ecology

Whose Fault is the European Starling?

Debbie Blicher is Senior Producer of Ray Brown's Talkin' Birds.

If you live in North America and you love the European Starling, most folks say you can credit Eugene Shieffelin. If you hate the European Starling, they say you can blame the same guy. It's Shieffelin who is largely credited with introducing 60 starlings to New York City's Central Park in the year 1890 and another 40 in 1891. As we all know, they thrived. And thrived. Today, they number around 200 million in North America, with a range all across the continent, and are considered one of the most invasive species on the planet. So if you love them, you can thank Mr. Shieffelin for the huge flocks of noisy, speckled black birds.

Shieffelin didn't act alone, however. He belonged to the American Acclimatization Society, an organization founded in New York City in 1871 whose goal was to introduce to North America useful species from other countries. In retrospect, we 21st-century types think "useful" was defined rather loosely. After all, the starling isn't especially useful—unless, as is rumored about Shieffelin, you have such a thing for the birds of Shakespeare that you want them all to live right near you. (There actually is not much evidence for this popular story.)

So how did the American Acclimatization Society come to be? Well, for that we can blame the Société zoologique d'acclimatation, founded in Paris in 1854 by naturalist Isidore Geoffroy Saint-Hilaire. He encouraged the French government to import and breed species that would help feed France and control pests. He encouraged other countries to start similar chapters. 

By 1877, the American Acclimatization Society was going strong, and Shieffelin, a drug manufacturer from the Bronx, was its chairman. We imagine he must have thought, "How pretty those starlings are! How intelligent and entertaining! What harm could they do?" What harm indeed! They have crowded out countless native North American bird species, interfered with agriculture, and even been a primary cause of airplane bird strikes. 

Some bad ideas that seem fun at the time are pretty harmless, such as shaving half your beard or adding extra hot pepper to your chili. But importing non-native species? Not harmless. So let's enjoy European Starlings, but let's also try to educate humankind about invasive species so we don't make such mistakes in the future. The fault? Quite simply, it's ours. 

 

Bird Food Source Alert: Declining Insects

Debbie Blicher is Senior Producer of Ray Brown's Talkin' Birds.

In recent years, we've seen well-documented declines in domesticated honey bees, monarch butterflies, and other insects that attract a lot of attention. But we haven't really noticed the moths, beetles, and other insects that flitter and crawl through our everyday life. Birds, however, probably notice their decline a lot, since they're a major food source. 

A recent story in the journal Science documents a new set of data gathered mostly by amateur entomologists in western Europe. These folks have tracked insect abundance at more than 100 nature reserves since the 1980s, and the news is not good.

This group of amateurs, named the Krefeld Entomological Society (after their location in Germany) has seen the insect catches in their traps fluctuate every year. This is normal. But in 2013, they noticed that one of their longest-running sites showed a decline by mass of almost 80%. The numbers were just as low in 2014. In fact, the group found dramatic declines across more than a dozen other sites, even in reserves where plant diversity and abundance had improved. 

The group has installed more traps each year since 2013. They've also begun working with university-based researchers to look for correlations with weather, changes in vegetation, and other factors. Unfortunately, no simple cause for the decline has yet emerged.

If you don't like bugs, you're probably asking, "Why does this research matter?" The answer is that other creatures eat insects—such as birds. Dave Goulson, an ecologist at the University of Sussex in the United Kingdom, explains, "If you're an insect-eating bird living in that area, four-fifths of your food is gone in the last quarter-century." No matter what your opinion of bugs, this is important news.

No one knows what this research in western Europe means for insects elsewhere. But we at Talkin' Birds think that anything that affects the food chain for birds anywhere is worth investigating for the good of us all. 

A male hoverfly on a Bermuda Buttercup. (Photo: Wikimedia Commons; author: Alvesgaspar.)

A male hoverfly on a Bermuda Buttercup. (Photo: Wikimedia Commons; author: Alvesgaspar.)

Birds Provide "Biodiversity Services" that Sustain Ecosystems

Debbie Blicher is Senior Producer of Ray Brown's Talkin' Birds.

"Biodiversity" means "the variety of life in a particular habitat." Each life form, from bacterium to towering tree, plays a role in sustaining its ecosystem. Therefore, each life form matters.

There are few ecosystems on Earth with more biodiversity than a rainforest. A recent study shows that the loss of even a few species from that rainforest adversely affects its longevity. Although a forest may look healthy, if the creatures required for maintenance are missing, the forest can't regenerate if it's disturbed, and its trees will eventually die out.

Research from the Department of Life Sciences at Imperial College London, published in Proceedings of the Royal Society Bshows that intensive land use, such as for agriculture and ranching, often leads to the extinction of local forest birds. These birds perform "biodiversity services" that are necessary for maintaining the rainforest's health, such as keeping down the population of plant-eating insects and dispersing the seeds of tree species. But it isn't just the individual birds species that guarantee the future health of the forest, nor is it the number of species left alive; it's the way these species interact with other kinds of life.

The research team studied the composition of bird communities from 330 study sites in the Brazilian Amazon, sampling more than 450 bird species. They also kept track of what special traits these species possessed, such as their beak size and tail and wing shape. (These traits indicate what kind of job a species has evolved to do.) Then they looked at how landscape change affected these bird populations, specifically those birds who eat insects and those who disperse seeds. 

The results were sobering. When insect-eating birds go locally extinct, leaf-eating insects can prevent young saplings from growing up into mature trees. When birds that eat certain seeds are missing, then the trees that grow from those seeds eventually go missing, too. 

Dr Joseph Tobias, senior author of the study, says that land-use management policy can positively affect forest recovery. He suggests that a forest's ability to regenerate can be preserved, even if it's largely cleared, as long as patches of primary forest survive. “Our findings are a warning flag that we can’t just look at a snapshot of forest health as it appears now—we need to think about preserving the ecosystem processes that will allow forests to survive in the future.”

Next, the team plans to examine the impact of human activity on global ecosystems by using bird traits as a window onto the effects of environmental change.