Wild Birds – Nests and Nest Building

Birds are the real masterminds behind the development of the natural world. Not only do they create interesting and complex structures, but the variety of materials they use is incredible. Birds use any natural substance they can manipulate with their beak or foot, from tree cavities to cliff banks to simple platforms. They’re not above using man-made structures or objects, which is why it’s so simple to improve your bird-watching experiences by simply having a well-designed bird house or some dog fur, then watching them go to work. If you would like to learn more about this, please check out Bird Nest Removal

Hormones are responsible for the act of constructing a nest. Other factors including migration, day length, food availability, and territoriality play a role, but these behaviours are influenced by hormones. Birds’ reproductive organs are greatly decreased in size for the majority of the year, as an adaptive technique to minimise the amount of weight they have to bear in flight. The size of a male’s testes and a female’s ovaries increases dramatically once hormones kick in. By examining the size of these organs during a post-mortem examination, it is easy to determine a bird’s reproductive status. Ovaries and testes shrink down to tiny little structures ventral to their kidneys until the breeding season is over.

Forms of nests

The size and shape of a robin’s nest, a mud and grass structure commonly found in our yards or even constructed over the porch light on the front steps, are familiar to most people. However, there are a variety of other types of nests constructed from a variety of materials. Here are a few examples of nests you might come across while exploring.

Cavity nests are a form of cavity nest. Tree cavities, which are created in trees by woodpeckers or natural weathering, provide homes for a variety of animals, including tree swallows, woodpeckers, nuthatches, chickadees, house wrens, bluebirds, wood ducks, saw whet owls, and others. Some birds may also build a nest in ‘artificial’ cavities found in human buildings, such as stove vents, dryer vents, chimneys, eaves, soffit, and under shingles. Many cavity nesters are satisfied by the traditional bird home, which is made by humans in a variety of shapes and styles.

Cups: A nest cup is a woven circular bowl made from grass, leaves, thread, hair, and mud or saliva to help keep it together. It is commonly seen on ledges or in the crook of a tree. Blackbirds, goldfinches, robins, and barn swallows, for example, build this sort of nest. The two latter species may use an artificial nest platform attached to the side of your house or garage to construct their nest cups.

Hanging baskets: A delicate grass basket made by the colourful Baltimore oriole hangs from a branch and sways in the breeze, looking for all the world as if it would fall apart in a mild storm. Orioles, on the other hand, aren’t the only ones who weave baskets. Other species, such as the bushtit, use moss, feathers, and plant fibres to weave baskets.

Mud tubes: Who hasn’t seen cliff swallows’ incredible globular nests? It takes hundreds of trips from the mud source to the cliff swallow’s tubular nest, which is located on a bridge, house, or cliff wall. Each mud ball is mixed with saliva to provide enough sticking power to keep it intact.

Platforms include: Many raptors build their nests on top of a supportive base, using both natural and man-made foundations, by gathering leaves, twigs, grass (even green herbs) into an untidy mass. Some are tiny and inconspicuous, allowing them to remain concealed from predators. Sharp-shinned hawks and Cooper’s hawks are likely to build these. Others, such as those made by osprey and eagles, are enormous in both scale and stature. Year after year, both ospreys and eagles can accumulate hundreds of pounds of nest material, which can grow to be as large as 7 feet wide and as deep as 10 feet. When it eventually fell, one nest was said to weigh well over a tonne. Platform nests can be found atop an old magpie nest, in a strong tree, on the edge of a cliff, or on a man-made structure like a power pole, a bridge, or an artificial nest platform. The green plants that are introduced each year are known to contain natural insect and parasite repellents.

Tunnels: Fish-eating kingfishers and puffins carve out tunnels in dirt banks or along cliff edges overlooking their preferred hunting grounds. The pre-made tunnels built by rodents like Richardson’s ground squirrels would be used by burrowing owls.

Land: Many species conceal their nests on the ground, sometimes covered by a low-growing bush, and sometimes only protected by the substrate’s fantastic camouflage. This type of nest is built by shorebirds, ducks, and many songbirds. Short-eared owls, snowy owls, and ferruginous hawks, for example, will build their nests on the ground. These raptors have evolved in environments where they may go weeks without seeing a tree, so they have adapted accordingly.