"What’s a sparrow?”

 RELEASE:  July 27, 2007 – Volume XXXVII, No. 30

When we think “endangered species,” we picture exotic or rare critters not usually encountered in our daily lives.  After all, when was the last time a spotted owl flew over your local mini-mart?

But a new report by the National Audubon Society exposes threats to the long-term viability of some of the most common birds in this state we’re in.  Birds like bobwhites, meadowlarks, field and grasshopper sparrows, common grackles and common terns are experiencing dramatic declines in their populations. Without a solution, the day may come when many of the birds we take for granted in our backyard become rare or endangered.

Audubon sifted through 40 years of bird population data collected by what they call ‘citizen-scientists’ – bird-watchers from around the country who take part in Audubon’s Christmas Bird Counts and Breeding Bird Surveys.  The startling results confirm what many casual birders have long observed:

• Populations of common birds are in serious decline. Since 1967 the average population of those in steepest decline is down by 68 percent, while some have declined by more than 80 percent. Topping Audubon’s list of disappearing birds is the bobwhite quail, once extremely common in New Jersey fields. Forty years ago there were an estimated 31 million in the continental United States; now there are 5.5 million, an 82 percent drop.

• For 20 bird species listed as “national common birds in decline,” at least half their populations have disappeared in just 40 years. And of those 20 species, about half are – or used to be – found in New Jersey. The pintail duck, also known as the “puddle duck,” has declined by 77 percent, from 16 million in 1967 to 6.9 million today. The meadowlark population is down 72 percent, from 24 million to 6.9 million. And so on.

The report also shows that birds of all habitats are affected. Factors causing these declines include suburban sprawl, industrial development, changing farming practices, global warming, destruction of the southern rainforests, habitat fragmentation and increased numbers of pests and predators.

“Here in New Jersey, the loss of farmland to development is pushing many open country bird species to the brink,” agrees Dr. Emile DeVito, Manager of Science and Stewardship for New Jersey Conservation Foundation (NJCF), “and many more forest-interior birds, like wood thrushes, scarlet tanagers and hooded warblers are declining rapidly due to the ecological collapse of our forest ecosystem.”

Three major factors are creating what DeVito calls ‘a giant feedback loop’ where the total damage to our forests is far greater than the sum of the individual parts. 

“Deer are the worst problem by far,” he explains.  “Our forests have never seen deer in these numbers, and they can’t regenerate the shrub layer fast enough to keep up with deer appetites.  This eliminates the nesting habitat for woodland bird species, as well as the food supply for migratory birds.”

The missing shrub layer creates a vacuum that invasive plant species are quick to fill.  These invasives disrupt the normal food chain and cause a loss of biodiversity, giving an unnatural advantage to those few species that thrive around human development, such as deer.

The context for both these problems is forest fragmentation.  “When a big forest with good interior habitat is fragmented by roads, development and power lines, edges are created,” DeVito explains.  “Birds find nice shrubs to nest in, but these edges leave them more exposed to predators.  The result is a population sink that produces few, if any, young.”

For some birds that seem to be holding their own, the numbers are also deceiving.  DeVito cites the whip-poor-will as an example:  “They are gone almost everywhere, but have a stronghold in the Pine Barrens.  What we are seeing is a 100 percent population decline over 95 percent of the landscape.”

What can be done to reverse address these dramatic declines in bird populations?  The Audubon report concludes that since citizen-scientists revealed the problems, citizen action is needed to solve them.  If we want future generations to enjoy the native, common birds we see and hear right now, citizens must be called to action to motivate legislators to renew funding for land preservation and wildlife habitat, encourage sound agricultural policies,  protect wetlands, combat invasive species, and fight global warming. Just a few challenges to take on, but if every citizen gets involved, we can make a difference!

I would encourage everyone to review the Audubon report.  You can find it online at www.audubon.org.  And I hope you’ll contact me at info@njconservation.org, or visit NJCF’s website at www.njconservation.org, for more information about conserving New Jersey’s precious land and natural resources.

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