WHEN I WAS GROWING UP ON LONG ISLAND, IT WAS NOT UNCOMMON TO SEE COLORFUL SONGBIRDS IN MY NEIGHBORHOOD: TANAGERS, ORIOLES, BUNTINGS, AND MORE.
Later, as a Boy Scout, I recorded more than 50 local species for the birding merit badge.
Over the years, these sightings diminished, as woodland and other natural habitats were replaced by homes and asphalt.
But suburban and urban development are not the only factors affecting birds.
The domestic cat population is estimated to exceed 80 million; feral cats a similar number. Of the 80 million “home” cats, many roam free during the day or night and do what all carnivores do: hunt.
It’s likely that at any hour, at least 100 million cats are free to kill birds and small mammals. (Please note that all figures in this article vary up or down according to a particular study.)
Estimates place the number of birds killed by all cats at 1.4 to 3.7 billion annually, with most researchers agreeing that 2.4 billion is a fairly solid number, or roughly 24 per year per free-ranging cat.
Less appreciated because they go largely unseen is the number of small mammals (e.g., mice, voles, chipmunks) that are killed by cats, estimated at 27 billion annually. Feline neutering programs, although laudable, have only a marginal impact.
Habitat loss is the greater factor contributing to bird species, indeed all species losses. At least 30 bird species have gone extinct in the U.S., and hundreds more are endangered.
There are protected areas around the country where species survive in much-reduced variety and numbers. These range from local nature preserves to huge national parks and other state and federal protected areas. But these “oases” are under constant assault from business interests that have only intensified with the recent election of Trump as President.
By definition, habitat oases like parks and preserves are limited in their impact on species loss. They are largely “feel-good” endeavors, not solutions. Even the once-ubiquitous box turtle requires up to one square mile in which to roam. In addition, because these oases are largely discontinuous, many bird and other animal species have difficulty maintaining both their populations and their genetic vigor.
Florida’s gopher tortoise, scrub jay and panther are good examples of this difficulty.
Compounding the above-mentioned causes is the fact that migratory birds especially are falling out of sync with their environment due to climate change.
Spring in northern regions arrives two week or more earlier than it did 10 or 15 years ago. This means that birds arrive too late to feed on the burst of insect life that thrives on new vegetation soon turns bitter and is often indigestible to those insects.
Some, but not all birds, compensate for this by flying north faster or sooner. In addition, increasing global temperatures are causing southern plant species to march northward, further disrupting bird habitats.
Spring Leaf Index Anomaly, February 24, 2017
Migratory birds in particular are killed by building impacts, although most of us have been startled by a bird crashing into a picture window in broad daylight.
Estimates vary widely, but a minimum of 300 million birds are killed annually from such impacts, with some claiming that the number is closer to a billion. Similarly, several hundred million are killed by vehicle impacts each year.
The synchrony is obvious: As human populations increase, wild habitats are reduced with concomitant decreases in the numbers and variety of wild populations, all while the survival risks to those populations increase.
Of course, some will say, “What’s the big deal? They’re only birds.”
But like the proverbial canary in the coal mine, bird losses are indicative of a greater world problem: as stewards of the natural world, we have been a failure, both individually and collectively.
To paraphrase Pete Seeger’s tune: “Where have all the songbirds gone? / Long time passing . . .”
Florida Scrub Jay
Bill Britton is a freelance writer for John Hopkins University and a contributing editor for Vero Communiqué.