Owls are territorial, a fact that is particularly evident during the
breeding season. Most owls are fearless when it comes to defending their
nests from attack. Attacks on intruders are invariably uninhibited and
vicious if the intruder stands its ground. They vigourously defend the
nest and a well-defined, surrounding feeding territory against members
of the same species and other birds that might conceivably compete for
the same resources.
If the owls are dispersive, this territoriality lasts only for the duration
of the breeding season. Year-round residents such as Tawny Owls and Eagle
Owls will defend their territories throughout the year, their efforts
extending to offspring of the pre-months past fledging. Tawny Owls will
readily kill Long-Eared Owls - potential competitors for food and nesting
sites in their territory: this effectively results in the fact that two
species do not overlap in terms of their precise distributions.
A Burrowing Owl (Athene cunicularia).
This Burrowing Owl is showing threatening behaviour toward an intruder.
Owls are able to alter their shape markedly by stretching or contracting
their bodies and flattening or fluffing up their feathers. The Burrowing
Owl spreads its wings to increase its size and thus makes itself seem more
threatening. This owl's alarm call sounds rather like a rattlesnake, a
creature which itself can pose a threat to the owls when nesting. Diurnal
species of owls will sometimes advertise their territories in a visual
manner. Thus, Short-Eared Owls perform buoyant flight and wing-clapping
displays to announce their presence to other birds, both potential mates
and intruders. Nocturnal species of owls invariably use sound as a means
of advertisement. The call of sedentary species often involve duets
between established pairs, rather than individual birds.
