Daniel Twedt, Ph.D.
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
The Challenge: Management of bottomland forests using wildlife forestry silviculture is being undertaken to achieve desired forest conditions for priority silvicolous wildlife, such as Louisiana black bear, migratory birds, and resident game species. Wildlife forestry management results in forests that have more open canopies and increased understory vegetation yet exhibit heterogeneous structure with retained dominant trees and cavities. Creating these conditions on recently reforested sites and maintaining these conditions in mature forests, without undesirable shifts shade-tolerant tree species composition are management concerns.
The Challenge: Within the Mississippi Alluvial Valley (MAV), forest managers may prescribe variable retention silvicultural treatments within bottomland hardwood forests on public lands to improve forest conditions (i.e., structural heterogeneity, species composition, and senescence) for priority wildlife species. This is referred to as wildlife-forestry silviculture. However, concerns have been voiced regarding loss of available cavities for wildlife use if hollow trees are removed or become inaccessible due to management. Of particular concern are bat species and their occurrence and use of forests subjected to wildlife-forestry silviculture.
The Challenge: Avian monitoring within the Gulf Coast Network of the National Park Service is challenged to provide valid quantitative data on bird populations within park boundaries with limited financial input. Thus, citizen science (volunteer) bird monitoring has been proposed to achieve reliable estimates of bird populations and to assess the effects of habitat change and temporal dynamics of bird populations.
North American Breeding Bird Survey in Mississippi
Does it seem like you are hearing fewer Northern Bobwhite (Colinus virginianus) calls in recent years than you remember when you were younger? Conversely, have you also noticed hearing more “cooing” of Eurasian Collared-Doves (Streptopelia decaocto)? Do such experiences reflect changes in bird populations or are they false impressions? Well,...Twedt, Daniel J.; Pardieck, Keith L.
Nocturnal insect availability in bottomland hardwood forests managed for wildlife in the Mississippi Alluvial Valley
Silviculture used to alter forest structure and thereby enhance wildlife habitat has been advocated for bottomland hardwood forest management on public conservation lands in the Mississippi Alluvial Valley. Although some songbirds respond positively to these management actions to attain desired forest conditions for wildlife, the response of other...Loraine Ketzler; Christopher Comer; Twedt, Daniel J.
Breeding birds in managed forests on public conservation lands in the Mississippi Alluvial Valley
Managers of public conservation lands in the Mississippi Alluvial Valley have implemented forest management strategies to improve bottomland hardwood habitat for target wildlife species. Through implementation of various silvicultural practices, forest managers have sought to attain forest structural conditions (e.g., canopy cover, basal area...Twedt, Daniel J.; Wilson, R. Randy
Object-based forest classification to facilitate landscape-scale conservation in the Mississippi Alluvial Valley
The Mississippi Alluvial Valley is a floodplain along the southern extent of the Mississippi River extending from southern Missouri to the Gulf of Mexico. This area once encompassed nearly 10 million ha of floodplain forests, most of which has been converted to agriculture over the past two centuries. Conservation programs in this region revolve...Mitchell, Michael; Wilson, R. Randy; Twedt, Daniel J.; Mini, Anne E.; James, J. Dale
Forest structure of oak plantations after silvicultural treatment to enhance habitat for wildlife
During the past 30 years, thousands of hectares of oak-dominated bottomland hardwood plantations have been planted on agricultural fields in the Mississippi Alluvial Valley. Many of these plantations now have closed canopies and sparse understories. Silvicultural treatments could create a more heterogeneous forest structure, with canopy gaps and...Schweitzer, Callie Jo; Clatterbuck, Wayne K.; Oswalt, Christopher M.; Twedt, Daniel J.; Phillip, Cherrie-Lee P.; Guilfoyle, Michael P.; Wilson, R. Randy
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 nonbreeding 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.