No wonder all those birds were going after Tippi Hedren in Hitchcock’s classic thriller, “The Birds.”
They were onto something.
Their numbers were under assault. Damn humans.
According to an exhaustive study published recently in the journal Science, bird populations in North America are down 29 percent since 1970.
With climate change, deforestation, and general habitat loss a known reality to scientists, they knew that certain populations were declining. As one of the head researchers on the project Ken Rosenberg explained, “We also knew that other bird populations were increasing, and what we didn’t know is whether there was a net change.”
The difference was a loss of about three billion birds over the nearly 50 year period since 1970. 90% of the loss can be attributed to just a dozen bird populations including sparrows, warblers, blackbirds and finches. Up to 53% of grassland birds have disappeared as well as about a third of shorebirds.
Certain populations are surprisingly up in numbers such as raptors, bald eagles, and waterfowl. Another interesting find is that duck and geese populations are up as a direct result of hunters maintaining these populations for sport.
Directed conservation efforts work for hunters but the general population has not followed suit.
Nationally renowned birders Tom and Jo Heindel of Big Pine have been researching bird decline in the Eastern Sierra over a similar time period as the original study. Mr. Heindel reiterated some of the findings from the study, “We have seen a significant decline in just about all native populations here (in the Eastern Sierra).”
The Heindels are set to release a book sometime next year that details their findings, “We have been researching birds in Inyo County since the 1970s and we have a significant amount of data,” said Tom. They sent their book to a group of ornithologists for peer review and are working on the additions that were suggested.
The first page of the Heindels book describes how the data is collected, “A number of the most highly respected birders quickly sent us copies of their data and these, plus our field notes from 1972 through 2019, were added to the database. These data now number almost 485,000 entries (2019) and continues to grow each season.”
Mr. Heindel couldn’t divulge too much of the specifc datapoints but was able to give a conceptual framework to understand the extent of decline. “It is hard to see the decline on a day-to-day basis; every day the numbers come in and the change is extremely subtle. Most species are really down, especially neotropical migrants. Local birds are down as well but not as much. The only increase you see is in bird species introduced to the area like euroasian doves,” he said.
He also brought up ducks, anecdotally referencing the lengths hunters will go to in order to preserve the species they want to hunt.
Heindel explained that neotropical migratory birds are experiencing the highest rates of decline because any habitat destruction along their migration routes can have an impact on his bird count in Inyo County. But he maintained that his findings were consistent across species and even birds that never leave the Eastern Sierra have experienced a population downturn.
Nora Livingston, lead naturalist guide for the Mono Lake Committee and board member of the Eastern Sierra Audubon Society, expressed a similar interpretation of the study “When you are out birding it is hard to tell that there is a decline happening, but the study was so widespread we can assume it’s happening here, too.”
Livingston has been involved in multiple studies in the Eastern Sierra through Point Blue Conservation Science, but explains data is sometimes difficult to interpret, “There are a lot of studies that look specifically at birds in the Eastern Sierra but most of them are short term,” she said, voicing a “need for more long term research projects.”
She couldn’t speak to any data relevant to the Eastern Sierra but maintained the viewpoint of a conservationist, “Regardless of whether or not we see proof of the decline, we should be proactive in maintaining [bird] habitats.”
Both Livingston and Heindel explained that birds are often a good indication of the overall health of an ecosystem. Head researcher on the Science paper, Ken Rosenberg, told the Wall Street Journal, “Birds are literally the canary in the coal mine.”
Heindel worries we may be reaching an inflection point where too much decline in population could lead to a negative population spiral with unforeseen consequences.
When asked what regular people can do about the issue, Heindel responded, “We need to tune into what is happening. We have to keep an eye on our government and sound off when they do something bad or make an ignorant decision.”
In an email to the Sheet, Livingston laid out how and why the declining populations can be slowed down, “They (the birds) can’t protect themselves from climate change and habitat destruction, so people need to protect bird habitats locally and continue to gather data about their populations. Most of the birds that breed here are migratory, so we also need to do what we can to encourage protection of their wintering grounds and migratory pathways too. It’s a pretty daunting task, but it is so important. More researchers from different states and countries are joining forces to share data and develop conservation plans that address the whole migration pathways—that is essential going forward.”