The need to implement the landscape of fear within rodent pest management strategies

Current reactive pest management methods have serious drawbacks such as the heavy reliance on chemicals, emerging genetic rodenticide resistance, and high secondary exposure risks. Rodent control needs to be based on pest-species ecology and ethology to facilitate development of ecologically-based rodent management (EBRM). An important aspect of EBRM is a strong understanding of rodent pest species ecology, behaviour, and spatiotemporal factors. Gaining insight in the behaviour of pest-species is a key aspect of EBRM. The landscape of fear is a mapping of the spatial variation in the foraging cost arising from the risk of predation and reflects levels of fear a prey species perceives at different locations within its home range. In practice, the landscape of fear (LOF) is a mapping of habitat use as a result of perceived fear, which shows where bait or traps are most likely to be encountered and used by rodents. Several studies link perceived predation risk of foraging animals with quitting-harvest rates or giving-up densities (GUDs). GUDs have been used to reflect foraging behaviour strategies of predator avoidance, but to our knowledge very few papers have directly used GUDs in relation to pest management strategies. An opportunity for rodent control strategies lies in the integration of the LOF of rodents in EBRM methodologies. Rodent management could be more efficient and effective by concentrating on those areas where rodents perceive the least levels of predation risk

Snow vole (Chionomys nivalisMartins) affects the redistribution of soil organic matter and hormone-like activity in the alpine ecosystem: ecological implications

In alpine environments, colonies of snow vole (Chionomys nivalis Martins) cause strong pedoturbation, which may affect humification process and soil organic matter (SOM) cycling, with repercussions on the hormone-like activity of organics. We investigated the effect of snow vole pedoturbation on the chemical and spectroscopic features of soil organic fractions, and the potential hormone-like activity of humic and fulvic acids (HA, FA). The study site was located on the high-mountain environment of the Majella massif (central Italy). Pedoturbated and regular soils were morphologically described and characterized for pH and content of total organic carbon, total extractable carbon, HA, and FA. Both HA and FA were extracted and investigated using attenuated total reflectance/Fourier transform infrared (ATR/FTIR), nuclear magnetic resonance with high-resolution magic angle spinning (HRMAS-NMR), and H-1-C-13 heteronuclear single quantum coherence (HSQC). HA and FA were also tested for their auxin-like and gibberellin-like activities. Results provide evidences that bioturbated and regular soils contain a poorly decomposed SOM, but HA and FA with a well-defined molecular structure. The HA and FA from both bioturbated and regular soils show a hormone-like activity with a different allocation along the soil profile. In the regular soil, the highest auxin-like activity was shown by HA and FA from Oe1 horizon, while gibberellin-like activity was expressed by FA from Oe2 horizon. Burrowing activity determines a redistribution of organics throughout the profile with a relatively high auxin-like activity in the FA from straw tunnel wall (STW) and gibberellin-like activity in the HA from vole feces (VF). The relative high presence of carboxylic acids, amides, proteins, and amino acids in the FA from STW and the aromatic moieties in the HA from VF put evidences for their different behavior. The fact that snow vole activity has modified the chemical and biological properties of SOM in these soils otherwise considered governed only by low temperature has important ecological implications such as the preservation of soil fertility and vegetal biodiversity

Carbon stable isotope analysis of cereal remains as a way to reconstruct water availability: preliminary results

Reconstructing past water availability, both as rainfall and irrigation, is important to answer questions about the way society reacts to climate and its changes and the role of irrigation in the development of social complexity. Carbon stable isotope analysis of archaeobotanical remains is a potentially valuable method for reconstructing water availability. To further define the relationship between water availability and plant carbon isotope composition and to set up baseline values for the Southern Levant, grains of experimentally grown barley and sorghum were studied. The cereal crops were grown at three stations under five different irrigation regimes in Jordan. Results indicate that a positive but weak relationship exists between irrigation regime and total water input of barley grains, but no relationship was found for sorghum. The relationship for barley is site-specific and inter-annual variation was present at Deir ‘Alla, but not at Ramtha and Khirbet as-Samra

Predator occurrence and perceived predation risk determine grouping behavior in guanaco (Lama guanicoe)

WILEY: "This is the peer reviewed version of the following article: Esperanza C. Iranzo Heiko U. Wittmer Juan Traba Pablo Acebes Cristina Mata Juan E. Malo, Predator occurrence and perceived predation risk determine grouping behavior in guanaco (Lama guanicoe), Ethology 124.5 (2018): 1699-1711, which has been published in final form at DOI: http://doi.org/10.1111/eth.12727. This article may be used for non-commercial purposes in accordance with Wiley Terms and Condictions for Use Self-Archived VersionGrouping behavior of social ungulates may depend on both predator occurrence and perceived predation risk associated with habitat structure, reproductive state, and density of conspecifics. Over 3 years, we studied grouping behavior of guanaco (Lama guanicoe) families in Chilean Patagonia during the birthing season and determined their response to variation in predator occurrence and perceived predation risk (habitat structure, calf/adult rate, and density of conspecifics). We considered the effect of two predators, puma (Puma concolor) and culpeo fox (Lycalopex culpaeus). We measured two common (family group size and vigilance) and one novel (family group cohesion) behavioral responses of guanaco. Our results show that guanaco family groups adapted their grouping behavior to both predator occurrence and perceived predation risk. Larger family groups were found in open habitats and areas with high puma occurrence, while guanacos stayed in small family groups in areas with high shrub cover or low visibility. Group cohesion increased in areas with higher occurrence of pumas and culpeo foxes, and also increased in smaller family groups and in areas with low guanaco density. Vigilance (number of vigilant adults) was mainly related to group size and visibility, increasing in areas with low visibility, while residual vigilance (vigilance after removing the group-size effect) did not vary with the explanatory variables examined. Our results suggest that a mix of predator occurrence and perceived predation risk influences guanaco grouping behavior and highlights the importance of evaluating different antipredator responses together and considering all predator species in studies aimed at understanding ungulate behaviorFunding was provided by Program UAM‐CEAL (Santander Bank) during 2011‐2012, 2013‐2014, and 2015‐2016; Foreign Affairs Ministry, Spanish Agency for Development and International Cooperation (A/9875/07, A/016431/08, and A/024945/09); Agriculture Ministry and Environment Ministry, Chile, Servicio Agrícola y Ganadero 2011‐2012; and the REMEDINAL‐3CM network (S2013/MAE‐2719). ECI was supported by a PhD grant from the Spanish Ministry of Education (FPU) and is currently supported by a post‐doctoral grant from National Scientific and Technical Research Council (CONICET

Avian top predator and the landscape of fear: responses of mammalian mesopredators to risk imposed by the golden eagle

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Behavioural responses of free-ranging western grey kangaroos (Macropus fuliginosus) to olfactory cues of historical and recently introduced predators

Predation risk influences foraging decisions and time allocation of prey species, and may result in habitat shifts from potentially dangerous to safer areas. We examined a wild population of western grey kangaroos (Macropus fuliginosus) to test the efficacy of predator faecal odour in influencing time allocated to different behaviours and inducing changes in habitat use. Kangaroos were exposed to fresh faeces of a historical predator, the dingo (Canis lupus dingo), a recently introduced predator, the red fox (Vulpes vulpes), a herbivore (horse, Equus caballus) and an unscented control simultaneously. Kangaroos did not increase vigilance in predator-scented areas. However, they investigated odour sources by approaching and sniffing; more time was spent investigating fox odour than control odours. Kangaroos then exhibited a clear anti-predator response to predator odours, modifying their space use by rapidly escaping, then avoiding fox and dingo odour sources. Our results demonstrate that wild western grey kangaroos show behavioural responses to predator faeces, investigating then avoiding these olfactory cues of potential predation risk, rather than increasing general vigilance. This study contributes to our understanding of the impact of introduced mammalian predators on marsupial prey and demonstrates that a native Australian marsupial can recognize and respond to the odour of potential predators, including one that has been recently introduced

Feeding in fear: Indirect effects of predatory fish on macrophyte communities mediated by altered crayfish foraging behaviour

The threat of predation influences decisions made by prey animals and alters the way that prey interact with other species in their environment. Animals often alter their foraging behaviour in response to a predatory threat by increasing or decreasing food consumption or by changing their feeding preferences to focus on foods that limit their exposure to the threat. Changes in grazing pressure and diet selectivity can have significant impacts on the abundance and diversity of the prey’s food resources. In this study, we examined the indirect effects of a predatory fish on macrophyte biomass, mediated by crayfish responses to predator odours.Largemouth bass (Micropterus salmoides, Centrarchidae) were housed in flow‐through stream mesocosms to produce odour cues that initiated a nonconsumptive effect on rusty crayfish (Faxonius rusticus, Cambaridae) held in an adjacent section of the stream. Crayfish were offered three species of macrophytes (Myriophyllum exalbescens, Haloragaceae; Elodea canadensis, Hydrocharitaceae; Chara spp., Characeae) and were allowed to graze for 48 hr. Consumption of each plant species was measured by weighing the plant samples before and after every trial. The plant samples were further analysed for total phenolic content using the Folin–Ciocalteu method. Foraging and shelter use behaviours were quantified by analysis of video recordings for time spent foraging in the mesocosm and time spent in the shelter zone of the mesocosm.Crayfish consumed greater quantities of macrophyte tissue when predator cues were present, and this result was unexpected and is contrary to most observations in the literature.When threatened, the crayfish also showed a preference for two of the macrophyte species, which did not exist in trials without bass odour. This could be due to differences in total phenolic content among the three plant species tested.The results provide evidence for a strong indirect effect of predatory fish on the macrophyte community mediated by changes in crayfish behaviour under threat. Crayfish act as keystone species in stream ecosystems; thus, changes in their foraging behaviour and dietary preferences caused by exposure to predator odour cues could have important effects on macrophyte communities in lotic systems.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146642/1/fwb13181_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146642/2/fwb13181.pd

Aspen Recruitment in the Yellowstone Region Linked to Reduced Herbivory After Large Carnivore Restoration

Quaking aspen (Populus tremuloides) recruitment during the 1980s–90s was suppressed by Rocky Mountain elk (Cervus canadensis) herbivory on winter ranges in the Yellowstone region, and saplings (young aspen taller than 2 m) were rare. Following the 1995–96 reintroduction of gray wolves (Canis lupus), browsing decreased and sapling recruitment increased in Yellowstone National Park. We compared aspen data from inside the park to data collected in three winter ranges outside the park. For most areas, the percentage of young aspen browsed annually was 80–100% in 1997–98, decreasing to 30–60% in 2011–15. Sapling recruitment was inversely correlated with browsing intensity, and increased despite climate trends unfavorable for aspen. Browsing decreased with decreasing elk density, a relationship suggesting that densities greater than about 4 elk/km2 resulted in consistently strong browsing effects likely to suppress aspen recruitment. Changes in elk density and distribution were influenced by predators, as well as human hunters. Most evidence for trophic cascades involving large terrestrial mammals has been from protected areas within national parks. This study provides evidence of widespread changes in plant communities resulting from large carnivore restoration, extending outside a protected national park to areas with hunting, livestock grazing, and other human activities