Nest searching requires patience, a keen eye, determination, and often a bit of luck.
Nesting activity is greatest in May and June, but keep your eyes open throughout the year as some birds have extended nesting periods. In southern parts of Canada for example, species like Great Horned Owls start nesting in February, while other species start to nest in March or April. Some species, like Northern Cardinals and Mourning Doves, may have two or even three broods annually and can sometimes be found feeding young into September, or even later.
This depends on the species. American Robins, for example, will often nest in your own backyard, an urban park, or a schoolyard. Heavily built-up areas like city centres are likely to have nesting House Sparrows, Rock Pigeons, and European Starlings. Suburban areas will have birds nesting in trees and hedges, including Common Grackles, Mourning Doves, and Song Sparrows. In open areas, Bluebirds and Tree Swallows will often use nest boxes on fence posts. Rural areas and forested landscape (including large forested urban parks) will generally have the highest diversity of nesting species.
You can find more information on where species nest in field guides, Breeding Bird Atlases, and online resources such as the Cornell Lab of Ornithology All About Birds website.
The most effective way of finding nests is by observing and understanding bird behaviour. Nests are easiest to find during nest building and during the nestling stage because one or both parents will be making frequent trips to and from the nest. During the nest building stage, you also often have the advantage of better visibility as this generally occurs early in the season, before vegetation is fully leafed out. It is more difficult to locate a nest during laying and incubation because there is less activity at the nest during these stages.
What's a clutch?
All of the eggs a female lays in a single nesting attempt.
Nest building requires numerous trips to the nest and the length of time it takes to build a nest varies greatly by species. A female American Robin can make up to 180 trips a day to build her nest. Some species build their nests much more slowly, with less frequent trips to the nest. If you see a bird carrying material such as a piece of grass, a twig, or a feather, it is likely the bird is carrying this material to a nest. Try to observe where the bird flies, and watch from a distance to observe several trips so that you can be sure of the nest location. Do not approach the nest at this point; wait until your next visit to check for eggs in the nest. Birds are more likely to abandon a nest due to disturbance before eggs are laid.
Most passerines (songbirds) will lay one egg per day, often in the early morning, until the clutch is complete. Many birds don't start incubating until all of their eggs have been laid, making nests harder to find during this stage.
During incubation one parent (often the female) sits tight on the eggs to keep them at the optimal temperature for development. For some species, the female and the male take turns incubating the eggs, sometimes vocalizing when they switch. For species in which only the female incubates, males often take food to the female; sometimes she leaves the nest to feed herself. As you become familiar with the behaviour of the species you are monitoring, you'll be able to pick up on more clues that provide information about the location and stage of a nest.
What's a brood?
The group of young hatched from a single clutch of eggs.
Another good time to locate a nest is when there are nestlings. For most birds, both parents make dozens of trips daily to feed the brood, and you may be able to locate a nest by watching an adult carrying food. Be careful when approaching a nest with nestlings. If the young are fully feathered, do not approach closely as there is a risk of startling the young and causing them to leave the nest prematurely.
Keep in mind! The best way to find a nest is to observe birds from a distance as they go about their natural nesting behaviour. If they perceive you as a threat, you may hear distress calls or frantic chipping, or they may be silent but stop what they are doing. For example, if you see a bird carrying food, it is likely heading to a nest to either feed an incubating female, or to feed nestlings. If the bird does not go to a nest, but instead stops and waits, still carrying the food, it is likely worried that you are a predator and does not want to reveal the location of the nest to you. Back up and try to get out of sight, while still keeping an eye on the bird. Once you are no longer perceived as a threat, the bird will resume its activity.
Many shorebirds use a broken- wing display to protect their nest. When a predator approaches, the adult attempts to lure it away by pretending to be injured while moving away from the nest. If you witness this behaviour, you are likely close to the nest. Back away slowly, being very careful where you step, until the bird is no longer displaying. Try to get out of sight and watch to see if the adult returns to the nest.