Yesterday while doing fieldwork in La Habra Heights, I was surprised to see a young Northern Harrier sail overhead. These hawks are uncommon migrants in the hills, and a handful may winter. They require large blocks of undeveloped grassland and low scrub, and not surprisingly, have very little habitat left in the Los Angeles Area. Ten years ago, we found them nesting in just one spot in the Puente-Chino Hills - a single pair in the wet grasslands of upper Tonner Canyon, visible from Grand Ave.
Wintering areas are now almost as scarce, and folks should let me know if they run across any this winter. Males are pale grayish above and clear white below, while females and especially first-year birds are brownish below. Both sexes have bright white rumps, which may be seen as they tilt back and forth.
In the same area of La Habra Heights, I also observed an Osprey circling, and then later in the afternoon, another first-year harrier over Turnbull Canyon. Late fall (October) is when hawk migration peaks through our area, and folks may be seeing increased numbers of raptors these days. They aren't being displaced by fires, but are just following well-worn pathways through the sky, heading southeast into Mexico.