Small pieces of peat or pebbles may be assembled around the nest or on one side of it. The eggs are laid at daily intervals and incubated by the female for 10 to 14 days. They are cared for by both adults and leave the nest after 9 to 12 days. Horned lark populations have steadily declined as dry, open uplands have reverted to forests or have been destroyed by development. As with other ground-nesting birds, high populations of predators, such as raccoons, skunks, and housecats, have also contributed to the decline of this species.
Horned larks are common migrants and winter visitors in Connecticut, but are rare nesters.
Through the early 1900s, horned larks expanded their nesting areas south through Litchfield County. Scattered nesting occurred throughout Connecticut and the number of nesting pairs was never very high. As agricultural practices changed and development increased, horned lark nesting decreased and a population decline was noted for the Northeast. In its courtship flight, the male horned lark quietly ascends 300 to 800 feet or more above ground and begins a high-pitched, tinkling flight song as it circles. When the song ends, the lark drops headfirst, with closed wings, waiting until it almost crash-lands, before opening its wings and pulling out of the dive.