Publications

Previously published studies of the age estimation of channel catfish Ictalurus punctatus based on otoliths have reported using the sagittae, whereas it is likely they were actually using the lapilli. This confusion may have resulted because in catfishes (ostariophyseans) the lapilli are the largest of the three otoliths, whereas in nonostariophysean fish the sagittae are the largest...

Stream fish managers often use fish sample data to inform management decisions affecting fish populations. Fish sample data, however, can be biased by the same factors affecting fish populations. To minimize the effect of sample biases on decision making, biologists need information on the effectiveness of fish sampling methods. We evaluated single-pass backpack electrofishing and...

Climate creates environmental constraints (filters) that affect the abundance and distribution of species. In estuaries, these constraints often result from variability in water flow properties and environmental conditions (i.e. water flow, salinity, water temperature) and can have significant effects on the abundance and distribution of commercially important nekton species. We...

The Least Bittern (Ixobrychus exilis) and the Pied-billed Grebe (Podilymbus podiceps) are secretive marsh bird species that breed in the Illinois and Upper Mississippi River Valleys. Marsh bird surveys were conducted on public and private wetlands in this region during the breeding seasons of 2006 and 2007. Detection probability (ῥ) and site occupancy probability (ψ) were estimated for...

River otters (Lontra canadensis) are important predators in aquatic ecosystems, but few studies quantify their prey consumption. We trapped crayfish monthly as an index of availability and collected otter scat for diet analysis in the Ozark Mountains of northwestern Arkansas, USA. We measured otter daily energy expenditure (DEE) with the doubly labeled water method to develop a...

We designed a digital underwater video camera system to monitor nesting centrarchid behavior in the Tallapoosa River, Alabama, 20 km below a peaking hydropower dam with a highly variable flow regime. Major components of the system included a digital video recorder, multiple underwater cameras, and specially fabricated substrate stakes. The innovative design of the substrate stakes...

A mark-recapture field study was conducted to determine fish passage at 5 concrete box culverts and 5 low-water crossings (concrete slabs vented by culverts) as well as 10 control sites (below a natural riffle) in Flint Hills streams of northeastern Kansas. Additionally, we tested the upstream passage of four fish species native to Great Plains streams (Topeka shiner Notropis topeka...

Governmental entities are responsible for managing and conserving large numbers of lake, river, and wetland ecosystems that can be addressed only rarely on a case-by-case basis. We present a system for predictive classification modeling, grounded in the theoretical foundation of landscape limnology, that creates a tractable number of ecosystem classes to which management actions may be...

Avian studies conducted in the 1970s on Alaska’s Arctic Coastal Plain (ACP) indicated that coastal littoral habitats are important to Arctic-breeding shorebirds for staging prior to fall migration. However, relatively little recent, broad-scale, or quantitative information exists on shorebird use of staging areas in this region. To locate possible shorebird concentration areas in the...

The western arctic population of King Eiders (Somateria spectabilis) has declined by >50% in recent years. A health assessment was conducted for adult King Eiders breeding on the north slope of Alaska, USA, to evaluate body condition (n=90, 2002–2006) and baseline biochemical and hematologic values (n=20–30, 2005–2006). Body condition for males and females was excellent. Total protein...

Anthropogenic subsidies are used by a variety of predators in areas developed for human use or residence. If subsidies promote population growth, these predators can have a negative effect on local prey species. The Glaucous Gull (Larus hyperboreus) is an abundant predator in northern Alaska that is believed to benefit from garbage as a supplemental food source, but this supposition has...

Almost three-quarters of the 46 young adult and sub-adult striped bass Morone saxatilis that were acoustically tagged in Plum Island Estuary, Massachusetts, U.S.A., in the summer of 2006 were detected in one or more southern coastal arrays during their autumn migration. On the basis of the trajectories along which these M. saxatilis moved from feeding to overwintering areas, three...