scholarly journals Impacts of cattle grazing on small-rodent communities: an experimental case study

2012 ◽  
Vol 90 (1) ◽  
pp. 22-30 ◽  
Author(s):  
C. Bueno ◽  
K.E. Ruckstuhl ◽  
N. Arrigo ◽  
A.N. Aivaz ◽  
P. Neuhaus
Keyword(s):  
Species Interactions ◽  
Grazing Intensity ◽  
Cattle Grazing ◽  
Grazing Pressure ◽  
Rodent Species ◽  
Deer Mice ◽  
Small Rodent ◽  
Meadow Voles ◽  
Complex Species ◽  
Survival Sex

We used experimental cattle ungrazed and grazed sites to evaluate what impact different intensities of cattle grazing have on deer mice ( Peromyscus maniculatus (Wagner, 1845)) and meadow voles ( Microtus pennsylvanicus (Ord, 1815)). Live-trapping of these small rodents was conducted on paired treatment plots (grazed and ungrazed) at Sheep River Provincial Park in southwestern Alberta, Canada. Before grazing started, both rodent species were equally abundant in either grazed or ungrazed sites. Introduction of grazing resulted in strong but differing responses by both rodent species. Deer mice had higher population density (measured as individual animals trapped) in the grazed than in ungrazed plots, but their body mass was negatively correlated with increasing grazing pressure. Meadow voles were more heavily affected by grazing, as a strong avoidance of cattle-grazed plots was observed already at low grazing intensity. In addition, cattle grazing had noticeable effects, impacting the survival, sex and age ratios, and the ectoparasite prevalence of these two rodent populations. We conclude that there are diverse and different levels of impact of cattle grazing on those two rodents, leading to much more complex species interactions than previously thought. We suggest that the presence or absence, density, and body condition of small mammals could be used as a tool for ecosystem health assessment.

scholarly journals Small Rodent Populations and Conifer Seedling Damage on a Reclaimed Area in West Central Alberta

1989 ◽  
Vol 65 (4) ◽  
pp. 271-275 ◽  
Author(s):  
Alan J. Kennedy ◽  
David F. Penner ◽  
Jeffrey E. Green
Keyword(s):  
Picea Glauca ◽  
Pinus Contorta ◽  
Seedling Survival ◽  
Deer Mice ◽  
Small Rodent ◽  
Small Rodents ◽  
Meadow Voles ◽  
West Central ◽  
Rodent Populations ◽  
Conifer Seedling

Small rodent populations and conifer seedling survival were monitored on a reclaimed area in west central Alberta from September 1979 to September 1985. Although several species of cricetid rodents and shrews were captured during the live-trapping program, only meadow voles (Microtus pennsylvanicus) and deer mice (Peromyscus maniculatus) occurred in sufficient number to monitor annual changes in abundance. Meadow voles increased rapidly on the reclaimed area from 1979–1981, remained at high numbers until 1984, then declined sharply in 1985. Deer mice increased to moderate numbers from 1979–1981 and declined gradually until 1983. By 1984–1985, very few deer mice were present.Two species of conifer seedlings, lodgepole pine (Pinus contorta) and white spruce (Picea glauca) were planted on the reclaimed area in 1979 and 1980. Numbers of seedlings killed or damaged by small rodents, primarily by girdling, increased sharply in 1981 and remained at high levels through to 1984. Significant correlations between the percentage of the annual mortality of seedlings attributed to small rodents or the percentage of live seedlings damaged by small rodents, and the abundance of meadow voles the previous winter, indicate that the amount of mortality and damage to seedlings in this reclamation area is in part determined by the overwintering abundance of meadow voles. This is in direct agreement with conclusions from similar studies in other areas of North America and Europe.

Fertilisation, cattle grazing and voles: collapse of meadow vole populations in young forests?

2014 ◽  
Vol 41 (5) ◽  
pp. 367 ◽  
Author(s):  
Thomas P. Sullivan ◽  
Druscilla S. Sullivan
Keyword(s):  
North America ◽  
Cattle Grazing ◽  
Grazing Pressure ◽  
Meadow Vole ◽  
Population Fluctuations ◽  
Herbaceous Vegetation ◽  
Meadow Voles ◽  
North West ◽  
The Pacific ◽  
Young Forests

Context A puzzling aspect of microtine population fluctuations is the damping out or collapsing of cycles over the last three decades, particularly in northern Europe. Occasional population fluctuations of Microtus may also have been damped out in temperate and boreal forests of the Pacific North-west of North America. One cause might be the presence of cattle (Bos taurus) grazing in forest habitats that offer summer forage. Aims We tested hypotheses (H) that abundance, population fluctuations, and demographic parameters of reproduction, recruitment and survival, of Microtus pennsylvanicus would be driven by understory plant productivity. Two predictions follow from this hypothesis: (H1) enhanced abundance and demography in fertilised stands, and (H2) reduced abundance and demography in stands with cattle grazing. Methods Study areas were located in ‘grazed’ and ‘ungrazed’ young forests in south-central British Columbia, Canada. Each study area had four replicate units of unfertilised and repeatedly fertilised stands. Herbaceous vegetation and meadow vole (M. pennsylvanicus) populations were sampled from 1993 to 2002. Key results Mean abundance of total herbs, grasses, and fireweed (Epilobium angustifolium) increased dramatically (8 to 34 times higher) with fertilisation in the ungrazed stands. Mean abundance of meadow voles was 3.1 to 8.5 times higher in the nutrient-enriched herbaceous vegetation in the ungrazed fertilised than grazed fertilised stands. Demographic variables also followed this pattern of abundance. Except for two years, mean abundance of meadow voles was similar between fertilised and unfertilised stands at the grazed area, with some degree of fluctuations generated in grazed stands. Thus, H1 and H2 were at least partly supported for M. pennsylvanicus in fertilised stands. Conclusions In high-quality habitats where cover and other attributes of vegetation are substantial enough to generate population increases and fluctuations of Microtus, grazing of vegetation by cattle or other livestock may indeed lead to potential collapse of fluctuations. Degree of grazing pressure would be crucial, but considering the widespread nature of grazing in the continuum of post-harvest forested sites in the Pacific North-west of North America, moderate to heavy grazing pressure is common. Implications Reductions in populations of microtines have serious consequences for predator communities and other ecological functions.

Contrasting effects of fire on populations of two small rodent species in fragments of Atlantic Forest in Brazil

2004 ◽  
Vol 20 (2) ◽  
pp. 225-228 ◽  
Author(s):  
Marcos de Souza Lima Figueiredo ◽  
Fernando Antonio dos Santos Fernandez
Keyword(s):  
Atlantic Forest ◽  
Feedback System ◽  
Rodent Species ◽  
Primary Forest ◽  
Small Rodent ◽  
Forest Species ◽  
The Core ◽  
Higher Temperature ◽  
Disturbed Habitats

Habitat fragmentation causes a sharp increase in the forested area affected by edge effects (Murcia 1995). Compared with the core of the forest, edges present higher litterfall rates, air and soil humidity reduction, higher temperature and increased wind incidence (Bierregaard et al. 1992, Didham & Lawton 1999, Laurance et al. 1998, Matlack 1993). These features of edges may increase the probability of fire occurrence, especially if the surrounding vegetation is composed of grasses (D'Antonio & Vitousek 1992, Freifelder et al. 1998). After a fire, the damaged edge will grow substantial amounts of herbaceous vegetation, extending the inflammable area into the forest, and thereby creating a positive feedback system of fire susceptibility and intensity (Cochrane & Schulze 1999, Cochrane et al. 1999). Fires may affect the structure and composition of the vegetation (Cochrane & Schulze 1999, Didham & Lawton 1999, Sanaiotti & Magnusson 1995), favouring, in the long-term, the dominance of the community by species characteristic of disturbed habitats and making the habitat unsuitable to primary forest species (Malcolm 1994, Possingham et al. 1994). Unfortunately, there are few studies on the effects of fires on neotropical small-mammal populations (Borchert & Hansen 1983, Ojeda 1989, Vieira & Marinho-Filho 1998). The objective of this study was to analyse the influence of a fire on populations of two rodent species, Akodon cursor (Winge) and Oecomys concolor (Wagner) in two fragments of Atlantic Forest in Brazil.

scholarly journals Does EO NDVI seasonal metrics capture variations in species composition and biomass due to grazing in semi-arid grassland savannas?

2015 ◽  
Vol 12 (14) ◽  
pp. 4407-4419 ◽  
Author(s):  
J. L. Olsen ◽  
S. Miehe ◽  
P. Ceccato ◽  
R. Fensholt
Keyword(s):  
Time Series ◽  
Species Composition ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Regional Scale ◽  
Grazing Intensity ◽  
Test Site ◽  
Grazing Pressure ◽  
Modis Ndvi ◽  
Coarse Resolution

Abstract. Most regional scale studies of vegetation in the Sahel have been based on Earth observation (EO) imagery due to the limited number of sites providing continuous and long term in situ meteorological and vegetation measurements. From a long time series of coarse resolution normalized difference vegetation index (NDVI) data a greening of the Sahel since the 1980s has been identified. However, it is poorly understood how commonly applied remote sensing techniques reflect the influence of extensive grazing (and changes in grazing pressure) on natural rangeland vegetation. This paper analyses the time series of Moderate Resolution Imaging Spectroradiometer (MODIS) NDVI metrics by comparing it with data from the Widou Thiengoly test site in northern Senegal. Field data include grazing intensity, end of season standing biomass (ESSB) and species composition from sizeable areas suitable for comparison with moderate – coarse resolution satellite imagery. It is shown that sampling plots excluded from grazing have a different species composition characterized by a longer growth cycle as compared to plots under controlled grazing or communal grazing. Also substantially higher ESSB is observed for grazing exclosures as compared to grazed areas, substantially exceeding the amount of biomass expected to be ingested by livestock for this area. The seasonal integrated NDVI (NDVI small integral; capturing only the signal inherent to the growing season recurrent vegetation), derived using absolute thresholds to estimate start and end of growing seasons, is identified as the metric most strongly related to ESSB for all grazing regimes. However plot-pixel comparisons demonstrate how the NDVI/ESSB relationship changes due to grazing-induced variation in annual plant species composition and the NDVI values for grazed plots are only slightly lower than the values observed for the ungrazed plots. Hence, average ESSB in ungrazed plots since 2000 was 0.93 t ha−1, compared to 0.51 t ha−1 for plots subjected to controlled grazing and 0.49 t ha−1 for communally grazed plots, but the average integrated NDVI values for the same period were 1.56, 1.49, and 1.45 for ungrazed, controlled and communal, respectively, i.e. a much smaller difference. This indicates that a grazing-induced development towards less ESSB and shorter-cycled annual plants with reduced ability to turn additional water in wet years into biomass is not adequately captured by seasonal NDVI metrics.

scholarly journals Flea Communities on Small Rodents in Eastern Poland

Insects ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 894
Author(s):  
Zbigniew Zając ◽  
Joanna Kulisz ◽  
Aneta Woźniak
Keyword(s):  
Mixed Forest ◽  
Flea Species ◽  
Rodent Species ◽  
Small Rodent ◽  
Grassland Vegetation ◽  
Rodent Host ◽  
Host Preferences ◽  
Wide Range ◽  
A Site ◽  
Ecological Habitats

Fleas are hematophagous insects infesting mainly small mammals and, less frequently, birds. With their wide range of potential hosts, fleas play a significant role in the circulation of pathogens in nature. Depending on the species, they can be vectors for viruses, bacteria, rickettsiae, and protozoa and a host for some larval forms of tapeworm species. The aim of this study was to determine the species composition of fleas and their small rodent host preferences in eastern Poland. Animals were captured in traps in various types of ecological habitats (a site covered by grassland vegetation within city limits, an unused agricultural meadow, and a fallow land near a mixed forest). The following rodent species were caught: Apodemus agrarius, Apodemus flavicollis, Microtus arvalis, and Myodesglareolus. Additionally, Ctenophthalmus agyrtes, Ctenophthalmus assimilis, Hystrichopsylla talpae, and Nosopsyllus fasciatus flea species were identified. The peak of the flea activity was noted in summer months. C. agyrtes was found to be the most abundant flea species in eastern Poland, while the greatest numbers of fleas were collected from the rodent species A. agrarius.

Rangeland condition in relation to environmental variables, grazing intensity and livestock owners' perceptions in semi-arid rangeland in western Iran

2010 ◽  
Vol 32 (4) ◽  
pp. 367 ◽  
Author(s):  
M. Faramarzi ◽  
S. Kesting ◽  
J. Isselstein ◽  
N. Wrage
Keyword(s):  
Environmental Variables ◽  
Management Practices ◽  
Grazing Intensity ◽  
Bare Soil ◽  
Grazing Pressure ◽  
Botanical Composition ◽  
Western Iran ◽  
Range Condition ◽  
Rangeland Condition ◽  
Semi Arid

Rangeland condition has often been assessed in relation to either botanical, edaphic, environmental or management factors. In this investigation, we analysed the interaction of soil and topographic variables, management and range condition against the background of a sociological survey of livestock owners in western Iran to better understand the main influencing factors of rangeland quality in the area. In four grazing areas in Kermanshah differing in grazing pressure, environmental variables and livestock owners’ perceptions on range condition, investigations of botanical composition, soil and topographic variables were carried out on 43 main plots. To evaluate range condition, four factors were considered, namely litter frequency, herbage palatability, amount of biomass, and percentage of bare soil. A questionnaire was used to obtain information about management practices, the perception of livestock owners on range condition and suggested solutions to problems in the different grazing areas. The range condition scores showed that the condition of the sites was either fair or poor. Of the soil and topographic factors, only north-facing aspect explained part of the variation in range condition scores. High grazing intensity was associated with poor range condition. To improve the rangeland condition, measures influencing water availability and a reduction of grazing pressure seem to be more relevant in the study area than fertilisation or seeding.

Insights on the relationship between total grazing pressure management and sustainable land management: key indicators to verify impacts

2019 ◽  
Vol 41 (6) ◽  
pp. 535 ◽  
Author(s):  
C. M. Waters ◽  
S. E. McDonald ◽  
J. Reseigh ◽  
R. Grant ◽  
D. G. Burnside
Keyword(s):  
Land Management ◽  
Management Practices ◽  
Temporal Trends ◽  
Grazing Intensity ◽  
Grazing Pressure ◽  
Environmental Stewardship ◽  
Grazing Management ◽  
Sustainable Land Management ◽  
Key Indicators ◽  
The Impact

Demonstrating sustainable land management (SLM) requires an understanding of the linkages between grazing management and environmental stewardship. Grazing management practices that incorporate strategic periods of rest are promoted internationally as best practice. However, spatial and temporal trends in unmanaged feral (goat) and native (kangaroo) populations in the southern Australian rangelands can result land managers having, at times, control over less than half the grazing pressure, precluding the ability to rest pastures. Few empirical studies have examined the impacts of total grazing pressure (TGP) on biodiversity and resource condition, while the inability to manage grazing intensity at critical times may result in negative impacts on ground cover, changes in pasture species composition, increased rates of soil loss and reduce the ability for soils to store carbon. The widespread adoption of TGP control through exclusion fencing in the southern Australian rangelands has created unprecedented opportunities to manage total grazing pressure, although there is little direct evidence that this infrastructure leads to more sustainable land management. Here we identify several key indicators that are either outcome- or activity-based that could serve as a basis for verification of the impacts of TGP management. Since TGP is the basic determinant of the impact of herbivory on vegetation it follows that the ability for rangeland pastoral management to demonstrate SLM and environmental stewardship will rely on using evidence-based indicators to support environmental social licence to operate.

Distribution and aggregation of engorging ticks on body parts of small rodent hosts

2020 ◽  
Vol 25 (11) ◽  
pp. 2018-2032
Author(s):  
László Egyed ◽  
Zsolt Lang
Keyword(s):  
Control Strategies ◽  
Natural Habitat ◽  
Neck Region ◽  
The Body ◽  
Rodent Species ◽  
Small Rodent ◽  
Body Parts ◽  
Lactating Females ◽  
Tick Survival ◽  
Disease Risks

Small rodent species are the most important blood source of tick larvae, their role is crucial for tick survival, maintainance and spread in nature. From data of 1409 ticks collected from 282 individuals of three small rodent species live-trapped at a natural habitat, we drew conclusions about aggregation of ticks, the anatomical sites most frequently used for engorgement, different susceptibility of host species to tick infestation. We studied data of various age and sex groups of hosts, individuals of different reproductive status and recaptured rodents. The tick load of A. agrarius and A. flavicollis differed significantly, accumulation of ticks was shown on the auricles of both Apodemus species, and on the throat-neck region of A. agrarius. Old rodents carried more, lactating females less ticks, than the average. Data of recaptured hosts showed, that ticks invade the body via the toes and nose and they are aiming for the auricles. Voles were significantly more heavily infested with nymphs which fed in the auditory tracts, which were free of ticks in mice. The phenomenon of aggregation is important for understanding the ecology of tick-borne diseases, as only a minority of the hosts are responsible for disease risks, and it is particularly important for control strategies that apply acaricides to reservoir hosts.

Grazing intensity of cattle on a complex of rangeland communities in Central Australia.

1980 ◽  
Vol 2 (1) ◽  
pp. 76 ◽  
Author(s):  
WA Low ◽  
WJ Muller ◽  
ML Dudzinski
Keyword(s):  
Perennial Grass ◽  
Grazing Intensity ◽  
Cattle Grazing ◽  
Annual Grass ◽  
Range Condition ◽  
Aerial Surveys ◽  
The Mean ◽  
Central Australia ◽  
Free Ranging

Distribution of cattle grazing the rangeland communities of Kunoth Paddock in central Australia was determined from aerial surveys at fortnightly intervals over a 4.5 year period. Mean density throughout the study was 3.5 cattle/km2 and varied between communities from 8.0 cattle/km2 to 0.4 cattle/km2 on the major communities and from 25.6 cattle/km2 to 3.2 cattle/km2 on the minor communities. Cow-days of use were calculated for seasonal intervals to show grazing intensity on the communities over ti~ne. Grazing concentrations throughout the study revealed three groups of utilization levels of the major communities. Foothill fans, Woodlands, Floodplains and Gilgaied plains received about twice the mean grazing intensity for the paddock. Mulga-annual grass received about average grazing intensity and Hills and Mulga-perennial grass received less than half the average grazing intensity. Our sti~dy shows that cattle graze range communities differentially in a free-ranging situation. This information is useful in interpreting results of range condition and trend studies, and also suggests that more uniform utilization of all the communities might be obtained by controlhng grazing distribution.

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