Daniel Twedt, Ph.D.
Biography
Daniel J. Twedt received graduate degrees from Western Kentucky and North Dakota State University for his work on starling and yellow-headed blackbird ecology, respectively. For the past 20+ years, Dr. Twedt has been a research wildlife biologist with the USGS Patuxent Wildlife Research Center, stationed in Vicksburg, MS and Memphis, TN. During this time, his research has focused on avian ecology within bottomland hardwood forests, including bird response to forest restoration and silvicultural management, and assessment of alternative restoration and management techniques. Ongoing projects address forest structure and bird response to silvicultural prescriptions targeting wildlife in bottomland hardwoods, survival and productivity of birds in bottomland forests, and landscape scale integration of national land cover and forest inventory databases for assessment of bird distribution and abundance.
My published papers and PDF copies of poster presentations are available at: https://www.researchgate.net/profile/Daniel_Twedt
Science and Products
Flight feather molt in Yellow-headed Blackbirds (Xanthocephalus xanthocephalus) in North Dakota
Yellow-headed Blackbirds (Xanthocephalus xanthocephalus) in central North Dakota undergo prebasic molt or prejuvenile molt during late summer. Nestling Yellow-headed Blackbirds initiate a complete prejuvenile molt, grow their primary and secondary regimes in about 40 days, completing molt after they leave the nest by the first week in August....
Twedt, Daniel J.; Linz, George M. Estimating regional landbird populations from enhanced North American Breeding Bird Surveys
Estimating the size of bird populations is central to effective conservation planning and prudent management. I updated estimated regional bird populations for the East Gulf Coastal Plain of Mississippi using data from 275 North American Breeding Bird Surveys from 2009 to 2013. However, regional bird populations estimated from count surveys of...
Twedt, Daniel J. Leaf-on canopy closure in broadleaf deciduous forests predicted during winter
Forest canopy influences light transmittance, which in turn affects tree regeneration and survival, thereby having an impact on forest composition and habitat conditions for wildlife. Because leaf area is the primary impediment to light penetration, quantitative estimates of canopy closure are normally made during summer. Studies of forest...
Twedt, Daniel J.; Ayala, Andrea J.; Shickel, Madeline R. Avian response to conservation buffers in agricultural landscapes during winter
Native herbaceous vegetation cover along row‐crop field edges (i.e., field buffers) increases breeding densities of many bird species. However, the effect of field buffers on bird species during the non‐breeding season is less understood. We compared density, avian richness, and avian conservation value on row‐crop fields containing buffers...
Evans, Kristine O.; Burger, L. Wes; Riffell, Samuel K.; Smith, Mark D.; Twedt, Daniel J.; Wilson, R. Randy; Vorisek, Shawchyi; Rideout, Catherine; Heyden, Kate Wintering and breeding bird monitoring data analysis 2010-2013: San Antonio Missions National Historical Park
Following guidance issued within the Avian Inventory and Monitoring in National Parks of the Gulf Coast Network: Gulf Coast Network Avian Monitoring Plan, 40 point locations were established and monitored within San Antonio Missions National Historical Park. During three breeding seasons (May – Jun) and winters (Dec – Feb) between 2010 and 2013,...
Twedt, Daniel J. Regeneration in bottomland forest canopy gaps six years after variable retention harvests to enhance wildlife habitat
To promote desired forest conditions that enhance wildlife habitat in bottomland forests, managers prescribed and implemented variable-retention harvest, a.k.a. wildlife forestry, in four stands on Tensas River National Wildlife Refuge, LA. These treatments created canopy openings (gaps) within which managers sought to regenerate shade-intolerant...
Guldin, James M.; Twedt, Daniel J.; Somershoe, Scott G. Foraging habitat for shorebirds in southeastern Missouri and its predicted future availability
Water management to protect agriculture in alluvial floodplains often conflicts with wildlife use of seasonal floodwater. Such is the case along the Mississippi River in southeastern Missouri where migrating shorebirds forage in shallow-flooded fields. I estimated the current availability of habitat for foraging shorebirds within the New Madrid...
Twedt, Daniel J. Dead wood relative to slope severity in mesic loess bluff hardwood forests
To aid in identification of land within Vicksburg National Military Park that was subjected to forest restoration during the 1930s, I evaluated the hypothesized relationships between maximum live tree diameter or dead wood (standing and down) and severity of slope. Disproportionate mortality among early-successional, pioneer tree species suggested...
Twedt, Daniel J. Wildlife forestry
Akais, Okia Clement; Twedt, Daniel J. Wildlife forestry: Chapter 10
Wildlife forestry is management of forest resources, within sites and across landscapes, to provide sustainable, desirable habitat conditions for all forest-dependent (silvicolous) fauna while concurrently yielding economically viable, quality timber products. In practice, however, management decisions associated with wildlife forestry often...
Twedt, Daniel J. Common Grackle breeding on bottomland forest restoration sites
Two of 36 forest restoration sites in the Mississippi Alluvial Valley surveyed from 2000-2002 harbored Quiscalus quiscula (Common Grackle). Occupied sites were in less-forested landscapes and had sparser understory vegetation due to flooding. Probability of daily nest survival (0.9077) of 169 Common Grackle nests was influenced by nest-placement,...
Twedt, Daniel J. Landscape and vegetation effects on avian reproduction on bottomland forest restorations
Forest restoration has been undertaken on >200,000 ha of agricultural land in the Mississippi Alluvial Valley, USA, during the past few decades. Decisions on where and how to restore bottomland forests are complex and dependent upon landowner objectives, but for conservation of silvicolous (forest-dwelling) birds, ecologists have espoused...
Twedt, Daniel J.; Somershoe, Scott G.; Hazler, Kirsten R.; Cooper, Robert J.