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Full-Text Articles in Ornithology
Effects Of Leafy Spurge (Euphorbia Esula) Infestation On Breeding Birds Of The Sheyenne National Grassland, Nd, Daniel M. Scheiman
Effects Of Leafy Spurge (Euphorbia Esula) Infestation On Breeding Birds Of The Sheyenne National Grassland, Nd, Daniel M. Scheiman
Masters Theses
Leafy spurge (Euphorbia esula) is an exotic invasive weed in the northern Great Plains. We examined the effects of leafy spurge infestation on densities and nest success of breeding birds in grasslands on the Sheyenne National Grassland (SNG), ND. We categorized spurge-infested grasslands into three levels of infestation, based on the area covered by spurge patches: (a) low (0-20%), (b) medium (20-60%) and, (c) high (> 60%). We surveyed 60 100-m radius circular plots (20 in each category), and searched for nests in three 16-ha plots (one in each category). There were no statistically significant differences in mean species richness …
Patterns And Implications Of Aberrant Singing Behaviors Of Black-Capped (Poecile Atricapillus) And Carolina (Poecile Carolinensis) Chickadees In Illinois, Patrick Caesar Enstrom
Patterns And Implications Of Aberrant Singing Behaviors Of Black-Capped (Poecile Atricapillus) And Carolina (Poecile Carolinensis) Chickadees In Illinois, Patrick Caesar Enstrom
Masters Theses
I studied the singing behavior of the closely related Black-capped (Poecile atricapillus) and Carolina (Poecile carolinensis) Chickadees along their range interface in central Illinois. These sibling species are parapatrically distributed from the Appalachians through the Midwest to Kansas. Where their ranges do overlap, small hybrid zones form and chickadees in these areas frequently sing aberrant songs. The majority of the songs studied were recorded 17 April-16 July 1999 in fifteen counties throughout central Illinois. I measured 8 frequency and duration characteristics of the first two notes of songs that began with two whistled notes. The averages of these characteristics …