Rigor Vitae: Life Unyielding

Tuesday, June 19, 2007

TOP 20 DECLINING COMMON BIRDS


Over the past 40 years, North America's bird fauna has changed remarkably. It includes several species like the Bluethroat (Luscinia svecica – above) that didn't appear on pre-1967 checklists. Some species have increased in numbers while others have decreased. Thanks to Rob at Birdchaser for alerting me to the Audubon Society's new webpage of the top 20 declining common birds of North America, complete with entries describing problems and potential solutions. The list is surprising to me; it contradicts much of what I see in my unique area: a big city in the center of the least densely populated part of the lower 48. Having lived in the same part of the country for practically all of the past half-century, I've watched local trends with interest. Anyway, here's the Audubon list, the estimated decline in the United States since 1967, and how that compares to what I've seen locally.

20. RUFFED GROUSE (Bonasa umbellus) 54% This is one of two common forest grouse in my area, the other being the Blue Grouse (Dendragapus obscurus). Populations of both appear to be healthy and steady here, and about equal in number, although I seem to recall Ruffeds being the more numerous prior to about 1970.
19. LITTLE BLUE HERON (Egretta caerulea) 54% I have no long-term experience with this bird.
18. HORNED LARK (Eremophila alpestris - above) 56% Throughout the year, this bird has always been the most conspicuous avian resident of the open plains of my area. At the age of 16, I was involved in an automobile accident while watching a group of these birds instead of the road. I've noticed no decline.
17. WHIP-POOR-WILL (Caprimulgus vociferus) 57% I have no long-term experience with this bird. It appears very similar to its rather distant relative, the Poor-will (Phalaenoptilus nuttallii) which occurs here, and appears to be far less common in Northern Utah than it was before 1980. It's still plentiful in the southwest part of the state.
16. RUFOUS HUMMINGBIRD (Selasphorus rufus) 58% Once every three Augusts or so, I see one of these birds on passage here—not frequently enough to make a judgment concerning any trends.
15. AMERICAN BITTERN (Botaurus lentiginosus) 59% This bird occurs in my area, but I'm too lame to see it enough to know how common it is.
14. COMMON GRACKLE (Quiscalus quiscala) 61% This bird is accidental in my area. I've seen three, one in 1984, one in the late '90s, and one last year.
13. LARK SPARROW (Chondestes grammacus) 63% If anything, this handsome little sparrow is more common in open parts of my area than it was 30 years ago.


12. BLACK THROATED SPARROW (Amphispiza bilineata - right) 63% Another handsome sparrow whose numbers seem to have remained steady in southern Utah, where it has always been fairly common.
11. SNOW BUNTING (Plectrophenax nivalis) 64% I don't even know that I've seen one of these.
10. GRASSHOPPER SPARROW (Ammodramus savannarum) 65% I have no long-term experience with this bird.
9. FIELD SPARROW (Spizella pusilla) 68% Another sparrow I have no long-term knowledge of.
8. LOGGERHEAD SHRIKE (Lanius ludovicianus) 71% This has never been a common bird around here. It's probably even less common now than 30 years ago.
7. COMMON TERN (Sterna hirundo) 71% This bird is occasionally seen here on transit, where I would be likely to mistake it for the common Forster's Tern (S. forsteri).
6. EASTERN MEADOWLARK (Sturnella magna) 72% I have no long-term experience with this bird. The Western Meadowlark (S. neglecta) continues to be abundant in open plains and agricultural areas.
5. BOREAL CHICKADEE (Poecile hudsonica) 73% I have no long-term familiarity with this bird.
4. GREATER SCAUP (Aythya marila) 75% I have no long term experience with this bird.
3. NORTHERN PINTAIL (Anas acuta) 77% From the late '70s through the early '90s, I did a lot of duck hawking in northern Utah, and sought out this challenging quarry, which became common towards the end of the season (late January). Today it is still common, though probably less so.
2. EVENING GROSBEAK (Hesperiphona vespertina) 78% This bird occurs here in the winter, where transient flocks may turn up for a few days. Most years I don't see any, some years I see several flocks. I can't make much sense of my observations.
1.BOBWHITE (Colinus virginianus) 82% I have no long-term knowledge of this bird.

Here is my own list, complete with built-in bias, of birds that appear to have declined markedly in my location.

RUDDY DUCK (Oxyura jamaicensis)
ROUGH-LEGGED HAWK (Buteo lagopus)
SAGE GROUSE (Centocercus urophasianus)
FRANKLIN'S GULL (Larus pipixcan)
BURROWING OWL (Speotyto cunicularia)
FLAMMULATED OWL (Otus flammeolus)
LONG-EARED OWL (Asio otus)
POOR-WILL (Phalaenoptilus nuttallii)
BROAD-TAILED HUMMINGBIRD (Selasphorus platycercus)
BROWN CREEPER (Certhia familiaris)
PINE SISKIN (Spinus pinus)
_____________________
upper: BLUETHROAT (2002) acrylic 8" a 10"
photographs by CPBvK

9 Comments:

Blogger naturegirl said...

Interesting blog,Carel. I was just listening to a report on this on the radio. I have noticed a rapid decline in grosbeaks and orioles over the last couple of years at my feeders. My first year here, we counted as many as 30 orioles a day and countless grosbeaks (sp?). This year I only have a couple of them and have not seen any orioles as of yet. The DNR feel that the oriole population has plummeted because of our warm winters and the amount of trees being cut down in the area. I miss all that color in my back yard. Keep up all the good work!

10:16 AM  
Blogger Steve Bodio said...

My experiences correlate broadly with yours. Most declining species that I have are doing well here-- but I live in a tiny town surrounded by vast rangelands. Two that are doing well here that you have seen declines in are loggerhead shrikes and pine siskins. Evening grosbeaks haven't been by in a few years but it is hard to tell because they are irregular wanderers. Horned larks are extremely common.

One bird that is definitely down in NM is the pinyon jay. There have been huge pinon pine die- offs in Santa Fe and to the north though not here (beetles, drought, climate?) and as the birds are nomadic this could be a cause.

I think most western bird decline is due to habitat loss-- development, "ranchettes", subdivisions. The east and CA may have problems with even more extensive building. A lot of eastern birds also depend on Neotropical forests for winter as well...

11:13 AM  
Blogger cpbvk said...

Vikki: Thanks for the Minnesota perspective. I see that no orioles appear on the Audubon list (unless you consider meadowlarks orioles).

Steve: I agree with your conjectures. Sorry to hear about your Pinyon Jays. Those birds are the best.

8:10 PM  
Blogger Shauna said...

On my bike commute home from campus the other day I thought to myself how long it had been since I'd heard a whip-poor-will in my neck of the woods - I spend most of my time over a range of Southern/Central Ontario. I can remember their voices being a whole separate layer of the soundscape here atop the crickets on summer evenings when I moved to Ontario as a young child 20 years ago. I realized on my bike I can't recall hearing one in my adult life.

Blue Herons are another indigenous bird in the area whose numbers have seen a decline (although I'm not sure I'd recognize species variants of the bird). It's always an event to see one, and they do seem to be more rare than they once were. This is possibly because of the precipitous drop in the water levels of Lake Huron - yearly habitat no longer reliably appears in the same places as the shoreline retreats by sometimes meters per year. Wetlands in the area are also in crisis for much the same reason. Now I find I'm most likely to see them along quiet stretches of riverbeds that remain fairly constant year-to-year.

I'm happy to report that the chickadees here are doing as well as ever, though! They're plentiful residents all year round and some of the smartest, most sociable birds in the area. However, during the early spring I've found that some of the chickadees in provincial parks will actually land in one's hand if there's birdseed to be had, and this perhaps is a signal of loss of habitat and natural food sources.

6:05 AM  
Anonymous Brian said...

This post makes clear how statistics tend to be useless if only applied over a very large area. In measuring population dynamics, localised monitoring is best, it seems.

Though living in the Netherlands, rather then in the USA, I would like to add my two cents to these observations.

In the 12 years or so that I've been actively looking out for birds I can name species that have seemingly underwent a population change in this period.

In the area that I regularly visit, about 75 square kilometers at most, I think these species have markedly declined in the time-frame I mentioned. (I'll often use scientific names, for reasons of clarity):

- Little Grebe (Declined from uncommon to all-but-absent)
- Bluethroat ( I haven't seen one in years where I regularly saw some before)
- Saxicola saxicola (same story as for Bluethroat. Both were residents of the same spots. Is this coincedence?)
- Streptopelia turtur (Used to be very rare, seems gone now)
- Falco tinunculus (went from very common to common at best)
- White Wagtail (went from common to somewhat rare)

Luckily, there are also species that seem to have increased:
- Eurasian Jackdaw (went from common to extremely common, with a remarkable, massive and somewhat sudden move into build-up areas)
- Carrion Crow (Went from rare to common)
- Accipiter nisus (Used to be all-but-absent, quite regularly seen now)
- Picus viridus (went from absent to quite common)
- Little Egret (went from absent to not uncommon)
- Eurasian Spoonbill (moved from rare to not unusual)
- Wood Pigeon (used to be common, is very common now)
- Stock Pigeon (went from uncommon to common)
- Avocette (Used to be rare, now regularly seen (though localised))
- Northern Shoveler (Used to be absent, appears quite often now)
- Greylag Goose (used to be gone as a resident breeding species but thanks to reintroduction programs, habitat creation and decreased hunting it is very common yearrond by now)
- Canada Goose (Exotic species that is still somewhat uncommon, but gaining in numbers)
- Long-tailed Tit- (Was remarkable, is not unusual now)
-

Aside from these, there are a variety of species that are either seen so often or so little that it is hard to make a meaningful statement. Also there are species that have increased in this period, only to decrease later or vice versa. To this category belong:

- Dendrocopus major (went from uncommon, to rare, to quite common)
- Eurasian Buzzard (Unusual, quite common, rare)

Of course, there are a few pitfalls here. For one, the time I've been looking for birds has decreased over the years.

8:06 AM  
Anonymous romunov said...

Hehe, a funny fact: Svecica (L. svecica) is at least a Slovenian word for "little candle". Probably occurs in other Slavic languages as well, but only god knows what they mean. :)

6:52 AM  
Anonymous Anonymous said...

I ran across a website of interesting photo's and I'm wondering if their is a connection to the declining bird popualtion and these photo's.
http://imageevent.com/firesat/strangedaysstrangeskies?z=3&c=4&n=1&m=-1&w=4&x=0&p=14
Please, someone give me a comment on this.
Thank You Harold J.
email hcj2042@joimail.com

2:00 PM  
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8:31 PM  
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8:41 PM  

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