other males. It is not known if the display in the Cape sparrow has a similar significance. When ready to mate, the female crouches in solicitation and is mounted by the male. Instances of hybridisation with the house sparrow, the southern grey-headed sparrow, and captives or escapees of the Sudan golden sparrow have been reported. Nesting The Cape sparrow utilises a variety of nesting sites. Bushes and trees, especially acacias, seem to be preferred, and many nests may be built in a single tree. Holes and other covered sites are chosen less frequently. Nests have been recorded from the eaves of buildings, on creepers on walls, in holes in earth banks, and in holes in haystacks. Sometimes the Cape sparrow nests in the disused nests of other birds, such as weavers and swallows. Pairs that nest away from colonies usually choose low bushes or utility poles as nesting sites. Nests are placed at least a metre above the ground, and can be only a few centimetres apart in colonies. Only the nest and its very close vicinity are defended as a territory. Males defend their territory with threatening postures, and sometimes by fighting with bills on the ground. Nests built in the open are large and untidy domed structures, built of dry grass, twigs, and other plant materials. Any leaves or thorns present in a tree may be worked into the nest. In cavity nests, the hole is filled with a shapeless mass of grass with a cup of soft material containing the eggs on the inside. When the disused domed nests of weavers are used, they are given a soft lining. The nest entrance is on the side, and is sometimes extended into a short funnel. The male and the female construct the nest together, keeping close when finding material and weaving it together. The inside linings of Cape sparrow nests can incorporate large portions of aromatic leaves such as wolbossie (Helichrysum pumilio), thyme (Thymus vulgaris), and camphor (Cinnamomum). This consistent use of aromatics suggests that they have some purpose such as protection against parasites. Eggs and young Clutches contain between two and six eggs, typically three or four. Variation in clutch size depends on the amount of food available for young birds. Presumably owing to the greater availability of food, clutches are larger during the peak of the breeding season, and in more southern latitudes of the Cape