Evaluation of harvest indices for monitoring cougar survival and abundance

Wolfe, Michael L.; Gese, Eric M.; Terletzky, Patricia A.; Stoner, Dayton; Aubry, Lise M.

doi:10.1002/jwmg.985

Cited by 13 publications

(22 citation statements)

References 26 publications

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“…Cougars are classified as a hunted game mammal across much of their current range (Anderson et al ), and state and provincial managers should clearly define population and harvest objectives for cougars that do not threaten their long‐term conservation. Anderson and Lindzey () and Wolfe et al () found that monitoring hunter success rates and ages of female cougars harvested provided guidance on appropriate harvest rates to reduce or maintain cougar densities. Management actions to reduce cougar densities may be short‐lived given the dispersal patterns and reproductive potential of cougars (Clark ).…”

Section: Management Implicationsmentioning

confidence: 99%

Roles of maternal condition and predation in survival of juvenile Elk in Oregon

Johnson

Jackson

Cook

et al. 2019

Wildlife Monographs

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Understanding bottom‐up, top‐down, and abiotic factors along with interactions that may influence additive or compensatory effects of predation on ungulate population growth has become increasingly important as carnivore assemblages, land management policies, and climate variability change across western North America. Recruitment and population trends of elk (Cervus canadensis) have been downward in the last 4 decades across the northern Rocky Mountains and Pacific Northwest, USA. In Oregon, changes in vegetation composition and land use practices occurred, cougar (Puma concolor) populations recovered from near‐extirpation, and black bear (Ursus americanus) populations increased. Our goal was to provide managers with insight into the influence of annual climatic variation, and bottom‐up and top‐down factors affecting recruitment of elk in Oregon. We conducted our research in southwestern (SW; Toketee and Steamboat) and northeastern (NE; Wenaha and Sled Springs) Oregon, which had similar predator assemblages but differed in patterns of juvenile recruitment, climate, cougar densities, and vegetative characteristics. We obtained monthly temperature and precipitation measures from Parameter‐elevation Regressions on Independent Slopes Model (PRISM) and estimates of normalized difference vegetation index (NDVI) for each study area to assess effects of climate and vegetation growth on elk vital rates. To evaluate the nutritional status of elk in each study area, we captured, aged, and radio‐collared adult female elk in SW (n = 69) in 2002–2005 and NE (n = 113) in 2001–2007. We repeatedly captured these elk in autumn (n = 232) and spring (n = 404) and measured ingesta‐free body fat (IFBF), mass, and pregnancy and lactation status. We fitted pregnant elk with vaginal implant transmitters (VITs) in spring and captured their neonates in SW (n = 46) and NE (n = 100). We placed expandable radio‐collars on these plus an additional 110 neonates in SW and 360 neonates in NE captured by hand or net‐gunning via helicopter and estimated their age at capture, birth mass from mass at capture, and sex. We monitored their fates and documented causes of mortality until 1 year of age. We estimated density of cougars by population reconstruction of captured (n = 96) and unmarked cougars killed (n = 27) and of black bears from DNA analysis of hair collected from snares. We found evidence in lactating females of nutritional limitations on all 4 study areas where IFBFautumn was below 12%, a threshold above which there are few nutritional limitations (9.8% [SE = 0.64%, n = 17] at Toketee, 7.9% [SE = 0.78%, n = 17] at Steamboat, 7.3% [SE = 0.33%, n = 46] at Sled Springs, and 8.9% [SE = 0.51%, n = 23] at Wenaha). In spring, of females known to have been lactating the previous autumn, 48% (SE = 3.3%, n = 56) had IFBFspring <2%, a level indicating severe nutritional limitations, compared to 20% (SE = 1.7%, n = 91) of those not lactating the previous autumn. These low levels of IFBFspring of lactating females likely resulted from a carry...

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Section: Management Implicationsmentioning

confidence: 99%

Roles of maternal condition and predation in survival of juvenile Elk in Oregon

Johnson

Jackson

Cook

et al. 2019

Wildlife Monographs

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“…In particular, studies need to be carefully designed when trying to assess how the harvest of predators is related to variation in the vital rates of prey [80]. The connection between predator harvest, predator population dynamics and predation risk to ungulates is unclear and has rarely been evaluated [81]. This lack of clarity is worsened where predator harvest regulations are set in response to a combination of social, biological, and political factors or where harvest can fluctuate in response to any factors unrelated to population vital rates.…”

Section: Discussionmentioning

confidence: 99%

An improved understanding of ungulate population dynamics using count data: Insights from western Montana

et al. 2019

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Understanding the dynamics of ungulate populations is critical given their ecological and economic importance. In particular, the ability to evaluate the evidence for potential drivers of variation in population trajectories is important for informed management. However, the use of age ratio data (e.g., juveniles:adult females) as an index of variation in population dynamics is hindered by a lack of statistical power and difficult interpretation. Here, we show that the use of a population model based on count, classification and harvest data can dramatically improve the understanding of ungulate population dynamics by: 1) providing estimates of vital rates (e.g., per capita recruitment and population growth) that are easier to interpret and more useful to managers than age ratios and 2) increasing the power to assess potential sources of variation in key vital rates. We used a time series of elk (Cervus canadensis) spring count and classification data (2004 to 2016) and fall harvest data from hunting districts in western Montana to construct a population model to estimate vital rates and assess evidence for an association between a series of environmental covariates and indices of predator abundance on per capita recruitment rates of elk calves. Our results suggest that per capita recruitment rates were negatively associated with cold and wet springs, and severe winters, and positively associated with summer precipitation. In contrast, an analysis of the raw age ratio data failed to detect these relationships. Our approach based on a population model provided estimates of the region-wide mean per capita recruitment rate (mean = 0.25, 90% CI = 0.21, 0.29), temporal variation in hunting-district-specific recruitment rates (minimum = 0.09; 90% CI = [0.07, 0.11], maximum = 0.43; 90% CI = [0.38, 0.48]), and annual population growth rates (minimum = 0.83; 90% CI = [0.78, 0.87], maximum = 1.20; 90% CI = [1.11, 1.29]). We recommend using routinely collected population count and classification data and a population modeling approach rather than interpreting estimated age ratios as a substantial improvement in understanding population dynamics.

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“…Under the food limitation and competition regulation hypotheses, hunting mortality ranging from 10–44% of independent pumas is expected to be additive, and reduce puma populations within a few months or years (Logan and Sweanor ; Anderson and Lindzey ; Robinson et al ; Wolfe et al , ). When this happens, hunting mortality limits puma populations, overriding natural limitation and regulation.…”

Section: Discussionmentioning

confidence: 99%

“…Consequently, the sexual selection process is altered (Murphy ; Logan and Sweanor , ; Mysterud ). Conversely, hunting mortality averaging 5–18% of independent pumas (Anderson and Lindzey , Wolfe et al ) or its elimination, could result in higher puma survival and population growth, if not already limited by food, maintain an older age structure, and allow for natural sexual selection processes (Logan and Sweanor , ). Recruitment of male pumas into local populations will depend primarily upon immigration, and of females, a combination of in situ reproduction and immigration (Seidensticker et al , Anderson et al , Logan and Sweanor ).…”

Section: Discussionmentioning

confidence: 99%

Puma population limitation and regulation: What matters in puma management?

Logan

2019

J Wildl Manag

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Wildlife managers require reliable information on factors that influence animal populations to develop successful management programs, including the puma (Puma concolor), in western North America. As puma populations have recovered in recent decades because of restrictions on human‐caused mortality, managers need a clear understanding of the factors that limit or regulate puma populations and how those factors might be manipulated to achieve management objectives, including sustaining puma and other wildlife populations, providing hunting opportunity, and reducing puma interactions with people. I synthesized technical literature on puma populations, behavior, and relationships with prey that have contributed to hypotheses on puma population limitation and regulation. Current hypotheses on puma population limitation include the social limitation hypothesis and the food limitation hypothesis. Associated with each of those are 2 hypotheses on puma population regulation: the social regulation hypothesis and the competition regulation hypothesis. I organize the biological and ecological attributes of pumas reported in the literature under these hypotheses. I discuss the validity of these hypotheses based on the limits of the research associated with the hypotheses and the evolutionary processes theoretically underlying them. I review the management predictions as framed by these hypotheses as they pertain to puma hunting, puma‐prey relationships, and human‐puma interactions. The food limitation and competition regulation hypotheses explain more phenomena associated with puma and likely would guide more successful management outcomes. © 2019 The Wildlife Society.

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Evaluation of harvest indices for monitoring cougar survival and abundance

Cited by 13 publications

References 26 publications

Roles of maternal condition and predation in survival of juvenile Elk in Oregon

Roles of maternal condition and predation in survival of juvenile Elk in Oregon

An improved understanding of ungulate population dynamics using count data: Insights from western Montana

Puma population limitation and regulation: What matters in puma management?

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