That Bird Blog – Bird Care and History for Pet Birds
The National Audubon Society has released the 2012 State of North American Birds Report, an impressive annual study that highlights species and habitats at risk. Because many birds respond quickly to changes in their environments, the report’s findings are also useful to organizations studying pesticide use, air quality, pollution, climate change and similar concerns. Compiled in conjunction with the US Fish & Wildlife Service and the North American Bird Conservation Initiative, the report also relies heavily upon the input of “citizen scientists” participating in the Christmas Bird Count and similar projects (please see the articles linked below to learn how to become involved…help is needed and appreciated!). Today I’ll summarize some of the report’s key points, including the disturbing finding that populations of many common birds, including typical garden and feeder visitors, are in steep decline.
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Common Birds in Decline
I was especially troubled to read about the population crashes being experienced by quite a few species that were so common that we might have been tempted to “take them for granted”. But as with so many other animals around the world, large populations are proving no match for rapidly changing environmental conditions. All of the common species on Audubon’s watch list have declined by at least 50%, while the 10 mentioned below have lost 70-82 % of their populations. Bobwhite Quails (one of my all-time favorites to observe and care for), for example, have decreased from approximately 31 million to 5.5 million individuals!
The 10 worst-hit common species are the Bobwhite Quail, Common Tern, Boreal Chickadee, Eastern Meadowlark, Northern Pintail, Greater Scaup, Grasshopper Sparrow, Field Sparrow, Loggerhead Shrike and Evening Grosbeak.
Habitat loss is a major problem for all, but factors such as pesticide use (Evening Grosbeak) and climate change (Boreal Chickadee) also come into play. The Common Tern is, sadly, being hit on several fronts simultaneously – garbage dumps and development have caused various gulls (which compete with terns for nesting sites) to explode in numbers, pollution has decreased their food supply, and the terns themselves are hunted on their Latin American wintering grounds.
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Climate Change
Forty years’ worth of Christmas Bird Count statistics (please see below for information on participating) concerning 305 wide-ranging bird species has revealed a frightening trend. Sixty percent of these birds, and 70% of all common feeder visitors, have shifted their ranges northward by an average of 35 miles. This type of change, on such a huge scale in a brief time period, has major implications that reach far beyond the species studied.
Birds on Public Lands
Because so much undeveloped land in the USA is publicly owned (1/3 of all land, all oceans) and, therefore, easier to manage for conservation purposes (in theory!), the Audubon report examines bird populations in a variety of habitats on state and federal lands. Public lands have been shown to be critical to the survival of many birds and habitats, but there is room for much improvement.
Forests: the largest blocks of undisturbed forest are on federal lands, and they are key to the survival of several endangered species. For example, 97% of the Kirtland’s Warbler’s range lies within publicly-owned forests.
Oceans and Coastlines: all 260 native species of oceanic and shoreline-associated birds reside, breed and/or forage on public lands. Over 50% of the populations of 16 sea birds nest on publicly-owned islands.
Deserts and Arid Habitats: one half of the USA’s deserts and arid habitats are found on public lands. Although 75% of the ranges of the critically endangered Sage Sparrow and Gunnison’s Sage Grouse lie within these protected spaces, both species continue to decline in numbers.
Islands: Hawaii’s bird life has been decimated by introduced predators and habitat loss, more so perhaps than any other region in the USA. Four of its endangered birds live entirely on federal land, while 78% of Kawai’s declining birds depend heavily upon state land.
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Arctic and Alpine Habitats: 90% of Alaska’s boreal arctic species depend upon public land; 34 of these are of high conservation concern.
Grasslands: Meadowlarks, Grasshopper Sparrows, Bobwhite Quail and other grassland and prairie birds are declining faster than all other groups. Unfortunately, only 13% of the nation’s grasslands are publicly owned, and these are largely managed for cattle and energy production rather than conservation.
Wetlands: marshes and other wetlands, and the birds that utilize them, have fared better than most. All 40 species of native waterfowl rely heavily upon wetlands within the National Wildlife Refuge system.
As someone who grew up in the country with birds (and frogs) singing news like this is quite depressing.
Hi Sandy,
Tough problems, but monitoring etc is a step in the right direction, best, Frank
Forty years worth of census taking does not create enough data for any conclusive analysis. I have not spent the time to thoroughly investigate the research, but I suspect that the data collected was primarily closer to urban areas (warmer due to increase in heat retentive structures and heat production (leaking out of homes, commercial areas, et al) which can be attributed to the northward moving species. Populations of species in urban areas rarely reflect the populations of species in rural areas, despite similarities in habitat. Forty years, in fact, is demonstrably a cyclical pattern of typical climate change and we are arguably moving into a colder part of that cycle, not a warmer one.
There is no doubt that many bird populations are being threatened; the bobwhite being a prime example. The reason for this decline is totally habitat related, not climate. The effect of reducing rural farmland to suburban sprawl means a loss of suitable habitat. Here in Texas, the effect of eliminating cereal and many native grasses in favor of cattle forage means a loss of food source and the ever growing population of people is also reducing their range. I do know of programs here, however, that are beginning to educate landowners about what they can do to change this trend. In the midwest, the change from small independent farms who provided fencerow habitat to large corporate landowners who have increased efficiency over a much wider area with no fencerow habitat, has severely impacted this species. Since there is presently little or no incentive to provide suitable habitat in this country, I would imagine that the population of bobwhite quail will continue this decline.
When I was a child growing up in Ohio, the Miami River behind my house was severely impacted by the paper companies upstream. The river would run the color of the paper being manufactured that week. There were few fish species, few wading birds, no deer, etc. With the change in manufacturing standards, and the eventual loss of manufacturing altogether, the rivershed rebounded remarkably. Today, there are fish, deer, birds, you name it that came back as a result of the natural habitat restoration. My point is, this is the end of the line for populations of animals if we so choose it. We can reverse the trend for many, not all, but it needs to be in a sustainable way that is good for both the animals and the people who live there.
Hello,
Thanks for your interest and insightful comments.
The study relies on the input of private citizens, birders, etc., and a variety of other sources that change yearly in some cases. Therefore it’s value is compromised, and indeed this could lead to misappropriated funds, etc. But it is not, as far as I know, relied upon solely regarding major decisions…more to illustrate possible trends, etc., I believe.
As for the time period needed to draw conclusions, etc., that is of course a very difficult problem. A colleague was involved in a study of Red (?) Kangaroos that seemed to establish that, in order to arrive at an accurate understanding of the relationship between rainfall, forage and births, one would need to consider 100 years worth of data. On the other hand, some biologists feel that some situations are so threatening that it is worthwhile to risk action before proper studies can be done (as in the current Chytrid epidemic affecting many amphibians)…tough call, and a staggering number of variables of course. best regards, Frank