172



Dr. Arthur G. Butler,



conclude that both sexes are not equally capable ; for I have had

definite evidence that they are so; thus, as stated in my ‘ Foreign

Birds for Cage and Aviary ’ (vol. i, p. 196), owing to the ill-health of

the male of a pair of Orange Weavers (Pyromclana franciscana)

which I purchased in 1885, the hen started to build a nest for herself

which she had almost completed when both sexes died, and I had the

pair mounted with the hen at the entrance of the nest as I had seen

her when occupied in building it.


Then, again, in 1895, as recorded in 1 British Birds with their

Nests and Eggs’ (vol. ii, p. 68), the hen of a pair of Goldfinches in

one of my aviaries built a nest in a Hartz cage, laying and hatching

out four eggs, of which three left the nest; but before this occurred

the male built a second nest which the hen inspected, approved of,,

and, immediately after the flight of her first family, started laying

again in the second nest, leaving her husband to complete the

bringing up of the newly-fledged youngsters.


Although many male birds provide the materials with which

their wives build, two hens associated in a cage will collect their own

material and together build a very satisfactory nest, as was the case

with my two Rock-sparrows. On the other hand, where it is the

habit of the group to which they belong for both sexes to unite their

labours in the construction of their home, the absence of one sex

appears to be fatal; thus in the genus Icterus (typical hang-nests), as

with the somewhat similar Weavers of the genus Ploceus, both sexes

appear to contribute to the plaiting of the remarkable pensile nests.

It is therefore not surprising that my female Hangnest, although

she made repeated attempts to do so, utterly failed to build a

receptacle for her eggs and eventually deposited the material in a

nest-box and dropped her eggs on the floor. I was afraid to intro¬

duce my male bird into her tiny aviary lest they might kill each

other; for though the height of her compartment measured about

9 ft. in the centre, the floor-space covered only about 3| ft. square.


Now 7 , we know that in the Fringillidce and some other groups

the male only, or both sexes conjointly, collect nesting materials, and

the hen only utilises them in nest-construction ; then again, in the

case of the Fire-weavers ( Pyromelana ) and some others, the males

normally both collect the materials and build the nest; in the



