A Study of Reproduction in Water Buffalo in the Northern Territory of Australia.

1981 ◽  
Vol 8 (2) ◽  
pp. 335 ◽  
Author(s):  
DG Tulloch ◽  
A Grassia

Data were obtained on 1094 females and 859 males killed at an abattoir, and 135 females and 32 males shot in the field. The data indicated that cows calve during the late wet or early dry season, after a pregnancy of 10-11 months. Age at 1st conception averaged 28.5 months; puberty occurred at 14-19 months. Pregnancy rate was 76% for the abattoir sample; it was <5% for females aged less than or equal to 3 yr. Bulls were probably fertile for 8 months of the year, the infertile period occurring during the 2nd half of the dry season.

1979 ◽  
Vol 6 (3) ◽  
pp. 265 ◽  
Author(s):  
DG Tulloch

Water buffalo in the Northern Territory of Australia have a well defined breeding season in the wet or very early dry season. The birth of a calf is of major importance for the clan and for the family group of which that clan is a part. A number of calves are left in the care of an adult while their mothers go to graze. The female calf remains with its mother for many years, possibly for life, but at 2-3 y old the male calf is driven from the group by an adult bull when a cow in the group comes into oestrus. Most buffalo cows will readily adopt an orphan calf and within 8 days it is impossible to distinguish between the orphan and the group calves.


1970 ◽  
Vol 18 (4) ◽  
pp. 399 ◽  
Author(s):  
DG Tulloch

Regular aerial and land surveys of the coastal plains and adjoining high ground in the northern portion of the Northern Territory between the Adelaide and Wildman Rivers showed variations in the number of buffalo on the plains. When there were very few buffalo on the plains there were large numbers on the adjoining high timbered country. During the wet season the plains flooded to varying depths and in those areas where the water was very deep all buffalo moved to higher ground. In the Northern Territory the wet season is the main breeding season, and at this time adult bulls were seen with cows in oestrus. During the dry season, which is the non-breeding season, the bulls and cows inhabited separate areas; the cows and their calves preferred those areas of the black soil plains adjoining high ground where there was water, shade, and some green feed. When rain fell at the end of the dry season, the buffalo moved to areas where it had rained.


2000 ◽  
Vol 6 (1) ◽  
pp. 61 ◽  
Author(s):  
John C. Z. Woinarski ◽  
Greg Connors ◽  
Don C. Franklin

We create monthly maps of nectar availability for the 1.4 x 106 km2 jurisdiction of the Northern Territory, Australia. These are based on a combination of vegetation mapping and a series of indices of plant species specific nectar scoring. The maps reveal complex spatial and temporal variation in nectar availability, but most notably a greater nectar resource in the monsoon-influenced north than in the arid south, and a peak in nectar availability in the dry season. The latter is associated with the extensive tropical eucalypt forests (especially those co-dominated by Eucalyptus miniata and E. tetrodonta). In contrast, wet season nectar availability in these forests is limited, but riparian and swampland forests, typically dominated by Melaleuca species, provide rich but spatially restricted nectar resources. The extensive and rich nectar resources available in eucalypt forests in the dry season supplement the diets of many species which are not primarily nectarivorous. This resource helps shape the singularity of northern Australian eucalypt forests relative to other extensive forests elsewhere in the world. Nectarivores remain in the system through a combination of movements across a number of scales, habitat shifting, and diet shifting. The latter is aided by the peaking of invertebrate and fruit resources at the times of minimum nectar production; a shuffling in resource availability brought about by the extreme climatic seasonality.


1988 ◽  
Vol 28 (1) ◽  
pp. 11 ◽  
Author(s):  
RG Holroyd ◽  
GWJ Mason ◽  
ID Loxton ◽  
PT Knights ◽  
PK O'Rourke

In a 3-year study in the dry tropics, 2 management practices of dry season supplementation of cows and early weaning of calves were concurrently examined as possible techniques for improving reproductive, liveweight and survival performance of Brahman cross cows (phenotypically 1/2 - 3/4 Bos indicus) grazing native pastures. Cows were either supplemented with a drylick mixture of salt, urea and sulfur (DL) commencing in July for 4-6 months; supplemented with a crisis mixture of salt, urea, grain, molasses, meatmeal and monoammonium phosphate (CM) in the latter part of the dry season; or were not supplemented (C). Mating commenced in January, and calves were either early weaned (EW) at the end of mating in April (mean age of 5 months) or late weaned (LW) in July (mean age of 8 months). Supplements and weaning treatments had little effect on cow liveweight, except between early weaning and late weaning when EW cows gained more or lost less weight (mean advantage of 30.8 kg) than LW cows and were heavier (mean advantage of 44.8 kg) than LW cows at late weaning time. Across all years, 1.4, 2.1 and 4.2% of cows in DL, CM and C groups respectively died from malnutrition or required survival feeding; whereas, in the second and third years, mortality rates due to malnutrition were 0.7 and 2.1% in EW and LW groups respectively. Neither supplement nor weaning treatments had any significant effect on lactating cow pregnancy rates, although data pooled across treatments showed that liveweights at various stages pre-mating were correlated with pregnancy rate. Supplementation or weaning treatments did not influence calving date or birth weight, but LW calves grew significantly faster (mean advantage of 0.52 kg/day) between early weaning and late weaning and were significantly heavier (mean advantage of 57.4 kg) at late weaning than EW calves.


1993 ◽  
Vol 15 (2) ◽  
pp. 339 ◽  
Author(s):  
NJ Tapper ◽  
G Garden ◽  
J Gill ◽  
J Fernon

In most areas of Australia the calculation of a fire danger index (FDI) is the cornerstone of fie weather forecasting and provides an operationally objective basis for the issue of fire weather warnings. FDI's are derived from the observation or prediction of a number of basic meteorological parameters which are then combined with information on fuel characteristics. The forest and grassland fire danger in southern Australia is greatest during the austral summer and is characterised by long periods of low fire danger interspersed with occasional extreme fire danger events. By contrast, much of tropical and subtropical Australia shows a distinctly different seasonality, magnitude and frequency of fire danger. The problem is essentially one of the austral winter-spring (dry season) period and is characterised by extended periods of moderate to high fire danger. This paper provides a broad climatological background to the problem of high fire danger in northern Australia, concentrating in particular on the Northern Territory. The paper also addresses particular meteorological situations in northern Australia which give rise to elevated fire danger. Two synoptic-scale weather patterns are discussed in particular; the passage of prefrontal troughs which seasonally produce high fire danger in the region of the tropic, and winter subtropical ridging which produces strong winds and high fire danger over the north of the continent during the dry season.


2007 ◽  
Vol 16 (3) ◽  
pp. 295 ◽  
Author(s):  
Owen F. Price ◽  
Andrew C. Edwards ◽  
Jeremy Russell-Smith

We investigated the efficacy of firebreaks in the prevention of wildfires in the Arnhem Land Plateau, a vast, rugged and sparsely populated region with high biodiversity value and frequent wildfires. A total of 623 events where a fire met a permanent firebreak (cliffs, stream order, tracks and roads) in different fire seasons were compiled. Cliffs were more effective than streams at stopping fires, which were more effective than roads. Larger streams were more effective than small ones. The largest streams stop 75% of early dry season fires, but there are no firebreak types with more than 50% likelihood of stopping a late dry season fire. Geographic Information System (GIS) surfaces of the relative density of the three firebreak features in the landscape were randomly sampled and compared with the total number of fires and late dry season fires using generalised linear modelling. Several of the density variables were weakly but significantly related to fire frequency, and it appears that late dry season fires are influenced by features at a larger scale (16-km radius) than total fires (4 km). The Aerial Prescribed Burning program for 2004 was studied to identify how effective it was at stopping subsequent wildfires by dividing ignition lines into 137 5-km sections. Only 20% of sections achieved a 100% burn and where gaps occurred, a subsequent fire was 88% likely to penetrate the line. Firebreaks are not certain instruments for fire management in this area.


1990 ◽  
Vol 17 (6) ◽  
pp. 573 ◽  
Author(s):  
SR Morton ◽  
KG Brennan ◽  
MD Armstrong

Aerial surveys between 1981 and 1984 were used to identify monthly trends in the abundance of wandering whistling-duck Dendrocygna arcuata, plumed whistling-duck D. eytoni, radjah shelduck Tadorna radjah, Pacific black duck Anas superciliosa, and grey teal A. gibberifrons on five floodplains of the Alligator Rivers region, 250 km east of Darwin in the monsoonal north of the Northern Territory. Ground surveys were conducted during the same period on one of the floodplains, the Magela plain, to provide more detailed information. The Magela floodplain was inhabited by few ducks during the wet season (November to March), but numbers then increased to dramatic peaks in the late dry season. The Nourlangie floodplain and Boggy Plain (a large backswamp of the South Alligator floodplain) showed similar patterns, but the numbers of ducks were usually fewer. Ducks were uncommon on the shallower East Alligator and Cooper floodplains except for relatively brief periods in the wet season. The ground surveys suggested that ducks sought out the persistent swamps that characterise the Magela floodplain in the dry season. Ground surveys also indicated that aerial surveys underestimated densities; on the basis of correction factors calculated from the ground surveys, peak numbers on the five floodplains were roughly estimated to be 400 000 wandering whistling-ducks, 70 000 plumed whistling-ducks, 20 000 radjah shelducks, 50 000 Pacific black ducks, and 50 000 grey teal. Pink-eared ducks Malacorhynchus membranaceus and hardhead Aythya australis were recorded sporadically in low numbers. The Alligator Rivers region acted as a dry season refuge for large concentrations of ducks because of the atypical persistence of freshwaters on the Magela and Nourlangie floodplains and some of the backswamps of the South Alligator, such as Boggy Plain. The large aggregations appear to be unique in Australia.


Sign in / Sign up

Export Citation Format

Share Document