Role of habitat in the distribution and abundance of marsh birds

The recent drouth of the late 1950’s and early 1960’s produced some dramatic effects on the quality and quantity of emergent vegetation in glacial marshes of the central United States and Canada. These vegetative changes have had great impact on the distribution and size of marsh bird populations. Similar plant responses must have resulted from the dry years of the late 1800’s and the 1930’s, and intervening wet years produced opposite extremes on many marshes. Such habitat changes undoubtedly have occurred throughout the racial history of many marsh animals, and the maintenance of a species depended upon its adaptability.https://lib.dr.iastate.edu/specialreports/1041/thumbnail.jp

The Geomorphology of Teshekpuk Lake in Relation to Coastline Configuration of Alaska's Coastal Plain

Observations on a drained and a partially drained lake basin adjacent to Teshekpuk Lake led to the conclusion that the drainage was a result of erosion produced by the moat-current phenomenon of Teshekpuk Lake. The processes of shoreline erosion and lake-capture seem to be responsible for the growth and configuration of Teshekpuk Lake. Similar phenomena between large lakes and the Beaufort Sea may also have influenced the shoreline configuration of vast coastal areas such as Admiralty Bay, Dease Inlet and Harrison Bay

Book Review: Iowa Birds

Despite considerable ornithological research and increasing bird activity in Iowa, a revision of a major book on Iowa birds has been long overdue. This Iowa State Press publication by five experienced and competent ornithologists/birders/ecologists finally brings together what is known in a precise and thorough manner that will be useful to anyone interested in midcontinent birds

Controlled Waterfowl Hunting At Lake Odessa, Louisa County, Iowa

The Lake Odessa Public Hunting Area supports two systems of regulated waterfowl hunting. Control Area A consists of 55 marked blind sites which are chosen randomly by hunters during a daily drawing. Hunters using the second area, Control Area B, are not restricted to blind sites and a daily fee is not required, but all parties must possess a valid permit. Hunter use of Control Area A was uniform throughout the 1972 and 1973 hunting seasons due to the better mallard (Anas platy rhynchos) shooting on that area. Control Area B hunter use decreased as the season progressed, reflecting the early migration of wood ducks (Aix sponsa) which were more prevalent. In 1973, a year of poor mallard production but good wood duck production, hunter use of Control Area B increased over the previous year as hunters sought wood ducks. Hunters using Control Area A belonged to higher income, education, and occupation brackets, spent more money on equipment, and drove further to hunt than hunters in Control Area B. Hunter success was positively related to increasing values of vegetation parameters, but the dominant influence was not apparent. A heavy zone of annual emergent vegetation appeared to influence hunter success, but a lack of this zone could be compensated for with a strong representation of buttonbush (Cephalanthus occidentalis). Sites on medium-sized water areas (14-20 ac.) with a strong zone of annual emergent vegetation produced the highest success rates in 1972, but the same or similar sites produced low success rates in 1973 after severe loss of vegetation. Because of reduced annual emergent vegetation on the area and the receding zones of bottonbush, a summer drawdown of water level was recommended

Changes in the Vegetation and Wildlife Use of a Small Prairie Wetland Following a Drought

Several transect methods were used to study marsh vegetation resulting from drought-induced mud flats of a 1.7-ha wetland in northwestern Iowa. All three methods produced comparable results, but point-count and interval transects were most rapid and reflected submergent and floating as well as emergent plants. Most wet meadow plants were eliminated in about three years, whereas shallow marsh and deep marsh species survived until muskrats eliminated all emergent plants. Both vegetation and wildlife responses were typical of shallow prairie wetlands of the region

Mapping the medical outcomes study HIV health survey (MOS-HIV) to the EuroQoL 5 Dimension (EQ-5D-3L) utility index

10.1186/s12955-019-1135-8Health and Quality of Life Outcomes1718

Notes on Some Argentine Anatids

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