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.
Science and Products
Bird Habitat Needs in the Mississippi Alluvial Valley
Monitoring Birds in National Parks of the Gulf Coast Network
Forest Structure Resulting from ‘Wildlife Forestry Silviculture’
Bats in Forests Managed for Wildlife
Eastern Ecological Science CenterxLegacy Data ReleasesPatuxent Wildlife Research CenterPredicted Avian Species Occupancy, Area of Sustainable Forest Habitat, and Area of Occupied Habitat within the Mississippi Alluvial Valley Bird Conservation Region Pred
Forests in the Mississippi Alluvial Valley Lacking Sufficient Conservation Protection
Forest area to support landbird population goals for the Mississippi Alluvial Valley
Mississippi Alluvial Valley Forest-breeding landbird population & quantitative habitat objectives
Conservation–Protection of forests for wildlife in the Mississippi Alluvial Valley
Influence of forest harvest severity and time since perturbation on conservation of North American birds
Rapid adoption of nestboxes by Prothonotary Warblers (Protonotaria citrea) in mesic deciduous forest
Consistency counts: Modeling the effects of a change in protocol on Breeding Bird Survey counts
Bat community response to silvicultural treatments in bottomland hardwood forests managed for wildlife in the Mississippi Alluvial Valley
North American Breeding Bird Survey in Mississippi
Nocturnal insect availability in bottomland hardwood forests managed for wildlife in the Mississippi Alluvial Valley
Breeding birds in managed forests on public conservation lands in the Mississippi Alluvial Valley
Object-based forest classification to facilitate landscape-scale conservation in the Mississippi Alluvial Valley
Forest structure of oak plantations after silvicultural treatment to enhance habitat for wildlife
Science and Products
- Science
Bird Habitat Needs in the Mississippi Alluvial Valley
Historically the Mississippi Alluvial Valley (MAV) was predominantly bottomland hardwood forest and most birds of conservation concern depend on bottomland hardwood forest. Past conservation planning has focused on habitat objectives with presumption that bird population goals would be met by habitat provision.Monitoring Birds in National Parks of the Gulf Coast Network
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...Forest Structure Resulting from ‘Wildlife Forestry Silviculture’
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 reflect a desire to provide suitable habitat for rare...Bats in Forests Managed for Wildlife
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... - Data
Eastern Ecological Science CenterxLegacy Data ReleasesPatuxent Wildlife Research CenterPredicted Avian Species Occupancy, Area of Sustainable Forest Habitat, and Area of Occupied Habitat within the Mississippi Alluvial Valley Bird Conservation Region Pred
Values for predicted probabilities of avian species occupancy were determined using colonization-extinction models (MacKenzie and others, 2003) as implemented in R (Version 3.4.4; https://www.r-project.org/) via the colext function of the Unmarked package (Version 0.12-0; Fiske and Chandler 2011). Performance of a null model (without covariates) and 153 additional models that assessed the effectsForests in the Mississippi Alluvial Valley Lacking Sufficient Conservation Protection
Based on forest patch area, location, and hydrologic influence, we ranked the purported need of forest patches for additional conservation-protection. Qualities for higher ranking included forest patches with & greater than 2000 ha of core-forest that was more than 250 m from an edge, forest patches within high priority areas for reforestation, and forest patches with less propensity f - Publications
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Forest area to support landbird population goals for the Mississippi Alluvial Valley
Historically, the Mississippi Alluvial Valley (MAV) (Partners in Flight Bird Conservation Region #26) was predominantly bottomland hardwood forest, but natural vegetation has been cleared from about 80 percent of this ecoregion and converted primarily to agriculture. Because most bird species that are of conservation concern in this region are dependent on forested wetlands, bottomland hardwood foMississippi Alluvial Valley Forest-breeding landbird population & quantitative habitat objectives
The Mississippi Alluvial Valley (MAV) is a 9 million ha (22-million-acre) floodplain that supports a diverse and ecologically rich bottomland hardwood forest ecosystem – one of the most productive in North America. It extends from roughly Cape Girardeau, Missouri, to the Gulf of Mexico and features a mosaic of ridges, swales, meander belts, and backswamps. Small changes in elevation (Conservation–Protection of forests for wildlife in the Mississippi Alluvial Valley
The nearly ubiquitous bottomland hardwood forests that historically dominated the Mississippi Alluvial Valley have been greatly reduced in area. In addition, changes in hydrology and forest management have altered the structure and composition of the remaining forests. To ameliorate the detrimental impact of these changes on wildlife, conservation plans have emphasized restoration to increase inteInfluence of forest harvest severity and time since perturbation on conservation of North American birds
I calculated avian conservation scores, based on published quantitative assessment of bird presence (typically relative abundance) and regional Partners in Flight conservation concern score of each species. I related these avian conservation scores to severity of forest perturbation (i.e., % retention) and number of years since perturbation for forest stands within North America. I characterized aRapid adoption of nestboxes by Prothonotary Warblers (Protonotaria citrea) in mesic deciduous forest
Breeding territory selection in Prothonotary Warblers (Protonotaria citrea (Boddaert, 1783)) is thought to hinge on standing water, with a strong preference for low-lying areas prone to seasonal flooding. However, we have observed this species nesting in much drier areas than previously reported. We recently initiated a study of the Carolina Wren (Thryothorus ludovicianus (Latham, 1790)) using wooConsistency counts: Modeling the effects of a change in protocol on Breeding Bird Survey counts
Analysis of North American Breeding Bird Survey (BBS) data requires controls for factors that influence detectability of birds along survey routes. Identifying factors that influence the counting process and incorporating them into analyses is a primary means of limiting bias in estimates of population change. Twedt (2015) implemented an alternative counting protocol on operational and non-randBat community response to silvicultural treatments in bottomland hardwood forests managed for wildlife in the Mississippi Alluvial Valley
Silvicultural treatments (e.g., selective timber harvests) that are prescribed to promote wildlife habitat are intended to alter the physical structure of forests to achieve conditions deemed beneficial for wildlife. Such treatments have been advocated for management of bottomland hardwood forests on public conservation lands in the Mississippi Alluvial Valley. Although some songbirds respond posiNorth 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, fortunately for us, we have one of the most powerful wilNocturnal 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 species, is largely unknown. Nocturnal insects areBreeding 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, etc.) within values postulated to benefit wildlife. WeObject-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 around protection of existing forest and reforestatiForest 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 increased understory vegetation for wildlife. La