Rufous Hummingbirds Turning Up in Unusual Places

Rufous Hummingbirds Turning Up in Unusual Places

Is climate change the reason, or are birders just paying closer attention?

By Andrew Lawler
Published: March-April 2010

A quantifiable shift in migration offers an exciting opportunity, says Scott Weidensaul. The boyish-faced bird bander and author is taking a break at the same Alabama site where Bassett is gathering spring migrants. Crouching on the sandy ground, Weidensaul says the potential shift of the rufous and others "shows the surprising degree of plasticity in bird migration--that's a hopeful thing given the decades ahead of us."

Weidensaul notes that the blackcap warbler traditionally migrated from central Europe to the Iberian peninsula, then south across Gibraltar to Africa. But since the 1950s British birdwatchers have observed an increase in blackcaps wintering in the British Isles--something rarely observed before. Today an estimated 10,000 blackcaps swarm to Britain rather than Africa. For years researchers wondered whether this shift was due to chance, environmental changes, or an alteration in the birds' genetic code itself. German and U.K. scientists finally resolved the issue when they caught 40 "British" birds and bred them with one another, while doing the same for birds that wintered in Africa. When given the chance to fly, the "British" blackcaps headed for London, while the others went in the direction of Madrid. Today Britain's milder climate, increased food sources, and lack of competition make it a smart destination for blackcaps, which passed on that information encoded in their genes.

Weidensaul suspects something similar may be taking place with western hummingbirds. Several centuries ago any that strayed too far east in the winter encountered dense forest cover and colder winter temperatures. But those conditions have been superseded by a plethora of gardens and feeders that increase the probability that errant birds will survive. "Once a death trap for hummingbirds, the suburban Southeast is now a land of milk and honey," he writes in his 1999 book Living on the Wind. That's true, however, only for the tougher western species, like the rufous, which can put on a gram of fat in a day. Before migrating, from 25 percent to 40 percent of their body weight is typically fat, which they will burn over the vast distances they cover. They can survive temperatures below zero degrees Fahrenheit by dramatically slowing down their metabolism. Such freezing temperatures, however, are likely to kill off any ruby-throated hummingbirds, which don't have to live through extreme temperature as consistently as some of the western hummingbirds do.

 

Back in the Owens yard, Newfield files down a band that is too large for her latest captive, as it lets out a plaintive cry from a cloth bag. "This is really all bookkeeping," she says, gesturing at her data notebook. "It's important that I like to catch them--but not worth a damn if you don't do something with it."

Despite decades of meticulous data gathering, Newfield expresses some intrigue. "We are finding questions, not answers," she says, slipping the custom-altered band on the tiny leg and frowning as she adjusts it. "It's complicated." Both Newfield and Remsen are skeptical of those who want to point the finger at human-induced climate change to account for the potential shift in hummingbird migration.

"Everyone wants to blame everything on global warming," says Remsen later that day in his cluttered office at LSU behind the Museum of Natural History. "It is tempting to believe, but the link is tenuous." He notes that in the past few years there has been a drop in counts among the more western species in the area, despite relatively mild winters. That may have to do with Katrina effects or specific conditions--drought, for instance--at a breeding ground thousands of miles away rather than a long-term global trend. And despite the increasing numbers of western species counted in the Southeast during winters in the 1980s and 1990s, the overwhelming majority of the birds remain true to their ancient migration path, which stretches from Mexico to Alaska. "It is
really hard to make any inference in a population when you are focusing on a peripheral area like the Gulf," he adds.

There also is a lack of hard data on the status of the Mexican wintering grounds. Though habitat destruction there is frequently cited, Remsen says it remains unclear whether that could be forcing some birds north and east. "You could go either way--there is a loss of habitat or they are doing so well they need to migrate to find greener pastures," he says. And areas considered degraded by humans--that is, fallen trees and debris--can be rich habitats for many hummingbird species.

It may be surprising that despite the intense focus on hummingbirds in recent decades, there is not even a consensus on what they eat. Some argue that the bulk of their calories come from insects; others say from nectar. Such a prosaic detail matters if you want to pinpoint the role of feeders in hummingbird migration. "It's not what we know that is so striking," says Sargent, who is busy at work with Bassett and Weidensaul gathering and banding migrating birds in Alabama. "It is what we don't know."

That mystery continues to power this small group of hummer lovers. "None of us would have been doing this if it wasn't for Nan Newfield," says Weidensaul. Here in the Owens yard, the banding is done for the morning. Three decades after starting her five-year-project, Newfield is grayer and more solid but no less passionate. She recalls a recent trip to Cuba, where she spotted the rare bee hummingbird. "It was one of the high points of my life," she says. Then, shyly, Newfield pulls out two pictures. The first is of her two-year-old grandson. And the second? A rare hybrid hummingbird.

This story originally ran as "The Drifter" in the March-April 2010 issue of Audubon magazine.

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Andrew Lawler

Andrew Lawler lives in rural Maine and contributes to Science Magazine, Smithsonian, National Geographic, and others.

Type: Author | From: Audubon Magazine

Comments

Early hammers

We have had two regular Anna's all winter. We live right outside Seattle, Wa. This last week a Rufous showed up at my window feeder for the first time. It was quite tattered looking and quite hungry as we have very few flowers out yet. I've also has the largest hummingbird come to my back yard feeder that I've ever seen here in the last ten years. It stayed for only a few days and left. The rufous is still with me though along with my Anna's and some others that appear to be in transit as they are all tired and very Hungry. It appears that we are getting some that we have not seen before possibly due to our very mild winter. Not even one frozen feeder this year. We feed all year as we have many that nest in our trees and hanging flower baskets and several usually stay for the winter as well, as we have good hiding places for them to view their feeders.

Rufous in Greater Atlanta

I have had the joy of "hosting" rufous hummingbird(s) for at lest the last three years. I live just north of Atlanta and they show up around November and as of today 3/21/13 one is still here. My neighbor also keeps feeders out year 'round. I expect he will move on soon and will be replaced by our Ruby-throated.

Hummingbirds Can Surprise You

I've had the great pleasure for over 15 years to be acquainted with virtually all of the individuals mentioned in this article plus Allen Chartier who bands fair numbers of birds at our home in Michigan every year. You can never be sure what kind of hummingbird will arrive at your feeders/flowers. In 2005, we had a White-eared Hummingbird visit for several days - in Michigan. This species is expected in the mountains of Mexico, hardly in semi-rural Michigan.

RUFOUS HUMMINGBIRD

I have had a rufous hummingbird at my house in South Williamson, KY since October 26, 2012. There were numerous times when I thought that she couldn't survive the severe wintry weather. But, then she would appear at the feeder when the temperature was 14 degrees. My husband and I rotated feeders, bringing one indoors and taking another one out, so there was always one that wasn't frozen. Recently she has been feeding at the Oregon Holly blossoms. Plus several other flowers are now available. Our friend, Brainard Palmer-Ball from Louisville came to our house and banded the little female on Dec. 2, 2012.

Allen's Hummingbirds

I wonder if the Rufous hanging around Marco's house in Buena Park could be an Allen's. I live in northeast Fullerton and have lots of Allen's - or what I have always thought were Allen's because of their small size.

Hummingbirds/general comments

As a lifelong resident of Ohio and admirer of hummingbirds I find it interesting to note the changes in their migratory habits. But one need only look at the Canadian Goose to know that something has been going on for some time with regards to climate. As a boy growing up in the 1960's I cannot recall seeing these birds during the winter. But sometime within the last 15 or 20 years, some of them at least, started staying behind during the winter months. Milder winters perhaps?
Back to the topic of hummingbirds, I just wondered if anyone else has ever seen this or knows anything about it. I've kept at least of couple of feeders out for them for as long as I can remember. One day about ten years ago I was watching the feeder and I noticed a couple of paper wasps supping at it when along came a hummingbird. As it approached the feeder the wasps rose from it ominously, like they do, and confronted the bird. Discretion being the better part of valor, the hummingbird decided it had best find a meal elsewhere and promptly left. While I don't know it to be fact I would have to imagine that wasps are quite capable of killing a hummingbird having been stung by them on several occasions myself, and I was glad the bird moved on.

wasp / hummiers.......

wasp in e-texas also run of humming birds...

Canada Geese

The reason for the "Canada" Geese over-wintering is explainable. Humans have set up perfect habitats for them to take up permenant residence. They have adapted to our parks, golf courses, and agriculture practices. States have made efforts to slow down the migration so their hunters could harvest birds before they headed to their wintering areas by planting and flooding fields, No reason to fly south when everything they need is available.

Hummingbirds in strange places

Growing up in upstate NY we saw hummers by the thousands, but since moving to Illinois 50 years ago I can almost count all I've seen on my fingers.

Rufous'

Yes, I know. I have seen a Rufous hanging around my home in Buena Park, CA...I have a bottlebrush tree that a Anna's uses for her nest, but have seen this smaller species since end of fall early winter. Although I haven't seen it for a couple of weeks now.

The Anna's are battling for mates; found a dead one in my yard above the bottlebrush tree.

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