Now that it is "officially" summer, you may wonder if you can expect any changes in terms of the wild bird activity in your yard. In a lot of ways, this is a very stable time of year in terms of bird movement. Spring migration is over and fall migration hasn't kicked into gear - yet.

If you look at the totality of summer (it extends from June 21 to September 22this year), there will be a tremendous amount of change in bird activity. During this span of time, we will experience nearly a complete reversal of spring migration with many of our songbirds leaving North America to return to their winter range - be it Mexico, Central America or even South America.

However, for now, many wild bird species are still breeding and rearing young. Some species could be on their second or third clutch by now, while other species may have yet to start breeding, nest building, egg-laying, or rearing young. For some species, breeding is timed to coincide with the arrival of our summer monsoon rains and the resultant profusion of plants and insects. This time period can, in some ways, be likened to a "second" spring here in the Arizona Central Highlands.

While we may have our own mental image of what migration looks like, or when it occurs, it is actually a very dynamic process driven by the uniqueness of each species. Factors such as their biological clock, length of day, food availability, wind, and temperature influence when birds migrate.

Probably the first fall migratory species to arrive in the Arizona Central Highlands each year is the rufous hummingbird. As soon as next week, I'll likely start receiving reports from customers of rufous hummingbird sightings.

Other than the act of mating, male hummingbirds don't share in any of the parental duties such as nest building, incubation of eggs, and feeding and rearing young. For male rufous hummingbirds, their whole purpose in migrating is the perpetuation of their species. Having successfully mated, their work is done. There is no reason for them to stay in their summer range, so they begin making their way south.

These hummingbirds are truly a marvel. Based on body-length, rufous hummingbirds are considered the world's longest migrator. The average length of a rufous hummingbird is only 3.75 inches. If you divide their body length into the distance they migrate - from Alaska to Central America - this species qualifies as the longest migrator based on this metric.

When you see rufous hummingbirds in your yard, it should inspire feelings of wonder and awe. The fact that this tiny creature - weighing only 3.4 grams - can successfully navigate an annual migration route spanning thousands of miles is amazing!

Of course, when they show up in your yard, chaos and mayhem will follow. Of all the hummingbirds we get in the Prescott area, rufous are the most aggressive. They will effectively disrupt the balance of power - the pecking order - at your feeders.

Typically, hummingbird feeders are guarded by a dominant male. Here in Prescott, this is usually either an Anna's or a black-chinned - until the rufous show up. This is a good time of year to increase the number of feeders you have out. Put them near one another, making it more difficult for one hummingbird to guard all the feeders simultaneously.

Putting multiple feeders (they don't need to be big) within a few feet of each other usually disrupts the pattern of one aggressive hummingbird from being a bully, keeping other hummers away.

Until next week, Happy Birding!