River Otter (<i>Lontra canadensis</i>) Killed by Wolves (<i>Canis lupus</i>) during Winter in Northern Minnesota

Winter Prey Caching by Northern Hawk Owls in Minnesota

—Northern Hawk Owls (Surnia ulula) have been reported to cache prey during the breeding season for later consumption, but detailed reports of prey caching during the non-breeding season are comparatively rare. We provided prey to four individual Northern Hawk Owls in wintering areas in northeastern Minnesota during 2001 and 2005 and observed their caching behavior. These owls cached 93% (n 14) ...

Status of the Northern River Otter in Nebraska

River Otter Monitoring by Citizen Science Volunteers in Northern California: Social Groups and Litter Size

Opportunistic observations of Nearctic River Otter (Lontra canadensis) were collected by volunteer observers in Humboldt and Del Norte counties to describe group and litter size patterns. In the first 5 y, 709 records were sent by email, mail, or an online form. River Otter pups were characterized relative to adult body size. Group sizes, ranging from 1 to 9 otters, were larger in summer and sm...

Estimated Age Structure of Wolves in Northeastern Minnesota

Information about population age structures is useful to understand survival rates, longevity, and population turnover. However, little such information is available about wolf (Canis lupus) populations. Mech (1970) estimated age structures of wolf-population age structure from pup:adult ratios applying various demographic assumptions, but no direct information has been published to test his es...

Quantification of Walleye Spawning Substrate in a Northern Minnesota River using Side-Scan Sonar

Evaluating aquatic habitats is an important component of many ecological studies and natural resource assessments, but traditional habitat evaluations are time and labor intensive and do not provide continuous data. Side-scan sonar (SSS) can provide a low-cost method that collects continuous aquatic habitat data. We used SSS mapping to quantify suitable spawning substrate available toWalleye Sa...