A Determination of Defecation Rate for Elk

Neff, Don J.; Wallmo, O. C.; Morrison, D. C.

doi:10.2307/3798454

Cited by 8 publications

(4 citation statements)

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“…One obvious source of variation results from interspecific, temporal, or spatial variations in faecal production rates (Thompson, White & Gowan 1998). Previous studies indicate that defection rates of ungulates often varies among individual animals and seasons (Neff, Wallmo & Morrison 1965;Mitchell et al 1985;Rogers 1987), suggesting that comparisons of faecal indices should be limited to within seasons (Thompson, White & Gowan 1998). Additional geographic variation in faecal production rate in relation to forage quality, precipitation, and other environmental gradients are poorly understood and warrant additional study.…”

Section: Discussionmentioning

confidence: 99%

A double‐observer method for reducing bias in faecal pellet surveys of forest ungulates

Jenkins

Manly

2008

Journal of Applied Ecology

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Summary 1.Faecal surveys are used widely to study variations in abundance and distribution of forestdwelling mammals when direct enumeration is not feasible. The utility of faecal indices of abundance is limited, however, by observational bias and variation in faecal disappearance rates that obscure their relationship to population size. We developed methods to reduce variability in faecal surveys and improve reliability of faecal indices. 2. We used double-observer transect sampling to estimate observational bias of faecal surveys of Roosevelt elk Cervus elaphus roosevelti and Columbian black-tailed deer Odocoileus hemionus columbianus in Olympic National Park, Washington, USA. We also modelled differences in counts of faecal groups obtained from paired cleared and uncleared transect segments as a means to adjust standing crop faecal counts for a standard accumulation interval and to reduce bias resulting from variable decay rates. 3. Estimated detection probabilities of faecal groups ranged from < 0·2-1·0 depending upon the observer, whether the faecal group was from elk or deer, faecal group size, distance of the faecal group from the sampling transect, ground vegetation cover, and the interaction between faecal group size and distance from the transect. 4. Models of plot-clearing effects indicated that standing crop counts of deer faecal groups required 34% reduction on flat terrain and 53% reduction on sloping terrain to represent faeces accumulated over a standard 100-day interval, whereas counts of elk faecal groups required 0% and 46% reductions on flat and sloping terrain, respectively. 5. Synthesis and applications. Double-observer transect sampling provides a cost-effective means of reducing observational bias and variation in faecal decay rates that obscure the interpretation of faecal indices of large mammal abundance. Given the variation we observed in observational bias of faecal surveys and persistence of faeces, we emphasize the need for future researchers to account for these comparatively manageable sources of bias before comparing faecal indices spatially or temporally. Double-observer sampling methods are readily adaptable to study variations in faecal indices of large mammals at the scale of the large forest reserve, natural area, or other forested regions when direct estimation of populations is problematic.

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Section: Discussionmentioning

confidence: 99%

A double‐observer method for reducing bias in faecal pellet surveys of forest ungulates

Jenkins

Manly

2008

Journal of Applied Ecology

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“…[5][6][7]32,36,38 Deer and elk defecate approximately 900,000 kg of feces and urinate approximately 14 million liters of urine in the area immediately surrounding the Cache la Poudre river per year. [39][40][41][42] Although urine and feces likely contain much lower prion loads than blood or saliva, the sheer amount of excreta may contribute significantly to overall environmental prion contamination.…”

Section: Prionmentioning

confidence: 99%

Detection of protease-resistant cervid prion protein in water from a CWD-endemic area

Nichols

Pulford

Wyckoff

et al. 2009

Prion

111

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“…The mean deer pile density was <2 per 100 m 2 in all valleys. Deer defecate at approximately the same daily rate as elk (ϳ12.5 times per day); therefore, the number of piles of deer pellets and the number of piles of elk pellets can be compared to estimate the relative density of deer and elk with respect to one other (Neff et al 1965). Based on this comparison, elk were the dominant herbivore in the study area.…”

Section: (B)mentioning

confidence: 99%

Effects of predation risk on elk (Cervus elaphus) landscape use in a wolf (Canis lupus) dominated system

2015

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Food acquisition and predation avoidance are key drivers of herbivore behaviour. We investigated the interaction of top-down (predator) and bottom-up (food, fire, thermal) effects by measuring the relationship between wolf (Canis lupus L., 1758) predation risk perceived by elk (Cervus elaphus L., 1758) and elk landscape use. We conducted fecal pellet and wolf scat surveys in three valleys with three wolf population levels (Saint Mary: low; Waterton: moderate; North Fork: high). In the North Fork, 90% of quaking aspen (Populus tremuloides Michx.) stands burned recently; the other valleys had no fire. We created predictive models of elk pellet density that incorporated bottom-up and top-down variables. All valleys had a high elk pellet density (≥10 per 100 m 2 ). Wolf scat density was similar where there was no fire, but one order of magnitude greater in burned areas. Elk pellet density was lower in the North Fork, a predation-related response. In all valleys, site-specific elk density declined as impediments to detecting or escaping wolves increased, and elk avoided aspen, except for North Fork unburned areas. Models that best predicted elk density contained bottom-up and top-down effects. At local scales, high predation risk negatively influence elk occurrence, suggesting that even with minimal wolf exposure elk avoid risky sites.Résumé : L'acquisition de nourriture et l'évitement de la prédation sont des moteurs clés du comportement des herbivores. Nous avons examiné l'interaction d'effets descendants (prédateur) et ascendants (nourriture, feu, chaleur) en mesurant le lien entre les risques de prédation par des loups (Canis lupus L., 1758) perçus par les wapitis (Cervus elaphus L., 1758) et l'utilisation du paysage par ces derniers. Nous avons effectué des levés de boulettes fécales et de fèces de loup dans trois vallées présentant des populations de loups de trois niveaux différents (Saint Mary : faible; Waterton : modérée; North Fork : élevée). Dans la vallée de la North Fork, 90 % des peuplements de trembles (Populus tremuloides Michx.) avaient brûlé récemment; aucun feu n'avait eu lieu dans les deux autres vallées. Nous avons créé des modèles prédictifs de la densité des boulettes de wapiti qui intègrent des variables ascendantes et descendantes. Toutes les vallées présentaient des densités de boulettes de wapiti élevées (≥10 par 100 m 2 ). La densité des fèces de loup était semblable là où il n'y avait pas eu de feu, mais d'un ordre de grandeur plus élevée dans les zones brûlées. La densité des boulettes de wapiti était plus faible dans la vallée de la North Fork, une réaction reliée à la prédation. Dans toutes les vallées, la densité de wapitis propres à des sites précis diminuait inversement à l'augmentation des entraves à la détection des loups ou à la fuite de ces derniers, et les wapitis évitaient les trembles, sauf dans les zones non brûlées de la North Fork. Les modèles qui prédisaient le mieux la densité des wapitis contenaient des effets ascendants et descendants. Aux échelles locales, un risque de...

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A Determination of Defecation Rate for Elk

Cited by 8 publications

References 0 publications

A double‐observer method for reducing bias in faecal pellet surveys of forest ungulates

A double‐observer method for reducing bias in faecal pellet surveys of forest ungulates

Detection of protease-resistant cervid prion protein in water from a CWD-endemic area

Effects of predation risk on elk (Cervus elaphus) landscape use in a wolf (Canis lupus) dominated system

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