Download or read book The Effect of Aggression on Breeding Territory in the Savannah Sparrow Passerculus Sandwichensis written by Christopher Marc Rogers and published by . This book was released on 1982 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Agricultural Management on Breeding Savannah Sparrows Passerculus Sandwichensis Mediated Through Food Availability written by Nathan J. Zalik and published by . This book was released on 2007 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: Invertebrate prey is an essential food resource for most breeding songbirds. For grassland birds such as Savannah Sparrows nesting in hayfields, this resource may be affected by the harvesting process, which likely destroys and removes invertebrates as well as reduces the amount of vegetation on which invertebrates live and feed. Thus, for birds whose first nests fail due to the harvesting of hay, renesting may take place in a dramatically altered habitat that may be less suitable for raising young.
Download or read book Influence of Habitat Quality and Gender on the Variable Mating System of a Territorial Passerine the Savannah Sparrow written by Elizabeth Irene Rogers and published by . This book was released on 1990 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Territorial and Nesting Behavior in the Savannah Sparrow written by Cynthia Paszkowski and published by . This book was released on 1973 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Survey of the Belding s Savannah Sparrow Passerculus Sandwichensis Beldingi in California 2001 written by Richard Zembal and published by . This book was released on 2002 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Habitat Selection on the Reproductive Success of Savannah Sparrows Passerculus Sandwichensis written by Peter J. Hodum and published by . This book was released on 1988 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Habitat Loss on the Savannah Sparrows Passerculus Sandwichensis of La Perouse Bay Manitoba written by Rachel Jane Sturge and published by . This book was released on 2007 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: Heavy grazing by lesser snow geese (Chen caerulescens caerulescens) in the coastal salt marshes of La Perouse Bay (Manitoba) has caused a shift from shrub-grassland habitat to barren patches (exposed mineral sediments and associated plant species), which has been linked to a decline in savannah sparrow (Passerculus sandwichensis) nesting densities. To determine the effects of this shift at a local scale, I monitored male territories for mating and fledging success, and compared these values to historic data. I measured various aspects of each territory and ran statistical tests to determine if any were correlated with reproductive success (measured by mating/fledging success). Positive correlations were found with the presence of graminoids, and medium-sized shrubs with graminoid ground cover, within a territory. Territories with larger patches of shrubs also had positive correlations with reproductive success. The territory's perimeter/area ratio and the presence of barren habitat had negative correlations with reproductive success.
Download or read book Breeding and Territoriality of the Savannah Sparrow Passerculus Sandwichensis on a Dune Beach in Nova Scotia written by Daniel Albert Welsh and published by . This book was released on 1970 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Agricultural Intensification on An Obligate Grassland Bird of North America written by Heidi Elizabeth Joy Van Vliet and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Grassland birds are in decline worldwide and the leading cause of this decline is habitat loss and degradation through agricultural intensification. The purpose of this study is to investigate the impacts of agricultural intensification on a declining grassland bird, the Savannah Sparrow (Passerculus sandwichensis). Over two breeding seasons nests were located and monitored, adults and nestlings were measured to assess body condition, and fledglings were manually radio tracked to quantify survival. Nesting success over the two-years was significantly lower on agricultural sites. However, nest predation was higher in agricultural sites in only one of the two years, fledgling survival was not significantly different, and no differences were found in the nest productivity, nor body condition of adults and nestlings. Long-term monitoring is needed to determine if nest predation is consistently higher in intensive agriculture, but at present our results indicate that in some years intensive agriculture may provide adequate habitat.
Download or read book Behavioral and Reproductive Consequences of Predator Activity to Grassland Birds written by Jennifer Lee Thieme and published by . This book was released on 2011 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Grassland birds are declining at greater rates than any other habitat guild in North America, yet conservation remains difficult due to extensive habitat loss and fragmentation throughout the urbanizing Midwest. Human presence is often associated with non-native predators (e.g., cats) and anthropogenic food sources, which collectively can promote high densities of nest predators in urban landscapes. High densities of nest predators are a concern because predation is the leading source of nest failure. Behavioral responses to predators may further diminish the value of urban habitats if birds avoid areas with high levels of predator activity, which could result in lower occupancy rates or densities of birds in urban habitat patches. In my research, I examined how habitat heterogeneity and variation in the predator community influenced the breeding ecology of grassland and early successional birds in urban parks. I asked two broad questions: (1) how do birds respond behaviorally to abundance and activity of predators in urban natural areas? (2) to what extent is avian reproductive success linked to predator communities and/or activity at plot and site scales? I collected data on avian density, nest placement, and reproductive success of eight focal species of grassland birds within 46 2-ha plots at seven urban parks near Chicago, Illinois, during 2009 and 2010. Relative abundance and activity levels of potential nest predator species, including mesopredators, small mammals, snakes, and avian predators, were estimated for each plot during surveys and as part of a collaborative study. As capture rates of small mammals increased, territory densities of Field Sparrow (Spizella pusilla), Common Yellowthroat (Geothlypis trichas), and Savannah Sparrow (Passerculus sandwichensis) declined, but density of Song Sparrow (Melospiza melodia) rose. Mesopredator capture rates were negatively associated with Common Yellowthroat and Savannah Sparrow densities within 2-ha plots, as well as Eastern Meadowlark (Sturnella magna) at the site level. Whereas small mammal and mesopredator capture rates explained some of the observed variation in territory density, daily nest survival of both Field and Song Sparrows was best explained by numbers of snakes observed within plots. Interestingly, snake activity was positively associated with nest survival of Field Sparrows, though negatively associated with that of Song Sparrows. At large scales, vegetation characteristics best predicted nest survival of both species, with nest survival of Field Sparrow improving as density of groundcover increased and nest survival of Song Sparrow improving as structural complexity increased. While the structural complexity of vegetation at nest sites was not explained by predator activity, Song Sparrows selected nest sites with lower groundcover density than available as activity of Brown-headed Cowbird (Molothrus ater) increased. As a whole, these results provide evidence that breeding grassland and early successional birds respond to both habitat structure and activity of potential predators at different scales. I also found that behavioral (e.g., territory selection) and demographic (e.g., nest survival) associations with predators do not necessarily match. For example, snakes had the strongest, though sometimes counterintuitive, relationship with nest success of Field and Song Sparrows, yet appeared to elicit no response during territory or nest site selection. My results are also consistent with other studies demonstrating the importance of vegetation structure to both settlement and reproductive success. Consequently, the best management practices in urban parks will both maintain vegetation structure that promotes successful nesting and discourage activities that promote high abundances of predators.
Download or read book Masters Abstracts written by and published by . This book was released on 1983 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wildlife Review written by and published by . This book was released on 1984 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings written by and published by . This book was released on 2003 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ecology written by and published by . This book was released on 1973 with total page 742 pages. Available in PDF, EPUB and Kindle. Book excerpt: Publishes essays and articles that report and interpret the results of original scientific research in basic and applied ecology.
Download or read book Animal Behavior Abstracts written by and published by . This book was released on 1997 with total page 1408 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ecology Abstracts written by and published by . This book was released on 1985 with total page 1220 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coverage: 1982- current; updated: monthly. This database covers current ecology research across a wide range of disciplines, reflecting recent advances in light of growing evidence regarding global environmental change and destruction. Major ares of subject coverage include: Algae/lichens, Animals, Annelids, Aquatic ecosystems, Arachnids, Arid zones, Birds, Brackish water, Bryophytes/pteridophytes, Coastal ecosystems, Conifers, Conservation, Control, Crustaceans, Ecosyst em studies, Fungi, Grasses, Grasslands, High altitude environments, Human ecology, Insects, Legumes, Mammals, Management, Microorganisms, Molluscs, Nematodes, Paleo-ecology, Plants, Pollution studies, Reptiles, River basins, Soil, TAiga/tundra, Terrestrial ecosystems, Vertebrates, Wetlands, Woodlands.
Download or read book The Condor written by and published by . This book was released on 1956 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt:
