Trophic cascades linking wolves (Canis lupus), coyotes (Canis latrans), and small mammals

2012 ◽  
Vol 90 (1) ◽  
pp. 70-78 ◽  
Author(s):  
Brian J. Miller ◽  
Henry J. Harlow ◽  
Tyler S. Harlow ◽  
Dean Biggins ◽  
William J. Ripple

When large carnivores are extirpated from ecosystems that evolved with apex predators, these systems can change at the herbivore and plant trophic levels. Such changes across trophic levels are called cascading effects and they are very important to conservation. Studies on the effects of reintroduced wolves in Yellowstone National Park have examined the interaction pathway of wolves ( Canis lupus L., 1758) to ungulates to plants. This study examines the interaction effects of wolves to coyotes to rodents (reversing mesopredator release in the absence of wolves). Coyotes ( Canis latrans Say, 1823) generally avoided areas near a wolf den. However, when in the proximity of a den, they used woody habitats (pine or sage) compared with herbaceous habitats (grass or forb or sedge)– when they were away from the wolf den. Our data suggested a significant increase in rodent numbers, particularly voles (genus Microtus Schrank, 1798), during the 3-year study on plots that were within 3 km of the wolf den, but we did not detect a significant change in rodent numbers over time for more distant plots. Predation by coyotes may have depressed numbers of small mammals in areas away from the wolf den. These factors indicate a top–down effect by wolves on coyotes and subsequently on the rodents of the area. Restoration of wolves could be a powerful tool for regulating predation at lower trophic levels.

2003 ◽  
Vol 81 (6) ◽  
pp. 985-993 ◽  
Author(s):  
T Adam Switalski

Coyotes (Canis latrans) in Yellowstone National Park (YNP) have lived in the absence of wolves (Canis lupus) for over 60 years. I examined whether wolf reintroduction in 1995 and 1996 in YNP influenced coyote vigilance and foraging ecology. From December 1997 to July 2000, my co-workers and I collected 1708 h of coyote activity budgets. Once wolves became established in the Park, they once again provided a continuous source of carrion in the Lamar Valley and we found that coyotes began feeding on carcasses throughout the year. Although we documented that wolves killed coyotes, it also became clear that surviving coyotes quickly adjusted their behaviors when wolves were present. When coyotes were near wolves or in areas of high wolf use, they fed on carcasses much more; however, they increased the amount of time spent in vigilance activities and decreased rest. There appears to be a trade-off in which wolf kills provide a quick source of food that is energetically advantageous to coyotes; however, attendant costs included increased vigilance, decreased rest, and a higher risk of being killed. Changes in the behavior of coyotes in response to the reintroduction of this large carnivore may ultimately have wide-ranging cascading effects throughout the ecosystem.


2012 ◽  
Vol 8 (5) ◽  
pp. 776-779 ◽  
Author(s):  
L. Mark Elbroch ◽  
Heiko U. Wittmer

Large carnivores perform keystone ecological functions through direct predation, or indirectly, through food subsidies to scavengers or trophic cascades driven by their influence on the distributions of their prey. Pumas ( Puma concolor ) are an elusive, cryptic species difficult to study and little is known about their inter-trophic-level interactions in natural communities. Using new GPS technology, we discovered that pumas in Patagonia provided 232 ± 31 kg of edible meat/month/100 km 2 to near-threatened Andean condors ( Vultur gryphus ) and other members of a diverse scavenger community. This is up to 3.1 times the contributions by wolves ( Canis lupus ) to communities in Yellowstone National Park, USA, and highlights the keystone role large, solitary felids play in natural systems. These findings are more pertinent than ever, for managers increasingly advocate controlling pumas and other large felids to bolster prey populations and mitigate concerns over human and livestock safety, without a full understanding of the potential ecological consequences of their actions.


1996 ◽  
Vol 74 (5) ◽  
pp. 769-783 ◽  
Author(s):  
Eric M. Gese ◽  
Robert L. Ruff ◽  
Robert L. Crabtree

We examined the influence of intrinsic (age, sex, and social status) and extrinsic (snow depth, snowpack hardness, temperature, available ungulate carcass biomass) factors in relation to time–activity budgets of coyotes (Canis latrans) in Yellowstone National Park, Wyoming. We observed 54 coyotes (49 residents from 5 packs, plus 5 transients) for 2507 h from January 1991 to June 1993. Snow depth, ungulate carcass biomass, and habitat type influenced the amount of time coyotes rested, travelled, hunted small mammals, and fed on carcasses. Coyotes decreased travelling and hunting and increased resting and feeding on carcasses as snow depth and available carcass biomass increased. Age and social status of the coyote influenced activity budgets. During times of deep snow and high carcass biomass, pups fed less on carcasses and hunted small mammals more than alpha and beta coyotes. Pups apparently were restricted by older pack members from feeding on a carcass. Thus, pups adopted a different foraging strategy by spending more time hunting small mammals. Coyotes spent most of their time hunting small mammals in mesic meadows and shrub–meadows, where prey densities were highest. Prey-detection rates and prey-capture rates explained 78 and 84%, respectively, of the variation in the amount of time coyotes spent hunting small mammals in each habitat in each winter. Our findings strongly suggested that resource partitioning, as mediated by defense by older coyotes, occurred among coyote pack members in Yellowstone National Park.


Author(s):  
Kaija Klauder ◽  
Bridget Borg ◽  
Laura Prugh

Understanding how mesopredators manage the risks associated with apex predators is key to explaining impacts of apex predators on mesopredator populations and patterns of mesopredator space use. Here we examine the spatial response of coyotes (Canis latrans Say, 1823) to risk posed by wolves (Canis lupus Linnaeus, 1758) using data from sympatric individuals fitted with GPS collars in subarctic Alaska, near the northern range limit for coyotes. We show that coyotes do not universally avoid wolves, but instead demonstrate season-specific responses to both wolf proximity and long-term use of the landscape by wolves. Specifically, coyotes switched from avoiding wolves in summer to preferring areas with wolves in winter, and this selection was consistent across short and longer-term temporal scales. In the summer, coyotes responded less strongly to risk of wolves when in open areas than when in closed vegetation. We also demonstrate that coyotes maintain extremely large territories averaging 291 km2, and experience low annual survival (0.50) with large carnivores being the largest source of mortality. This combination of attraction and avoidance predicated on season and landcover suggests that mesopredators use complex behavioral strategies to mediate the effects of apex predators.


1998 ◽  
Vol 76 (6) ◽  
pp. 1037-1043 ◽  
Author(s):  
Eric M Gese ◽  
Robert L Ruff

From January 1991 to June 1993 we observed 54 coyotes (Canis latrans) for 2507 h in Yellowstone National Park,Wyoming, during which we observed 517 howling events. Among coyotes of different types of social organization (residentversus transient), members of resident packs initiated or participated in howling events, while transient individuals were neverobserved howling (n = 51 h of observation). For members of resident packs, alpha coyotes spent more time howling and had ahigher rate of howling events than beta coyotes and pups; beta coyotes and pups howled similarly. The percentage of time andthe rate of howling events typically peaked in the dispersal and breeding seasons, with the lowest rate of howling during puprearing. Social rank and season did not influence the length of howling events. Pack size did not affect howling rates amongindividuals in a pack or the alpha pair. With respect to space-use patterns, coyotes in resident packs howled more frequentlythan expected along the periphery of the territory than in the core area. We concluded that, like wolves (Canis lupus), allcoyotes in the resident pack did not contribute equally to howling duties; alpha coyotes howled more than all coyotes. Howlingby coyotes appears to serve a territorial spacing function that is mainly performed by the alpha pair of the resident pack.


2020 ◽  
Vol 47 (4) ◽  
pp. 269-276
Author(s):  
Mariano R Recio ◽  
Håkan Sand ◽  
Emilio Virgós

SummaryThe human abandonment of rural areas facilitates rewilding, which is also supported by European projects and initiatives. Rewilding often implies the return of iconic predators such as the wolf (Canis lupus), leading to human–wildlife conflicts. To reverse human depopulation, initiatives such as the European Union’s Common Agricultural Policy (CAP) subsidize extensive grazing of areas unsuitable for intensive agriculture. Therefore, rewilding and reversing depopulation initiatives seem to be mutually incompatible, and further insight into controversial aspects of the return of apex predators is needed when considering the reform of the CAP for post-2020. To develop understanding of these different objectives in the context of large carnivore recolonizations, we analysed wolf attacks on livestock in central Spain, where livestock is managed differently between the plateau and the mountains. As with other European regions, this area is undergoing rural abandonment and is subsidized by the CAP. Free-roaming cattle at higher elevations were subject to increased attacks irrespective of the abundance of wild prey. Efforts to subsidize human repopulation of areas experiencing recolonization by large carnivores require consideration of a model of cohabitation with these predators assisted by mitigation and compensation measures. Rewilding could bring alternative sustainable income based on the values brought by the presence of large carnivores and associated ecosystem services.


Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1735
Author(s):  
Marcello Franchini ◽  
Mirco Corazzin ◽  
Stefano Bovolenta ◽  
Stefano Filacorda

Conflicts between large carnivores and human activities undermine both the maintenance of livestock practices as well as the conservation of carnivores across Europe. Because large carnivore management is driven by a common EU policy, the purpose of this research was to assess stakeholders’ perception towards bears and wolves at an EU level. We conducted a systematic search and subsequent analysis of 40 peer-reviewed studies collected from 1990 to September 2020 within Member States of the EU. Rural inhabitants and hunters exhibited the most negative attitude compared to urban inhabitants and conservationists, whose attitude was more positive. We showed that direct experience with predators as a consequence of ongoing re-colonization may have affected the degree of acceptance of certain categories and that the long-term coexistence between humans and carnivores does not necessarily imply increased tolerance. To encourage coexistence, we recommend monitoring changes in attitudes over time relative to carnivore population dynamics.


Author(s):  
Arthur M. Spickett ◽  
Gordon J. Gallivan ◽  
Ivan G. Horak

The study aimed to assess the long-term population dynamics of questing Rhipicephalus appendiculatus and Rhipicephalus zambeziensis in two landscape zones of the Kruger National Park (KNP). Ticks were collected by dragging the vegetation monthly in three habitats (grassland, woodland and gully) at two sites in the KNP (Nhlowa Road and Skukuza) from August 1988 to March 2002. Larvae were the most commonly collected stage of both species. More R. appendiculatus were collected at Nhlowa Road than at Skukuza, with larvae being most abundant from May to August, while nymphs were most abundant from August to December. Larvae were most commonly collected in the gullies from 1991 to 1994, but in the grassland and woodland habitats from 1998 onwards. Nymphs were most commonly collected in the grassland and woodland. More R. zambeziensis were collected at Skukuza than at Nhlowa Road, with larvae being most abundant from May to September, while nymphs were most abundant from August to November. Larvae and nymphs were most commonly collected in the woodland and gullies and least commonly in the grassland (p < 0.01). The lowest numbers of R. appendiculatus were collected in the mid-1990s after the 1991/1992 drought. Rhipicephalus zambeziensis numbers declined after 1991 and even further after 1998, dropping to their lowest levels during 2002. The changes in numbers of these two species reflected changes in rainfall and the populations of several of their large herbivore hosts, as well as differences in the relative humidity between the two sites over time.


2018 ◽  
Vol 285 (1892) ◽  
pp. 20181582 ◽  
Author(s):  
Calum X. Cunningham ◽  
Christopher N. Johnson ◽  
Leon A. Barmuta ◽  
Tracey Hollings ◽  
Eric J. Woehler ◽  
...  

Top carnivores have suffered widespread global declines, with well-documented effects on mesopredators and herbivores. We know less about how carnivores affect ecosystems through scavenging. Tasmania's top carnivore, the Tasmanian devil (Sarcophilus harrisii) , has suffered severe disease-induced population declines, providing a natural experiment on the role of scavenging in structuring communities. Using remote cameras and experimentally placed carcasses, we show that mesopredators consume more carrion in areas where devils have declined. Carcass consumption by the two native mesopredators was best predicted by competition for carrion, whereas consumption by the invasive mesopredator, the feral cat ( Felis catus ), was better predicted by the landscape-level abundance of devils, suggesting a relaxed landscape of fear where devils are suppressed. Reduced discovery of carcasses by devils was balanced by the increased discovery by mesopredators. Nonetheless, carcasses persisted approximately 2.6-fold longer where devils have declined, highlighting their importance for rapid carrion removal. The major beneficiary of increased carrion availability was the forest raven ( Corvus tasmanicus ). Population trends of ravens increased 2.2-fold from 1998 to 2017, the period of devil decline, but this increase occurred Tasmania-wide, making the cause unclear. This case study provides a little-studied potential mechanism for mesopredator release, with broad relevance to the vast areas of the world that have suffered carnivore declines.


Koedoe ◽  
1975 ◽  
Vol 18 (1) ◽  
Author(s):  
P. Swanepoel

A survey of the small mammals of the Addo Elephant National Park resulted in a checklist, as well as information on relative numbers, distribution within the Park, reproductive activity, sex ratios, and body measurements. Forty mammals species occur in the Park, while three re-introduced species probably do not occur any longer. Of the 40 species 28 are considered small mammals comprising 13 rodent, eight carnivore, two shrew, two bat, one primate and one lagomorph species, as well as the aardvark: Crociduraflavescens, C. cyanea infumata, Rousettus aegyptiacus, Eptesicus capensis, Cercopithecus pygerythrus, Canis mesomelas, Ictonyx striatus, Poecilogale albinucha, Genetta sp., Herpestes pulverulentus, Suricata suricatta, Proteles cristatus, Felis caracal, Orycteropus afer, Lepus saxatilis, Cryptomys hottentotus, Hystrix africae-australis, Pedetes capensis, Graphiurus murinus, Aethomys namaquensis, Praomys natalensis, Rhabdomys pumilio, Mus minutoides, Rattus rattus, Saccostomys campestris, Desmodillus auricularis, Otomys irroratus and 0. unisulcatus.


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