Can outbreaks of house mice in south-eastern Australia be predicted by weather models?

2004 ◽  
Vol 31 (5) ◽  
pp. 465 ◽  
Author(s):  
Charles J. Krebs ◽  
Alice J. Kenney ◽  
Grant R. Singleton ◽  
Greg Mutze ◽  
Roger P. Pech ◽  
...  
Keyword(s):  
Large Scale ◽  
Southern Oscillation ◽  
Plant Production ◽  
House Mice ◽  
Weather Variables ◽  
Mouse Population ◽  
Enso Events ◽  
South Eastern ◽  
Eastern Australia ◽  
South Eastern Australia

Outbreaks of house mice (Mus domesticus) occur irregularly in the wheat-growing areas of south-eastern Australia, and are thought to be driven by weather variability, particularly rainfall. If rainfall drives grass and seed production, and vegetation production drives mouse dynamics, we should achieve better predictability of mouse outbreaks by the use of plant-production data. On a broader scale, if climatic variability is affected by El Niño–Southern Oscillation (ENSO) events, large-scale weather variables might be associated with mouse outbreaks. We could not find any association of mouse outbreaks over the last century with any ENSO measurements or other large-scale weather variables, indicating that the causal change linking mouse numbers with weather variation is more complex than is commonly assumed. For the 1960–2002 period we were only partly successful in using variation in cereal production to predict outbreaks of mice in nine areas of Victoria and South Australia, and we got better predictability of outbreaks from rainfall data alone. We achieved 70% correct predictions for a qualitative model using rainfall and 58% for a quantitative model using rainfall and spring mouse numbers. Without the detailed specific mechanisms underlying mouse population dynamics, we may not be able to improve on these simple models that link rainfall to mouse outbreaks.

The El Nino-Southern Oscillation in south-eastern Australian waters

1991 ◽  
Vol 42 (3) ◽  
pp. 263 ◽  
Author(s):  
WW Hsieh ◽  
BV Hamon
Keyword(s):  
Sea Level ◽  
Coastal Upwelling ◽  
Southern Oscillation ◽  
Geostrophic Wind ◽  
Air Pressure ◽  
Ekman Transport ◽  
Hydrographic Data ◽  
South Eastern ◽  
Eastern Australia ◽  
South Eastern Australia

Using four decades of hydrographic data collected off the coast near Sydney, New South Wales, and sea-level data at Sydney, we studied the interannual variability in south-eastern Australian shelf waters. The first two empirical orthogonal function (EOF) modes of the band-pass-filtered 50-m-depth hydrographic data (temperature, T; salinity, S; nitrate, N; inorganic phosphate, P; and oxygen, O) and the sea level (SL) and adjusted sea level (ASL) data accounted respectively for 51 and 27% of the total variance. Both modes were significantly correlated with the Southern Oscillation Index (SOI). The first mode, with T, S, O and ASL varying in opposition to N and P, represented the internal or baroclinic response, associated with vertical displacements of the isopycnals. The second mode, with large in-phase fluctuations in SL and ASL but small changes in the hydrographic variables, represented mainly the external or barotropic response during the El Niiio-Southern Oscillation (ENSO). Three-year composites centred around seven ENSO warm episodes revealed that T, S, O and ASL were generally low and N, P, SL and SO1 were high in the year before each ENSO warm episode, but the former group rose while the latter group dropped in the year of the warm episode. The changes in the hydrographic variables at 50 m depth were consistent with relatively shallow isopycnals in the year before the ENSO warm episode, followed by a deepening of the isopycnals during the warm episode. Estimates of this downward displacement of isopycnals, as determined from T, N, P and O, were in the range 7-10 m. The geostrophic wind arising from the pressure fluctuations during ENSO is proposed as a probable cause for the vertical displacement of the isopycnals. In the year before the warm episode, the low air pressure over Australia would produce a clockwise geostrophic wind around south-eastern Australia, generating offshore Ekman transport and coastal upwelling. During the warm episode, air pressure over Australia rises, the geostrophic wind reverses, and downward movement of the isopycnals would occur off south-eastern Australia.

scholarly journals Effects of large fires on biodiversity in south-eastern Australia: disaster or template for diversity?

2008 ◽  
Vol 17 (6) ◽  
pp. 809 ◽  
Author(s):  
Ross A. Bradstock
Keyword(s):  
Large Scale ◽  
Fire Regimes ◽  
Ecological Communities ◽  
South Eastern ◽  
Habitat Variation ◽  
Eastern Australia ◽  
Rate Adaptive ◽  
Large Fires ◽  
South Eastern Australia

Large fires coincident with drought occurred in south-eastern Australia during 2001–2007. Perceptions of large, intense fires as being ecologically ‘disastrous’ are common. These are summarised by four hypotheses characterising large fires as: (i) homogenous in extent and intensity; (ii) causing large-scale extinction due to perceived lack of survival and regeneration capacity among biota; (iii) degrading due to erosion and related edaphic effects; (iv) unnatural, as a consequence of contemporary land management. These hypotheses are examined using available evidence and shown to inadequately account for effects of large fires on biodiversity. Large fires do not burn homogeneously, though they may produce intensely burnt patches and areas. The bulk of biota are resilient through a variety of in situ persistence mechanisms that are reinforced by landscape factors. Severe erosive episodes following fire tend to be local and uncertain rather than global and inevitable. Redistribution of soil and nutrients may reinforce habitat variation in some cases. Signals of fire are highly variable over prehistoric and historic eras, and, in some cases, contemporary and pre-European signal levels are equivalent. The most important effects of large fires in these diverse ecological communities and landscapes stem from their recurrence rate. Adaptive management of fire regimes rather than fire events is required, based on an understanding of risks posed by particular regimes to biota.

Trapping efficiency of Ugglan traps and Longworth traps for house mice in south-eastern Australia

2002 ◽  
Vol 29 (1) ◽  
pp. 101 ◽  
Author(s):  
J. Jacob ◽  
H. Ylönen ◽  
C. G. Hodkinson
Keyword(s):  
Field Studies ◽  
Trapping Efficiency ◽  
House Mice ◽  
Target Species ◽  
Trapping Mechanism ◽  
South Eastern ◽  
Eastern Australia ◽  
Single Capture ◽  
Open Mesh ◽  
South Eastern Australia

Small mammal studies require traps that efficiently capture the target species, are cheap, and preferably have no adverse effects on the animals. We compared the trapping efficiency of Ugglan multiple-capture live-traps with Longworth single-capture live-traps in field studies of house mice (Mus domesticus) in the Victorian Mallee of south-eastern Australia. More captures and recaptures were made with Longworth traps and fewer mice died while in these traps. There was no difference in mean body mass of captured mice between Ugglan and Longworth traps but relatively more males were trapped with Ugglan traps. The trapping mechanism that requires the mouse to activate a trap door, and open mesh wire along the sides of the Ugglan trap may be the main reasons for low trappability. In addition, the open sides could have contributed to the lower survival observed for mice in Ugglan traps. Although Ugglan traps have the potential for multiple captures, are cheaper, and their trapping mechanism is less prone to failure than Longworth traps, they were not as efficient in trapping house mice at low and medium densities.

Holocene ‘megadroughts’ in south-eastern Australia: deciphering regional patterns from lake sediment archives

2020 ◽  
Author(s):  
Jonathan Tyler ◽  
Cameron Barr ◽  
John Tibby ◽  
Asika Dhar ◽  
Chapman Andrew ◽  
...  
Keyword(s):  
Climate Model ◽  
Southern Oscillation ◽  
Global Climate ◽  
Climate Science ◽  
Natural Phenomenon ◽  
Geochemical Data ◽  
Regional Patterns ◽  
South Eastern ◽  
Eastern Australia ◽  
South Eastern Australia

<p>Documenting and understanding centennial scale hydroclimatic variability in Australia is significant both to global climate science and to regional efforts to predict and manage water resources. In particular, multidecadal to centennial periods of low rainfall – ‘megadroughts’ – have been observed in semi-arid climates worldwide, however they are poorly constrained in Australia. Here, we bring together multiple, sub-decadally resolved records of hydrological change inferred from lake sediments in western Victoria, Australia. Our analyses incorporate new elemental (ITRAX µXRF) and stable isotope (oxygen, carbon isotopes) geochemical data from West Basin and Lake Surprise, both augmented by high quality radiometric chronologies based on radiocarbon, <sup>210</sup>Pb and <sup>239/240</sup>Pu analyses. Collectively, the records document a transition towards a more arid and variable climate since the mid-late Holocene, which is comparable to reports of an intensification of the El Nino Southern Oscillation (ENSO) through this period. Furthermore, during the last 2000 years, the records exhibit marked periods of reduced effective moisture which contrast with records of Australian hydroclimate inferred from distal archives, as well those predicted by climate model hindcasts. Our analyses indicate that megadroughts are a natural phenomenon in south-eastern Australia, requiring greater attention in efforts to predict and mitigate future climatic change.</p>

Evidence of large-scale spatial declines in recruitment patterns of southern rock lobster Jasus edwardsii, across south-eastern Australia

2010 ◽  
Vol 105 (3) ◽  
pp. 163-171 ◽  
Author(s):  
Adrian Linnane ◽  
Caleb Gardner ◽  
David Hobday ◽  
André Punt ◽  
Richard McGarvey ◽  
...  
Keyword(s):  
Large Scale ◽  
Rock Lobster ◽  
South Eastern ◽  
Eastern Australia ◽  
Jasus Edwardsii ◽  
Recruitment Patterns ◽  
South Eastern Australia

Effects of large-scale high-severity fire on occupancy and abundances of an invasive large mammal in south-eastern Australia

2012 ◽  
Vol 39 (7) ◽  
pp. 555 ◽  
Author(s):  
David M. Forsyth ◽  
Andrew M. Gormley ◽  
Luke Woodford ◽  
Tony Fitzgerald
Keyword(s):  
National Park ◽  
Large Scale ◽  
Survey Methods ◽  
Large Mammal ◽  
South Eastern ◽  
High Severity ◽  
Eastern Australia ◽  
Pellet Counts ◽  
Sambar Deer ◽  
South Eastern Australia

Context Despite large mammals being an important component of many ecosystems, there is little information on the impacts of fire on large mammal populations. Aims We evaluated the effects of the large-scale high-severity ‘Black Saturday’ fires of 7 February 2009 on occupancy and abundances of an invasive large mammal, the sambar deer (Cervus unicolor), in south-eastern Australia. Methods The effects of the Black Saturday fires on the abundance of sambar deer were assessed using repeated annual counts of faecal pellets during 2007–11 in Kinglake National Park, which was burnt, and in Mount Buffalo National Park, which was not burnt. Pre-fire occupancy was modelled from data collected at 80 4-km2 cells using three survey methods. The same survey methods were used at 15 burnt (n = 9 sampled pre-fire) and 15 unburnt (n = 5 sampled pre-fire) cells 16–24 months after Black Saturday. Because multiple surveys were performed in each cell, we used a Bayesian state–space site-occupancy model to partition changes in the probability of occupancy from changes in the probability of detection. Key results Counts of sambar deer pellets increased linearly during 2007–11 in the unburnt Mount Buffalo National Park. Pellet counts also increased linearly in Kinglake National Park from 2007 to 2008, and then decreased (to zero) following Black Saturday; pellet counts increased again in 2010 and 2011. Sambar deer occupancy was weakly reduced (from 0.99 to 0.88) in burnt cells 16–24 months after Black Saturday, but was little changed in unburnt cells (from 0.99 to 0.98). Conclusions We conclude that the abundance of sambar deer was substantially reduced by the large-scale high-severity Black Saturday fires, but that most burnt habitat was reoccupied 16–24 months later. Implications There is concern about the negative impacts of invasive sambar deer on native biodiversity, particularly immediately post-fire. Our study suggests that it takes at least 8 months before sambar deer recolonise areas burnt by a large-scale high-severity fire; however, a risk-averse approach would be to act (e.g. by erecting fences or culling) sooner than that.

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