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1.
Ecology ; 104(1): e3864, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36062374

RESUMO

Following the near extinction of bison (Bison bison) from its historic range across North America in the late 19th century, novel bison conservation efforts in the early 20th century catalyzed a popular widespread conservation movement to protect and restore bison among other species and places. Since Allen's initial delineation (1876) of the historic distribution of North American bison, subsequent attempts have been hampered by knowledge gaps about bison distribution and abundance prior to and following colonial arrival and settlement. For the first time, we applied a multidisciplinary approach to assemble a comprehensive, integrated geographic database and meta-analysis of bison occurrence over the last 200,000 years, with particular emphasis on the 450 years before present. We combined paleontology, archaeology, and historical ecology data for our database, which totaled 6438 observations. We derived the observations from existing online databases, published literature, and first-hand exploration journal entries. To illustrate the conservative maximum historical extent of occurrence of bison, we created a concave hull using observations occurring over the last 450 years (n = 3379 observations), which is the broadly accepted historical benchmark at 1500 CE covering 59% of the North American continent. Although this distribution represents a historic extent of occurrence-merely delineating the maximum margins of the near-continental distribution-it does not replace a density-based approach reconstructing potential historical range distributions, which identifies core and marginal ranges. However, we envision the observations contained in this database will contribute to further research in the increasingly evidence-based disciplines of bison ecology, evolution, rewilding, management, and conservation. There are no copyright or proprietary restrictions on these data, and this data paper should be cited when the data are reused.


Assuntos
Bison , Animais , América do Norte , Ecologia
2.
Artigo em Inglês | MEDLINE | ID: mdl-36437837

RESUMO

Several quantitative diagnostic techniques are available to estimate gastrointestinal parasite counts in the feces of ruminants. Comparing egg and oocyst magnitudes in naturally infected samples has been a recommended approach to rank fecal techniques. In this study, we compared the Mini-FLOTAC (sensitivity of 5 eggs per gram (EPG)/oocysts per gram (OPG)) and different averaged replicates of the modified McMaster techniques (sensitivity of 33.33 EPG/OPG) in 387 fecal samples from 10 herds of naturally infected North American bison in the Central Great Plains region of the USA. Both techniques were performed with fecal slurries homogenized in a fill-FLOTAC device. In the study population, prevalence of strongyle eggs, Eimeria spp. oocysts, Moniezia spp. eggs and Trichuris spp. eggs was 81.4%, 73.9%, 7.5%, and 3.1%, respectively. Counts of strongyle eggs and Eimeria spp. oocysts obtained from 1 to 3 averaged technical replicates of the modified McMaster technique were compared to a single replicate of the Mini-FLOTAC. Correlation between the two techniques increased with an increase in the number of averaged technical replicates of the modified McMaster technique used to calculate EGP/OPG. The correlation for Moniezia spp. EPG when averaged triplicates of the modified McMaster technique were compared to a single replicate of the Mini-FLOTAC count was high; however, the correlation for Trichuris spp. eggs was low. Additionally, we used averaged counts from both techniques to show the overdispersion of parasites in bison herds.

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