Ecology of the red fox (Vulpes vulpes) in an agricultural landscape. 1. Den-site selection

2012 ◽  
Vol 34 (2) ◽  
pp. 145 ◽  
Author(s):  
Andrew Carter ◽  
Gary W. Luck ◽  
Ben P. Wilson
Keyword(s):  
Site Selection ◽  
Agricultural Landscape ◽  
Prey Species ◽  
Clay Content ◽  
Agricultural Landscapes ◽  
Breeding Period ◽  
Den Site Selection ◽  
Eastern Australia ◽  
Soil Clay Content ◽  
Fox Control

Foxes concentrate their activities around den sites during the breeding period and regularly visit dens at other times of the year, meaning den location is an important consideration in efforts to control foxes and protect native prey species. We investigated factors that influence den-site selection by foxes to improve information on potential interactions with prey species, and assess the usefulness of targeting den sites for fox control. We measured 76 earthen and non-earthen fox dens on farmland in south-eastern Australia and compared these with paired random sites in relation to vegetation/land-use type, soil clay content, and proximity to landscape features (tree, water, fence and road). Most dens were earthen and primarily located in open farmland, whereas non-earthen dens were mostly found in roadsides. The proportion of non-earthen dens located by landholders (7.8% of 51 dens) was substantially lower than the proportion of non-earthen dens identified with radio-tracking (77.8% of 18 dens). The average clay content at earthen dens was significantly lower than that at non-earthen dens (t′ = –5.192, P < 0.001) and random sites (t′ = –5.196, P < 0.001). Soil texture was a key factor influencing fox den location, and this information should greatly improve fox control in agricultural landscapes for the benefit of native and non-native prey.

Survival and biomass of exotic earthworms, Aporrectodea spp. (Lumbricidae), when introduced to pastures in south-eastern Australia

1999 ◽  
Vol 50 (7) ◽  
pp. 1233 ◽  
Author(s):  
G. H. Baker ◽  
P. J. Carter ◽  
V. J. Barrett
Keyword(s):  
South Australia ◽  
Clay Content ◽  
Total Biomass ◽  
Soil P ◽  
South Eastern ◽  
Inoculation Density ◽  
Eastern Australia ◽  
Exotic Earthworms ◽  
Soil Clay Content ◽  
South Eastern Australia

The earthworm fauna of pastures in south-eastern Australia is dominated by exotic lumbricid earthworms, in particular the endogeic species, Aporrectodea caliginosa and A. trapezoides. Anecic species such as A. longa are very rare. All 3 species were introduced within cages in 10 pastures on a range of soil types within the region. Five months later, A. longa had generally survived the best and A. trapezoides the worst. The survivals and weights of individual worms varied between sites for all 3 species. The survivals of A. caliginosa and A. longa, and to a lesser extent A. trapezoides, were positively correlated with soil clay content. The weights of A. caliginosa and A. longa, but not A. trapezoides, were positively correlated with soil P content. The survivals and weights of A. longa and A. trapezoides and the weights only of A. caliginosa decreased with increasing inoculation density, suggesting increased intraspecific competition for resources, particularly in the first two species. A. longa reduced the abundance and biomass of the exotic acanthodrilid earthworm, Microscolex dubius, at one site, and the total biomass of 3 native megascolecid species at another, when these latter species occurred as contaminants in A. longa cages. The addition of lime had no effect on the survivals and weights of A. caliginosa, A. longa, and A. trapezoides, although the soils were acid at the sites tested. The addition of sheep dung increased the survival and weights of some species at some sites. Mechanical disturbance of the soil within cages reduced the survivals of A. longa and A. trapezoides. A. longa was released without being caged at 25 sites within one pasture in South Australia. Four years later, it was recovered at all release points. A. longa has the potential to colonise pastures widely throughout the higher rainfall regions of south-eastern Australia.

Links between riparian characteristics and the abundance of common wombat (Vombatus ursinus) burrows in an agricultural landscape

2008 ◽  
Vol 35 (8) ◽  
pp. 760 ◽  
Author(s):  
Philip Borchard ◽  
John McIlroy ◽  
Clare McArthur
Keyword(s):  
Agricultural Landscape ◽  
Riparian Zone ◽  
Agricultural Landscapes ◽  
Weed Invasion ◽  
South Eastern ◽  
South Wales ◽  
Eastern Australia ◽  
Common Wombat ◽  
Restoration Strategies ◽  
Native Shrubs

Agricultural riparian zones are often vulnerable to weed invasion and degradation of the physical streambank character through the trampling of livestock. Riparian zone restoration seeks to improve habitat biodiversity, minimise streambank erosion and improve water quality. In order for this to be effective land managers need to broadly understand the connections between riparian systems and adjoining agricultural ecosystems and to understand the habitat requirements of wildlife species adapted to the evolving riparian landscape. Common wombats (Vombatus ursinus) are abundant in the riparian agricultural landscapes of south-eastern Australia, but there is concern about their persistence in other landscapes. To understand the importance of riparian characteristics for wombats, we examined five physical and five vegetative characteristics associated with abundance of wombat burrows in the riparian zone of an agricultural landscape in south-eastern New South Wales, using two independent datasets. The abundance of wombat burrows increased substantially with increasing shrub cover in both datasets. There was weaker but consistent support for an association between wombat burrows and stream order and vegetation width. There were more burrows per metre by high than low order streams and burrows were most abundant at an intermediate vegetation width. In one of the two datasets, burrow abundance declined as the proportion of native shrubs in the shrub layer increased. As wombats are generally limited to riparian buffers in agricultural landscapes, these results are important as a first step toward managing and restoring the riparian zone. Restoration strategies, for example, may need to consider retaining patches of shrubs, even if they are weeds, whereas native shrubs are established in interspersed patches along larger rivers, in order to maintain suitable wombat habitat.

Fox baiting in agricultural landscapes: preliminary findings on the importance of bait-site selection

2013 ◽  
Vol 40 (3) ◽  
pp. 184 ◽  
Author(s):  
Andrew Carter ◽  
Gary W. Luck
Keyword(s):  
Site Selection ◽  
Habitat Complexity ◽  
Ground Cover ◽  
Low Complexity ◽  
Agricultural Landscapes ◽  
Landscape Elements ◽  
Remnant Vegetation ◽  
Roadside Vegetation ◽  
Bait Stations ◽  
Fox Control

Context Little is known about the importance of bait-site selection during lethal fox-baiting programmes. Improved bait placement may increase the efficacy of baiting and help reduce fox impacts on wildlife and livestock. Aims To determine whether bait uptake by the red fox (Vulpes vulpes) differed among five landscape elements (roadsides, fence lines, open paddocks, creek lines and remnant vegetation) and at sites with high or low habitat (ground cover) complexity. Methods We measured bait uptake at 300 bait stations distributed evenly among the landscape elements in agricultural landscapes in northern Victoria, Australia. Bait uptake was also compared between sites with low and high habitat complexity in districts subject to no fox control and annual fox control. Key results Among landscape elements, bait uptake was significantly higher in roadside vegetation and along vegetated creek lines than it was along fence lines and in open paddocks (P < 0.05 in each case). Within roadside vegetation, bait uptake was significantly (P = 0.001) lower at sites with a high habitat complexity than at sites with low complexity, particularly in areas subject to annual fox control. Conclusions Bait placement influences bait-uptake rates considerably and greater consideration should be placed on bait-site selection during fox-baiting programmes. Habitat complexity limited bait uptake, which may indicate a reduced capacity of foxes to find baits in complex habitats. Implications Our results should help improve bait-site selection in agricultural landscapes and may increase the efficacy of fox baiting to the benefit of native fauna and livestock.

Use and characteristics of nocturnal habitats of the squirrel glider (Petaurus norfocensis) in Australian temperate woodlands

2012 ◽  
Vol 60 (5) ◽  
pp. 320 ◽  
Author(s):  
M. J. Crane ◽  
D. B. Lindenmayer ◽  
R. B. Cunningham
Keyword(s):  
Regression Models ◽  
Agricultural Landscape ◽  
Agricultural Landscapes ◽  
Nocturnal Activity ◽  
Eastern Australia ◽  
Temperate Woodlands ◽  
Multiple Regression Models ◽  
Squirrel Glider ◽  
Direct Management ◽  
Different Parts

In Australian temperate woodlands, most squirrel glider (Petaurus norfolcensis) habitats exist outside formal conservation reserves, often in highly fragmented agricultural landscapes. To conserve squirrel glider populations in such woodlands it is essential to define important habitats and understand how they are used. This study examines the nocturnal habitat use of squirrel gliders across five sites within an agricultural landscape in south-eastern Australia. Over a five-month period we radio-tracked 32 gliders to 372 nocturnal locations. We quantify characteristics of key nocturnal habitats and describe their use. Gliders were more likely to use large eucalypt trees, particularly yellow box (Eucalyptus melliodora) and mugga ironbark (E. sideroxylon). Nocturnal activity mostly took place high in the canopy of eucalypts, accounting for 74% of fixes. Multiple regression models revealed that feeding was more likely to occur in large, healthy trees close to drainage lines, with a preference for E. melliodora, when eucalypts were not flowering. Flowering trees were preferentially sought and were strongly associated with being large healthy trees that occur on ridges and upper slopes. Showing that the squirrel glider utilises key feeding structures (large healthy Eucalyptus trees) in different parts of the landscape at different times has direct management implications in the conservation and restoration of squirrel glider habitat, particularly in fragmented temperate woodland.

Nesting sites in agricultural landscapes may reduce the reproductive success of populations of Blanding’s Turtles (Emydoidea blandingii)

2016 ◽  
Vol 94 (1) ◽  
pp. 61-67 ◽  
Author(s):  
A.B. Mui ◽  
C.B. Edge ◽  
J.E. Paterson ◽  
B. Caverhill ◽  
B. Johnson ◽  
...  
Keyword(s):  
Site Selection ◽  
Vegetation Cover ◽  
Environmental Variables ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Agricultural Landscape ◽  
Agricultural Landscapes ◽  
Turtle Species ◽  
Emydoidea Blandingii ◽  
Parallel Change

Almost all turtle species nest in terrestrial environments and maternal site selection represents a critical component of nest success. Females use cues in the current environment to predict the future conditions for embryo development. However, in disturbed landscapes, current and future conditions may not be correlated. We compared selection of nest sites by Blanding’s Turtles (Emydoidea blandingii (Holbrook, 1838)) in a (relatively undisturbed) park and a (heavily disturbed) agricultural landscape in Ontario, Canada, using field measurements and satellite imagery. Environmental variables were compared using logistic regression and Akaike’s information criterion (AIC) based on data measured at nest (presence) and random (pseudoabsence) locations. Specific environmental variables associated with site selection differed between study areas. Most notably, NDVI (normalized difference vegetation index, a proxy for vegetation cover) increased significantly during the year at the agricultural locale, corresponding with the growth of planted fields. No parallel change was observed at the park locale where canopy cover remained more consistent. An increase in vegetation cover may alter nest temperatures and soil moisture. Combined with the unpredictability in timing of crop sowing and harvesting, findings suggest that nests in agricultural fields may act as ecological sinks and that other species nesting in similarly altered habitats may be subjected to the same threats.

Ecology of the red fox (Vulpes vulpes) in an agricultural landscape. 2. Home range and movements

2012 ◽  
Vol 34 (2) ◽  
pp. 175 ◽  
Author(s):  
Andrew Carter ◽  
Gary W. Luck ◽  
Simon P. McDonald
Keyword(s):  
Home Range ◽  
Vulpes Vulpes ◽  
Agricultural Landscape ◽  
Red Fox ◽  
Radio Telemetry ◽  
Home Range Size ◽  
Agricultural Landscapes ◽  
Range Size ◽  
Minimum Convex Polygon ◽  
Eastern Australia

The red fox (Vulpes vulpes) is a major predator of Australian wildlife and livestock, but relatively few data exist on fox home-range size and movements in agricultural landscapes. We used radio-telemetry to measure variability in fox home-range size and overlap, and to quantify nightly movements in farmland in south-eastern Australia. Home-range estimates were calculated using the Minimum Convex Polygon (MCP) and Kernel Contours methods. Fourteen foxes were radio-tracked, with home-range size varying from 287 to 3574 ha (mean = 1177 ha, ±920 ha (s.d.), n = 10 foxes) based on the 100% MCP and 151–3196 ha (mean = 639 ha, ± 930 ha (s.d.), n = 10 foxes) based on 95% Kernel. Home-range overlap was greater between subadults than adult foxes; especially at the core home-range level where adult home ranges were virtually exclusive. The average (minimum) area covered by adult foxes during a 12-h nightly period was 383 ha (±347 ha (s.d.), range = 136–1446 ha, n = 4 foxes). The minimum (straight-line) distance travelled by adult foxes during a night was 4.8–16 km (mean = 9.4 km, ± 3.7 km (s.d.), n = 4 foxes). Through continuous radio-tracking, we found that foxes habitually travel over the same ground when moving between foci of interest. Our results improve understanding of fox ranging behaviour in the agricultural landscapes of southern Australia.

scholarly journals The Relict Ecosystem of Maytenus senegalensis subsp. europaea in an Agricultural Landscape: Past, Present and Future Scenarios

Land ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 1
Author(s):  
Antonio J. Mendoza-Fernández ◽  
Fabián Martínez-Hernández ◽  
Esteban Salmerón-Sánchez ◽  
Francisco J. Pérez-García ◽  
Blas Teruel ◽  
...  
Keyword(s):  
Plant Communities ◽  
Ecological Niche ◽  
Agricultural Landscape ◽  
Agricultural Landscapes ◽  
Eastern Coast ◽  
Ecological Value ◽  
Distribution Models ◽  
European Continent ◽  
Major Interest ◽  
Maytenus Senegalensis

Maytenus senegalensis subsp. europaea is a shrub belonging to the Celastraceae family, whose only European populations are distributed discontinuously along the south-eastern coast of the Iberian Peninsula, forming plant communities with great ecological value, unique in Europe. As it is an endangered species that makes up plant communities with great palaeoecological significance, the development of species distribution models is of major interest under different climatic scenarios, past, present and future, based on the fact that the climate could play a relevant role in the distribution of this species, as well as in the conformation of the communities in which it is integrated. Palaeoecological models were generated for the Maximum Interglacial, Last Maximum Glacial and Middle Holocene periods. The results obtained showed that the widest distribution of this species, and the maximum suitability of its habitat, occurred during the Last Glacial Maximum, when the temperatures of the peninsular southeast were not as contrasting as those of the rest of the European continent and were favored by higher rainfall. Under these conditions, large territories could act as shelters during the glacial period, a hypothesis reflected in the model’s results for this period, which exhibit a further expansion of M. europaea’s ecological niche. The future projection of models in around 2070, for four Representative Concentration Pathways according to the fifth report of the Intergovernmental Panel on Climate Change, showed that the most favorable areas for this species would be Campo de Dalías (southern portion of Almería province) as it presents the bioclimatic characteristics of greater adjustment to M. europaea’s ecological niche model. Currently, some of the largest specimens of the species survive in the agricultural landscapes in the southern Spain. These areas are almost totally destroyed and heavily altered by intensive agriculture greenhouses, also causing a severe fragmentation of the habitat, which implies a prospective extinction scenario in the near future.

scholarly journals Predation on Drosophila suzukii within Hedges in the Agricultural Landscape

Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 305
Author(s):  
Alexandra Siffert ◽  
Fabian Cahenzli ◽  
Patrik Kehrli ◽  
Claudia Daniel ◽  
Virginie Dekumbis ◽  
...  
Keyword(s):  
Agricultural Landscape ◽  
Vital Role ◽  
Agricultural Landscapes ◽  
Gut Content ◽  
Drosophila Suzukii ◽  
Natural Habitats ◽  
Host Fruit ◽  
Molecular Gut Content Analysis ◽  
Wild Fruits ◽  
Diverse Community

The invasive Drosophila suzukii feeds and reproduces on various cultivated and wild fruits and moves between agricultural and semi-natural habitats. Hedges in agricultural landscapes play a vital role in the population development of D. suzukii, but also harbor a diverse community of natural enemies. We investigated predation by repeatedly exposing cohorts of D. suzukii pupae between June and October in dry and humid hedges at five different locations in Switzerland. We sampled predator communities and analyzed their gut content for the presence of D. suzukii DNA based on the COI marker. On average, 44% of the exposed pupae were predated. Predation was higher in dry than humid hedges, but did not differ significantly between pupae exposed on the ground or on branches and among sampling periods. Earwigs, spiders, and ants were the dominant predators. Predator communities did not vary significantly between hedge types or sampling periods. DNA of D. suzukii was detected in 3.4% of the earwigs, 1.8% of the spiders, and in one predatory bug (1.6%). While the molecular gut content analysis detected only a small proportion of predators that had fed on D. suzukii, overall predation seemed sufficient to reduce D. suzukii populations, in particular in hedges that provide few host fruit resources.

scholarly journals Determinants of bird assemblage composition in riparian vegetation on sugarcane farms in the Queensland Wet Tropics

2015 ◽  
Vol 21 (1) ◽  
pp. 60 ◽  
Author(s):  
Anita F. Keir ◽  
Richard G. Pearson ◽  
Robert A. Congdon
Keyword(s):  
Riparian Vegetation ◽  
Wildlife Conservation ◽  
Agricultural Landscape ◽  
Riparian Zone ◽  
Riparian Forest ◽  
Agricultural Landscapes ◽  
Generalist Species ◽  
Assemblage Composition ◽  
Bird Assemblages ◽  
Wet Tropics

Remnant habitat patches in agricultural landscapes can contribute substantially to wildlife conservation. Understanding the main habitat variables that influence wildlife is important if these remnants are to be appropriately managed. We investigated relationships between the bird assemblages and characteristics of remnant riparian forest at 27 sites among sugarcane fields in the Queensland Wet Tropics bioregion. Sites within the remnant riparian zone had distinctly different bird assemblages from those of the forest, but provided habitat for many forest and generalist species. Width of the riparian vegetation and distance from source forest were the most important factors in explaining the bird assemblages in these remnant ribbons of vegetation. Gradual changes in assemblage composition occurred with increasing distance from source forest, with species of rainforest and dense vegetation being replaced by species of more open habitats, although increasing distance was confounded by decreasing riparian width. Species richness increased with width of the riparian zone, with high richness at the wide sites due to a mixture of open-habitat species typical of narrower sites and rainforest species typical of sites within intact forest, as a result of the greater similarity in vegetation characteristics between wide sites and the forest proper. The results demonstrate the habitat value for birds of remnant riparian vegetation in an agricultural landscape, supporting edge and open vegetation species with even narrow widths, but requiring substantial width (>90 m) to support specialists of the closed forest, the dominant original vegetation of the area.

scholarly journals Environmental determinants of haemosporidian parasite prevalence in a declining population of Tree swallows

Parasitology ◽  
2017 ◽  
Vol 145 (7) ◽  
pp. 961-970 ◽  
Author(s):  
Audrey Turcotte ◽  
Marc Bélisle ◽  
Fanie Pelletier ◽  
Dany Garant
Keyword(s):  
Forest Cover ◽  
Agricultural Landscape ◽  
Parasite Prevalence ◽  
Landscape Composition ◽  
Breeding Period ◽  
Tree Swallows ◽  
Environmental Determinants ◽  
Negative Effects ◽  
Haemosporidian Parasite ◽  
Haemosporidian Parasites

AbstractThe prevalence of vector-borne parasites such as haemosporidian species is influenced by several environmental factors. While the negative effects of parasitism on hosts are well documented, these can also be amplified by interactions with environmental stressors, many of which are anthropogenic. Yet, we know little about the possible effects of anthropogenic perturbations on parasite prevalence. The goals of this study were to assess the prevalence and environmental determinants of haemosporidian parasites in a declining population of Tree swallows (Tachycineta bicolor) living in an agricultural landscape in southern Québec, Canada. Overall, a low prevalence and a moderate lineage diversity were identified in both adults and nestlings, confirming that transmission can occur during the breeding period. Anthropic areas, extensive cultures (hayfields and pastures) and forest cover within 500 km of nest boxes, as well as daily temperature fluctuations, were all related to infection by haemosporidian parasites. These findings suggest that anthropogenic alterations of landscape composition can modulate the prevalence of haemosporidian parasites in Tree swallows. Our results represent a baseline for future comparative studies assessing haemosporidian parasite prevalence in human-modified landscapes.

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