Rachel Carson’s book, Silent Spring, was published in September of 1962. In it, she sounded the alarm about the effects that pesticides were having on wildlife and human populations, particularly the effects of aerial spraying of DDT on farmland and for mosquito control. Chemical companies and many politicians responded with disinformation and slanted propaganda that disavowed or minimized the considerable body of evidence showing there was harm to animals and people. Eventually, the data were so clear, and the support of the public so great, that many pesticides, including DDT, were banned or restricted, and the Environmental Protection Agency was created with the intent of preventing future damage to nature and the US population. The idea of using biological methods of control rather than relying solely on synthetic pesticides, and of evaluating possible effects carefully, has become mainstream and for decades has been part of the Integrated Pest Management programs taught in colleges. So you’d think we’d solved that problem and our bird populations would no longer be in danger. Alas, that is not the case.
Now that I have more time for sitting in my garden, I’d expected to see and hear a multitude of birds, but no; there are some but not as many as when I moved to Claremont thirty-odd years ago, and this doesn’t seem to be an isolated incident. In the last few years, a number of studies have documented a rapid and substantial decline in the number of birds worldwide. In the US alone, we have lost billions of birds, amounting to almost a third of the number that were here in the 1970s, and the effect has been on both common and rare species. This loss is having a huge effect on other part of our ecosystems: animals that eat birds or their eggs have less food; insect populations that the birds would control are exploding; plants that depend on birds for pollination and seed dispersal are seeing affects on their success and distribution.
So, why is this happening? There isn’t one single reason, of course, but here are some of them with suggestions about what we, as individuals, can do to help slow the loss of our birds.
- Habitat loss: This is probably the number one reason for the decline. As people convert wildlands to buildings and agricultural uses, natural habitats are degraded or completely disappear, along with the living space and food that supported our feathered friends. We can do our best to support local and federal efforts to preserve wild areas and we can create gardens that provide nesting sites, water, and food. This means a landscape that includes a lot of variety: bare areas and ones where leaves are left as mulch; ground covers, shrubs, and trees; plants that provide nectar, seeds, and insects throughout the year; local native plants for any specialist insects and the birds that relish them.
- Poisons: The chemicals that kill insects, rodents, or weeds can also kill birds if they ingest them, eat the dead animals, or eat seeds coated with the pesticide. If they don’t die from this, they can still become unhealthy enough so that they do not reproduce well or migrate successfully. We should especially avoid using neonicotinioid pesticides and try to buy plants grown without them because these chemicals are transported to all parts of the plant. The resultant contamination of nectar and pollen kills bees, and the loss of pollinators means problems for our food supply and for plant survival. And if there is less for insectivorous birds to eat or feed their young, then there will be fewer of them. If no plants are allowed to go to seed, including weeds, then the seed-eaters will suffer. I personally don’t use any pesticides, and embrace the holes I see in leaves as evidence of life in my garden and that the leaf-munchers are providing food for the birds; if you are against plants seeding themselves around, you might consider a bird feeder--just be sure dropped seed doesn’t introduce unwelcome additions to your garden.
- Buildings: Flying into windows kills huge numbers of birds, around a billion a year. On large, commercial buildings, anything that prevents the windows from reflecting the sky and tricking the birds into thinking there is a clear flight path is helpful. On home windows, blinds, decals or streamers can help the birds realize this. Putting something like a row of tall, airy plants or dead branches a few feet away from the windows can also alert the birds. And if you do opt for bird feeders, position them either within 3 ft of a window (so birds can’t build up much speed leaving) or 30 ft away (so it’s less likely birds will see reflections of the sky).
- Cats: I’m a cat person myself, but I’ve always kept mine inside so they are safe from the perils of the outdoors, like cars, coyotes, and assorted diseases, and so that the local bird, small mammal, and lizard populations are safe from them. There is good evidence that cats are responsible for the death of well over a billion birds a year, so keeping our feline friends inside is a good idea. I personally support efforts to trap and sterilize feral cats as well.
Is there any good news? Yes: populations of some water birds like mallard ducks and Canada geese have grown around 50% since the 1970s due to the environmental efforts of hunters and others to protect the birds and their habitats.
So it is possible to slow or reverse the decline if we have the will. Of course, it will take a lot of effort on the part of all of us individually and by our elected leaders to put protections in place and see that they are carried out. We also need to do all we can to combat the changes that are occurring due to our warming climate and to restore lost habitats. The alternative is the loss of so many birds that there will be a silent spring from which we can’t recover.