Differential responses by sympatric macropodids to severe drought.

2004 ◽  
Vol 26 (2) ◽  
pp. 185
Author(s):  
PE Hornsby ◽  
EY Corlett

Responses to severe drought by two sympatric macropodids, the yellow-footed rock-wallaby (Petrogale xanthopus) and the euro (Macropus robustus erubescens) were examined at a site in the North Flinders Ranges of South Australia. The results indicate that the two species respond differentially to drought conditions. It was observed that small fluctuations occurred in the P. xanthopus population. In contrast, M. r. erubescens evidenced significant mortality, especially among larger animals.


1982 ◽  
Vol 30 (1) ◽  
pp. 49 ◽  
Author(s):  
FJ Odendaal ◽  
CM Bull

Ranidella signifera has a wide distribution in south-eastern Australia; R. riparia is endemic to the Flin- ders Ranges in South Australia. The ranges of the two species are largely allopatric, but they contact and overlap in a zone about 10 km wide, in the southern Flinders Ranges. The nature of the creeks changes across this zone. Immediately to the south and east, where only R. signifera is found, the creeks are slow-flowing and heavily vegetated, with mud or sand substrates. To the north and west the creeks are swift-flowing, and have rocky substrates and little vegetation; only R. riparia is found in these. In the sympatric overlap zone creeks are heterogeneous, with both habitat types represented. The close association between species and creek habitat is lost in populations not immediately adjacent to the overlap zone. This implies that each species can survive in both creek habitats but that R. riparia has a competitive advantage in swift, rocky creeks and R, signifera has an advantage in slow, vegetated creeks. This prevents either species from expanding its distribution beyond the narrow overlap area.



1957 ◽  
Vol 5 (2) ◽  
pp. 151 ◽  
Author(s):  
RL Specht

Heath vegetation shows a major flush of growth during the mediterraneantype summer season, a time when calculations of the soil moisture storage by the techniques of Thornthwaite (1948) or Prescott, Collins, and Shirpurkar (1952) indicate that severe drought conditions should oocur. Monthly observations on the moisture status of the Makin sand under heath vegetation and, for comparison, under various pastures are therefore recorded. The problems of obtaining an accurate water balance-sheet for such a heterogeneous vegetation as the heath are discussed. Difficulties in the use of the various techniques for measuring soil moisture in sand, which has a low pF of 1.85 at field capacity, are enumerated. The following relationships were found between the evapotranspiration index (Itr = Etr / Ew0.75) and the available water (W). These data were calculated for 6 ft of sand. (i) Heath vegetation (10–14 years old) log (2.4–Itr) = 0.420–0.0383 W (ii) Heath vegetation (burnt) log (2.4–Itr) = 0.461–0.0380 W (iii) Oenothera odorata Jacq. pasture log (2.4–Itr) = 0.395–0.0269 W (iv) Medicago sativa L. pasture log (2.4–Itr) = 0.390–0.0270 W (v) Ehrharta calycina Sm. pasture log (2.4–Itr) = 0.400–0.0339 W From these equations the mean monthly quantities of rainfall which may be stored in 6 ft of sand under the various treatments described were calculated. Drought conditions are shown to occur in December and January, but are relieved in the later months of summer. Even if the stored moisture below 8 ft is considered, the soil moisture status would be expected to be just sufficient to maintain the vegetation in a "dormant" state, and yet the major growth of the heath vegetation occurs at this time. The calculated mean annual values of Itr range from 0.53 to 0.60 for these perennial communities. Close approximations to the actual soil moisture status can be obtained by substituting these values for K in Prescott's formula for potential evaporation, i.e. Etr = K x Ew0.75. Supplementary data on transpiration, growth, and the root systems of the pastures are also included.



1996 ◽  
Vol 19 (2) ◽  
pp. 245
Author(s):  
P. Hornsby

The causes of mortality were analysed for 23 Yellow-footed Rock-wallabies, Petrogale xanthopus found on or near the dry bed of the Hamilton Creek in the North Flinders Ranges of South Australia. The results showed the Red Fox, Vulpes vulpes to be the more frequently identified predator. On the basis of size, 13 of the wallabies were classed as adult and seven were immature, while the remaining three were unknown. Three were male; seven were female, and 13 were of unknown sex. 15 of the 23 were found during the period April - July; the time of year when there is a peak of young leaving the pouch.



1983 ◽  
Vol 10 (1) ◽  
pp. 47 ◽  
Author(s):  
PB Copley

Petrogale xanthopus still occurs over most of its former range in South Australia. It is widespread in the Flinders Ranges, where almost 200 colonies are now known, and is locally common in areas of both the Rinders Ranges and Olary Hills. Six colonies are currently known in the western Gawler Ranges with an outlying population on Carriewerloo Station only 50 km west of Port Augusta. Seven colonies have been found in the Olary Hills, to the north and north-west of Olary. The species has suffered a major decline in abundance since European settlement, having become extinct locally throughout this range. Hunting for skins, competition with introduced herbivores for food and shelter, and predation by foxes seem to be the main reasons for this decline. However, it is still not possible to say whether the species currently has a decreasing population and is at risk, is in equilibrium, or is increasing. Information published in this paper and current studies in South Australia and New South Wales should soon determine this.



Zootaxa ◽  
2012 ◽  
Vol 3499 (1) ◽  
pp. 1 ◽  
Author(s):  
S. DONNELLAN ◽  
M. ANSTIS ◽  
L. PRICE ◽  
L. WHEATON

We describe, as a new species, the northern Flinders Ranges populations of the myobatrachid frog Crinia riparia. It isdistinguished from C. riparia sensu stricto on the basis of reciprocal monophyly of mitochondrial genes, absence ofhaplotype sharing in a nuclear gene, fixed differences in allozyme loci and differences in larval oral disc morphologyconsistent with less adaptation to stream habitats. We were not able to reliably distinguish the taxa on the basis of adultmorphology. The geographic range of C. riparia sensu stricto is now reduced to a 75 kilometre section of the southernFlinders Ranges from Napperby Gorge in the south to Mt Brown in the north suggesting that an assessment of its conservation status is warranted.



Episodes ◽  
2012 ◽  
Vol 35 (1) ◽  
pp. 247-255 ◽  
Author(s):  
James B. Jago ◽  
James G. Gehling ◽  
John R. Paterson ◽  
Glenn A. Brock ◽  
Wenlong Zang


2020 ◽  
Vol 11 (S1) ◽  
pp. 85-114 ◽  
Author(s):  
Hassan Al-Najjar ◽  
Gokmen Ceribasi ◽  
Emrah Dogan ◽  
Mazen Abualtayef ◽  
Khalid Qahman ◽  
...  

Abstract The Eastern Mediterranean region of the Middle East and North Africa (MENA) is experiencing patterns of major drought due to the effects of rising temperatures and falling precipitation levels. The multiscale drought evaluation Standardized Precipitation Evapotranspiration Index (SPEI) reveals evolving and severe drought from North Africa and the Sinai desert toward the Middle East. While there has been a period without drought between 1970 and 1990, the severity and frequency of drought increased considerably after 1990. Current drought conditions in the Eastern Mediterranean region of MENA are moderate to severe with a 60–100% likelihood of occurrence, according to time parameters. The Gaza Strip is especially vulnerable to the consequences of increasing drought because it is situated in the vicinity of the Sinai Desert; therefore, a downscaled study of drought in the region is essential to implement mitigation measures for the sustainable management and planning of coastal aquifer and agricultural activities in the Gaza Strip. Considerable availability of precipitation time series from various meteorological stations helped provide a local drought study for the Gaza Strip, in accordance with the Standardized Precipitation Index (SPI). The stochastic time-series model of (4,0,1) (5,1,1)12 shows a robust simulator for modeling and forecasting the future trend of precipitation at the nine meteorological stations. In terms of correlation accuracy, the model achieves a correlation (r) of approximately 93–97% in the calibration range and a correlation (r) of about 92–99% in the validation range. In terms of measuring the difference between the values, the root mean squared error (RMSE) of the model results shows that the RMSE was between 7–21 in the calibration range and 11–21 in the validation range. The model reveals a slightly stable trend in precipitation patterns at the northern meteorological stations of Beit Hanon, Beit Lahia, Shati, and Remal. However, declining precipitation tendency was recorded at the southern meteorological stations of Mughraka, Nussirat, Beir Al-Balah, Khanyounis, and Rafah. The SPI-based drought assessment implies that the precipitation annual threshold levels at SPI = 0 drop territorially from 474 mm in the north to about 250 mm in the south of the Gaza Strip. In this study, a representative 12-month local scale SPI12 at an annual precipitation threshold level of 370 mm was formulated to address the drought conditions in the Gaza Strip. Standing on the outputs of the local SPI12 scale might signify that the region of the Gaza Strip risks drought status with an incidence likelihood varying from 8% in the north to 100% in the south. Regular drought is prevalent in the northern governorates, but the hazards of extreme and severe drought are high in the southern areas with an incidence risk of about 83%. Sequentially, southern governorates of Rafah and Khanyounis experience chronic annual drought, while the return period of drought is reported to be every 9–12 years in the northern governorates of the Gaza Strip. The rain-fed years of 1998 and 2010 reported the worst periods of drought, while the period of 2016 showed a good droughtless water balance. Overall, the no-drought status might define the prospective conditions in the governorates of North Gaza, Gaza, and central Gaza over the next 20 years, while Rafah and Khanyounis are anticipated to be under normal to severe drought conditions.



1999 ◽  
Vol 26 (4) ◽  
pp. 453 ◽  
Author(s):  
J. Read ◽  
P. Copley ◽  
P. Bird

Recent surveys have shown that the desert mouse (Pseudomys desertor), which was once considered to be rare in South Australia, is relatively widespread throughout the north-west of the State. However, historical localities in the Flinders Ranges and Nullarbor Plain were not matched with contemporary records, suggesting a range contraction to the central desert regions. Habitat preferences were determined from 78 captures at 41 sites, which revealed that samphire, sedge and nitrebush habitats, along with spinifex grassland, were favoured. A high tolerance to high rabbit numbers, mining activity, moderate cattle grazing pressures and cohabitation with Mus domesticus was evident. Pseudomys desertor is sometimes diurnal, possibly as a result of the time-consuming and regular foraging requirements of its folivorous diet. High mortality rates, resulting from prolonged exposure to predators, and lack of complex deep burrow systems are offset by its high fecundity and ecological plasticity. We consider that P. desertor is secure in the north-western arid zone of South Australia.



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