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THE ESSEX NATURALIST
Red-backed Shrikes at Colchester
By Shane Parker
IN 1959 observations were made on the breeding of a pair of
Red-backed Shrikes (Lanius collurio) in a sandpit in Colchester.
A map of the territory and some records of territorial behaviour
and feeding habits are included, with extracts from the observer's
field notebook.
The disused pit has a mean diameter of 100 yards with three
steep sides. The fourth side is level with and adjoins a main
road. Hawthorns, small beeches, ashes, sycamores and prunus
trees grow perhpherally, while sallow and crackwillow occur
centrally. Brambles are general. The floor of the pit is littered
with dumps of concrete slabs, rock and bricks.
History
Red-backed Shrikes bred in the pit until 1952, when, because
of vegetation clearance, they moved to another site. Building on
the fresh site disturbed the birds again and from 1954 to 1958
they bred at a third site. In 1959 building nearby again moved
the birds, this time back to the pit.
Extracts from Field Log
June 4th. A cock and hen were in the pit, the cock carrying
nest material.
June 5th. Both birds were watched all day.
June 6th. The nest with one egg was located in a Prunus shrub.
The hen was escorted back to the nest by the cock.
June 8th. Three eggs of the cream-pink variety. The hen lays
one egg a day between evening and early morning.
June 9th. Instead of containing an expected four eggs the nest
had been robbed.
June 10th. The cock was seen in a nearby garden.
June 11th. They had nested again in a tall formidable haw-
thorn.
June 13th. The nest had one egg. The cock perched very much
on the nest tree.
June 14th. Two eggs. The cock was seen chasing away a
sparrow from the nest site. No sound has been heard from
either bird so far.
June 15th. Three eggs, one which was broken and removed
from nest.
June 16th. Three eggs (four laid). The hen was always off the
nest before being approached too closely.
June 17th. First complete day of incubation. When the nest
was approached the cock flew into the nest tree and sat
in full view.
June 18th. A small pellet was found beneath a favourite sallow
of the cock.