The Horned Lark is not considered rare however it is seldom found in Orange County. Two repeatedly good places (year round) are Bolsa Chica just off the walk bridge in Huntington Beach and this location, Orchard Hills in Irvine. (note the MAP link within each photo). They typically enjoy open areas such as this new housing development area. I might suggest getting familiar with their calls as this can help in tracking down this species. The Xeno-Canto web site is a good starting point hearing their vocalization or your favorite bird app should have their songs and calls. Here's more from Wikipedia on the Horned Lark: Unlike most other larks, this is a distinctive-looking species on the ground, mainly brown-grey above and pale below, with a striking black and yellow face pattern. Except for the central feathers, the tail is mostly black, contrasting with the paler body; this contrast is especially noticeable when the bird is in flight. The summer male has black "horns", which give this species its American name. America has a number of races distinguished by the face pattern and back colour of males, especially in summer. The southern European mountain race Eremophila alpestris penicillata is greyer above, and the yellow of the face pattern is replaced with white. Vocalizations are high-pitched, lisping or tinkling, and weak. The song, given in flight as is common among larks, consists of a few chips followed by a warbling, ascending trill. There's more on this pecies at Wikipedia go here: https://en.wikipedia.org/wiki/Horned_lark