Why are bird nests round?

Bird nests are round. Construction plans are part of the animal's genetic code. Sometime long ago, a bird or birds learned that there is an advantage to having a round, tubular, or globular nest. A circle is the most economical way to define space. read more

I think the shape of bird nests is somewhat governed by the reach of the bird in all directions, which would logically be a circle. The distribution (and distance) of nests in several coastal birds is also governed by same phenomenon, i.e. out of the reach of quarrelsome and competing neighbors. read more

Bird nests are round. Construction plans are part of the animal’s genetic code. Sometime long ago, a bird or birds learned that there is an advantage to having a round, tubular, or globular nest. read more

The smallest bird nests are those of some hummingbirds, tiny cups which can be a mere 2 cm (0.79 in) across and 2–3 cm (0.79–1.18 in) high. At the other extreme, some nest mounds built by the dusky scrubfowl measure more than 11 m (36 ft) in diameter and stand nearly 5 m (16 ft) tall. Not all bird species build nests. read more