Using ungulate biomass to estimate abundance of wolves in British Columbia

Kuzyk, Gerald W.; Hatter, Ian W.

doi:10.1002/wsb.475

Cited by 11 publications

(19 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…). For that reason, we applied the more contemporary Kuzyk and Hatter () function, but this resulted in relatively fewer wolves for the Chinchaga ( K w = 4.4 and 6.2 wolves/1000 km 2 , respectively) and more wolves for the Charlevoix population ( K w = 16.3 and 14.5 wolves/1000 km 2 , respectively).…”

Section: Discussionmentioning

confidence: 99%

“… Functions published by Kuzyk and Hatter (),

K_{normalw} = 5.40 x - 0.166 x^{2}

, or Fuller et al. (),

K_{normalw} = 3.5 x + 3.3 x

; user must define total biomass of ungulates ( U ) other than moose or caribou. …”

Section: Methodsmentioning

confidence: 99%

“…For wolves, K is a function of the biomass of prey. We used Kuzyk and Hatter's () non‐linear relationship between wolf density and an index of ungulate biomass ( U ) to predict the maximum number of wolves (Eq. ):

K_{normalw} = 5.40 x - 0.166 x^{2}

where x represents the sum of the ungulate biomass per km 2 .…”

Section: Methodsmentioning

confidence: 99%

“…In most cases, births decline and deaths increase as populations reach their ecological carrying capacity (K), but these effects are not consistent across life-history strategy, age, or gender class (Eberhardt 2002). A similar response may occur for very small populations that experience an Allee effect and benefit from positive density dependence (Boyce 1992 Kuzyk and Hatter (2014), K w ¼ 5:40x À 0:166x 2 , or Fuller et al (2003), K w ¼ 3:5x þ 3:3x; user must define total biomass of ungulates (U) other than moose or caribou. § Density-dependent function…”

Section: Density Dependencementioning

confidence: 99%

“…For the Charlevoix population, we had an empirical estimate of wolf density. We used a non-linear ungulate biomass-wolf density function (Kuzyk and Hatter 2014;Eq. 2) to generate estimates for the Chinchaga population.…”

Section: Insights From An Imperfect Model: Identifying Knowledge Gapsmentioning

confidence: 99%

See 4 more Smart Citations

Modeling multispecies predator–prey dynamics: predicting the outcomes of conservation actions for woodland caribou

2019

View full text Add to dashboard Cite

Woodland caribou is a Threatened or Endangered subspecies across much of Canada. In many cases, these caribou are declining because of human‐mediated predation in the form of apparent competition. Provincial and federal agencies have employed a number of conservation actions to arrest the decline, but insufficient time and limited replication make it difficult to test the efficacy of those activities. We built a three‐species population model that served as a tool to integrate current knowledge, explore uncertainties, and assess activities focused on the recovery of caribou. We applied the model to interconnected populations of caribou, moose, and wolves at two locations in Canada (Chinchaga [British Columbia], Charlevoix [Québec]) and explored the efficacy of conservation actions unique to each population: predator control, restoration of linear features, reduction of habitat for moose, supplementation, maternal pens, and predator exclosures. Results confirmed that caribou at these two locations faced different recovery challenges, dictated by specific population dynamics and threats. Wolf predation, enhanced by seismic lines and resource roads, was responsible for the decline of the simulated Chinchaga population. The most cost‐effective recovery actions for that population were long‐term lethal wolf control (λ1–50 = 1.014, $25,665/caribou), a large‐scale predator exclosure (λ1–50 = 1.015, $170,767/caribou), and the aggressive restoration of linear features (λ1–50 = 1.002, $531,675/caribou). In contrast, simulations suggested that calf predation by black bears, a fixed source of mortality in the model, limited the growth of the Charlevoix population. Assuming high survival of adult caribou and poor recruitment of juveniles, a maternal pen was the most effective action for the recovery of those caribou (λ1–50 = 1.004, $148,473/caribou). Short‐term population supplementation provided only a temporary increase in abundance (λ1–50 = 0.994, $62,143/caribou). The model was limited by ecological and data uncertainties, but served as an effective platform for representing and testing our understanding of the complex interspecific interactions that underlie the recovery of woodland caribou.

show abstract

Section: Discussionmentioning

confidence: 99%

“… Functions published by Kuzyk and Hatter (),

K_{normalw} = 5.40 x - 0.166 x^{2}

, or Fuller et al. (),

K_{normalw} = 3.5 x + 3.3 x

; user must define total biomass of ungulates ( U ) other than moose or caribou. …”

Section: Methodsmentioning

confidence: 99%

K_{normalw} = 5.40 x - 0.166 x^{2}

where x represents the sum of the ungulate biomass per km 2 .…”

Section: Methodsmentioning

confidence: 99%

Section: Density Dependencementioning

confidence: 99%

Section: Insights From An Imperfect Model: Identifying Knowledge Gapsmentioning

confidence: 99%

See 3 more Smart Citations

Modeling multispecies predator–prey dynamics: predicting the outcomes of conservation actions for woodland caribou

2019

View full text Add to dashboard Cite

show abstract

Ecological forecasts reveal limitations of common model selection methods: predicting changes in beaver colony densities

Johnson‐Bice

Ferguson

Erb

et al. 2020

Ecological Applications

View full text Add to dashboard Cite

Over the past two decades, there have been numerous calls to make ecology a more predictive science through direct empirical assessments of ecological models and predictions. While the widespread use of model selection using information criteria has pushed ecology toward placing a higher emphasis on prediction, few attempts have been made to validate the ability of information criteria to correctly identify the most parsimonious model with the greatest predictive accuracy. Here, we used an ecological forecasting framework to test the ability of information criteria to accurately predict the relative contribution of density dependence and density-independent factors (forage availability, harvest, weather, wolf [Canis lupus] density) on inter-annual fluctuations in beaver (Castor canadensis) colony densities. We modeled changes in colony densities using a discrete-time Gompertz model, and assessed the performance of four models using information criteria values: density-independent models with (1) and without (2) environmental covariates; and density-dependent models with (3) and without (4) environmental covariates. We then evaluated the forecasting accuracy of each model by withholding the final one-third of observations from each population and compared observed vs. predicted densities. Information criteria and our forecasting accuracy metrics both provided strong evidence of compensatory density dependence in the annual dynamics of beaver colony densities. However, despite strong within-sample performance by the most complex model (density-dependent with covariates) as determined using information criteria, hindcasts of colony densities revealed that the much simpler density-dependent model without covariates performed nearly as well predicting out-of-sample colony densities. The hindcast results indicated that the complex model over-fit our data, suggesting that parameters identified by information criteria as important predictor variables are only marginally valuable for predicting landscapescale beaver colony dynamics. Our study demonstrates the importance of evaluating ecological models and predictions with long-term data and revealed how a known limitation of information criteria (over-fitting of complex models) can affect our interpretation of ecological dynamics. While incorporating knowledge of the factors that influence animal population dynamics can improve population forecasts, we suggest that comparing forecast performance metrics can likewise improve our knowledge of the factors driving population dynamics.

show abstract

Demographic responses of nearly extirpated endangered mountain caribou to recovery actions in Central British Columbia

McNay¹,

Lamb

Giguere³

et al. 2022

Ecological Applications

View full text Add to dashboard Cite

Recovering endangered species is a difficult and often controversial task that challenges status quo land uses. Southern Mountain caribou are a threatened ecotype of caribou that historically ranged in southwestern Canada and northwestern USA and epitomize the tension between resource extraction, biodiversity conservation, and Indigenous Peoples' treaty rights. Human-induced habitat alteration is considered the ultimate cause of caribou population declines, whereby an increased abundance of primary prey-such as moose and deer-elevates predator populations and creates unsustainable caribou mortality. Here we focus on the Klinse-Za and Quintette subpopulations, part of the endangered Central Group of Southern Mountain caribou in British Columbia. These subpopulations were trending toward immediate extirpation until a collaborative group initiated recovery by implementing two short-term recovery actions. We test the effectiveness of these recovery actionsmaternity penning of adult females and their calves, and the reduction of a primary predator, wolves-in increasing vital rates and population growth.Klinse-Za received both recovery actions, whereas Quintette only received wolf reductions, providing an opportunity to test efficacy between recovery actions. Between 1995 and 2021, we followed 162 collared female caribou for 414 animal-years to estimate survival and used aerial counts to estimate population abundance and calf recruitment. We combined these data in an integrated population model to estimate female population growth, total population abundance, and recovery action effectiveness. Results suggest that the subpopulations were declining rapidly (λ = 0.90-0.93) before interventions and would have been functionally extirpated (<10 animals) within 10-15 years. Wolf reduction increased population growth rates by ~0.12 for each subpopulation.Wolf reduction halted the decline of Quintette caribou and allowed them to increase (λ = 1.05), but alone would have only stabilized the Klinse-Za

show abstract

Using ungulate biomass to estimate abundance of wolves in British Columbia

Cited by 11 publications

References 22 publications

Modeling multispecies predator–prey dynamics: predicting the outcomes of conservation actions for woodland caribou

Modeling multispecies predator–prey dynamics: predicting the outcomes of conservation actions for woodland caribou

Ecological forecasts reveal limitations of common model selection methods: predicting changes in beaver colony densities

Demographic responses of nearly extirpated endangered mountain caribou to recovery actions in Central British Columbia

Contact Info

Product

Resources

About