In dawn’s half-light a dark silhouette sits hunched at the top of a tall
birch. In one smooth motion it expands to a ragged-winged form to slip silently
from its perch. This is a Carrion Crow, patriarch of these woods, and a territory-holding
bird whose mate will be somewhere nearby. It is easy to see why these dark
sentinels have featured so prominently in legend and lore. There is something
ominous and broodingly expectant about the way in which they loiter, ever
watchful for the next meal. Our interest in crows, and more widely in other
members of the crow family, is rather ambivalent. Kept as pets, shot as pests,
viewed with respect but sometimes fear, there is a long history that exists
between us.
The Carrion Crow is an adaptable species, quick to learn and thus able
to exploit new opportunities. They are one of the species to have benefitted
from the new opportunities on offer in our ever-urbanising world. Even here, in
the centre of town, a pair has taken up residence and can be heard proclaiming
the ownership of their territory.
Crow populations can be divided into the territory-holding pairs and a
floating population of non-breeding birds, the latter predominantly comprised
of immature birds waiting for an opportunity to take on a territory. This
suggests that territories are a limiting factor, the resources and nesting
opportunities they contain restricted in their availability. Each territory,
which can be up to 110 acres in size, is defended with vigour by the male, supported
by his partner. Established neighbours, familiar to the territory-holding pair,
are treated less aggressively, leading to some overlap in neighbouring
territories and a shared defence of this airspace. In fact, neighbouring pairs
may work together to chase off intruders and would-be predators like Buzzards.
During the nesting season, activity is centred on the nest and birds
spend less time at the fringes of their territory. The males, however, continue
to advertise the ownership with much calling and posturing. Birds from the
non-breeding flock frequently test the resilience of established pairs by
making territorial incursions, with such activity peaking during the first
third of the year. Both the nest site and the breeding territory are defended throughout
the year, so even now my local birds are on the lookout for possible trouble.
Despite the rigid
territorial structure, Carrion Crows form large communal roosts (often with
other crow species). These are a familiar feature of the winter months and are
dominated by the non territory-holding birds, although territory holders may
join them. For me though, it is the solitary pairs that sit and watch from
their territories that are a feature of the dark winter mornings.
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