Habitat Characteristics of Some Passerine Birds in Western North American Taiga, by Brina Kessel

ARCTIC ◽  
1999 ◽  
Vol 52 (3) ◽  
Author(s):  
Christopher J. Norment
Keyword(s):  
North American ◽  
Habitat Characteristics ◽  
Passerine Birds

The Influence of Habitats on Mating Systems of North American Passerine Birds

Ecology ◽  
1966 ◽  
Vol 47 (1) ◽  
pp. 143-147 ◽  
Author(s):  
Jared Verner ◽  
Mary F. Willson
Keyword(s):  
North American ◽  
Mating Systems ◽  
Passerine Birds

scholarly journals Detection Probabilities of Electrofishing, Hoop Nets, and Benthic Trawls for Fishes in Two Western North American Rivers

2015 ◽  
Vol 6 (2) ◽  
pp. 371-391 ◽  
Author(s):  
Christopher D. Smith ◽  
Michael C. Quist ◽  
Ryan S. Hardy
Keyword(s):  
North American ◽  
Fish Assemblages ◽  
Habitat Characteristics ◽  
Sampling Techniques ◽  
Lota Lota ◽  
Specific Effects ◽  
Detection Probabilities ◽  
Species Specific ◽  
A Site

Abstract Research comparing different sampling techniques helps improve the efficiency and efficacy of sampling efforts. We compared the effectiveness of three sampling techniques (small-mesh hoop nets, benthic trawls, boat-mounted electrofishing) for 30 species in the Green (WY, USA) and Kootenai (ID, USA) rivers by estimating conditional detection probabilities (probability of detecting a species given its presence at a site). Electrofishing had the highest detection probabilities (generally greater than 0.60) for most species (88%), but hoop nets also had high detectability for several taxa (e.g., adult burbot Lota lota, juvenile northern pikeminnow Ptychocheilus oregonensis). Benthic trawls had low detection probabilities (<0.05) for most taxa (84%). Gear-specific effects were present for most species indicating large differences in gear effectiveness among techniques. In addition to gear effects, habitat characteristics also influenced detectability of fishes. Most species-specific habitat relationships were idiosyncratic and reflected the ecology of the species. Overall findings of our study indicate that boat-mounted electrofishing and hoop nets are the most effective techniques for sampling fish assemblages in large, coldwater rivers.

scholarly journals Group-foraging is not associated with longevity in North American birds

2009 ◽  
Vol 6 (1) ◽  
pp. 42-44 ◽  
Author(s):  
Guy Beauchamp
Keyword(s):  
Body Mass ◽  
Group Size ◽  
North American ◽  
Life History Theory ◽  
Foraging Efficiency ◽  
Passerine Birds ◽  
Group Foraging ◽  
Evolutionary Transitions ◽  
Age At First Reproduction ◽  
First Reproduction

Group-foraging is common in many animal taxa and is thought to offer protection against predators and greater foraging efficiency. Such benefits may have driven evolutionary transitions from solitary to group-foraging. Greater protection against predators and greater access to resources should reduce extrinsic sources of mortality and thus select for higher longevity according to life-history theory. I assessed the association between group-foraging and longevity in a sample of 421 North American birds. Taking into account known correlates of longevity, such as age at first reproduction and body mass, foraging group size was not correlated with maximum longevity, with and without phylogenetic correction. However, longevity increased with body mass in non-passerine birds. The results suggest that the hypothesized changes in predation risk with group size may not correlate with mortality rate in foraging birds.

Sign in / Sign up

Export Citation Format

Share Document