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Full-Text Articles in Physical Sciences and Mathematics

Evaluating The Effects Of Landscape Configuration On Site Occupancy And Movement Dynamics Of Odonates In Iowa, Tyler Harms, Karen Kinkhead, Stephen Dinsmore Mar 2016

Evaluating The Effects Of Landscape Configuration On Site Occupancy And Movement Dynamics Of Odonates In Iowa, Tyler Harms, Karen Kinkhead, Stephen Dinsmore

Tyler Harms

Odonates contribute highly to global biodiversity and are considered good indicators of environmental quality, but they are under-studied and quantitative information on their habitat associations is lacking. Our objective was to examine the effects of landscape configuration on site occupancy and movement dynamics of four odonate species in Iowa: Tramea onusta, Epitheca princeps, Pantala flavescens, and Calopteryx maculata. We conducted standardized visual encounter surveys for odonates at 233 public properties in Iowa from 2007 to 2011 and computed landscape variables within a 200, 600 m, and 1 km radius of each surveyed site. Using a robust design occupancy model in …


Density, Abundance, And Habitat Associations Of The Inland Swamp Sparrow (Melospiza Georgiana Georgiana) In Iowa, Tyler Harms, Stephen Dinsmore Mar 2016

Density, Abundance, And Habitat Associations Of The Inland Swamp Sparrow (Melospiza Georgiana Georgiana) In Iowa, Tyler Harms, Stephen Dinsmore

Tyler Harms

Wetlands continue to decline throughout North America and the Prairie Pothole Region, thus emphasizing the importance of understanding population trends and habitat associations of wetland species to ensure effective conservation and habitat management of those species. We estimated density and abundance and evaluated habitat associations of the Inland Swamp Sparrow (Melospiza georgiana georgiana) in Iowa. We conducted standardized distance sampling surveys for Swamp Sparrows and measured habitat characteristics at 307 wetlands in two regions of Iowa in 2009 and 2010. We used Program Distance to model detection probability and estimate region-specific breeding densities of Swamp Sparrows at Iowa …


Influence Of Season And Time Of Day On Marsh Bird Detections, Tyler Harms, Stephen Dinsmore Mar 2016

Influence Of Season And Time Of Day On Marsh Bird Detections, Tyler Harms, Stephen Dinsmore

Tyler Harms

Call-broadcast surveys are frequently used to elicit responses of secretive marsh birds and produce greater detection rates than passive surveys. However, little is known about how detection rates of birds from these surveys differ by season and time of day. We conducted call-broadcast surveys for eight focal species at 56 wetlands throughout Iowa from 15 May–13 June 2010 (early season) and from 15 June–10 July 2010 (late season). Our focal species were Pied-billed Grebe (Podilymbus podiceps), American Bittern (Botaurus lentiginosus), Least Bittern (Ixobrychus exilis), King Rail (Rallus elegans), Virginia Rail (Rallus …


Density And Abundance Of Secretive Marsh Birds In Iowa, Tyler Harms, Stephen Dinsmore Mar 2016

Density And Abundance Of Secretive Marsh Birds In Iowa, Tyler Harms, Stephen Dinsmore

Tyler Harms

A decrease in wetland habitats throughout North America has caused a decline in populations of marsh birds. The objective of this study was to estimate population densities and abundances of secretive marsh birds in Iowa. Call-broadcast surveys were conducted in conjunction with distance sampling for eight species of marsh birds at wetlands in three regions of Iowa during 2009 and 2010. Regions were defined by observed microhabitat characteristics which also corresponded to physiographic regions. Region-specific density estimates were obtained using Program Distance for four species of marsh birds for which sufficient detections existed (Pied-billed Grebe [Podilymbus podiceps], Least …


Influence Of Season And Time Of Day On Marsh Bird Detections, Tyler Harms, Stephen J. Dinsmore Mar 2016

Influence Of Season And Time Of Day On Marsh Bird Detections, Tyler Harms, Stephen J. Dinsmore

Tyler Harms

Call-broadcast surveys are frequently used to elicit responses of secretive marsh birds and produce greater detection rates than passive surveys. However, little is known about how detection rates of birds from these surveys differ by season and time of day. We conducted call-broadcast surveys for eight focal species at 56 wetlands throughout Iowa from 15 May–13 June 2010 (early season) and from 15 June–10 July 2010 (late season). Our focal species were Pied-billed Grebe (Podilymbus podiceps), American Bittern (Botaurus lentiginosus), Least Bittern (Ixobrychus exilis), King Rail (Rallus elegans), Virginia Rail (Rallus …