Supplying artificial nest boxes has helped local populations of Eastern Bluebirds rebound from historic lows. Most North American songbirds build open cup nests. The placement and construction of cup nests can increase their security. The bulky nests of Gray Catbirds are usually well concealed deep within a leafy bush or thicket. Hummingbird nests are often constructed over water and covered with materials that blend in perfectly with the tree limb.
Many species prefer to build their nests in thorny plants to discourage climbing predators.
In contrast, Blue Grouse in the mountains of North America move as little as a kilometer down the slopes to a lower altitude for the winter months and then return up the mountainside in the spring. While a Blue Grouse may not have much trouble finding its way up and down the hill most other migratory species face a daunting challenge that may involve ocean crossings and journeys of thousands of miles. Longer lived species such as geese, swans, and cranes migrate as family groups. The young may learn the migration route from their elders. Most migratory songbirds must make their first long journey on their own.