14 July 2008

Analysis of Waterfowl Populations Released by FWS

[Northern pintail pair; detail of FWS image]

A summary of waterfowl surveys in northern America shows dramatic fluctuations in populations this season, and during the historic period since 1955.

"The preliminary estimate of total ducks from the 2008 Waterfowl Breeding Population and Habitat Survey was just over 37 million, which is a nine percent decline from last year's estimate, but still 11 percent greater than the 1955-2007 average. In the U.S. and Canadian prairies, population estimates of many species declined; while populations increased in the boreal forest to the north, likely reflecting in part those birds that overflew the prairies because of drier habitat conditions there." Fish and Wildlife Service press release.

There are 50 survey transects within the traditional regions - whichh samples "two million square miles" and is the "largest and most comprehensive survey of its kind in the world" - around the following places:

Alaska - Yukon Territory -Old Crow Flats ¶ C. & N. Alberta - N.E. British Columbia - NWT ¶ N. Saskatchewan - N. Manitoba -W. Ontario ¶ S. Alberta ¶ S. Saskatchewan ¶ S. Manitoba ¶ Montana & western Dakotas ¶ Eastern Dakotas

There was also an eastern breeding area that continued to the Atlantic Coast of Canada and the United States.

"Figure 1: Strata and transects of the of the Waterfowl Breeding Population and Habitat Survey
(Yellow = traditional survey area, green = eastern survey area)."

The preliminary report "does not include estimates from surveys conducted by State or Provincial agencies." The extensive wetlands of the Nebraska Sandhills are not considered as a survey area.

Populations were graphically compared for each year since 1955, for these species:

Mallard ¶ Gadwall ¶ American Wigeon ¶ Green-winged Teal ¶ Blue-winged Teal ¶ Northern Shoveler ¶ Northern Pintail ¶ Redhead ¶ Canvasback ¶ Scaup (greater and lesser combined)

The latter portion of the report includes graphs of the trends from 1955 to 2008. Each chart includes a demarcation for the population goal desired according to the North American Waterfowl Management Plan.

There is a constant flux in numbers, with teal showing steady increases in numbers for the past couple of season. While the number of Redheads was up, Canvasback showed a dramatic decline, from above 800,000 to near 500,000 for the survey area considered.

Summary charts for the eastern breeding area are also included, from the period since 1990. This includes summary details with mergansers, the Ring-necked Duck, goldeneyes (common and Barrow's), Bufflehead, and the Black, White-winged and Surf Scoters.

"Trends in Duck Breeding Populations, 1955-2008" was issued in early July.

09 July 2008

Smithsonian a Complete Guide to Bird Identification

Example of a bird parts diagram included with the Smithsonian field guide.

When hiking in search of another look at some wild birds, through the decades a wide variety of guides have been used to identify the different species among the habitats.

Colorful and lively, the birds have been known and classified in many ways, at different times of history. Rock sketches were used to denote species during the Indian times on the great prairies. In North America, the diversity of species, with some variation in the clues provided for identification, started with detailed descriptions. There were always tips about their natural habits. Cultural changes and improvements brought along illustrations, first in black-and-white, then color, and then more recently, steadily suitable photographs. Then sound could be captured and was added to the mix of important tools for bird identification.

The evolution of the effective guide to bird identification has now achieved a new pinnacle in providing a complete guide which includes some essential avian sounds. The field guide is a single source to see and hear the essentials for learning to identify wild birds.

The Smithsonian Guide to the Birds of North America has pictorial illustrations, a natural history summation, the requisite maps, guides to featheration patterns and related miscellany. An outstanding feature is the disc with a 587 songs, calls and notes in a ready-to use format.

Author Ted Floyd was assisted by a whole cadre to publish this 500+ pages guide to the more than 750 species present northward from southern Mexico. Floyd's comments for each species, tend to be a general nature. There are only a few brief sentences given as a message of the times for the species. A numeric conservation status code is provided - important for knowing one's status - based on the latest details determined by bird conservationists. A quick index is provided inside the back page.

Taxonomy has been updated to match the elusive standard of the year. The colored maps - though a bit small - well represent the range. A general overview is also provided for the species order or family group.

An example of a species account page in the field guide.

A picture, or several - there are 2,000 - depict a particular species. The variety is a grand show of live birds captured somewhere in the nation, yet shown with a sense of liveliness. A pinnacle in photography is obvious in the imagery of the birds, with the variety capturing many of the scenes appreciated by birders that would find the guide useful.

A color option for the top of the pages is an improvement in pagination. This readily shows the pages for the particular order or family group in a matching color. A font a bit darker would have improved readability.

Having depicted illustrations could have been useful for showing the variations of hawk plumages, or as an assist in seeing a comparative group of gulls. A useful item typical for older guides, but not used with this update - and some other modern guides - are those pointers useful to point-out key identification features, perhaps even referencing a bit of behaviour typical for a shorebird or thrush.

Not the least of the features, the disc is an essential addition for learning about birds through their sounds. The audio addition is a distinct feature among modern guides. The birdsong DVD is setup for easy identification of tracks, readily apparent in the file name, and includes a picture to help with recognition of the species. This is another bunch of imagery to appreciate.

There are often several sound variations for each of the 138 species included. The files can be readily downloaded to versions a few modern, portable media players.

Enjoy browsing and learning with the complete and useful Smithsonian guide for your next outing to see the birds.

Find out more about the Smithsonian Guide to the Birds of North America...
Bird songs
About the book
About Ted Floyd

05 July 2008

Grackles Common Casualties at Buildings in Early Summer

July 11th

A Belted Kingfisher was the surprise find of this morning, at the Central Park Plaza, south tower corner.

Along south 18th, there were five carcasses on the street, on the north side beneath the Tower Park crosswalk. Four of these were formerly Common Grackles. The other carcass was that of an American Robin. Each had been well flattened by traffic.

The buildings to which the walkway is attached are owned by the Woodmen of the World Life Insurance company, according to the web site of the county assessor.

Reflective conditions at the State Office Building, downtown Omaha. There are two Common Grackle carcasses present. 05 Jul 2008.

July 8th

Two additional grackle carcasses were noted. One was an aged carcass at the OWH Freedom Center locale. The second, a juvenile, was at a new spot for a bird strike, the northwest corner of the Omaha Public Power District headquarters, on 17th Street.

Early Summer Mortality

Common Grackles have been the notable casualty at known hazardous buildings on the past two weekends.

Five carcasses were noted Saturday morning, July 5th in downtown Omaha. The first was noted in the courtyard at the Holland Performing Arts Center, and one bird glanced off the upper glass on the sky-like reflection on the upper west wall, when my disturbance caused it to fly from the enclosed area.

There was another grackle carcass at the northeast corner, on the sidewalk at Central Park Plaza.

The most notable carcass scene was on the north side of the Nebraska State Office building, at the glass walled, entry area. Three carcasses were present, and had signs that made them appear to be recent. These juveniles were probably raised in the area. The landscaped, Central Park Mall is across Farnam Street from the building.

Common Grackles were seen foraging in a few small groups at grassy places around the downtown area.

An injured juvenile Common Grackle at the north side of the Nebraska State Office Building. It has a severly injured, right leg. 5 July 2008.

Bony relict of the carcass of a Northern Cardinal on the north side of the Architecture Hall link. These remains have obviously been present for an extended period of time. Picture taken 29 June 2008.

Common Grackles were the notable remains noted on Sunday, June 29th on the UNL City campus. At least three were found in various conditions. Aged carcasses of two other species were also noted.

Two fatalities were at the CPN walkway, and an aged, third carcass at the west side of the passageway on the north side of Oldfather Hall.

Carcass below the walkway on the north side of Oldfather Hall, at UNL on 29 June.

Carcass on the stairway at the west side of the CPN walkway. There was a second carcass of a Common Grackle at this locale. Date: 29 Jun 2008.

Other locations where strikes have occurred, were checked to a lesser extent.

Walkway on the south side of Oldfather Hall. Note the smears, which with a closer look, a couple appeared to have indications of being caused by a bird strike. 29 Jun 2008.