An interesting commentary on the recent Audubon report concerning decline of certain bird populations.
Jim Williams Wayzata, Minnesota Begin forwarded message: From: "Barry K. MacKay" <[email protected]> Date: June 16, 2007 2:11:32 PM CDT For many years I've worried that "common" birds seem in serious decline that largely goes uncommented on since the species are still seen, and still show up on lists. I'm not a lister or diarist, so my personal experience with local bird populations here in southern Ontario necessarily are subjective, and yet even in making allowances for the youthful "wow" factor, and the spread of urbanization, it seems to me that there were just so many MORE birds of MORE species visible when I was young. So naturally I am happy that attention is being paid to the matter (and I'm not alone in my subjective impressions...unfortunately it is hard to find "benchmark" data from very far back by which to verify impressions, although I think monitoring is now pretty sophisticated and changes will be more objectively documented.) All that said, this article says some things that disturb me, or at least generate questions. For example: "Some of the birds, such as the evening grosbeak, used to be so plentiful that people would complain about how they crowded bird-feeders and finished off 50-pound sacks of sunflower seeds in just a couple days. But the colorful and gregarious grosbeak's numbers have plummeted 78 percent in the past 40 years." Forty five years ago we were banding large numbers of Evening Grosbeaks in my grandmother's garden. They were everywhere. BUT, they were relatively "new" to the province. I have been researching past population sizes of Double-crested Cormorants, which has led me to Thomas McIlwraith's compilation of birds of Ontario, published in, um...MDCCCXCIV. I think we tend to assume that the late 19th century probably would have been far more "birdy" than, say, the mid-20th, but I am increasingly thinking that view is erroneous...which is a topic for another day! What he says of the Evening Grosbeak is that it is "...a western species whose line of travel in the season of migration seems to be along the Mississippi Valley, casually coming as far east as Ontario. I have heard of its being observed during the winter at St. Cloud, St. Paul, in Minneapolis, and last winter I had a pair sent me by the mail in the flesh, from Redwing, Minnesota [how's that for superior mail delivery?]." He talks of some seen in 1871, and then said, "I did not hear of the species again till the 17th of March, 1883." My point is that bird populations do fluctuate, and there is nothing more "normal" about having so many Evening Grosbeaks that they polish off 50 pound sacks of sunflower seeds, than having to go years between sightings. The article also states: "Today there are 432 million fewer of these bird species, including the northern pintail, greater scaup, boreal chickadee, common tern, loggerhead shrike, field sparrow, grasshopper sparrow, snow bunting, black-throated sparrow, lark sparrow, common grackle, American bittern, horned lark, little blue heron and ruffed grouse." That's an eclectic admixture, but the one that stands out is the Common Grackle. This species is lumped with other Icterids and Common Starlings in the minds of "wildlife managers" and their ilk as being far too common! They are exempted from protection. Certainly there are not only many of them (to my own joy if not that of others) but their habitat has probably increased since colonial times (at least if not, the argument...which I dispute...about "agricultural subsidy pumping up populations of other species, from White-tailed Deer to Snow Geese, falls flat) and it also seems that their choice of nesting habitat may have broadened since the 19th century (hard to say). It states: "The bobwhite had the biggest drop among common birds. In 1967, there were 31 million of this distinctive plump bird. Now they number closer to 5.5 million." Yep, and yet the wildlife managers will continue to imply they know what they are doing and that hunting generates revenue helpful to these plump birds. One problem with hunting is that it decreases gene pool sizes, thus variability that can better lead to adaptation to changing conditions, such as climate, invasive species and other habitat alterations. It states: "While these common birds are in decline, others are taking their place or even elbowing them aside. The wild turkey, once in deep trouble, is growing at a rate of 14 percent a year." Actually in Ontario, where, after being extirpated, the not-so-wild turkey was "re" introduced (including, of course, into places it never previously was recorded) for the amusement of hunters I think it is increasing even faster. Both it, and the environment, would be different from what was here, but having read some of the very early accounts of Wild Turkey abundance well prior to the start of the 18th Century, I question if, in fact, it is anywhere yet near primal, pre-colonial numbers in the eastern U.S. It states:" The double-crested cormorant, pushed nearly to extinction by DDT, is growing at a rate of 8 percent a year and populations of the pesky Canada goose increase by 7 percent yearly." We now have ample evidence that the Double-crested Cormorant was once far more abundant in North America than it yet is (see, for example: Wires, Linda A., and Francesca J. Cuthbert, Historic Populations of the Double-crested Cormorant (Phalacrocorax auritus): Implications for Conservation and Management in the 21st Century, Waterbirds 29(1): 9-37, 2006.) In 1891 a flock of migrating cormorants that was described as being four miles long and one and a half miles wide was seen in Minnesota. And as late as 1926, a flock estimated to have between 100,000 and one million birds in it was seen migrating up the Mississippi River. I am sure that is true for the "pesky" Canada Goose, as well, a species whose eastern migratory population is in decline while non-migrant birds increase (except that non-migrants may join the migrants, and vice versa). It states that blue jays and crows are "doing just fine" although it cites West Nile Virus as a factor in bird declines. Corvids are main victims of WNV and in my area there appeared to be a distinct decline in Blue Jays, at least. It states: "The population of the greater scaup is only one quarter of what it was in 1967, the fourth biggest decline in common bird populations in North America, according to new study by The National Audubon Society." Scaup are also prime consumers of a major invasive species, the Zebra Mussel. So we have a species in decline, a species that serves human economic interests, and we...what...protect it? Don't be silly...bluebills are delicious and fun to shoot. Same with Northern Pintails, a species that, the article claims, has dropped 77 percent. If a species is in decline, does it really produce a "surplus" that can be hunted with no impact to the population? Makes no sense to me. Barry Kent MacKay Markham, Ontario, Canada
