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Cited by 350Wildlife Ecology and ConservationRangeland and Wildlife ManagementAnimal Ecology and Behavior Studies

Landscape heterogeneity shapes predation in a newly restored predator–prey system

Open access
Kauffman, Matthew J., Varley, Nathan, Smith, Douglas W., Stahler, Daniel R., MacNulty, Daniel R., Boyce, Mark S.·2007·Ecology Letters
DOI 10.1111/j.1461-0248.2007.01059.x
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Abstract

Because some native ungulates have lived without top predators for generations, it has been uncertain whether runaway predation would occur when predators are newly restored to these systems. We show that landscape features and vegetation, which influence predator detection and capture of prey, shape large‐scale patterns of predation in a newly restored predator–prey system. We analysed the spatial distribution of wolf ( Canis lupus ) predation on elk ( Cervus elaphus ) on the Northern Range of Yellowstone National Park over 10 consecutive winters. The influence of wolf distribution on kill sites diminished over the course of this study, a result that was likely caused by territorial constraints on wolf distribution. In contrast, landscape factors strongly influenced kill sites, creating distinct hunting grounds and prey refugia. Elk in this newly restored predator–prey system should be able to mediate their risk of predation by movement and habitat selection across a heterogeneous risk landscape.

Integrity signals

Registry

Crossref · 10.1111/j.1461-0248.2007.01059.x

Cites

57 of 57 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

4 of 66 cited sources checked · 3 supported · 0 flagged · accuracy not yet measured

  • Interpretationcitation

    Open habitats with few visual barriers may enhance wolves' ability to identify vulnerable individuals within an elk group.

    “With few visual barriers, open habitats could also enhance the wolvesÕ ability to sort through an elk group and scan its members for vulnerable individuals to attack (Mech et al. 1998;MacNulty et al. 2007)”
    Quote in the paperSubstantial claim1 of 2 sources checked
    • cites Mech et al. 1998

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites MacNulty et al. 2007 source

      The Discussion (page unavailable) says wolves likely assess prey vulnerability and that attacking a group is their primary method of selecting an individual. It does not say that open habitat or fewer visual barriers improves their ability to assess elk group members. (LLM, conf=0.85)

      Experimental — accuracy not yet measured
  • Findingown data

    In 2005, landscape features produced a highly variable predation-risk surface, with low- and high-risk areas differing by almost two orders of magnitude.

    “In 2005, the influence of landscape features created a predation-risk landscape that was highly variable, with areas of low and high risk varying by nearly two orders of magnitude (Fig. 2a).”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: The odds ratio from the case-control logistic regression can be interpreted as the relative probability of a kill.
    • The authors state this as an assumption: Apart from snow effects, the relative distribution of elk within each year was constant.
    • The authors state this as an assumption: Elk density across the study area is proportional to habitat use estimated by Mao et al. (2005).
  • Findingown data

    A model with both elk and wolf distributions explained kill locations far better than models with only predator or only prey distribution.

    “A model including both elk and wolf distributions fit the kill data much better than did single-term models that included the distribution of only predator or prey (likelihood ratio v 2 ¼ 88.57, d.f.¼ 1, P < 0.0001; Table S1 in Supplementary Material).”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: The odds ratio from the case-control logistic regression can be interpreted as the relative probability of a kill.
    • The authors state this as an assumption: Apart from snow effects, the relative distribution of elk within each year was constant.
  • Findingown data

    Conflict among wolf packs rose as pack density on the Northern Range increased.

    “There is ample evidence that inter-pack conflict has increased as the density of NR wolf packs has increased.”
    Quote in the paperNot a substantial claim
  • Findingown data

    Long-term monitoring recorded 2.8 aggressive inter-pack interactions per year in 1996-2000 and 11.8 per year in 2001-2005.

    “Long-term monitoring in this system has recorded 2.8 (±0.8 SE) aggressive inter-pack interactions (i.e.intraspecific chase/flee, attack or kill) per year during the first half of the study period (1996)(1997)(1998)(1999)(2000) and 11.8 (±2.6 SE) such interactions per year during the latter half of the study (2001)(2002)(2003)(2004)(2005).”
    Quote in the paperSubstantial claim
  • Classified as probably not a substantial claim. 15
  • May combine two claims. 31

  • Classified as probably not a substantial claim.

    Premisecitation

    Ungulates with no recent exposure to predators are thought to lose vigilance and become more vulnerable to predation.

    “Native ungulates that have lived without predators are expected to become naı ¨ve and less vigilant, increasing their vulnerability to predation (Berger 1999;Berger et al. 2001;Sand et al. 2006).”
    Quote in the paperSubstantial claim1 of 3 sources checked
    • cites Berger 1999 source
    • cites Berger et al. 2001 source
    • cites Sand et al. 2006 source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Several studies on Yellowstone's Northern Range suggest that wolves affect willow, cottonwood, and aspen communities by changing elk browsing behavior during winter.

    “Several studies on Yellowstone's NR have suggested that wolves are affecting willow (Salix spp.), cottonwood (Populus spp.) and aspen (P.tremuloides) communities by changing the behaviour of elk that heavily browse these woody plants during winter (Ripple et al. 2001;Ripple & Beschta 2004;Beyer et al. 2007).”
    Quote in the paperNot a substantial claim1 of 3 sources checked
    • cites Ripple et al. 2001 source
    • cites Ripple & Beschta 2004 source
    • cites Beyer et al. 2007 source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Elk respond to wolf predation risk by increasing vigilance or shifting habitat use temporally.

    “Several studies have shown that elk respond to the risk of predation by wolves by increasing vigilance levels (Laundre et al. 2001) or shifting habitat use temporally (Creel et al. 2005;Gude et al. 2006).”
    Quote in the paperNot a substantial claim1 of 3 sources checked
    • cites Laundre et al. 2001 source
    • cites Creel et al. 2005

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Gude et al. 2006 source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    Over the decade following reintroduction, the Northern Range wolf population grew from 14 wolves in three packs to 84 wolves in six packs.

    “During the 10 years since reintroduction, the NR wolf population increased from 14 wolves in three packs to 84 wolves in six packs (Fig. 1a).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The best landscape model contained all landscape variables and greatly outperformed the elk-plus-wolf encounter model.

    “The bestfit landscape model included all landscape variables and vastly outperformed the elk + wolf encounter model (likelihood ratio v 2 ¼ 270.11, d.f.¼ 6, P < 0.0001; Table 1; Table S1).”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: The odds ratio from the case-control logistic regression can be interpreted as the relative probability of a kill.
    • The authors state this as an assumption: Apart from snow effects, the relative distribution of elk within each year was constant.

  • May combine two claims.

    Findingcitation

    Per-capita wolf kill rate on the Northern Range did not drop sharply during the study, suggesting packs kept a fairly constant annual kill rate.

    “Similarly, the per-capita kill rate for wolves on the NR has not declined sharply over the study period (D.W. Smith, unpublished data), suggesting that wolf packs maintained a relatively constant annual kill rate.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites D.W. Smith, unpublished data

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Findingown data

    A few large, dominant packs kept the best hunting grounds throughout the decade, but most pack territories moved away from those grounds as wolf density rose.

    “A few large, competitively dominant packs retained access to the best hunting grounds over the 10 years, but the majority of pack territories shifted away from the best hunting grounds as wolf density increased.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: Annual catchability maps roughly approximate the relative quality of wolf habitat for finding and killing elk.

  • May combine two claims.

    Findingown data

    With pack size controlled, average elk catchability in each pack's winter territory declined over time, and a significant pack size-by-time interaction showed large packs held better hunting grounds while small packs were pushed to poorer ones.

    “After controlling for pack size, a decline through time in the average catchability of elk within each pack's winter territory area was evident (multiple regression; pack size: t ¼ )2.48, P ¼ 0.0166; year: t ¼ )3.47, P ¼ 0.0011), with a significant pack size • time interaction (t ¼ 2.33, P ¼ 0.0238) whereby large packs had access to high-quality hunting grounds and small packs were relegated to po”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: Annual catchability maps roughly approximate the relative quality of wolf habitat for finding and killing elk.

  • May combine two claims.

    Findingown data

    Predation risk is a function of both predator distribution and habitat features, with habitat playing the larger role at high predator densities.

    “however, our findings indicate that risk is a function of both predator distribution and habitat features, with habitat playing the larger role at high predator densities.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    When wolves were first reintroduced, wolf pack distribution strongly influenced predation risk, but this influence largely diminished after 10 years of wolf population expansion.

    “When first reintroduced, wolf pack distribution also strongly influenced predation risk (panel b), but this influence has largely diminished after 10 years of wolf population expansion.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Spatial variation in predation risk is largely driven by landscape features, creating a limited number of hunting grounds where predation risk is often 10 times higher than the landscape average.

    “Spatial variation in predation risk is largely driven by landscape features, which create a limited number of hunting grounds where predation risk is often 10 times higher than the landscape average (a map value of 1 denotes average risk).”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    During this period, elk made up 92% of winter ungulate prey killed by wolves.

    “Over this time period, 92% of the ungulate prey taken by wolves during winter have been elk (Smith et al. 2004).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Smith et al. 2004 source

  • May combine two claims.

    Interpretationown data

    Landscape features produce separate areas of high hunting success and areas of prey refuge.

    “In contrast, landscape factors strongly influenced kill sites, creating distinct hunting grounds and prey refugia.”
    • Also stated in: § D I S C U S S I O N · hedged
      “Our study suggests that hunting grounds -habitat patches with physical features favourable to hunting success of wolvesexist on the NR, and that their distribution on the landscape influences both territorial space used by wolves and spatial variation in predation risk for elk.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: The odds ratio from the case-control logistic regression can be interpreted as the relative probability of a kill.
    • The authors state this as an assumption: Apart from snow effects, the relative distribution of elk within each year was constant.

  • May combine two claims.

    Premisecitation

    Introductions of non-native predators to islands without predators demonstrate that novel predators can greatly reduce native prey numbers and drive local extinctions.

    “The history of introductions of exotic predators to predator-free islands illustrates that novel predators can markedly reduce populations of native prey and cause local extinctions (Fritts & Rodda 1998;Knapp et al. 2001;Blackburn et al. 2004).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Fritts & Rodda 1998 source
    • cites Knapp et al. 2001 source
    • cites Blackburn et al. 2004 source

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    Wolves were returned to Yellowstone in 1995, having been absent from the ecosystem since the 1930s.

    “Wolves were reintroduced to YNP in 1995 after being extirpated from this ecosystem in the 1930s (Bangs & Fritts 1996).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Bangs & Fritts 1996

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Classified as probably not a substantial claim.

    Premisecitation

    Theory holds that long-term persistence of native predator-prey systems depends on variable predation rates arising from spatial or temporal prey refuges.

    “Theory suggests that native predator-prey systems persist over the long term due to heterogeneity in predation rates caused by prey refugia in space or time (Fryxell et al. 1988;Kareiva & Wennegren 1995;Ellner et al. 2001).”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites Fryxell et al. 1988 source
    • cites Kareiva & Wennegren 1995 source
    • cites Ellner et al. 2001 source

  • Classified as probably not a substantial claim.

    Study design and conductreasoning

    Locations of wolf packs known to be at a kill were left out of the utilization distribution to lessen spatial dependence between kill sites and pack territories.

    “Aerial relocations of wolf packs known to be on a kill were excluded from the UD estimation to reduce the spatial dependence of kill sites on pack territories.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Study design and conductcitation

    Combining the two survey methods produced little detection bias for the landscape variables analyzed, even though about 27% of kills were missed.

    “While an estimated 27% of total kills went undiscovered, the two survey efforts conducted simultaneously (45% of our kills were detected from the air, 71% from the ground and 17% by both survey methods) resulted in minimal detection bias with respect to the landscape features used in our analysis (Smith et al. 2004).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Smith et al. 2004 source

  • May combine two claims.

    Interpretationown data

    Wolves did not kill in direct proportion to elk distribution or to their own winter territory use.

    “This indicates that wolves were not simply making kills on the landscape in strict proportion to the distribution of elk, or their own spatial patterns of winter territory use.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: The odds ratio from the case-control logistic regression can be interpreted as the relative probability of a kill.
    • The authors state this as an assumption: Apart from snow effects, the relative distribution of elk within each year was constant.

  • May combine two claims.

    Study design and conductown data

    Most landscape variables had low collinearity (r < 0.43), but snow water equivalent and elk were negatively correlated at r = -0.80.

    “All landscape variables showed relatively low levels of collinearity (r < 0.43), except for SWE and elk, which were negatively correlated with r ¼ )0.80.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Study design and conductcitation

    Ground surveys detect wolf-killed elk more often near roads, and no kills were found beyond 7.23 km from a road.

    “Smith et al. (2004) used a double-count method to evaluate observation error in these surveys and found that ground crews are biased towards detecting wolf-killed elk in close proximity to the road system, with no kills found further than 7.23 km from the road.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Smith et al. 2004 source

  • May combine two claims.

    Premisecitation

    At the edge of grizzly recolonization in greater Yellowstone, at least ten adult moose were killed by bears within four years, while no such kills were recorded where the two species had coexisted for over a century.

    “For example, in only 4 years at least 10 adult moose (Alces alces) fell prey to grizzly bears at the frontier of bear recolonization in the greater Yellowstone area as compared with no records of predation where both had existed for 100+ years (Berger et al. 2001).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Berger et al. 2001 source

  • May combine two claims.

    Interpretationreasoning

    The heterogeneity of the landscape that elk historically shared with wolves should allow them to mediate predation risk from the newly restored wolf population, unlike highly vulnerable native prey of introduced predators.

    “Unlike the highly vulnerable native prey of introduced predators, the heterogeneity of the landscape that elk historically shared with wolves should allow them to mediate their risk of predation from this newly restored predator.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    In wolf-ungulate systems, prime-age adult prey are largely invulnerable to predation, and predators selectively target young, old, or weak individuals.

    “In wolf-ungulate systems, as in other large mammal systems (Sinclair & Arcese 1995), prime-age adult prey are largely invulnerable to predation, and predators are highly selective, targeting the young, old or weak (Mech & Peterson 2003).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Sinclair & Arcese 1995 source
    • cites Mech & Peterson 2003

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    Elk move out of open areas when wolves are near or likely to occur, and aggregate in larger groups in open areas the longer wolves are absent.

    “This notion is supported by recent findings showing that elk move out of open areas when wolves are near (Creel et al. 2005) or likely to occur (Fortin et al. 2005), and aggregate in increasingly larger groups in open areas the longer wolves are absent (Creel & Winnie 2005).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Creel et al. 2005

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Fortin et al. 2005 source
    • cites Creel & Winnie 2005

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Classified as probably not a substantial claim.

    Interpretationcitation

    These results have implications for the potential of restored predators to initiate behaviorally mediated trophic cascades by changing prey habitat selection or foraging behavior.

    “These results have implications for the potential of restored predators to initiate trophic cascades by changing the habitat-selection patterns or foraging behaviour of their prey (i.e.behaviourally mediated trophic cascades; Schmitz et al. 2004).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Schmitz et al. 2004 source
    • Rests on an assumption: A rigorous test of behaviorally mediated trophic cascades has been hindered by the lack of an empirical assessment of landscape-level predation risk.

  • May combine two claims.

    Interpretationown data

    Landscape features may often tip the balance in predator-prey encounters, influencing post-encounter outcomes.

    “Our finding of strong landscape effects on predation suggests that landscape features may often Ôtip the balanceÕ in predator-prey encounters, thus influencing post-encounter outcomes.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationcitation

    Both pre-encounter and post-encounter interactions between predators and prey contribute to the riskiness of hunting grounds on the Northern Range.

    “Such habitat features can influence spatial patterns of predation by influencing either pre-or post-encounter interactions between predators and prey (Hebblewhite et al. 2005), and we believe both mechanisms play a role in conferring riskiness to the NR hunting grounds.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Hebblewhite et al. 2005 source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Wolves are inefficient predators with generally low hunting success (about 20%), partly because of the large size and defensive capabilities of their prey.

    “Wolves are inefficient predators with generally low hunting success (»20%; Smith et al. 2000) due, in part, to the large size and defensive capabilities of their prey.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Smith et al. 2000 source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    For Serengeti lions, kills were more closely associated with good hunting habitats (stalking cover) than with areas of high prey abundance.

    “Hopcraft et al. (2005) found similar patterns for Serengeti lions (Panthera leo), whereby lion kills were more closely associated with good hunting habitats (in this case, stalking cover) than areas of high prey abundance.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Hopcraft et al. 2005 source

  • May combine two claims.

    Premisecitation

    In Minnesota, wolf pack territory boundaries function as buffers where most interpack killings occur and where ungulate prey densities are elevated.

    “In Minnesota, boundaries between wolf pack territories appear to function as buffers where most interpack killings occur (Mech 1994) and where ungulate prey densities are elevated (Hoskinson & Mech 1976).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Mech 1994 source
    • cites Hoskinson & Mech 1976 source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    In a study decomposing predation stages, topographic features determined wolf-elk encounter patterns, while vegetation habitat mediated post-encounter outcomes.

    “In a study that was able to decompose the stages of predation, Hebblewhite et al. (2005) found that topographic features determined patterns of wolf-elk encounters, while habitat (i.e.vegetation) mediated postencounter outcomes.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Hebblewhite et al. 2005 source

  • May combine two claims.

    Premisecitation

    Streams and roads likely increase prey encounter rates by providing travel corridors, and open habitats likely facilitate prey detection.

    “Streams and roads provide convenient travel corridors that likely increase prey encounter rates (Kunkel & Pletscher 2000), while open habitats likely facilitate prey detection (Kunkel & Pletscher 2000;Creel et al. 2005).”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites Kunkel & Pletscher 2000 source
    • cites Creel et al. 2005

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    In ecological studies, predator distribution has commonly been used as a surrogate for predation risk.

    “Predator distribution has been commonly used as a surrogate for predation risk in ecological studies (e.g.Ripple et al. 2001;Creel et al. 2005;Fortin et al. 2005);”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Ripple et al. 2001 source
    • cites Creel et al. 2005

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Fortin et al. 2005 source

  • May combine two claims.

    Interpretationreasoning

    High densities of wolves and elk on the Northern Range and strong landscape influence on predation success interact to create high territorial overlap where the best hunting opportunities exist.

    “Instead, the relative high density of wolf and elk populations on the NR and the strong landscape influence on predation success interact to create a pattern of high territorial overlap where the best hunting opportunities exist.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    The results support the idea that packs moved their winter territories away from, but next to, the best hunting grounds, thereby weakening the link between kill sites and wolf distribution.

    “These results are consistent with our hypothesis that individual wolf packs shifted their winter territories away from but adjacent to the best hunting grounds, thus decoupling kill locations from wolf distribution.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: Annual catchability maps roughly approximate the relative quality of wolf habitat for finding and killing elk.

  • May combine two claims.

    Interpretationcitation

    The mosaic of risky and safe habitat patches on the Northern Range allows elk to reduce wolf predation risk by moving about 1-2 km, which is within daily movements.

    “The mosaic of risky and safe habitat patches available to NR elk suggests that elk can reduce their risk of wolf predation by making movements on the order of 1-2 km, easily achieved within daily movements (Fortin et al. 2005).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Fortin et al. 2005 source

  • May combine two claims.

    Interpretationown data

    Habitat shapes predation by affecting whether wolf-elk encounters happen and how they end.

    “Because we found a strong influence of landscape variables on kill-site occurrence after accounting for the distribution of predator and prey, we believe that habitat mediates predation by influencing the occurrence or outcome of wolf-elk encounters.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: The odds ratio from the case-control logistic regression can be interpreted as the relative probability of a kill.
    • The authors state this as an assumption: Apart from snow effects, the relative distribution of elk within each year was constant.

  • May combine two claims.

    Premisecitation

    Wolf territory locations were a positive predictor of elk habitat use, so wolf and elk distributions closely overlap.

    “In fact, wolf territory locations were a positive predictor of elk habitat use (i.e.wolf and elk distributions closely overlap).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Mao et al. 2005 source

  • Classified as probably not a substantial claim.

    Interpretationreasoning

    How elk perceive and manage the trade-off between food and safety will determine the existence and strength of a behaviorally mediated trophic cascade in the Northern Range system.

    “How elk perceive and manage the trade-off between food and safety will ultimately determine the existence and strength of a behaviourally mediated trophic cascade in the NR system.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    Northern Range elk in winter face a trade-off between forage quality and predation risk because most browse communities are in open, flat areas near rivers and roads, which are risky.

    “Our study makes clear that NR elk in winter face a clear trade-off between forage quality and predation risk: most of these browse communities are found in open, flat areas near rivers and roads, which are risky places for elk.”
    Quote in the paperSubstantial claim
41 of 41

  • The authors state this as an assumption.

    The odds ratio from the case-control logistic regression can be interpreted as the relative probability of a kill.

    “we assume the odds ratio to be interpretable as relative probability of kill (Keating & Cherry 2004).”

  • The authors state this as an assumption.

    Apart from snow effects, the relative distribution of elk within each year was constant.

    “our habitat model assumed (aside from the influence of snow) that the relative distribution of elk within each year was constant.”

  • The authors state this as an assumption.

    Elk density across the study area is proportional to habitat use estimated by Mao et al. (2005).

    “we assume that elk density across the study area is proportional to habitat use as estimated by Mao et al. (2005).”

  • The authors state this as an assumption.

    Annual catchability maps roughly approximate the relative quality of wolf habitat for finding and killing elk.

    “We assumed that annual catchability maps roughly approximate the relative quality of wolf habitat as it relates to their likelihood of successfully finding and killing elk.”

  • The paper relies on this without support.

    On the Northern Range, snow accumulation pushes elk to lower-elevation winter range, so elk distribution changes within and among winters.

    “On the NR, it is well known that snow accumulation throughout winter (if deep enough) pushes elk to lower-elevation winter range; thus, elk distribution on the landscape changes within and among annual winter seasons.”

  • The paper relies on this without support.

    A rigorous test of behaviorally mediated trophic cascades has been hindered by the lack of an empirical assessment of landscape-level predation risk.

    “However, in our view, a rigorous test has been hindered thus far by the lack of an empirical assessment of landscape-level predation risk.”
6 of 6

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Table S1 is given conflicting contents

    Minor

    The results cite Table S1 for a comparison of kill-occurrence models, but the supplementary-material list describes Table S1 as an analysis of variance in the wolf density index.

  • Figure S1 is given conflicting contents

    Minor

    The results cite Figure S1 as evidence about temporal variance in wolf density, whereas the supplementary-material list describes it as model-selection results.

2 of 2

Cites

Flagged first, then by citations

1 of the 58 references couldn’t be matched to a known paper.

Research works printed but not linked: 7

  1. Bangs E.E., 1996, Reintroducing the gray wolf to central Idaho and Yellowstone National Park, Wildl. Soc. Bull., 24, 402
  2. Garshelis D., 2000, Research Techniques in Animal Ecology, 111
  3. Hooge P.N., 1997, Animal Movement Extension to Arcview 3.2
  4. Manly B.F.J., 2002, Resource Selection by Animals: Statistical Analysis and Design for Field Studies
  5. Orians G.H., 1997, Wolves, Bears, and their Prey in Alaska: Biological and Social Challenges in Wildlife Management
  6. Skovlin J.M., 2002, North American Elk: Ecology and Management, 531
  7. Wockner G., 2006, Yellowstone Snow Model

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Related

Authors
Kauffman, M. J., Varley, N., Smith, D. W., Stahler, D. R., MacNulty, D. R., & Boyce, M. S.
Affiliations
  • University of Wyoming (US)
  • University of Alberta (CA)
  • Yellowstone National Park (US)
  • University of California, Los Angeles (US)
  • University of Minnesota (US)
Corresponding author
Kauffman, Matthew J.
ORCID
Venue
Ecology Letters
Publisher
Wiley
Published
2007-06-07
Volume
10
Issue
8
Pages
690-700
ISSN
  • 1461-023X (ISSN-L)
  • 1461-0248
DOI
10.1111/j.1461-0248.2007.01059.x
OpenAlex
W2163937023
Cited by
350
References
58
Citations by year
2026: 5 · 2025: 19 · 2024: 19 · 2023: 13 · 2022: 18 · 2021: 21 · 2020: 17 · 2019: 21 · 2018: 23 · 2017: 32 · 2016: 16 · 2015: 18 · 2014: 27 · 2013: 22 · 2012: 17
FWCI
12.68
Type
journal article
Language
en
Open access
Licence
onlinelibrary.wiley.com/termsAndConditions#vor (vor)
Locations
  • Ecology Letters (publishedVersion)
  • PubMed (publishedVersion)
  • Digital Commons - USU (Utah State University) (submittedVersion)
Funders
  • National Science Foundation (0613730)
  • Andrew W. Mellon Foundation
  • National Geographic Society
  • Alberta Conservation Association
  • Camp Fire Conservation Fund
Topics
  • Physical Sciences › Environmental Science › Ecology › Wildlife Ecology and Conservation
  • Physical Sciences › Environmental Science › Ecology › Rangeland and Wildlife Management
  • Physical Sciences › Environmental Science › Ecology › Animal Ecology and Behavior Studies
Keywords
wolf predation, elk, wolf, red deer, landscape heterogeneity, hunting grounds, territoriality, predation risk, habitat selection, Yellowstone National Park
MeSH terms
Animals, Deer, Demography, Models, Theoretical, Population Dynamics, Seasons, Wyoming, Logistic Models, Ecosystem, Wolves, Food Chain, Geographic Information Systems

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-09-29.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-09-29.

Cited sources are checked by gpt-6-sol.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

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