166 R. James—Curious Behaviour of Breeding Jackdaws


methods adopted by this fancier are by no means orthodox, which

makes many of his achievements all the more remarkable. However,

Mr. Conant has kept a film record of some of his experiments, which

leaves no room for doubt, otherwise some of the stories would sound

rather fantastic to most of us.


The Jackdaws in question are hand-reared, 1935 birds. Two hens

from one nest and one male from another district. All three birds

are housed in an aviary, some 30 feet long, 12 feet wide, and 9 feet high.

At each end of the aviary is fixed a box, near the roof, about 18 inches

square, with a round hole cut out of one side of each box, the hole

being 6 inches in diameter. In the spring of 1936 the cock bird mated

with one hen, and has at all times refused to mate with the spare hen,

in spite of repeated invitation to do so. A rough nest was built by the

mated pair—the cock finding most of the material, the hen would

discard anything she considered unsuitable. The owner of the birds,

acting on advice, removed the spare hen, after which all nesting

operations were discontinued and the nest was destroyed by the mated

pair. The spare hen was then returned to the aviary. The mated

pair then built another nest, and five eggs duly appeared, the

eggs were incubated (chiefly by the hen), for a week, and then the

eggs disappeared, it was thought the Jackdaws had eaten the eggs.


In the spring of 1937 the same birds built another nest, in the

same box, and again the spare hen was taken to another aviary ; as

a result, nesting operations again discontinued, and nest destroyed.


The spare hen was again returned to the Jackdaw aviary, nesting

operations were then resumed, and a clutch of eggs duly appeared.

A strict watch was kept as incubation proceeded, the eggs began to

disappear, and it was found that rats were the culprits. This must

have happened in the night, and it seems the Jackdaws would repair

the nest in the morning, and continue to incubate what eggs were

left. All eggs disappeared eventually, and so another season was lost.

The following autumn the aviary was reconstructed and made rat-proof.

The spare hen was kept with the mated pair the whole time after this,

and a nest was built again in the spring of 1938, and six eggs were

counted on the 22nd April. The nest was again examined on the

14th May, when seven eggs were counted. On the 16th May it was



