Download or read book A Comparison of Calving and Post calving Photo Surveys for the Bluenose East Herd of Barren ground Caribou in the Northwest Territories Canada in 2010 written by Jan Adamczewski and published by . This book was released on 2014 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: Overall, the preferred June estimate (114,472±15,845) and the preferred July estimate (122,697±31,757) showed overlap of confidence intervals as estimators of BNE caribou herd size in 2010. We believe the July estimate is likely the closest to true herd size as the June survey likely did not include all the bulls, yearlings and non-breeding cows in the herd.
Download or read book An Estimate of Breeding Females and Analyses of Demographics for the Bluenose East Herd of Barren ground Caribou written by John Boulanger and published by . This book was released on 2016 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This report details the calving ground photo survey of the Bluenose-East caribou herd conducted during June of 2015 in Nunavut (NU), near Kugluktuk, NU. The main objective was to obtain an estimate of breeding females that could be compared to estimates from previous calving ground surveys in 2010 and 2013. Consistent with previous calving ground photographic surveys, data from collared caribou and systematic reconnaissance survey flight lines flown at 10 km intervals on the calving grounds were used to delineate the core calving area, to assess calving status, to allocate sampling to geographic strata of similar caribou density, and to time the photographic survey plane to coincide with the peak of calving. Based on collar movements and observed proportions of calves, it was determined that the peak of calving would occur soon after June 5th and the photo plane survey was flown on June 5th. Photo plane survey effort (transect spacing) was allocated into a single high density block (stratum) where the majority of breeding females resided. Three other strata which had lower densities of breeding caribou were also surveyed visually on June 5th. A double observer method was used to estimate and correct for sightability of caribou from visual surveys. Survey conditions were favorable on June 5th with high ceilings and low snow cover. The estimate of 1+ year old caribou on the core calving ground was 38,041 (95% Confidence Interval (CI) =33,569-42,513) caribou. Using the results of the ground composition survey to adjust this number for breeding females, the estimate of breeding females was 17,396 (CI=15,088-19,704). The estimate of breeding females was very precise with a coefficient of variation of 6.3%. The pregnancy rate of females, as indexed by the proportion of adult females classified as breeding was lower in 2015 than the previous survey in 2013. For this reason, an alternative estimator that used an estimate of total adult females (breeders and non- breeders; 27,246 (CI=24,172-30,320) divided by the proportion females in the herd (from fall composition surveys) was used to estimate herd size. The resulting estimate of herd size was 38,592 (CI=33,859-43,325). Comparison of 2013 and 2015 adult female numbers indicate an annual rate of decline of 20% (CI=7-32%). Assessment of survey issues suggested that this difference could not be attributed to differences in surveys or bias. Assessment of movement of collared females between the Bluenose-East and surrounding herds from 2010-2015 documented minimal movement of collared cows to neighbouring herds. Demographic modeling that used composition, collared caribou, and survey data estimated that cow survival rate was low (0.71, CI=0.69-0.72) and calf recruitment has declined. These factors along with harvest pressure have led to the ongoing decline of the herd. We suggest that continued monitoring and proactive management of harvest with a shift from mostly cows to mostly bulls is recommended. In addition, continued monitoring of calving ground distribution and spring productivity should be conducted to allow ongoing monitoring of herd status"--Pages iii-iv .
Download or read book An Estimate of Breeding Females and Analyses of Demographics for the Bluenose East Herd of Barren ground Caribou written by John Boulanger and published by . This book was released on 2014 with total page 79 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report details the calving ground photo survey of the Bluenose-East caribou herd conducted during June of 2013 in Nunavut (NU), near Kugluktuk, NU. The main objective was to obtain an estimate of breeding females that could be compared to estimates from a previous calving ground survey in 2010. Consistent with previous calving ground photographic surveys, data from collared caribou and systematic reconnaissance survey flight lines at ten km intervals in the calving ground area were used to delineate the core calving area, to assess calving status, to allocate sampling to geographic strata of similar caribou density, and to time the photographic survey plane to coincide with the peak of calving. Based on collar movements and observed proportions of calves, it was determined that the peak of calving would occur soon after June 5th and the photo-plane survey was planned for June 5th. Photo-plane survey effort (transect spacing) was allocated into a single high density block (stratum) where the majority of breeding females resided. Four other strata which had lower densities of breeding caribou were surveyed visually June 5-7. A double observer method was used to estimate and correct for sightability of caribou from visual surveys. Survey conditions were acceptable for June 5th with moderate ceilings and lower snow cover in most areas. Conditions deteriorated later on June 6 th with an oncoming storm front. The photo - plane was unable to survey the entire high stratum due to technical issues and as a result part of it was surveyed using visual methods on June 6th. The rest of the survey stratum was surveyed on June 6th and 7th. A portion of the high-density block (nine lines) was flown visually and by photo-plane to verify similarity of counts. The estimate of 1+ year old caribou on the core calving ground was 60,387 (95% CI= 54,512-66,262) caribou. Using the results of the ground composition survey to adjust this number for breeding females, the estimate of breeding females was 34,472 (CI=30,109-38,836). The estimate of breeding females was very precise with a coefficient of variation of 5.5%. The extrapolated herd estimate was 68,295 1.5+ year old caribou (CI=50,255-86,336). The estimate of breeding females was 66.6% (CI=52.9-80.3%) lower than the 2010 estimate of 51,757 (CI=40,665-62,849) which amounted to a statistically significant annual rate of decline of 12.6% (CI=7.0-18.9%). Assessment of survey issues suggested that this difference could not be attributed to differences in surveys or estimate bias. Assessment of movement of collared females between the Bluenose-East and surrounding herds 2010-2013 documented no cases of emigration to other herds. Calf recruitment has been generally good for this herd in recent years. Estimation of survival rates and demographic modelling suggest that cow survival rates were low (0.73), which contributed to the decline. This may have been due to a combination of low natural survival and harvest. We suggest that continued monitoring and more complete harvest reporting are essential to better understand this decline. A conservative approach to harvest should be considered in the short-term, along with close monitoring of the herd.
Download or read book Estimates of Breeding Females Adult Herd Size and Analyses of Demographics for the Bluenose east Herd of Barren ground Caribou written by John Boulanger and published by . This book was released on 2019 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Estimates of Breeding Females Adult Herd Size and Analyses of Demographics for the Bluenose East Herd of Barren ground Caribou written by John Boulanger and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The estimates for the Bluenose-East herd in June 2021 were 12,863 (95%CI 10,816-15,298) breeding females, 13,991 (95%CI 11,805-16,585) adult females, and 23,202 (95%CI 19,247-20,822) adult caribou at least two years old. Estimates from 2018 were similar (not significantly different) at 11,675 (CI=9,971-13,670) breeding females, 13,988 (CI=12,042-16,249) adult females, and 19,294 caribou (95%CI=16,527-22,524) adult caribou at least two years old. The increase in estimated herd size was due to an increase in bulls as indicated by increasing fall bull-cow ratios; the adult female estimates indicated a stable population size. These estimates suggest that the herd stabilized between 2018 and 2021, in contrast to the rapid decline observed from 2010 to 2018. Demographic indicators (adult cow survival rates, proportions of breeding females, bull:cow ratios, and calf:cow ratios) showed generally improved trends from 2015 to 2018 when compared to 2018 to 2021, consistent with stabilization indicated by the similarities between estimates from 2018 and 2021 calving ground surveys. Integrated Population Model analyses also suggested that the apparent stability of the Bluenose-East herd was partially due to increased calf productivity; however, adult female survival rates are still at levels lower than needed for herd recovery (increase).
Download or read book July 2020 Composition Surveys of Bathurst and Bluenose East Barren ground Caribou Herds written by Jan Adamczewski and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Composition surveys near the peak of calving were planned as part of calving photo surveys of these two herds in June 2020, but were postponed to 2021 due to travel restrictions resulting from the COVID-19 pandemic. As a result, the proportion of breeding females at the peak of calving in June 2020 was not known. If the proportion of breeding females in June 2020 was about 81% (average for June 2018 and 2019 for the two herds), then the July calf-cow ratios we recorded may suggest substantial calf mortality in the first five weeks after birth in both herds.
Download or read book Estimates of Breeding Females Adult Herd Size and Analyses of Demographics for the Bathurst Herd of Barren ground Caribou written by Jan Adamczewski and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the results of a calving ground photo survey of the Bathurst barren-ground caribou herd conducted June 1-14, 2021 west and east of Bathurst Inlet in Nunavut. The main objectives were to estimate the numbers of breeding females, adult females, and adults in the herd, and to compare results to previous calving ground surveys of this herd, the last in 2018. A calving ground survey of the Bluenose-East caribou herd was carried out simultaneously and results from that survey are reported separately.
Download or read book An Estimate of Breeding Females and Analyses of Demographics for the Bathurst Herd of Barren ground Caribou written by John Boulanger and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "We conducted a calving ground photo survey of the Bathurst barren-ground caribou (Rangifer tarandus groenlandicus) herd from 3-8 June, 2012. The main objective was to obtain an estimate of breeding females that could be compared to estimates from previous similar surveys that have been conducted since 1986. Of particular interest was whether or not the herd had stabilized from the steep decline documented in the 2009 survey. Consistent with previous calving ground photographic survey methods, data from collared caribou and systematic reconnaissance surveys at ten km intervals in the calving ground area were used to delineate the core calving areas, to assess calving status, to allocate sampling to geographic strata of similar caribou density, and to time the photographic survey plane to coincide with the peak of calving. Unlike previous surveys, transect surveys were conducted at 5 km instead of 10 km intervals in the core calving area. Reconnaissance surveys revealed that the majority of breeding caribou were congregated in a relatively-small (914 km2) area with non-breeding caribou distributed in lower densities to the south. Based on collar movements and observed proportions of calves, it was determined that the peak of calving occurred on or about 5 June, 2012 and the photo plane survey was conducted on 6 June. Photo plane survey effort (transect spacing) was stratified into high- and medium-density blocks with the highest coverage (79.1%) in the high-density stratum where the majority of breeding caribou were. The higher level of coverage allowed an adequate number of lines (22) to be placed in the stratum as a means of offsetting potential variance caused by clumped distribution of caribou. Survey conditions were ideal with zero cloud cover, minimal winds and minimal snow cover. Two lower-density strata were also surveyed with visual strip-transect methods. Ground-based composition surveys were conducted from 6-8 June to estimate the proportion of breeding caribou in each of the strata. Survey results revealed that 87.4% of caribou on the core calving ground were within the high-density stratum (914 km2) with 8% occurring in the medium density stratum (644 km2) and the rest in the two low-density strata. The estimate of 1+-yr-old caribou on the core calving ground was 24,166 (SE=1,853.6, Cl=20,310-28,020) caribou. Using the results of the ground composition survey to adjust this number for breeding females, the estimate of breeding females was 15,935 (SE=1,407.2, Cl=13,009-18,861). The estimate of breeding females was very precise with a coefficient of variation (CV) of 8.8%. Comparison of this estimate with the previous estimate of breeding females from 2009 of 16,649 (SE=2, 181, 95% Cl=12, 188-21,110) suggests that the breeding female segment of the herd declined slightly, though not significantly. The rate of decline was much lower than between the 2006 and 2009 calving ground surveys. Results from a data-driven demographic modelling exercise suggest that adult female survival rate was 0.78 (Cl range 0.75-0.82) in 2012, which is still below levels needed for a stable herd. A conservative bull-dominated harvest strategy with minimal cow harvest is recommended to minimize adult cow mortality. An increase in the number of radio collars on the herd would greatly assist in managing and monitoring this herd, including more reliable estimates of adult female survival rate"--Pages iii-iv.
Download or read book Optimal Survey Design Survey Intervals and Analysis Strategies for Caribou Calving Ground Surveys Reconnaissance Surveys and Composition Surveys written by John Boulanger and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report provides statistical commentary on survey methods used to monitor barren-ground caribou herds in the Northwest Territories (NWT) with an emphasis on intervals between surveys and survey precision. I provide some comments on the statistical design of surveys and some ideas to improve precision. Calving ground photo surveys and post-calving photo surveys are the most important surveys for barren-ground caribou as they provide benchmarks for herd status and management. Results of power analyses suggest that the sampling interval for these surveys should never be less than three years unless a very large change in abundance is expected. For the most likely rates of change in population size (+/- 10% per year) then a survey interval of five to six years is adequate. Composition surveys in June, fall (rut, usually late October), and late winter (March/April) are used to assess initial calf productivity, calf survival to four to five months, calf survival to nine to ten months, and sex ratio (in the fall). Representative sampling across a herd’s range is key to obtaining reliable results. Late-winter surveys are best carried out annually to capture frequently high year-to-year variation. Fall surveys to assess sex ratio are usually carried out in years of calving ground photo surveys (every three years in most NWT herds 2006-2018) and may be conducted more often if a substantial male-dominated harvest is in place. Reconnaissance surveys on the calving grounds of some herds have been used to assess trend in caribou abundance on calving grounds in years between full photographic surveys. They are much simpler and far less costly. However, variance on survey results is usually high and assessment of composition (breeding cows, non-breeding cows, yearlings and bulls) on or near the calving grounds may not be reliable. I provide recommendations to improve precision of these surveys. I note that the primary analyses in this report occurred in 2011 and since then some of the methodologies have evolved. I provide updated citations to this current work.
Download or read book An Estimate of Breeding Females and Analyses of Demographics for the Bathurst Herd of Barren ground Caribou written by John Boulanger and published by . This book was released on 2017 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Population Estimates of Tuktoyaktuk Peninsula Cape Bathurst and Bluenose West Barren ground Caribou Herds Using Post calving Photography July 2018 written by Tracy M. Davison and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A post-calving photographic survey was conducted in 2018 to obtain population estimates for the Tuktoyaktuk peninsula, Cape Bathurst, and Bluenose-West barren-ground caribou herds in the Northwest Territories. A total of 103 collars were deployed on the three herds in March and April 2018 in anticipation of the survey. Photos of the main aggregations of the Bluenose-West herd were taken on July 10, 2018 with additional peripheral groups photographed or counted between July 8-18, 2018. There were 61 collars available for the Bluenose-West herd and 55 of them were counted. The minimum count was 13,390 adult caribou and the population estimate was 21,011±4,602 (with +95% confidence intervals). There is a non-significant population trend for this herd between 2005 and 2018 of -2% per year.
Download or read book An Operations Guide to Barren ground Caribou Calving Ground Density Dispersion and Distribution Surveys Based on an Assessment of the June 2007 and 2008 Surveys Northwest Territories and Nunavut written by Kim Gordon Poole and published by . This book was released on 2014 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Overview Monitoring of Bathurst and Bluenose East Caribou Herds October 2014 written by Jan Adamczewski and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: For the Bluenose-East herd, a combination of low natural survival, reduced calf recruitment, low pregnancy rates in some years, and a substantial cow harvest are the most probable reasons for the herd's substantial decline 2010-2013 and the continued and potentially accelerated decline to June 2014. Issues related to the reconnaissance survey methods may have affected the survey results but are unlikely to account for the large apparent decrease in caribou on the calving grounds. Assessment of movements of collared caribou between the Bluenose-East's calving grounds and its neighbouring herds' calving grounds showed no evidence of large-scale emigration from the Bluenose-East range 2010-2014.
Download or read book A Calving Ground and Population Estimate for the Bluenose Caribou Herd in 1983 written by Paul Bernard Latour and published by . This book was released on 1986 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: Report on two reconnaissance surveys conducted on the tundra and some forested section of the Bluenose caribou (Rangifer tarandus groelandicus) herd's range. The survey suggests low proportion of breeding cows on the calving grounds and a total herd size of between 30,000 and 50,000.
Download or read book Estimates of Breeding Females Adult Herd Size and Analyses of Demographics for the Bathurst Herd of Barren ground Caribou written by Jan Adamczewski and published by . This book was released on 2019 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: We suggest close monitoring of the herd in the next few years, including population surveys every two years, annual monitoring of cow survival, calf productivity and calf survival for this herd, and increased collar numbers for monitoring and management.
Download or read book Population Estimates of Tuktoyaktuk Peninsula Cape Bathurst and Bluenose West Barren ground Caribou Herds Using Post calving Photography July 2012 written by Tracy M. Davison and published by . This book was released on 2016 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: A post-calving photographic survey was conducted in 2012 to obtain population estimates for the Tuktoyaktuk, Cape Bathurst, and Bluenose-West caribou herds in the NWT. A total of 105 collars were deployed March 2012 in anticipation of the survey. Photos were taken of the Tuktoyaktuk Peninsula herd on 7 July 2012, Cape Bathurst herd on 6 July 2012 and Bluenose-West herd on 6 July 2012. The resulting Lincoln-Petersen population estimates (with ±95% confidence intervals) of non-calf caribou were 2,192±178 for the Tuktoyaktuk Peninsula herd, 2,427 for the Cape Bathurst herd and 20,465±3,490 for the Bluenose-West herd.
Download or read book Estimates of the Number of Barren ground Caribou in the Cape Bathurst and Bluenose West Herds and Reindeer caribou on the Upper Tuktoyaktuk Peninsula Derived Using Post Calving Photography July 2006 written by J. A. Nagy and published by . This book was released on 2006 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
