Paradise, Ariz.—The Chiricahua Mountains here in far southeastern Arizona boast some of the most spectacular birding in the country; at no other time is this truer than in the early fall during the peak of hummingbird migration.

The tiny travelers, which play crucial roles in pollination and ecological stability, make their way down the Rocky Mountains to the Sierra Madres. They are attracted to a major seasonal change that happens on this borderland sky island during these months. A strong influx of moisture streams northward from the Pacific Ocean and the Gulf of Mexico bringing late summer heavy rains that have turned the sea of surrounding grasslands green. In the canyons, last year’s monster flames are becoming a distant memory: shades of red, pink and yellow dot the charred landscapes, signaling the return of wildflowers during this “second spring.”

The wildflowers offer the hummingbirds, mostly juveniles, an opportunity to indulge and fatten up on nectar before continuing on to Mexico or Central America for the winter. Birders and tourists come from around the world to observe hummingbirds here simply because of their beauty; however, few are aware of the integral function that hummingbirds serve for biodiversity in the region.

»View the Hummingbirds Slide Show

A single hummingbird may visit more than a thousand wildflowers a day. In the process, it picks up pollen grains and carries them from one plant to another, serving as the basis for cross-fertilization needed by the flowering plants to produce seed. Because hummingbirds—along with bees, butterflies and bats—act as primary pollinators for about 150 species of flowering plants in the United States (and more in Mexico and Central and South America), land managers and scientists want to keep a close eye on their numbers.

In the early morning hours of a recent fall day in Cave Creek Canyon at the Southwest Research Station, ecologist Susan Wethington led a group of citizen scientists and volunteers to monitor and record the migration. Based in Patagonia, Arizona, she is the co-founder and executive director of the Hummingbird Monitoring Network (HMN), a group devoted to maintaining hummingbird populations and their habitats. 

Group members received instruction on how to perform their roles. They set up their stations and, for the next five hours, each group member trapped and banded the birds, recorded data, and marveled at the animals in hopes of understanding a little more about the journey they’d made thus far.

Despite one's fascination with these fairy-like creatures, Wethington told the group, "There is still too little known about hummingbirds." Among the questions that need answers include: What does it take for hummingbirds to survive, reproduce and maintain thriving populations?

On this day alone, the group trapped and processed almost 100 birds—the busiest day this year—and they recorded seven species (in order of number): Black-chinned, Blue-throated, Magnificent, Rufous, Broad-tailed, Anna's and Calliope. The numbers are encouraging, Wethington says, a sign of recovery after the harsh conditions brought on by freezing temperatures, drought and wildfire of the past couple of years.

How hummingbirds will respond to climate change is a major concern, Wethington says. The Chiricahuas serve as an exceptional location for studying how well hummingbirds adapt. Here, four different ecological regions meet—the Rocky Mountains, the Sierra Mountains, and the Sonoran and Chihuahuan deserts—and serve as a biological crossroads of flora and fauna. In total, researchers have recorded 18 species in this canyon, more than in any other area north of Mexico.

4 Comments

1. 1. Charles Hollahan 01:23 PM 10/18/12

   Driving past the Chiricahua Mountains in late August can be very surprising. There's an overlook a few miles out from the area just before getting back into the salt pan again and the view is stunning because of the moisture and life. This off Interstate 10, a highway the goes from the beach in Santa Monica to the other side of the continent.
   
   The Chiricahua Mountains themselves are too far away from the road to appreciate and I've never been able to get off and see them. It was near Cochise's last stronghold according to some of the road signs about 50 miles away.
   
   I've read a lot of comments by people who are now calling the changes in weather and the science of understanding the changes a "religion for global warming", usually on the pages of newspaper blogs. The parties don't seem to understand that it's no longer theoretical.
   
   It's nice to hear that Hummingbirds are evolving at least. The Chiricahua Mountains are a very small oasis out in the middle of the desert. If it fades away, as it did in the past, then it might take human intervention to keep their routes open until we find a solution to the fossil carbon energy economy.

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2. 2. Travashamockery 03:30 PM 10/18/12

   I'm expecting the usual SA climate change nay-sayers to be commenting on this innocuous little article any minute now....

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3. 3. pooka47401 10:48 AM 10/19/12

   I have noticed over the past couple of years,that there have been vastly more female than male hummers hatched. I usually end up feeding 20-30 on a regular basis, during the Southern Indiana Summer.This was true last year and this year. I had about 1 male to 5 female ratio. It reminded me that women have more male children when enduring War and more females in Peace time. If Hummers were under stress then it would make sense to have more females to breed, to replace those lost.

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4. 4. greenhome123 12:53 AM 10/23/12

   I have noticed that many people are concerned about pesticides hurting bee populations, but I haven't heard anything about pesticides hurting hummingbirds. I think that is an issue that needs more study, since hummingbirds are also important pollinators.

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