Download or read book Overwinter Survival and Habitat Selection of Baird s and Grasshopper Sparrows in the Marfa Grasslands Texas written by Denis Josefina Perez-Ordonez and published by . This book was released on 2019 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Habitat Use in Baird s and Grasshopper Sparrows written by Kelly Gamble and published by . This book was released on 2005 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Settlement Cues and Resource Use by Grasshopper Sparrows and Baird s Sparrows in the Upper Great Plains written by Marissa A. Ahlering and published by . This book was released on 2005 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: To date, studies of the habitat selection process in grassland passerines have neglected the role of settlement cues, the proximate habitat cues birds use to establish breeding territories. I evaluated the settlement cues and resource use for two species of grassland birds, Grasshopper Sparrows (Ammodramus savannarum) and Baird's Sparrows (Ammodramus bairdii), between 2002 and 2004 in North Dakota, USA and Saskatchewan, Canada. Regional settlement patterns for Grasshopper Sparrows and Baird's Sparrows may be partially driven by weather patterns. Spring densities of Grasshopper Sparrows were positively related to May precipitation, and spring densities of Baird's Sparrows were negatively related to the previous winter's snowfall. At the territory level, Grasshopper Sparrows responded negatively to the cover of woody vegetation in the habitat. Baird's Sparrow results suggest birds choose habitat based on characteristics conducive to their foraging behavior. Experimental playback results suggest the presence of conspecifics may be a cue for territory establishment by Baird's Sparrows. Social cues may play an important role in the habitat selection process for this species. I also assessed the potential use of vegetation as predictive cues for invertebrate food resources. Results indicate more cover of live forbs in early May predict higher densities of Lepidoptera larvae in June, and less open ground in early May indicates higher densities of Araneae in June. However, none of the vegetation parameters predicted the June densities of Orthoptera. Lepidoptera larvae and Orthoptera were the two dominant food items for both species. I examined the range of habitat use for both species. Baird's Sparrows showed the widest range of habitat use in Saskatchewan where densities were the highest. The presence of conspecifics may cause adults to be more flexible in their habitat use. Grasshopper Sparrows exhibited more variation in the range of habitat use across sites. For this species, the range of habitat use was constrained by the vegetation available at the site. By examining the range of use across multiple sites within both species' range and at different population densities, patterns of habitat use become more apparent.
Download or read book Habitat Selection in Restored Grasslands the Role of Social Cues in the Settlement of Grasshopper Sparrows written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Molt and Aging Criteria for Four North American Grassland Passerines written by Peter Pyle and published by . This book was released on 2008 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Habitat Selection and Reproductive Success of the Grasshopper Sparrow at the Santa Rosa Plateau Ecological Reserve written by Christine Lynn Collier and published by . This book was released on 1994 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Grasshopper Sparrows on the Move written by Emily Jean Williams and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Dispersal is a behavior common to virtually all taxa with important consequences for gene flow, demography, and conservation. Mobile animals such as birds frequently engage in breeding dispersal, but the factors shaping this behavior are not well understood. In mid-continental grasslands, preliminary evidence suggested that Grasshopper Sparrows (Ammodramus savannarum) engaged in breeding dispersal within a single breeding season. This intriguing pattern shaped my research questions: (1) what are the patterns of within-season breeding dispersal in Grasshopper Sparrows? (2) why do some individual sparrows disperse, and others do not? and (3) what shapes settlement decisions following dispersal? I tested hypotheses based on spatial and temporal variation in nest predation, nest parasitism, and food availability. I studied Grasshopper Sparrows at 18 experimentally-managed watersheds with different fire and grazing regimes at Konza Prairie Biological Station during 2013-2015. To describe patterns, I combined re-sighting of 779 marked individuals, territory mapping, and radio-telemetry to quantify territory densities, turnover, and dispersal distances. To determine if nest predation or nest parasitism affected dispersal, I monitored the fate of 223 nests. I estimated food intake rates using plasma metabolites, and prey availability using sweep sampling. Densities of territorial Grasshopper Sparrows varied seasonally in management-specific ways. Turnover was remarkably high, with over half of territorial males being replaced each month. Over a third of males changed territories within-season, dispersing 0.1-9 km between breeding attempts. Dispersal decisions were related to past nest predation, but not nest parasitism. Dispersal likely yields fitness benefits, as sparrows that dispersed increased their chances of nest survival by 23% relative to site-faithful individuals. However, food availability did not affect settlement decisions. My study provides the first evidence of within-season breeding dispersal in Grasshopper Sparrows, and represents one of few tests of alternative hypotheses explaining dispersal decisions of songbirds. My results are consistent with a growing literature on the role of predation shaping dispersal, but suggest, somewhat surprisingly, that food is not important in post-dispersal habitat selection. High dispersal capacity coupled with adaptability to temporal and spatial change may be typical of grassland songbirds, implying that demographic studies and management decisions must consider their mobility for conservation.
Download or read book Analysis of the Habitat of Henslow s Sparrows and Grasshopper Sparrows Compared to Random Grassland Areas written by and published by . This book was released on 2005 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: Henslow's Sparrows are endangered prairie birds, and Grasshopper Sparrows are considered rare prairie birds. Both of these birds were abundant in Illinois, but their populations have been declining due to loss of the grasslands. This begins an ongoing study of the birds habitat so Fermilab can develop a land management plan for the Henslow's and Grasshoppers. The Henslow's were found at ten sites and Grasshoppers at eight sites. Once the birds were located, the vegetation at their sites was studied. Measurements of the maximum plant height, average plant height, and duff height were taken and estimates of the percent of grass, forbs, duff, and bare ground were recorded for each square meter studied. The same measurements were taken at ten random grassland sites on Fermilab property. Several t-tests were performed on the data, and it was found that both Henslow's Sparrows and Grasshopper Sparrows preferred areas with a larger percentage of grass than random areas. Henslow's also preferred areas with less bare ground than random areas, while Grasshoppers preferred areas with more bare ground than random areas. In addition, Grasshopper Sparrows preferred a lower percentage of forbs than was found in random areas and a shorter average plant height than the random locations. Two-sample variance tests suggested significantly less variance for both Henslow's Sparrows and Grasshopper Sparrows for maximum plant height in comparison to the random sites. For both birds, the test suggested a significant difference in the variance of the percentage of bare ground compared to random sites, but only the Grasshopper Sparrow showed significance in the variation in the percentage of forbs.
Download or read book Habitat Selection of Florida Grasshopper Ammodramus Savannarum Floridanus and Bachman s Sparrows Aimophila Aestivalis written by W. Gregory Shriver and published by . This book was released on 1996 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Management Practices on Grassland Birds written by and published by . This book was released on 1998 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This report is one of a series of literature systheses on North American grassland birds. The need for these reports was identified by the Prairie Pothole Joint Venture (PPJV), a part of the North American Waterfowl Management Plan. The PPJV recently adopted a new goal, to stabilize or increase populations of declining grassland- and wetland-associated wildlife species in the Prarie Pothole Region. To further that objective, it is essential to understand the habitat needs of birds other than waterfowl, and how management practices affect their habitats. The focus of these reports is on management of breeding habitat, particularly in the northern Great Plains"--Page 2 of cover.
Download or read book The Effects of Prescribed Burning of Grasslands on Nesting Habitat of the Grasshopper Sparrow on Martha s Vineyard Massachusetts written by Johanna A. Harris and published by . This book was released on 1998 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Habitat Selection and Production of Nesting Birds on Two Lakes in South Texas written by Sandra Lou Haigh and published by . This book was released on 1984 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nesting Birds of a Tropical Frontier written by Timothy Brush and published by Texas A&M University Press. This book was released on 2005 with total page 277 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Halfway between Dallas and Mexico City, along the last few hundred miles of the Rio Grande, lies a subtropical outpost where people from all over the world come to see birds. Located between the temperate north and the tropic south, with desert to the west and ocean to the east, the Lower Rio Grande Valley of Texas provides habitat for a variety of birds seen nowhere else in the United States. If you want to see a Hooked-billed Kite, Muscovy Duck, or Altamira Oriole, this is the place." "Drawing on years of personal observation and study, Timothy Brush has written a classic work of natural history about the little-known breeding bird communities of the Valley and the diversity of nesting strategies and behaviors that can be seen. Brush estimates that there are more than 150 current breeding species in the Lower Rio Grande Valley. In Nesting Birds of a Tropical Frontier, he describes the habits, distribution, changes in occurrence, and general outlook of these as well as former breeders, concentrating on Valley specialties and other birds of particular interest in the Valley." "Art by Gerald Sneed and color photographs by several of Texas' top nature photographers show off some of the Valley's famous birds. Historical maps of vegetation and geology help us gain a better perspective on the changes that have taken place along the Rio Grande and on the breeding bird communities of the U.S.-Mexico frontier."--Jacket
Download or read book Birds of Western Africa written by William Swainson and published by . This book was released on 1862 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monographic Revision of the Pocket Gophers written by Clinton Hart Merriam and published by . This book was released on 1895 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Theoretical Approaches to Biological Control written by Bradford A. Hawkins and published by Cambridge University Press. This book was released on 2008-10-14 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biological control is the suppression of pest populations using predators, parasitoids and pathogens. Historically, biological control has largely been on a trial-and-error basis, and has failed more often than it has succeeded. However by developing theories based upon fundamental population principles and the biological characteristics of the pest and agent, we can gain a much better understanding of when and how to use biological control. This book gathers together recent theoretical developments and provides a balanced guide to the important issues that need to be considered in applying ecological theory to biological control. It will be a source of productive and stimulating thought for all those interested in pest management, theoretical ecology and population biology.
Download or read book On the Backs of Tortoises written by Elizabeth Hennessy and published by Yale University Press. This book was released on 2019-10-29 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: An insightful exploration of the iconic Galápagos tortoises, and how their fate is inextricably linked to our own in a rapidly changing world. Finalist for the 2020 E.O. Wilson Literary Science Writing Award, sponsored by PEN America Literary Awards The Galápagos archipelago is often viewed as a last foothold of pristine nature. For sixty years, conservationists have worked to restore this evolutionary Eden after centuries of exploitation at the hands of pirates, whalers, and island settlers. This book tells the story of the islands’ namesakes—the giant tortoises—as coveted food sources, objects of natural history, and famous icons of conservation and tourism. By doing so, it brings into stark relief the paradoxical, and impossible, goal of conserving species by trying to restore a past state of prehistoric evolution. The tortoises, Elizabeth Hennessy demonstrates, are not prehistoric, but rather microcosms whose stories show how deeply human and nonhuman life are entangled. In a world where evolution is thoroughly shaped by global history, Hennessy puts forward a vision for conservation based on reckoning with the past, rather than trying to erase it. “Fresh, insightful . . . Hennessy’s melding of human and natural history makes for thought-provoking reading.” —Booklist (starred review) “Gripping . . . well-researched and thought-provoking . . . whether you’re well-versed in the intricacies of conservation or have only just begun to long for a look at the tortoises yourself. On the Backs of Tortoises is a natural history that asks important questions, and challenges us to think about how best to answer them.” —Genevieve Valentine, NPR “Wonderfully interesting, informative, and engaging, as well as scholarly.” —Janet Browne, author of Charles Darwin: Voyaging and Charles Darwin: The Power of Place
