
Familiarity with mate
Staying paired means owls already know their mate’s habits, signals, and preferences. This coordination may improve hunting and breeding success.
Stability for raising offspring
Offspring may have better survival when both parents are very familiar with each other and their roles. The parents can also better defend familiar nest areas.
Easier than finding new mates
Established pairs don’t have to expend as much time and energy on courtship or seeking mates. Their focus stays on breeding rather than finding partners.
Mutual benefits
Close cooperation between the male and female may help ensure both partners receive benefits like shared food resources and nesting sites.
Why might barn owls find new mates?
On the other hand, there are also potential benefits for barn owls frequently getting new mates each breeding season:
Reduced inbreeding
Switching mates avoids inbreeding depression that can happen from related owls breeding together over many seasons.
Spreading genes
Males may be able to produce more offspring by mating with multiple females in a season rather than just one long-term partner.
Compatible genes
Finding a new mate may result in a better genetic match for producing healthy, fit offspring.
Back-up mate
If one mate dies, it may be easier to find a new partner quickly if bonds are temporary rather than permanent.
Change in conditions
A different mate may become more suitable if environmental conditions change or the owl settles in a new nesting area.
Geography and subspecies
Barn owl mating behaviors can also vary across their worldwide distribution. Some key regional patterns include:
United Kingdom
A 20-year study of barn owls in the UK found about 60% maintained pair bonds for multiple seasons while 40% changed mates. Pairs stayed together on average 2.5 years. Food supply was a major factor in mate switching.
Central Europe
In Germany, Switzerland, and surrounding areas, barn owls more strictly maintain long-term monogamy, only finding new mates when an established partner dies.
Israel
A study in Israel showed barn owls were mostly monogamous there. Pairs that lost mates would try to reunite the next breeding season.
North America
There is some evidence of both prolonged pair bonds and polygynous mating in North American barn owl populations.
Australia
Australian barn owls show very high mate fidelity. In a 30-year study, just 4% of females and 8% of males paired with new mates.
Differences across regions may be explained by variations in prey availability, nest site options, owl densities, and subspecies genetics.
Can paired barn owls be forced apart?
Even barn owl pairs exhibiting strong lifelong bonds can be forced apart in certain circumstances:
- One mate dying, leaving the other to find a new partner
- Lack of adequate food resources to sustain a breeding pair in an area
- Eviction from a nesting or roosting site by predators or human disturbance
- Capture and relocation of one mate away from the pair’s territory by wildlife rehabilitators
These kinds of disruptions require the remaining owl to search for a suitable new mate in order to breed again.
Are barn owl “divorces” common?
Barn owls dissolving an established pair bond and choosing new mates from one season to the next could be considered a type of “divorce”.
As mentioned earlier, one European study found about 40% of barn owl pairs switched mates between breeding attempts. However, most research shows a majority of barn owls maintain consistent bonds once paired:
- 75% fidelity found in Israeli barn owls
- 60-95% fidelity reported in other studies
- Average 2.5 years together for UK barn owls
So while mate switching certainly occurs in barn owls depending on conditions, it seems outright divorces are relatively uncommon compared to consistent pairings.
Do both parents raise barn owl chicks?
Barn owls display biparental care, meaning both the male and female parent are involved in raising offspring:
- The female incubates the eggs and broods the young chicks more at first.
- The male provides most of the food to the female and later the chicks as they grow.
- Both parents feed and care for chicks once they become older “branchers”.
- The parents continue hunting to feed fledglings once they leave the nest.
These shared duties may help reinforce the pair bond. Both parents invest significant time and energy into successfully raising their chicks.
Barn owl bonding behaviors
Barn owls exhibit various bonding behaviors between mated pairs beyond simply reproducing together. These include:
Nesting
Barn owls seek out cavities and sheltered spots to nest together during the breeding season.
Preening
Owls will gently nibble and trim feathers on their mate’s head and body with their beak to groom them.
Roosting
Mated pairs roost near each other even outside of the breeding season.
Food gifting
Male owls will pass food to the female as part of courtship feeding before breeding.
Duets
Paired owls may perform their screeches and calls together as a duo.
Displays
Owls execute exaggerated movements and upright stances to attract and reinforce bonds with mates.
These behaviors help maintain the pair bond when it exists. Even lone owls may do displays and calls to attract potential new mates.
Barn owl communication
Barn owls have a variety of vocalizations and gestures used to communicate with their mates:
- Screeches – Loud, shrill calls used to define territory, attract mates, signal alarms, etc.
- Shrieks – High-pitched squealing during aggressive encounters with intruders.
- Twittering – Softer chattering between mates at the nest.
- Hissing – Used towards unwanted intruders near the nest.
- Wing clapping – Clapping wings together makes a snapping sound to attract mates.
- Bowing – Male owls bow towards female with spread wings during courtship.
These vocalizations and displays facilitate communication between the male and female owl for maintaining their pair bond.
Barn owl nesting habits
Barn owl nesting habits are relevant to assessing their potential for lifelong pairing. Key nesting facts include:
- Don’t build nests. Occupy cavities like barn lofts, tree hollows, caves, etc.
- Line cavity with scattered pellets and debris.
- Females lay 4-7 smooth white eggs.
- Incubation about 30-34 days by female mostly.
- Young fledge at 50-70 days old.
- May reuse nest over multiple years.
- Nest defense by both owls against intruders.
The reuse of established nests across seasons and joint nest defense reflect barn owl behaviors that support prolonged pair bonding.
Conclusion
Barn owls display a mix of monogamous lifelong pair bonding and sequential polygamy depending on environmental conditions and owl demographics. While divorce does occur, most evidence indicates barn owls remain faithful to a mate across multiple seasons once a pair bond has formed. This is facilitated by cooperative breeding behaviors and shared nesting and hunting duties between the male and female owl.