1,721,126 research outputs found
Patch-burn grazing increases habitat heterogeneity and biodiversity of small mammals in managed rangelands
Get PDFCitation: Ricketts, A. M., & Sandercock, B. K. (2016). Patch-burn grazing increases habitat heterogeneity and biodiversity of small mammals in managed rangelands. Ecosphere, 7(8). doi:10.1002/ecs2.1431Habitat heterogeneity is a key driver of biodiversity in many ecosystems. Wildlife inhabiting the native prairies of North America evolved in a heterogeneous mosaic of habitat conditions created by fire and grazing by native ungulates. Current rangeland management practices in the tallgrass prairie ecosystem evenly distribute fire and grazing across management units and promote homogeneous habitat conditions. Patch-burn grazing is a rangeland management strategy that seeks to restore heterogeneity to rangelands via fire-grazing interactions. Our 3.5-year study tested the effects of patch-burn grazing on habitat heterogeneity and small mammal community dynamics in the Flint Hills ecoregion of eastern Kansas. To study the ecological effects of patch-burn grazing, we sampled habitat conditions and the small mammal community. We assessed habitat conditions once each growing season in a negative control that was annually burned and grazed, a positive control that was burned every four years and ungrazed, and within each of three units of a patch-burn grazing experiment (PBG) managed with rotational fire. Habitat conditions were significantly different among treatments, and a principal components analysis showed that the patch-burn grazing treatment had higher canopy cover of forbs and habitat heterogeneity than our two control units. To sample the small mammal community, we conducted monthly live trapping of small mammals on two randomly located trap grids in each of our two controls and three units of our PBG treatment. Small mammal diversity was significantly higher in the patch-burn grazing treatment and in the positive control, vs. the negative control. Moreover, a canonical correspondence analysis showed that a fire-grazing interaction was the major driver structuring small mammal communities. Patch-burn grazing is an effective strategy for restoring heterogeneity to vegetative structure and composition, and can increase biodiversity of small mammals in managed rangelands in the tallgrass prairie ecosystem. © 2016 Ricketts and Sandercock
First investigation on the diet of the eastern grass owl during the nesting period in Thailand
No full textKunsorn, Akalak, Chomdej, Siriwadee, Sitasuwan, Narit, Wangpakapattawong, Prasit, Suwannapoom, Chatmongkon, Sandercock, Brett K. (2015): First investigation on the diet of the eastern grass owl during the nesting period in Thailand. Raffles Bulletin of Zoology 63: 27-32, DOI: 10.5281/zenodo.538368
Fig. 1 in First investigation on the diet of the eastern grass owl during the nesting period in Thailand
No full textFig. 1. Typical pellet of an eastern grass owl (left) and a Circus harrier (right).Published as part of Kunsorn, Akalak, Chomdej, Siriwadee, Sitasuwan, Narit, Wangpakapattawong, Prasit, Suwannapoom, Chatmongkon & Sandercock, Brett K., 2015, First investigation on the diet of the eastern grass owl during the nesting period in Thailand, pp. 27-32 in Raffles Bulletin of Zoology 63 on page 28, DOI: 10.5281/zenodo.538368
Fig. 3 in First investigation on the diet of the eastern grass owl during the nesting period in Thailand
No full textFig. 3. Cladogram showing phylogenetic relationships of the sequenced mitochondrial DNA of three rodent prey species of the eastern grass owl.Published as part of Kunsorn, Akalak, Chomdej, Siriwadee, Sitasuwan, Narit, Wangpakapattawong, Prasit, Suwannapoom, Chatmongkon & Sandercock, Brett K., 2015, First investigation on the diet of the eastern grass owl during the nesting period in Thailand, pp. 27-32 in Raffles Bulletin of Zoology 63 on page 30, DOI: 10.5281/zenodo.538368
Flexibility in the Migration Strategies of Animals
No full textThis eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contac
Long-term continental changes in wing length, but not bill length, of a long-distance migratory shorebird
Get PDFCitation: Lank, D. B., Xu, C., Harrington, B. A., Morrison, R. I. G., Gratto-Trevor, C. L., Hicklin, P. W., . . . Ydenberg, R. C. (2017). Long-term continental changes in wing length, but not bill length, of a long-distance migratory shorebird. Ecology and Evolution, 7(9), 3243-3256. doi:10.1002/ece3.2898We compiled a >50-year record of morphometrics for semipalmated sandpipers (Calidris pusilla), a shorebird species with a Nearctic breeding distribution and intercontinental migration to South America. Our data included >57,000 individuals captured 1972–2015 at five breeding locations and three major stopover sites, plus 139 museum specimens collected in earlier decades. Wing length increased by ca. 1.5 mm (>1%) prior to 1980, followed by a decrease of 3.85 mm (nearly 4%) over the subsequent 35 years. This can account for previously reported changes in metrics at a migratory stopover site from 1985 to 2006. Wing length decreased at a rate of 1,098 darwins, or 0.176 haldanes, within the ranges of other field studies of phenotypic change. Bill length, in contrast, showed no consistent change over the full period of our study. Decreased body size as a universal response of animal populations to climate warming, and several other potential mechanisms, are unable to account for the increasing and decreasing wing length pattern observed. We propose that the post-WWII near-extirpation of falcon populations and their post-1973 recovery driven by the widespread use and subsequent limitation on DDT in North America selected initially for greater flight efficiency and latterly for greater agility. This predation danger hypothesis accounts for many features of the morphometric data and deserves further investigation in this and other species. © 2017 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd
Flexibility in the Migration Strategies of Animals
No full textThis eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contac
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
- …
