Every year I explain that ruby-throated hummingbird numbers ebb and flow in a predictable manner. May numbers peak as migrants return. Some move on, but some stay to nest. In June, we're left with the local breeders, and adult females spend most of their time tending to their nests. So in June and early July, it's normal to see just a few hummers at feeders.

In mid July, young hummingbirds fledge and visits to feeders increase dramatically. And that's exactly what has happened at my feeders over the last 20 years. In June, I rarely see more than two or three ruby-throated hummingbirds at a time.

But this year has been dramatically different. On June 16, I counted four hummers. The next day I counted 10; the following day 12. And every day since, I've seen more hummingbirds. Because they move so quickly, making an accurate count is difficult.

My point is that my hummingbird population exploded in mid-June this year, a full four weeks earlier than usual. I recorded the first returnee on April 26, so they didn't come back earlier than normal. They just began reproductive behavior almost immediately upon their return. Allowing six days for courting and mating, five days for nest building, two days to lay two eggs, 16 days for incubation and three weeks in the nest, that's 50 days needed to get young out of the nest. The April 26 arrival date allows time to spare. They were here 53 days by the time I saw young birds at feeders.

The question is, why the rush to nest this year? Nothing has changed in my backyard or in the immediate vicinity. Perhaps it's a response to climate change. If anything, I was expecting a delayed nesting season because it was such a wet spring. I'd like to hear from any readers who have observed similar early nesting success.

In the meantime, I'm filling my feeders twice a day. The little buggers are drinking nearly a gallon of nectar each day.