Accounts of hummingbird decline raise question: Is it trend or cycle?

2010-09-19T00:00:00Z 2014-07-15T17:58:06Z Accounts of hummingbird decline raise question: Is it trend or cycle?Tony Davis Arizona Daily Star Arizona Daily Star
September 19, 2010 12:00 am  • 

Two hummingbird feeders - but no hummers - were hanging out in front of the Chuparosa Inn in Madera Canyon last Thursday morning.

"This year, there was a crash - the bottom dropped out," said Luis Calvo, sitting outside the bed-and-breakfast he has owned for 14 years. "In a normal year, they are like bees, with every port on the feeders having a hummer on it and another one waiting to get on."

In the Huachuca Mountains, hummers darted that afternoon among 10 feeders dangling from a huge oak tree at Tom Beatty's Miller Canyon Guest Ranch. But Beatty, who has owned the bed-and-breakfast since 1998, observed that, "Right now, you see 50 birds here - but you used to see 500.

These stories match other accounts of a hummingbird population crash this year across Southeast Arizona, known as the hummingbird capital of the United States. But there is no evidence of a long-term decline, says a researcher who runs a four-state, one-Canadian-province, nonprofit hummingbird-monitoring network out of her Patagonia home.

That's because Arizona hummer counts this year, while significantly lower than from 2006 to 2009, are generally little different from those of 2005, said Susan Wethington, the Hummingbird Monitoring Network's executive director. Anecdotal accounts exist of long-term declines, but they date to before the network's 2002 startup.

Her data doesn't necessarily mean that hummer populations are fluctuating naturally, Wethington said, "But what I can say that this fluctuation is similar to what we saw in 2005 in Arizona. In the next couple of years, we'll have better data to see if populations rebound like they did from 2005 to 2009, or is this the start of a negative trend."

For this year's lower numbers at feeders, observers cite two possible reasons: Last year's dry weather, which could have reduced food production, and this year's wet weather, which generated more nectar-producing wildflowers, reducing birds' need for feeders.

Several species

Birding hotspots such as Madera Canyon, the Huachucas and the Cave Creek area in the Chiricahua Mountains each draw 14 or more hummingbird species a year. Eighteen hummingbird species live in Arizona, the most of any state, says the Bisbee-based Southeastern Arizona Bird Observatory.

Besides helping the ecosystem by pollinating food-producing wildflowers, hummers boost business by luring tourists to pay anywhere from $70 to $200 a night at Beatty's and Calvo's places in the peak summer season.

"People kind of identify with these birds," Chuparosa's Calvo said. "They are so tiny and fragile. They are like little helicopters."

Diane Durkos-Smith, a birder from Culver City, Calif., described the "feathered jewels" she had just seen at Beatty's last Thursday.

"When the sun hits the green on their throats - you get this jewel that pops out," said Durkos-Smith, who saw 10 species at visits of three hours each at Beatty's and the neighboring Nature Conservancy's Ramsey Canyon preserve and the Ash Canyon B&B.

But the hummingbird crash and the bad economy contributed to a 20 percent decline in business this year from 2009, said the Chuparosa Inn's Calvo.

"I've had guests comment to me on a number of occasions, 'We've been here before, and there are a lot of hummingbirds. Where are they now?' " Calvo said.

sites monitored

The Hummingbird Monitoring Network uses bird banding and other means to count populations that are drawn to monitoring sites by feeders. Volunteers track 10 Arizona sites, out of 30 across the West, every two weeks from late March through October.

When Wethington analyzed Chuparosa's data, she found that breeding populations of all hummers were twice as high in 2008 and 2009 as this year, but the 2005 and 2004 breeding populations equaled those of 2010.

Focusing on the black-chinned hummingbird, Southeast Arizona's most common breeder, Wethington found that its highest breeding numbers across all 10 stations occurred in 2002 and 2006, with the lowest in 2003, 2005 and 2010.

During migration, black-chinneds peaked in 2004 and 2009, and bottomed in 2005. Since black-chinned migration started late this year in late August and early September, the network doesn't have total migrant counts although early counts look better than in 2005, Wethington said.

These fluctuations explain why studying bird population trends takes time, Wethington said.

"Basically, there are normal cycles in population numbers that change through time. What you are looking for in trying to manage and maintain populations is that they are staying within a normal range of variation."

One Southeast Arizona migrant known to have declined is the rufous hummingbird. The federal Breeding Bird Survey estimates annual declines of 1 to 2.7 percent from 1966 through 2004, although its population is still secure.

consumption trend

B&B owner Beatty says he believes his businesses' sugar consumption patterns suggest a longer-term hummer decline. From 1999 through 2006, consumption ranged from 745 to 1,361 pounds annually, varying with rainfall and wildflower growth. Since 2007, he's never used more than 475 pounds. Beatty said he pulls down feeders nightly so bats don't use them and said they hardly draw bees.

Other B&B owners and residents with feeders have different accounts of hummingbird populations ranging from fluctuations to continuous declines.

Sherry Nelson, a wildlife artist who lives in Cave Creek Canyon, has been feeding hummers steadily since the 1990s. She started keeping records in 2002, when she fed more than 14,800 hummers, and watched numbers plummet to virtually none in 2005 and 2006. Then numbers rose, topping at 20,750 in 2009.

But Rick Taylor, a professional bird-watching guide who has observed hummingbirds in this region for three decades, said this summer's numbers were by far the worst he'd seen.

"I remember wet summers with abundant natural food for hummingbirds in the 1970s, '80s and '90s, and hummingbird feeding stations were never as slow as I saw them this July and August. I have vivid memories of walking across the Ramsey Canyon Preserve parking area through a blizzard of living darts, and seeing the feeders in Cave Creek literally swarming with hummingbirds."

But he said this year's good rainfall produced ample supplies of gnats and nectar for the birds in the wild, and predicts "2011 is going to be great."

On StarNet: The Critters of Southern Arizona database at azstarnet.com/critters can help you identify that visitor in your back yard. Readers, see other readers' hummingbird photos and share your own by uploading them to the reader gallery at go.azstarnet.com/hummingbirds

Contact reporter Tony Davis at tdavis@azstarnet.com or 806-7746.

Copyright 2014 Arizona Daily Star. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Activate

Most Popular

Follow the Arizona Daily Star


Deals, offers & events

View more...