Fifty years of data show new changes in bird migration

FEBRUARY 20, 2020

by American Ornithological Society

A growing body of research shows that birds' spring migration has been getting earlier and earlier in recent decades. New research from The Auk: Ornithological Advances on Black-throated Blue Warblers, a common songbird that migrates from Canada and the eastern U.S. to Central America and back every year, uses fifty years of bird-banding data to add another piece to the puzzle, showing that little-studied fall migration patterns have been shifting over time as well.

Loyola Marymount University's Kristen Covino and her colleagues used data housed at the USGS Bird Banding Laboratory on migrating Black-throated Blue Warblers between 1965 and 2015. Across the United States, researchers working with this program safely capture migrating birds, collect data on them, and fit them with metal leg bands with unique codes that allow them to be identified if they're captured again. Analyzing almost 150,000 individual records, Covino and her colleagues found that the timing of the birds' spring migration has advanced over the last fifty years, with early migrants passing through banding sites approximately one day earlier each decade. Crucially, their data also covered fall migration, which has been less well-studied, and found that while the timing of the peak of fall migration hasn't changed, fall migration takes longer today than it did fifty years ago.

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Hungry birds as climate change drives food 'mismatch'

April 23, 2018, University of Exeter

Warmer springs create a "mismatch" where hungry chicks hatch too late to feast on abundant caterpillars, new research shows.

With continued spring warming expected due to climate change, scientists say hatching of forest birds will be "increasingly mismatched" with peaks in caterpillar numbers.

The researchers, from the RSPB and the universities of Exeter and Edinburgh, used data collected across the UK—largely by citizen scientists—to study spring emergence of oak tree leaves and caterpillars, and timing of nesting by three bird species: blue tits, great tits and pied flycatchers.

They also tested a theory that some bird species in southern Britain may suffer most due to a greater mismatch effect—but they found no evidence of this.

"Forests have a short peak in caterpillar abundance, and some forest birds time their breeding so this coincides with the time when their chicks are hungriest," said Dr. Malcolm Burgess, of the University of Exeter and the RSPB.

"With spring coming earlier due to climate change, leaves and caterpillars emerge earlier and birds need to breed earlier to avoid being mismatched.

"We found that the earlier the spring, the less able birds are to do this.

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Migrating birds speed up in spring

Date: September 7, 2016

Source: Central Ornithology Publication Office

It turns out being the early bird really does have its advantages. A new study in The Auk: Ornithological Advances shows that migrating birds fly faster and put more effort into staying on course in spring than in fall, racing to arrive to their breeding grounds as soon as possible to get an edge in raising the next generation.

Migrating birds travel faster in spring than in fall because arriving late to their breeding grounds can affect their reproductive success. Past studies have shown that migrants take shorter breaks in spring, but it's harder to tell whether they also move faster in the air. When they used high-tech weather surveillance radars operated by NOAA and the Department of Defense on migrating birds, Kyle Horton of the University of Oklahoma and his colleagues found that birds did indeed fly faster in spring and compensated more for crosswinds that could blow them off course.

"Many migration studies look at a few individuals, maybe on the scale of hundreds, but with radar, we're now documenting the behaviors of millions of individuals on a given night. That's a lot of data, and when you do see flight behavior results that are regionally or seasonally different, it's quite compelling," says Horton. He hopes birds' ability to adjust their migratory behavior for different conditions will buffer them against the effects climate change, which may cause large-scale shifts in wind intensity.

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Songbirds Emerge for Spring, But Is the Timing Off? (Essay)

Naomi Eide, University of Maryland, College Park | April 23, 2015 04:15pm ET

Naomi Eide is a master's student in the Philip Merrill College of Journalism at the University of Maryland, College Park. She contributed this article to Live Science's Expert Voices: Op-Ed & Insights. 

Just before dawn, birds wreak havoc on the stillness, cackling and calling to the world that spring has arrived and that it is time to mate. It's 6:32 on Easter morning, the sunrise is 14 minutes away, and the world is a hazy mosaic of muted colors, too pale to call yellow or orange. 

A golden-crowned sparrow sings its three descending notes, sounding mournful in a minor key among the cheerful songs of avian neighbors. According to the Cornell Lab of Ornithology's guide, many say the golden-crowned sparrow's whistles sound like a phrase, such as "I'm so tired" or "Oh, dear me." The air is bustling with the songs of flirting birds, yet sleeping houses remain blissfully unaware that nature's instinct has taken over with the change in day length.

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Migrating birds sprint in spring, but take things easy in autumn

Date:

September 2, 2014

Source:

Springer Science+Business Media

Summary:

Passerine birds, also known as perching birds, that migrate by night tend to fly faster in spring than they do in autumn to reach their destinations. This seasonal difference in flight speed is especially noticeable among birds that only make short migratory flights, research shows. As short-distance migratory birds, they have the luxury to wait until winds are just right.

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Bird Notes | With longer days comes different, sometimes aggressive, bird behavior Read more here: http://www.myrtlebeachonline.com/2014/03/11/4087171/bird-notes-with-longer-days-comes.html#storylink=cpy

BY GARY PHILLIPS — For The Sun News

With the onset of spring-like weather and the lengthening of daylight hours, seasonal changes are becoming evident all around us.

Native red maples (Acer rubrum) have been in bloom for a few weeks now, and native Carolina laurel-cherry (Prunus caroliniana) are also flowering. Many deciduous plants are sprouting new growth, and some insect species are emerging.

Spring is a time of change, and in addition to changes of plants and insects in evidence, many other animals are exhibiting their own seasonal awakenings, and those of the birds are perhaps the most easily observed.

Invariably, there are some bird behavioral changes, usually most notable in mockingbirds, bluebirds and cardinals that become a cause for distress in some folks.

Bird behavior is under hormonal control. When to migrate north or south; when to start the breeding season; when to fatten up for migratory treks or to survive winter are all influenced by the amount of light in a day, known as photoperiod.

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Whether trill or gobble, birds sing song of attraction

Mar 27, 2013   Written by

Francis Skalicky

Missouri Department of Conservation

The more you know about bird song, the more you’re apt to be fascinated by this well-known ritual of spring.

We all know spring is a prime time to hear birds. These bird sounds can range from a cardinal’s melodious trill to a turkey’s loud gobble: All are forms of springtime bird vocalization.

These sounds that are often entertaining to human ears are necessary parts of a bird’s annual life cycle.

Why there’s so much bird song at this time of year is a well-known fact: It’s often the males that are vocalizing, and they’re usually either trying to court a female or are telling another male that he’s intruding. However, there are other details of bird song that are often overlooked, like, why does the bulk of spring bird song occur in the morning.

There are a number of theories about this and several probably have some validity.

Some biologists think birds instinctually know this is a good time to make noise — especially for courtship. There is generally little or no wind at this time of day and, as a result, bird sounds tend to carry greater distances.

There’s also a theory that, because the lower temperatures at sunrise tend to squelch insect activity and, thus, many types of birds can’t be feeding during this time, it’s a good time to work on the duties of courtship and territorial establishment.

If you stop and listen to bird songs, you’ll notice some males have a varied repertoire of calls and can sometimes make their calls quite complex. As with every other characteristic of nature, this is another form of biology at work.

In the bird world, having greater vocal skills is a sign of being stronger and healthier and a better mate. These are the kind of sounds female birds want to hear because besides survival, their other main goal is to produce strong, healthy offspring.

Physical makeup assists birds with their song variation. A bird’s syrinx — which is its voice box and the equivalent of a human’s larynx — is situated much closer to the lungs than a larynx is to human lungs. This arrangement allows birds to produce a greater variety of sounds than humans.

Read on:  http://www.news-leader.com/article/20130328/LIFE06/303280042/francis-skalicky-Whether-trill-or-gobble-birds-sing-song-of-attraction?nclick_check=1