Download or read book Sample Sizes of Collared Barren ground Caribou Required to Estimate Herd Size in Winter and Fall Management Areas to Allow Assessment of Harvest Risk written by John Boulanger and published by . This book was released on 2016 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: One challenge to harvest management of caribou herds on winter range areas is the uncertainty of caribou herd status when winter ranges of multiple herds overlap. In this paper I develop a methodology to estimate relative herd sizes on winter range management polygons through the use of location data from collared caribou and herd size estimates from calving ground surveys. In this paper, analyses were carried out to assist in recommending numbers of collars needed to reliably define proportions of each herd in harvest areas in fall and winter, using multi-strata models, existing management areas, and information from 2010-2013 on collar locations and herd size. In general, at least 20 collars would be needed for each herd in each area to define herd distribution and harvest risk with acceptable precision.
Download or read book Determining Optimal Radio Collar Sample Sizes for Monitoring Barren ground Caribou Populations written by William James Rettie and published by . This book was released on 2017 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: To detect moderate changes in annual adult female survival (e.g. 6-7% per year, persistent for three or more years) would require 80 or more radio collars in a herd and the monitoring would need to be conducted in two or more discrete time periods. The number of radio collared animals required is the same for all herds.
Download or read book A General Approach to Harvest Modeling for Barren ground Caribou Herds in the NWT and Recommendations on Harvest Based on Herd Risk Status written by John Boulanger and published by . This book was released on 2016 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: Previous modeling of barren-ground caribou demographics and harvest for the Bathurst and Bluenose-East herds was carried out under a limited range of demographic scenarios to evaluate the likely consequences of varying levels and sex ratio of harvest. The modeling in this report was carried out to assess risk associated with harvest in a wider range of conditions, to generate more general results that could be applicable to multiple herds varying in size and trend. A deterministic model was used with a caribou herd of 100,000 with low, moderate and high calf productivity and low, moderate and high levels of adult survival. Harvest levels modeled ranged from 0-8,000, and sex ratio of the harvest varied from 0-100% cows. Time-steps of three and six years were used to match the frequency of recent Government of the Northwest Territories population surveys of most caribou herds. With low adult survival, herd trend is likely to be negative and a substantial harvest would increase the risk of greater decline. Herds with high survival and high calf productivity can tolerate substantial harvest levels. Power to detect declines within three years was limited to larger scale (>31%) declines in herd size. Bull-cow ratios were sensitive to male and female harvest levels with increases in bull-cow ratios when female harvest was higher. Case studies of the Bathurst and Bluenose-East herds using the most recent demographic information suggest that harvest should be very conservative, given herd size, trend and relatively low cow survival in these herds. Recommended harvest should be re-assessed frequently because a herd's productivity and survival rates can change quickly. Results of the harvest modeling were used to develop approaches to recommending harvest level and sex ratio based on herd risk status, including a simple rule of thumb approach.
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 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 A National Ecological Framework for Canada written by Ecological Stratification Working Group (Canada) and published by Centre for Land and Biological Resources Research ; Hull, Quebec : State of the Environment Directorate. This book was released on 1996 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: [An] expanded attribute database [that] includes attribute data for the ecoprovince level of generalization.
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 October 2020 Fall Composition Surveys of Bathurst and Bluenose East Barren ground Caribou Herds 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: For the Bluenose-East herd, the survey resulted in an estimated ratio of 51.7 calves: 100 cows (95% CI 47.2-55.7). Of the 32 collared females and 18 collared males in the Bluenose-East herd at the time of the surveys, 29 females and 17 males (92% of total collars) were in the vicinity of caribou groups surveyed. This suggested that a large proportion of the herd was in areas surveyed and the sample was representative of the herd. The October bull:cow ratio was 63.3 bulls: 100 cows (95% CI 50.0-79.0). Overall, the calf:cow ratios in both herds in October were similar to the ratios found in July, suggesting that relatively little calf mortality occurred over this period. Ratios of 39 and 51 calves:100 cows indicate good recruitment in both herds for 2020. The bull:cow ratios were somewhat higher than has been recorded recently in the two herds, and may suggest that male survival rates have improved. Collar-based cow survival rates in both herds have improved in recent years. If these positive indicators continue, population trend may improve in the Bathurst and Bluenose-East herds. In addition to the survey results, this report includes three appendices: (1) a group by group listing of caribou composition survey results, (2) a summary of some unusual fall 2020 movements of Bathurst and Beverly caribou and a brief review of how newly placed cow and bull collars have been assigned to herd, and (3) an analysis of bull fidelity to herd in the Bathurst, Bluenose-East and Beverly herds.
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 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 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 October 2021 Fall Composition Survey of the Bathurst and Bluenose East Barren ground Caribou Herds 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 fall composition survey of the Bluenose-East barren-ground caribou herd conducted in October 2021. The main purpose of this survey was to estimate the sex ratio in the herd during the breeding season, and to estimate the proportion of females in the herd that were accompanied by a calf, as an index of calf mortality in the first four and a half months of age. We also attempted to carry out a fall composition survey of the Bathurst herd, but were unsuccessful because the herd was mixed with a portion of the much larger Beverly herd.
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 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 Satellite Collaring in the Bathurst Herd of Barren ground Caribou 1996 2005 written by Anne Gunn (Wildlife manager) and published by . This book was released on 2013 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1996, the first cows in the Bathurst herd of barren-ground caribou were satellite collared. Subsequently, the program was maintained by using between five and 21 collared cows transmitting locations between 1996 and 2005. The purpose of this report is to compile information about the collaring program and the chronology of collaring. The report is an update of a 2001 summary and it is meant to be an illustrative not exhaustive review of the analyses. Satellite collared caribou locations have been used to describe seasonal and annual movements, and movement relative to three diamond mines in the NWT. The collared cows demonstrated fidelity to calving and post-calving ranges. The amount of overlap in seasonal ranges between consecutive years increased from calving throughout post-calving and the summer, before decreasing to be lowest during the winter. The area used during calving was annually the smallest and most variable in size compared to the other seasonal life history ranges. No trend was apparent in the size of the ranges between 1996 and 2005, although the southern boundary of the winter range appears to have contracted northward since 2002. Individual movement rates were more synchronized during pre-calving, calving, and post-calving and more variable in the summer and fall with an increase in movement in the time of the fall rut (mid-October to November). Average movement rates dropped from a high of 16 km/day in early summer to 4 km/day in winter.
Download or read book Technical Rationale to Increase the Number of Satellite Collars on the Bathurst Caribou Herd written by Jan Adamczewski and published by . This book was released on 2016 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: Satellite and/or GPS-satellite radio collars are used for many applications in monitoring of all herds of migratory barren-ground caribou in North America. Until 2015, a maximum of 20 collars had been used on the Bathurst herd, all on cows, and at times there have been as few as eight to nine collared caribou in the herd. An independent review of the Government of the Northwest Territories barren-ground caribou program in 2009 recommended increases in radio collar numbers for all herds, and particularly for herds like the Bathurst where the collar numbers were low. In 2015, the number of Bathurst collars was increased to 50 (30 on cows and 20 on bulls) with approval of the Tłı̜cho Government. This document briefly reviews the main uses of radio collars in caribou monitoring and management, outlines recommended numbers of collars/herd for particular uses, and provides a rationale for increasing the number of collars on the Bathurst herd to 65, with some of these being on bulls. Areas of high priority in management for this herd in 2016 were in assigning and managing harvest from this herd in the winter, in monitoring mortality pattern rates in cows, and in designing reliable population surveys in June. All applications of collar information would benefit from higher collar numbers, including greater confidence in monitoring surveys and in assessing caribou range use in relation to development such as mines and roads.
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.
