Trek through Huntington Central Park and you are likely to see plenty of Allen's hummingbirds. And that, in its own way, is extraordinary: a little over a quarter century ago, the species was rarely seen here.

Actually, when talking about Allen's, we are really talking about two subspecies. One of them, Selasphorus sasin, is migratory. It does not nest here, but visits this time of year as it heads north - among the earliest species to do so.

The other has been given the name 'sedentarius,' and for good reason: it stays put in its home range all its life.

But that home range has been expanding. The subspecies was once found only on the California's Channel Islands. In the 1960s and 70s, however, it began spreading across the mainland.

The species worked its way south and east toward Orange County, and in 1980 the very first pair was found nesting here.

In the mid 1990s, the stay-put version was much more common, though it was still possible for birders to notice a spike in Allen's numbers this time of year as the migrants began to arrive.

Now, sedentarius is so widespread in the county that it is difficult to detect any spike at all. Meanwhile, sedentarius appears to be pushing its range toward San Diego.


Why the expansion? One answer might be human civilization. The subspecies does well among us, feasting on nectar from ornamental plants. It's especially fond of red flowering gum eucalyptus. (Source)


Live video by Ustream