Reader Bruce Lyon is busy documenting the lives of local peregrine falcons (Falco peregrinus), and sent some nifty photos:
In 2014 I discovered a peregrine falcon nest on the California coast between Santa Cruz and San Francisco just as the chicks were fledging. Jerry posted a couple of the photos I got at the time. The birds returned and used the same nest site the next year (2015) and I was able to follow them through an entire nesting season, including for about a month after the chicks fledged.
The birds were very tame, and only got tamer over time—they basically ignored me and went about their business. Being able to watch falcons closely without affecting their behavior was really a unique experience for me, and I soon came to see their daily rhythms and patterns. Jerry previously provided a brief review of J.A. Baker’s book, The Peregrine, which some believe to be among the finest pieces of nature writing ever done. Baker’s powerful writing allows us to see the world through the eyes of a peregrine. Baker watched his birds in winter (his birds were winter migrants to England)—I was lucky enough to do something similar for the breeding season.
The female sitting on a favorite perch, staring out to sea. Perhaps she is scanning for passing shorebirds—both the male and female frequently use this perch to search for birds flying by over the ocean and then give chase:
The female launches from the perch. Note the size of the legs and claws: a dove’s worst nightmare:
The male landing at the same perch.
The happy couple perched on the cliff near the nest. The male (lower, left) is noticeably smaller than the female. This ‘reverse size dimophism’ is particularly common in raptors and is most extreme in bird-eating species. Many hypotheses have been suggested to explain this size pattern, including niche separation within the pair and division of labor during nesting (females are large to defend the nest, males are small for agile hunting):
The female with a Red-necked Phalarope (Phalaropus lobatus) she caught out over the ocean. Phalaropes were not on the diet very often but on this day both the male and female brought in a phalarope. Coincidentally, a local bird website reported particularly large movements of phalaropes on this same day—I suspect the falcons just could not pass up the opportunity for abundant easy prey:
A very damp male falcon. A.J. Baker reported that his falcons were fastidious about keeping clean and always took daily baths. The only time I ever saw a damp falcon was the male, on the day that he brought in a phalarope. Since phalaropes are caught at sea I suspect that he took a dunk while going after a phalarope:
The male drying out after his dunking. Note the pellet on the rock below him:
The female brings a Eurasian Collared-Dove (Streptopelia decaocto) to the nest. This non-native species is by far the favorite prey item taken by this pair—this year (2016) over half of the prey items I have been able to identify have been collared-doves.