Nests

May 24, 2024

It is not surprising that with the bird feeders I have along the patio fence we would also have a number of bird nests in our yard. This included the bluebird (Sialia sialis) house situated above the container tomatoes.  We have several nests in the trees in the front yard.  The one in the Japanese maple (Acer palmatum) was hidden until I pruned the tree while making my hügelkultur beds (I kept the branch with the nest).  For the last several years the Northern mockingbirds (Mimus polyglottos) have made nests in the cover of the snowball bush (Viburnum macrocephalum) and the rose bush (genus, Rosa) that I have cleared out along with an annual pruning.  As I rounded the corner to check on my raised beds yesterday, I was startled as an American robin (Turdus migratorius) flashed by my head.  When I looked up, I saw a cup nest resting atop the curvature of the drain spout.  While I do not want this to be a permanent nest, I thought I would wait until the eggs hatch and the fledgling leave before I take it down.  That makes at least four nests from three (known) species of birds.

When I looked online, I found the study of birds’ nests is known as caliology and defines nests as the spot where the bird lays and incubates its eggs and raises its young.  While the term generally refers to a specific structure made by the bird this definition is too restrictive.  BirdChronicle describes 14 different types of bird nests, ranging from a shallow depression in sand, a burrow in the ground, a chamber drilled into a tree, a rotting pile of vegetation and earth, a shelf made of dried saliva, or a mud dome with an entrance tunnel.  The smallest are hummingbirds (genus, Trochilus) nests at 0.8 inches (2 cm) across and 0.8 to 1.2 inches (2 to 3 cm) high.  These nests are dwarfed by the mounds built by scrubfowl (genus, Megapodius) found on the Pacific Islands which can measure 36 feet (11 m) in diameter and 16 feet (5 m) tall.  Some species do not build nests and use the empty nests or burrows of other birds.  Pygmy falcons (Polihierax semitorquatus) and red-headed finches (Amadina erythrocephala) move into sociable weavers’ (Philetairus socius) nests while the brown-headed cowbird (Molothrus ater) lay their eggs in other birds’ nests and then abandon the eggs.  Birds like the White tern (Gygis alba) and emperor penguin (Aptenodytes forsteri) never build a nest and lay their eggs on the open ground.  Nest diversity has a function and purpose specific to the species.

While I have not seen any nests, we have a house sparrow that flies off when I exit the front door.  On inspection I found a 2-1/2 inch (10 cm) hole in the overhang.  My immediate thought was how to get rid of this intrusion.  While researching bird nests, I found US federal law makes it illegal to remove or destroy any active nest (a nest with eggs or brooding adults) from a native bird species.  If the nest has been abandoned or has no eggs, it can be removed or destroyed.  It is also illegal for anyone to keep a nest taken from a tree or found on the ground unless you have a permit issued by the US Fish and Wildlife Service.  Migratory birds (and native species) are protected, and tampering with or removing a nest or eggs can lead to fines or other penalties.  Nests of invasive birds, like house sparrows (Passer domesticus) or European starlings (Sturnus vulgaris), are not protected at any time.  Interestingly, starlings and sparrows are commonly found building house nests.

THOUGHTS:  I had different reactions to the nests around my house.  I placed the bluebird house to attract a nesting pair, avoided the nests in the tree and on the downspout, and left the nests of the mockingbirds until pruning.  I felt different about the house sparrow, perhaps as it made a hole and caused damage.  Humans often invite and embrace nature until we are faced with a negative impact.  Then we allow economics or expedience to dictate our actions.  Protecting the environment is both a global and individual response.  I can legally remove any sparrow nests, but should I do so morally?  Act for all.  Change is coming and it starts with you.