Demographic responses of arctic hares (Lepus timidus) to experimental reductions of red foxes (Vulpes vulpes) and martens (Martes martes)

Marcström, Vidar; Keith, Lloyd B.; Engren, E.; Cary, John R.

doi:10.1139/z89-095

Cited by 93 publications

(52 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Impacts of predators on density and survival of alternative prey species as a result of a cyclic decline in another herbivore are often reported (e.g., Angelstam et al 1984;Sutherland 1988;Marcström et al 1989;Keith and Cary 1991;Korpimäki and Norrdahl 1991;Small and Keith 1992;Patterson et al 1998;Angerbjorn et al 1999). Keith and Cary (1991) inferred that increased predation may have occurred on populations of alternative prey (including Franklin's ground squirrels, Spermophilus franklinii) during a snowshoe hare population decline in Alberta.…”

Section: Discussionmentioning

confidence: 99%

“…Steenhof and Kochert (1988) reported that Townsend's ground squirrels (Spermophilus townsendii) were alternative prey for golden eagles (Aquila chrysaetos) during a jackrabbit (Lepus californicus) decline in Idaho. Marcström et al (1989) concluded that arctic hare (Lepus timidus) population densities and growth rates declined in response to increased predation by red foxes (Vulpes vulpes) and martens (Martes martes), when populations of Microtus spp. and Clethrionomys spp.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Experimental manipulation of predation and food supply of arctic ground squirrels in the boreal forest

Byrom¹,

Karels²,

Boonstra³

2000

Can. J. Zool.

View full text Add to dashboard Cite

Abstract:We examined whether arctic ground squirrel (Spermophilus parryii plesius) populations in northern boreal forest in the Yukon Territory, Canada, were limited by food, predators, or a combination of both, during the decline and low phases of a snowshoe hare cycle. From 1990 to 1995, populations were monitored in large-scale (1 km 2 ) experimental manipulations. Squirrels were studied on eight 9-ha grids: four unmanipulated control grids, two foodsupplemented grids, a predator-exclosure grid, and a predator-exclosure + food-supplemented grid. Population density was measured on all grids by livetrapping and active-season survival was measured using radiotelemetry. Population densities were lowest in 1992 and 1993 (2 years after the snowshoe hare population decline). Rates of population change were negative from 1991 to 1993, when predation pressure was most intense after the snowshoe hare decline, and positive from 1993 to 1995, when hares and predators were at low densities. Predation accounted for 125 of 130 mortalities (96%) of radio-collared squirrels. Adult survival was significantly lower in 1992 and 1993 than in 1994 and 1995, and was a strong predictor of annual rates of population change in arctic ground squirrels. Treatments were ranked as follows in their effect on adult survival: predator exclosure + food-supplemented > food-supplemented > predator exclosure > controls. Juvenile survival was lowest in 1992, and food addition and predator removal separately increased juvenile survival. On average, predator exclusion increased population densities twofold, food supplementation increased densities fourfold, and food supplementation and predator removal together increased densities 10-fold. We conclude that food and predation interact to limit arctic ground squirrel populations in the boreal forest during the decline and low phases of the snowshoe hare cycle. The snowshoe hare cycle may indirectly create a lagged secondary fluctuation in arctic ground squirrel populations through shared cyclic predators. 1319Résumé : Nous avons tenté de déterminer si les populations du Spermophile arctique du nord (Spermophilus parryii plesius) de la forêt boréale, au Yukon, Canada, sont régies par la nourriture, par les prédateurs ou par une combinaison des deux variables durant les phases de déclin et de faible densité du cycle du Lièvre d'Amérique. De 1990 à 1995, les populations ont été suivies au cours de manipulations expérimentales à grande échelle (1 km 2 ). Les spermophiles ont été étudiés en huit parcelles de 9 ha : quatre parcelles témoins non manipulées, deux parcelles recevant de la nourriture additionnelle, une parcelle excluant les prédateurs et une parcelle sans prédateurs mais avec addition de nourriture additionnelle. La densité des populations mesuré dans toutes les parcelles par capture d'animaux vivants, et la survie au cours de la saison d'activité, par radio-télémétrie. C'est en 1992 et 1993 que les densités de population ont été le plus faibles (2 ans après le déclin des populations de lièvre...

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Experimental manipulation of predation and food supply of arctic ground squirrels in the boreal forest

Byrom¹,

Karels²,

Boonstra³

2000

Can. J. Zool.

View full text Add to dashboard Cite

show abstract

“…Predation has been the primary proximate cause of mortality in cyclic mainland populations of snowshoe hares that have been monitored by telemetry (Hodges 2000). A number of studies of mountain hares (Lepus timidus) and brown hares (Lepus europaeus) on islands off the coast of Scandinavia have produced strong evidence that predation, or lack of it, is a major factor driving the dynamics of these island populations (Häkkinen and Jokinen 1981;Lindlöf and Lemnell 1981;Marcström et al 1989).…”

Section: Introductionmentioning

confidence: 99%

Cyclic dynamics of snowshoe hares on a small island in the Yukon

Zimmerling¹,

Jardine²,

Trostel³

et al. 2002

Can. J. Zool.

View full text Add to dashboard Cite

Snowshoe hare (Lepus americanus) populations were monitored from 1977 to 2001 on Jacquot Island (5 km 2 ) in Kluane Lake, southwestern Yukon, and on nearby mainland sites. Jacquot Island hares averaged twice the density of mainland control populations and, although they show 10-year cycles, fluctuate with much lower amplitude than mainland populations. Three separate intensive studies over 6 years attempted to determine what caused these differences. We tested two hypotheses to explain the dynamics. Reproductive rates of hares were similar on Jacquot Island and the mainland. Adult survival rates were higher on the island in most years, with the exception of years of population decline. Juvenile survival rates from 0 to 30 days of life were much higher on the island than on the mainland except for decline summers. The adult-and juvenile-survival differences between the island and the mainland were explained most consistently by predation. Improved survival on the island is correlated with a reduction in the numbers and types of predators found on Jacquot Island compared with the mainland. In particular, red squirrels were rare on Jacquot Island, arctic ground squirrels were absent, and the larger predators, like lynx and great-horned owls, were sporadic in occurrence on this small island. 2 ) au Lac Kluane (sud-ouest du Yukon), ainsi qu'à des sites sur la terre ferme, à proximité. Les densités de liè-vres sur l'Île Jacquot équivalent en moyenne au double de celles des populations témoins sur la terre ferme et, quoique les premières fluctuent selon un cycle de 10 ans, leurs fluctuations sont d'une amplitude de beaucoup inférieure à celles des populations de terre ferme. Les causes de ces différences ont été examinées au cours de trois études intensives différentes s'échelonnant sur 6 ans. Nous avons testé deux hypothèses quant à la dynamique de ces populations. Les taux de reproduction sur l'île Jacquot et sur la terre ferme sont similaires. La plupart des années, le taux de survie des adultes est plus grand sur l'île que sur la terre ferme, sauf durant les années où les populations sont en déclin. Le taux de survie de 0 à 30 jours chez les juvéniles est beaucoup plus grand sur l'île que sur la terre ferme, excepté durant les étés de déclin. C'est l'effet des prédateurs résidants qui explique le mieux les différences de taux de survie entre les lièvres de l'île et ceux de la terre ferme, aussi bien chez les adultes que chez les juvéniles. Le meilleur taux de survie des lièvres sur l'île associé à une guilde de prédateurs plus pauvre en nombres et en espèces que celle des sites la terre ferme. Plus particulièrement, les écureuils roux sont rares sur cette petite île, les spermophiles arctiques y sont absents, et les plus gros prédateurs comme le lynx et le grand-duc ne s'y trouvent que sporadiquement. 1450Krebs et al.

show abstract

“…Predator removal was usually associated with an increase in numbers in the autumn, but only 50% of 10 studies found an effect on breeding numbers. The effects are apparently more marked for hares, for which most studies found positive effects (Marcstrom et al 1989, Jensen 1970, Trautman et al 1974, Lindstrom et al 1994, Smedshaug et al 1999; but see Guthery & Beasom 1977, Kauhala et al 1999. In rabbits, results are more contrasting (Trautman et al 1974, Guthery & Beasom 1977, Newsome et al 1989).…”

Section: Effect Of Predator Control On Small Game Speciesmentioning

confidence: 98%

Ecological effects of game management: does supplemental feeding affect herbivory pressure on native vegetation?

et al. 2015

View full text Add to dashboard Cite

Context Supplemental feeding of large mammalian herbivores is a common management tool mainly aimed at promoting healthy populations and at increasing productivity and trophy sizes. Such management measure may indirectly affect herbivore effects on plant communities through altered foraging patterns. The quantification of the ecological effects of large herbivore management is important for designing holistic management and conservation programs. Aims Here we aimed at quantifying the ecological effects of supplemental feeding of Iberian red deer, Cervus elaphus hispanicus, on the composition of and on the browsing effects on Mediterranean woody plant community. Methods An experiment was set up in a hunting rangeland located in central Spain, where female deer were kept in enclosures with either exclusive access to natural forages or with additional ad libitum access to a nutritionally rich concentrate. The experiment also included a control area where deer were absent. Key results We observed significant differences in browsing impacts among the supplemented, non-supplemented and control areas, and such effect varied for the different plant species. Plant species which nutritional content complemented that of fodder were more highly consumed, for instance, Erica spp., which digestible fibre content is higher and N content lower than that of provided fodder. The presence of deer and the concentrate supplied, instead, did not influence the relative abundances of shrub species. Conclusions Artificial supplemental feeding provided to ungulates led to increased browsing on plant species which nutritional composition complemented that of the supplement provided. Implications So as to alleviate herbivory impact on all shrubs, we suggest that composition of supplemental feeding should adjust both to the natural forage availability and quality and to ungulate requirements across seasons.

show abstract

Demographic responses of arctic hares (Lepus timidus) to experimental reductions of red foxes (Vulpes vulpes) and martens (Martes martes)

Cited by 93 publications

References 19 publications

Experimental manipulation of predation and food supply of arctic ground squirrels in the boreal forest

Experimental manipulation of predation and food supply of arctic ground squirrels in the boreal forest

Cyclic dynamics of snowshoe hares on a small island in the Yukon

Ecological effects of game management: does supplemental feeding affect herbivory pressure on native vegetation?

Contact Info

Product

Resources

About