and the tail is flicked laterally,
but not fanned. The intensity of the singing increases and is
supplemented by scolding, also delivered at a rapid rate. The intruder
normally retreats at this juncture.

3. Wing-flicking and submaximal tail-fanning. If the interloper
remains, the anxiety of the resident male increases. He slightly
depresses the tail and, at the same time, rapidly fans and closes it.
The tail is only partially fanned. The wings are held slightly away
from the body and rapidly flicked above the back. This flicking should
not be confused with quivering of the wings associated with begging
and other solicitory postures. Song is now almost completely replaced
by high-intensity scolding. Associated with this high degree of
anxiety are displacement behaviorisms, including bill-wiping, reversal
of direction on a single perch, and a nervous hopping from one perch
to another.

4. Ruffling and maximum tail-fanning. This display is most often seen
in conjunction with the harassment of predators, but occasionally it
is observed in territorial disputes occurring at the boundary of
adjacent territories where neither male is strictly dominant and in
which there is much vacillation prior to attack. The feathers of the
abdomen are ruffled. The term "ruffled" pertains to a full erection of
the feathers, giving a ragged appearance to the body outline (Morris,
1956:80). Ruffling of the abdominal feathers emphasizes their yellow
color and seemingly heightens the intimidatory effect. The tail is
fully fanned, and so maintained, for a few seconds at a time; it is
held at a 45 deg. angle to the body. The scold becomes an extremely
intense, stacatto buzz, ZZ-ZZ-ZZ-ZZ.

5. Supplanting attack. The attack directed against a trespassing male
is initiated as a lunge that results in a collision with the opponent
in mid-air or on his perch. The bird attacked is struck by his
adversary's open beak or body.

Hinde (1952:71-72) indicates four courses of action followed by a
Great Tit (_Parus major_) when attacked under similar circumstances.
"(a) It flies away: The attacker usually flies after it and a chase
ensues. (b) It shifts its perch a few inches: the attacker lands in
its place, and both usually show head-up postures. (c) It remains
where it is, but adopts a head-up posture: the attacker usually then
shows upright flight. (d) It may fly up and meet the attacker in
mid-air: in that case an actual combat may result, or both com