Some little birdies are key indicators of the overall health of the earth’s ecosystem, biodiversity and environmental justice.
Two of the biggest drivers of the extinction of species are loss of habitat and climate change. Each aspect of the environment depends on one another for survival, so when one part of the system gets interrupted, the entire thing becomes out of whack. This is why the steep decline in birds has become so telling and alarming.
A State of the Birds report from 2022 lists 70 bird species that have lost half or more of their breeding population in the last 50 years and are projected to lose another 50% in the coming decades. A number of those birds, including the Blue-Winged Warbler and the Yellowlegs Prairie Warbler, can be seen in Indiana, according to Matt Williams, director of conservation programs for the Indiana chapter of The Nature Conservancy.
“A lot of factors are coming together to put a lot of pressure on birds as one indicator of the overall biodiversity crisis that we’re facing,” Williams said.
Birds bring people together, like Black Birders Week attendees and they also provide important ecosystem services like consuming millions of mosquitos a year and controlling agricultural pests, according to Williams. Birds are also important to public health because they carry emerging disease pathogens and the data from infected birds has the potential to provide an assortment of benefits in understanding the spread of diseases, according to a study published in the National Library of Medicine.
“Birds are something a lot of people pay attention to, and you can, relatively easily, measure the populations of birds, you can track those numbers, and you can plot their population trends … And so it tells you something — something’s happening here,” Williams said.
‘A Great Success Story’ inspires change
For almost a century, the bald eagle all but vanished from Indiana. Decimated by habitat destruction, the contamination of their food sources and illegal shootings, the last bald eagle nest in the state was found in 1897, and the next one did not appear until 1991, according to Williams. Threatened with extinction, the bird became federally protected in 1940, making it illegal for anyone without a permit to take, injure or kill bald eagles and anything connected to them, including their feathers and nests.
Then, shortly after World War II, a harmful pesticide called DDT was hailed as the new pest control, and its use as a pesticide became widespread. Its residues washed into nearby waterways, contaminated fish and aquatic plants, and, in turn, poisoned bald eagles, inhibiting their ability to produce strong eggshells, according to the Fish and Wildlife Services. Bald eagles continued to approach extinction, with only about 400 nesting pairs remaining by 1963.
Because of mounting evidence of the harmful effects of the chemical and increasing public concern, spurred largely in part by a 1962 publication of Rachel Carson’s “Silent Spring” that meticulously described how DDT entered the food chain. Almost a decade later, the EPA issued a cancellation order for the chemical based on its “adverse environmental effects to wildlife, and the potential human health risks.” Based on continued studies of animals, the relationship between DDT exposure and reproductive effects in humans is suspected, according to the EPA. Today, the chemical is classified as a probable human carcinogen by the United States and other global authorities, like the World Health Organization and has been banned for agricultural use worldwide since 2001. The use is still permitted in small quantities in countries that need it, like Africa, where malaria remains a major health problem. It’s been deemed that the benefits of using the pesticide to control the mosquito population outweigh the health and environmental risks that can come along with it.
In the 1980s, the situation had improved enough to reintroduce bald eagles back into the state.
More than 100 years after the last known nest, a new bald eagle nest was discovered, Williams said. Now, more than 300 nesting pairs of bald eagles live in the state, and just recently the bird was removed from the state’s endangered species list.
“It’s really cool to see those kinds of national symbols for the country, but also a symbol of conservation success, and how, if we work together, identify the issues and figure out how to solace it, we can bring back birds,” Williams said.
Contact environmental reporter Jayden Kennett at 317-762-7847 or by email JaydenK@IndyRecorder.com. Follow her on Twitter @JournoJay.