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

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.

2002 ◽  
Vol 29 (4) ◽  
pp. 329 ◽  
Author(s):  
Rodney van der Ree

The geographic range of the squirrel glider (Petaurus norfolcensis) in south-eastern Australia largely corresponds with fertile soils highly suited for agriculture. As a consequence of extensive clearing for agriculture, the conservation of P. norfolcensis in south-eastern Australia is now reliant on a mosaic of many fragmented and isolated patches of woodland and forest. In this study, I investigated the population dynamics of P. norfolcensis in an agricultural landscape where most remnant woodland occurs as linear strips along roadsides, unused road reserves and watercourses. A total of 251 gliders were trapped 1343 times within the linear habitats between December 1996 and November 1998. Gliders were resident within the linear strips at 0.95–1.54 individuals ha–1, a density equal to, or greater than, that recorded elsewhere for the species in continuous forest. All adult females were reproductively active and the mean natality rate was 1.9 young per adult female per year. Overall, the population age-structure appeared to be stable. While currently supporting a stable, high-density population, the long-term viability of these remnants as habitat is not assured because roadside reserves are narrow, easily fragmented and subjected to a host of deleterious processes causing ongoing habitat loss and degradation.


2003 ◽  
Vol 25 (1) ◽  
pp. 97 ◽  
Author(s):  
der Ree R van

THE yellow-footed Antechinus Antechinus flavipes is distributed from South Australia, through central Victoria, New South Wales and into Queensland as well as in south-western Australia (Van Dyck 1998). In south-eastern Australia, the conservation of A. flavipes is not assured because its range largely corresponds with the temperate woodlands that have undergone extensive clearing and degradation (Menkhorst 1995). Despite this, no studies on the effects of the loss and fragmentation of habitat on A. flavipes have been published in the scientific literature. In contrast, numerous ecological studies that investigate the consequences of anthropogenic disturbance have been undertaken on its congeners, the brown antechinus Antechinus stuartii and agile antechinus Antechinus agilis (e.g., Bennett 1987; Downes et al. 1997; Knight and Fox 2000). These studies indicate that the abundance of these species may be influenced by patch size (Bennett 1987; Dunstan and Fox 1996), distance to large forest blocks (Downes et al. 1997), habitat structure (Knight and Fox 2000) and degree of tolerance to modified habitats that surround the patch (Knight and Fox 2000). Can the response of A. stuartii and A. agilis be used to predict how the loss, fragmentation and degradation of habitat may affect A. flavipes? In this note, I provide preliminary information about a population of A. flavipes occupying linear fragments of woodland in an agricultural landscape in southeastern Australia.


2008 ◽  
Vol 35 (8) ◽  
pp. 760 ◽  
Author(s):  
Philip Borchard ◽  
John McIlroy ◽  
Clare McArthur

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.


2012 ◽  
Vol 34 (2) ◽  
pp. 145 ◽  
Author(s):  
Andrew Carter ◽  
Gary W. Luck ◽  
Ben P. Wilson

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.


2012 ◽  
Vol 34 (2) ◽  
pp. 175 ◽  
Author(s):  
Andrew Carter ◽  
Gary W. Luck ◽  
Simon P. McDonald

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.


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 ◽  
...  

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.


Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 305
Author(s):  
Alexandra Siffert ◽  
Fabian Cahenzli ◽  
Patrik Kehrli ◽  
Claudia Daniel ◽  
Virginie Dekumbis ◽  
...  

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.


2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 10-11
Author(s):  
Esther D McCabe ◽  
Mike E King ◽  
Karol E Fike ◽  
Maggie J Smith ◽  
Glenn M Rogers ◽  
...  

Abstract The objective was to determine effect of trucking distance on sale price of beef calf and feeder cattle lots sold through Superior Livestock Video Auctions from 2010 through 2018. Data analyzed were collected from 211 livestock video auctions. There were 42,043 beef calf lots and 19,680 feeder cattle lots used in these analyses. Six states (Colorado, Iowa, Kansas, Nebraska, Oklahoma, and Texas) of delivery comprised 70% of calf lots and 83% of feeder cattle lots and were used in these analyses. All lot characteristics that could be accurately quantified or categorized were used to develop multiple regression models that evaluated effects of independent factors using backwards selection. A value of P &lt; 0.05 was used to maintain a factor in the final models. Based upon reported state of origin and state of delivery, lots were categorized into one of the following trucking distance categories: 1) Within-State, 2) Short-Haul, 3) Medium-Haul, and 4) Long-Haul. Average weight and number of calves in lots analyzed was 259.2 ± 38.4 kg BW and 100.6 ± 74.3 head, respectively. Average weight and number of feeder cattle in lots analyzed was 358.4 ± 34.3 kg BW and 110.6 ± 104.1 head, respectively. Beef calf lots hauled Within-State sold for more ($169.24/45.36 kg; P &lt; 0.0001) than other trucking distance categories (Table 1). Long-Haul calf lots sold for the lowest (P &lt; 0.0001) price ($166.70/45.36 kg). Within-State and Short-Haul feeder cattle lots sold for the greatest (P &lt; 0.0001) price ($149.96 and $149.81/45.36 kg, respectively; Table 2). Long-Haul feeder cattle lots sold for the lowest (P &lt; 0.0001) price, $148.43/45.36 kg. These results indicate there is a price advantage for lots expected to be hauled shorter distances, likely because of cost and risk associated with transportation.


Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 729
Author(s):  
Chanida Puttichaem ◽  
Guilherme P. Souza ◽  
Kurt C. Ruthe ◽  
Kittipong Chainok

A novel, high throughput method to characterize the chemistry of ultra-thin diamond-like carbon films is discussed. The method uses surface sensitive SEM/EDX to provide substrate-specific, semi-quantitative silicon nitride/DLC stack composition of protective films extensively used in the hard disk drives industry and at Angstrom-level. SEM/EDX output is correlated to TEM to provide direct, gauge-capable film thickness information using multiple regression models that make predictions based on film constituents. The best model uses the N/Si ratio in the films, instead of separate Si and N contributions. Topography of substrate/film after undergoing wear is correlatively and compositionally described based on chemical changes detected via the SEM/EDX method without the need for tedious cross-sectional workflows. Wear track regions of the substrate have a film depleted of carbon, as well as Si and N in the most severe cases, also revealing iron oxide formation. Analysis of film composition variations around industry-level thicknesses reveals a complex interplay between oxygen, silicon and nitrogen, which has been reflected mathematically in the regression models, as well as used to provide valuable insights into the as-deposited physics of the film.


2015 ◽  
Vol 21 (1) ◽  
pp. 60 ◽  
Author(s):  
Anita F. Keir ◽  
Richard G. Pearson ◽  
Robert A. Congdon

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.


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