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You searched for +publisher:"Colorado State University" +contributor:("Baker, Dan"). Showing records 1 – 3 of 3 total matches.

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Colorado State University

1. Ransom, Jason Ian. Population ecology of feral horses in an era of fertility control management.

Degree: PhD, Ecology, 2012, Colorado State University

Management of wildlife often requires intervention to regulate growth of populations that would otherwise become overabundant. Controlling fecundity using contraceptives has become an increasingly popular tool for attempting to manage locally overabundant wildlife species, but the population-level effects of such applications are largely unknown. Contraceptive treatments can produce unexpected feedbacks that act on births, survival, immigration, and emigration. Such feedbacks may considerably influence our ability to regulate populations using fertility control. I followed feral horses (Equus caballus) in three intensively managed populations to assess longitudinal treatment effects on demography. The transient contraceptive porcine zona pellucida (PZP) produced longer duration of infertility than intended. Repeated PZP vaccinations of females extended the duration of infertility far beyond the targeted management period, with time to first post-treatment parturition increasing 411days for every annual inoculation received. When these animals did conceive and give birth, parturition was later in the year and temporally asynchronous with forage abundance. An average of 30% (range=11-77%) of females were contracepted annually during the treatment period in all three populations and apparent annual population growth rate was 4-9% lower in the post-treatment years as compared to pretreatment years. Population growth was positive, however, and increased steadily every year that a management removal did not occur. The observed number of births was 33% fewer than the expected number of births, based on number of treated females, individual efficacy of treatment, and number of untreated females and their age-specific fecundity rates. Only half of this difference was explained by the apparent residual effect of treatment. Birth rate in the youngest untreated females (age 2-5 years old) was reduced in years when their conspecifics were treated, enhancing the effects of treatment at the population-level. This was partially offset by increased survival in adults, including a 300% increase in presence of horses >20 years old during the post-treatment period. In closed populations of feral horses, the positive feedbacks appear to outweigh the negative feedbacks and generate a larger contraceptive effect than the sum of individual treatments. The role of fertility control is uncertain for open populations of many wildlife species, with broad consensus across a synthesis of research that negative feedbacks on fertility control performance are occurring, and in many cases increased survival and increased immigration can compensate entirely for the reduction in births attributed to treatment. Understanding species' life-history strategies, biology, behavioral ecology, and ecological context is critical to developing realistic expectations of regulating wildlife populations using fertility control. Advisors/Committee Members: Hobbs, N. Thompson (advisor), Baker, Dan (committee member), Boone, Randall (committee member), Bruemmer, Jason (committee member).

Subjects/Keywords: fertility control; horse; population dynamics; population ecology; wildlife contraception; Equus

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APA (6th Edition):

Ransom, J. I. (2012). Population ecology of feral horses in an era of fertility control management. (Doctoral Dissertation). Colorado State University. Retrieved from http://hdl.handle.net/10217/68192

Chicago Manual of Style (16th Edition):

Ransom, Jason Ian. “Population ecology of feral horses in an era of fertility control management.” 2012. Doctoral Dissertation, Colorado State University. Accessed April 23, 2021. http://hdl.handle.net/10217/68192.

MLA Handbook (7th Edition):

Ransom, Jason Ian. “Population ecology of feral horses in an era of fertility control management.” 2012. Web. 23 Apr 2021.

Vancouver:

Ransom JI. Population ecology of feral horses in an era of fertility control management. [Internet] [Doctoral dissertation]. Colorado State University; 2012. [cited 2021 Apr 23]. Available from: http://hdl.handle.net/10217/68192.

Council of Science Editors:

Ransom JI. Population ecology of feral horses in an era of fertility control management. [Doctoral Dissertation]. Colorado State University; 2012. Available from: http://hdl.handle.net/10217/68192


Colorado State University

2. Eddy, Kathleen M. Use of fecal and serum estradiol analysis for estimation of pregnancy status in the mare.

Degree: MS(M.S.), Biomedical Sciences, 2020, Colorado State University

Overabundant feral horse populations within the United States cause significant and detrimental economic and ecological impacts. Aside from helicopter roundups and long-term holding facilities, current management practices of feral horses include application of contraception in conjunction with non-invasive determination of pregnancy through the measurement of fecal steroid metabolite monitoring. Prior to this study, the earliest timing of definitive pregnancy diagnosis was between 120 – 180 days of gestation, when measuring total unconjugated fecal estrogens (Bamberg et al 1984; Kirkpatrick et al 1989), or from samples taken at least 150 days of gestation when measuring fecal estrone sulfate (Henderson et al 1998 and 1999). The studies in this thesis examined measurement of estradiol 17β, an estrogen that has yet to be quantified in the feces of domestic and feral mares. The overall objectives of the studies in this thesis were to determine the efficacy of fecal and serum estradiol measurement in the estimation of pregnancy in the mare, as well as the definitive timing within gestation when fecal and serum concentrations diverged from those of non-pregnant mares. The first study of this thesis utilized 8 pregnant domestic mares with known embryo transfer dates, as well as 8 non-pregnant cycling mares. Weekly fecal and blood samples were collected from the pregnant mares for the entirety of gestation, while daily fecal and blood samples were taken from the cycling mares for 23 days. Radioimmunoassay (RIA) specific for estradiol 17β was used to quantify extracted fecal and serum samples for the two groups. It was found that at a mean of 105 days of gestation, fecal estradiol concentrations in pregnant mares surpassed non-pregnant mare concentrations, with a calculated cut-off value of 10 pg/mg feces. Serum estradiol concentrations of pregnant mares surpassed those of non-pregnant mares at an average of 128 days of gestation, with a concentration of at least 46 pg/mL serum. Additionally, aside from increasing earlier in gestation, compared to serum, fecal estradiol was found to fluctuate less throughout pregnancy. The second study of this thesis examined 77 fecal and serum samples collected from 51 feral mares during two roundups in Theodore Roosevelt National Park (THRO), as well as 272 individual fecal samples collected over a 6 year period from the same 51 mares. Using the cut-off days and concentrations affiliated with the first study, correlative comparisons were made for the feral mare samples, and pregnancy status was elucidated. Of the 62 fecal samples taken during the roundups past the cut-off day of 105 days, 60 of them surpassed the fecal cut-off concentration of 10 pg/mg feces. Thirty-four of 49 serum samples taken past the cut-off day of 128 surpassed the cut-off concentration of 46 pg/mL. While only two of the 62 fecal samples taken past the cut-off of 105 days were below the cut-off concentration, 14 of the 49 serum samples taken past cut-off day 128 were below the serum cut-off concentration of 46 pg/mL… Advisors/Committee Members: Nett, Terry M. (advisor), Eckery, Douglas C. (advisor), Baker, Dan L. (committee member), Bruemmer, Jason E. (committee member), Hollinshead, Fiona K. (committee member).

Subjects/Keywords: feces; serum; mare; estradiol

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APA (6th Edition):

Eddy, K. M. (2020). Use of fecal and serum estradiol analysis for estimation of pregnancy status in the mare. (Masters Thesis). Colorado State University. Retrieved from http://hdl.handle.net/10217/219569

Chicago Manual of Style (16th Edition):

Eddy, Kathleen M. “Use of fecal and serum estradiol analysis for estimation of pregnancy status in the mare.” 2020. Masters Thesis, Colorado State University. Accessed April 23, 2021. http://hdl.handle.net/10217/219569.

MLA Handbook (7th Edition):

Eddy, Kathleen M. “Use of fecal and serum estradiol analysis for estimation of pregnancy status in the mare.” 2020. Web. 23 Apr 2021.

Vancouver:

Eddy KM. Use of fecal and serum estradiol analysis for estimation of pregnancy status in the mare. [Internet] [Masters thesis]. Colorado State University; 2020. [cited 2021 Apr 23]. Available from: http://hdl.handle.net/10217/219569.

Council of Science Editors:

Eddy KM. Use of fecal and serum estradiol analysis for estimation of pregnancy status in the mare. [Masters Thesis]. Colorado State University; 2020. Available from: http://hdl.handle.net/10217/219569


Colorado State University

3. Powers, Jenny. Reproductive, behavioral, and first generational effects of gonadotropin releasing hormone vaccination in female Rocky Mountain elk (Cervus elaphus nelsoni).

Degree: PhD, Biomedical Sciences, 2011, Colorado State University

To view the abstract, please see the full text of the document. Advisors/Committee Members: Nett, Terry (advisor), Baker, Dan (advisor), Hansen, Thomas (committee member), Rhyan, Jack (committee member), Peel, Kraig (committee member).

Subjects/Keywords: fertility control; wildlife; immunocontraception; GnRH; elk

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Powers, J. (2011). Reproductive, behavioral, and first generational effects of gonadotropin releasing hormone vaccination in female Rocky Mountain elk (Cervus elaphus nelsoni). (Doctoral Dissertation). Colorado State University. Retrieved from http://hdl.handle.net/10217/48211

Chicago Manual of Style (16th Edition):

Powers, Jenny. “Reproductive, behavioral, and first generational effects of gonadotropin releasing hormone vaccination in female Rocky Mountain elk (Cervus elaphus nelsoni).” 2011. Doctoral Dissertation, Colorado State University. Accessed April 23, 2021. http://hdl.handle.net/10217/48211.

MLA Handbook (7th Edition):

Powers, Jenny. “Reproductive, behavioral, and first generational effects of gonadotropin releasing hormone vaccination in female Rocky Mountain elk (Cervus elaphus nelsoni).” 2011. Web. 23 Apr 2021.

Vancouver:

Powers J. Reproductive, behavioral, and first generational effects of gonadotropin releasing hormone vaccination in female Rocky Mountain elk (Cervus elaphus nelsoni). [Internet] [Doctoral dissertation]. Colorado State University; 2011. [cited 2021 Apr 23]. Available from: http://hdl.handle.net/10217/48211.

Council of Science Editors:

Powers J. Reproductive, behavioral, and first generational effects of gonadotropin releasing hormone vaccination in female Rocky Mountain elk (Cervus elaphus nelsoni). [Doctoral Dissertation]. Colorado State University; 2011. Available from: http://hdl.handle.net/10217/48211

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