SIERRA VISTA — With the news of staggering losses of birds, some 2.7 billion over the past 50 years, of a study released last week, Tucson Audubon Society and all Audubon Societies are taking the multi-agency study released to heart.
Several universities and avian groups gathered information across the continent and found the decline of many common bird species like sparrows, finches, warblers and swallows are in decline, while studying 529 species.
Tucson Audubon staff members spoke with the Herald/Review, bringing a perspective to what the impact of the study meant to them. Conservation advocate Nicole Gillett, bird Conservation Biologist Jennie MacFarland and Director of Conservation and Research Jonathan Horst are concerned with the prospect of losing even more birds in the future. So, they and other avian experts around the country will be addressing the situation from Alaska to the Florida coast striving to understand the decline in North America, including Canada and Mexico, and what is needed for their recovery.
Herald/Review: How does the findings of the latest study impact your mission locally?
Jonathan Horst: The Cornell study, that nationwide we’ve got almost 3 billion fewer birds than 50 years ago provides a giant wake-up call nationwide. Tucson Audubon has been working in southeastern Arizona for 70 years to help recover or increase populations of rare birds, and to keep common birds common. But, clearly there’s more to do. Just in our region, the desert southwest, we’ve lost 42 percent of our birds — that’s 250 million.
It’s so hard to think that there used to be almost twice as many birds flying around here as there are today! And, nearly 75 percent of our species are declining. That’s a pretty startling number. While there’s some good news from their study overall, that the rate of loss is slowing nationwide (though almost everywhere we’re still losing birds), that doesn’t appear to be the case in the desert southwest. Here, we’re still in a fairly steady decline.
One of the most important things about a study like this, and a reason that ongoing monitoring is important, is that it takes a long–term view to understand the full impact of such a loss. I was born at the end of the ‘70s, 1 billion fewer birds than when the study started. I was probably 10 before I started noticing birds — 1.8 billion fewer than when the study started. That means that in the 30 years I’ve been paying attention, a decent amount of time, from 1990 to today, we’ve lost 1.1 billion.
That’s still a staggering number, but only one third of the total loss. My personal observation of the situation is limited and makes me less aware of the gravity of the problem. Studies like this, and by listening to people with longer memories than my own, are the main way to overcome a shifting baseline.
The study also highlights that some of the most common birds are suffering the greatest losses. This goes against common wisdom that birds that thrive around people will continue to benefit from urbanization and suburbia. Turns out, almost everything is decreasing across the board, even those that seem to be more common in populated areas.
HR: What are the causes of bird population declines?
JH: The primary causes for the steep decline of bird populations nationwide include habitat loss and degradation, collisions with buildings, windows and communication towers, invasive species including outdoor cats, and widespread use of commercial and consumer pesticides. Even common birds that usually thrive around humans are declining — including those seen right here around Tucson, Nogales, and Sierra Vista. The greatest single loss, by numbers, has been due to widespread conversion of native grasslands to agriculture in the middle of the country.
The primary causes of decline in southeastern Arizona are impacts to our rivers and riparian areas, as well as widespread conversion of natural landscapes to urban areas and agriculture. In Arizona we’ve lost about 90 percent of our riparian forests—that’s the habitat that’s most critical during breeding season — and is the main migratory pathway through here. Not only do our rivers have less water in them — in many places we’ve built right up to the banks — there’s no longer a big floodplain with mesquite bosques and other types of important riparian habitat.
The desert southwest also has many of the fastest growing urban centers in the country, and it’s a sprawling expansion outward instead of increasing density. So, for here, were facing primarily impacts from habitat loss in general, and impacts to our rivers, streams and other riparian areas is a specific area of concern.
Invasive species, like buffelgrass and Lehmann lovegrass, are also a major problem. When buffelgrass burns it changes the way the Sonoran Desert functions, completely changes the plant composition and habitat value. With Lehmann lovegrass, now pervasive throughout pretty much all our historical grasslands, it’s, well, kind of like what you learned about eating celery it has calories, but it burns more to eat it than you get from it. The Lehmann lovegrass seeds are so small that collecting and eating them takes more energy than our grassland sparrows and longspurs get from them. They eat them and slowly starve.
HR: Can you speak on the importance of the annual Christmas Bird Count and how it helps researchers?
Jennie MacFarland: The Christmas Bird Count has been going for 100 years now; that’s one of the things that makes it really stand out. Without long running data sets you can’t track big trends. And it’s a really social thing. It gets lots of people involved in counting birds. In southeast Arizona at least 400 people participate in the Christmas Bird Count each year. These insidious, incremental decreases are so hard to see, especially when everyone is focused on cool rare species that are showing up. It makes these long term studies so much more important.
HR: Has there been a noticeable drop in bird populations in Arizona or southeastern Arizona compared with past years?
JM: Especially in the winter grassland surveys we’ve been doing for the last 10 years, I’ve noticed a distinct decline in wintering sparrows and longspurs. The Tucson Bird Count, started at the UA in 2001 that I now compile, shows that things like Cactus Wrens are being pushed out into very sparsely inhabited areas and as native desert disappears their numbers decrease. Even where I live in Tucson the widespread White–crowned Sparrows seem to be less common.
JH: It’s a case of perspective. I’ve lived in the area for only 15 years; there are some birds that I see noticeable declines, like Inca Doves, but overall it’s a steady decrease that’s not easy to notice from one year to the next. And, every year there are more and more birds that are usually limited to Mexico that are showing up in southeastern Arizona and capture lots of attention that probably distracts even more from noticing the greater overall decline.
HR: What are some steps people can take to help our avian friends?
JH: Planting native plants around your house, especially plants that specifically create habitat for birds, is a good start toward reducing the impacts of development. Tucson Audubon’s Habitat at Home program provides people with some of the key resources and tools to be able to create habitat in their own yard to greatest effect.
Keeping your cats indoors, unless you’re outside with them, is important too. At least 1 billion birds are killed every year in North America by house cats. That’s a pretty significant impact. And one can put decorative decals or a film that’s almost invisible to us but looks solid to birds on windows that birds regularly fly into.
Nicole Gillete: I think the most important thing is to cultivate and spread a passion for the outdoors and stewardship of the land. Planting native plants in home and community landscaping is important and something that anyone can do. Water conservation is also important. Keeping wildlife and pets separate is important too and protects both. Supporting regional conservation groups is also a direct way to make a difference.
HR: The SPRNCA is important to migrating birds and a nesting site for many species. What can Tucson Audubon do to help maintain the important flyway?
JM: Doing what we to prevent or limit external threats to the San Pedro River is extremely important. And, supporting the BLM (who manages the SPRNCA) to pursue best management practices for birds is key. The SPRNCA is listed as a globally Important Birding Area — it’s a key area for Bell’s Vireos and Lucy’s Warblers among many others. We’re continuing to support research on sensitive species there, including gray hawks, western yellow–billed cuckoos and others.
NG: Tucson Audubon is part of a large network of individuals and groups working to protect the SPRNCA. People from all over the country care about the SPRNCA and we’re helping mobilize volunteers for ongoing monitoring of birds there and to engage in limiting or preventing ongoing external threats. We’re focusing on the flyway aspect but it’s also an important migration corridor for a wide variety of wildlife; that’s led to involvement from a wide range of groups.