Wasp-Pollinated Species of Caladenia (Orchidaceae) in South-Western Australia

1983 ◽  
Vol 31 (4) ◽  
pp. 383 ◽  
Author(s):  
WP Stoutamire
Keyword(s):  
Western Australia ◽  
Food Advertising ◽  
Genetic Isolation ◽  
Limited Evidence ◽  
Flight Behaviour ◽  
Wasp Species ◽  
Pollination Mechanisms ◽  
Flower Form

Twelve of the 40 Caladenia species of Western Australia have been observed to attract male wasps (Tiphiidae; subfamily Thynninae) by visual and pheromonal mechanisms. Floral colours are predominantly combinations of green, cream and brown. Labella bear dark maroon tips or dark calli on the upper surface which are visual wasp equivalents. Glandular areas on perianth tips are demonstrated to be sources of sexual attractants in some species. Flower form and position are adjusted to the flight behaviour of the wasps. Each Caladenia species appears to attract and be pollinated by only one wasp species at the orchid site although there is limited evidence of geographic pollinator replacement in some species. Sexually attracting Caladenia species form occasional hybrids with food- advertising species. Divergent pollination mechanisms have not resulted in complete genetic isolation.

Cytogeography of the genus Eremophila

1971 ◽  
Vol 19 (3) ◽  
pp. 295 ◽  
Author(s):  
BA Barlow
Keyword(s):  
Western Australia ◽  
Frequent Occurrence ◽  
Cell Physiology ◽  
Genetic Isolation ◽  
Ploidy Levels ◽  
Chromosome Races ◽  
Geographical Expansion ◽  
Land Surfaces ◽  
Diploid Populations

Polyploidy is of relatively frequent occurrence in Eremophila (x = 18). In 27 species examined karyologically from four or more localities, 13 were uniformly diploid, one was uniformly tetraploid, and 13 showed infraspecific polyploidy, diploid and/or tetraploid and/or hexaploid races being recorded. In most cases the chromosome races within a species have a pattern of geographical replacement. It is suggested that the formation of polyploid biotypes may lead to geographical expansion into new territory. Polyploidy may be effective in fixing adaptive recombinants near the margins of the diploid area, or may have direct adaptive effects on cell physiology. The ancient land surfaces of Western Australia appear to be a reservoir for relic diploid populations. In a few cases closely related entities which occur sympatrically have been found to be at different ploidy levels in the area of overlap. It is suggested that polyploidy in Eremophila has also facilitated the establishment of genetic isolation between differentiating biotypes.

Broad-scale coastal movements of white sharks off Western Australia described by passive acoustic telemetry data

2017 ◽  
Vol 68 (8) ◽  
pp. 1518 ◽  
Author(s):  
R. B. McAuley ◽  
B. D. Bruce ◽  
I. S. Keay ◽  
S. Mountford ◽  
T. Pinnell ◽  
...  
Keyword(s):  
Western Australia ◽  
Ecological Factors ◽  
Late Summer ◽  
Early Summer ◽  
Telemetry Data ◽  
Limited Evidence ◽  
The South ◽  
Seasonal Movement ◽  
Passive Acoustic ◽  
Broad Scale

Movements of 89 acoustically tagged subadult and adult white sharks (Carcharodon carcharias) were monitored off the south and west coasts of Western Australia (WA) between December 2008 and May 2016 by a network of up to 343 passive acoustic receivers. In all, 290 inter-regional movements, totalling 185092km were recorded for 73 of these sharks. Estimated rates of movement in excess of 3kmh–1 (mean 1.7kmh–1; maximum 5.6kmh–1) were common, even over distances of thousands of kilometres. Detections indicated that white sharks may be present off most of the south and lower west coasts of WA throughout the year, although they are more likely to be encountered during spring and early summer and are least likely to be present during late summer and autumn. There was limited evidence of predictable return behaviour, seasonal movement patterns or coordination of the direction and timing of individual shark’s movements. Nevertheless, the data suggest that further analyses of movements in relation to ecological factors may be useful predictors of shark activity at local scales. It is hoped that these data may be useful for informing public safety initiatives aimed at mitigating the risks associated with human encounters with white sharks off the WA coast.

Persistence of giants: population dynamics of the limpet Scutellastra laticostata on rocky shores in Western Australia

2020 ◽  
Vol 646 ◽  
pp. 79-92
Author(s):  
RE Scheibling ◽  
R Black
Keyword(s):  
Population Dynamics ◽  
Western Australia ◽  
Size Structure ◽  
Survival Rates ◽  
Maximum Size ◽  
High Rate ◽  
Adult Survival ◽  
Rocky Shores ◽  
Adult Size ◽  
Decadal Time Scale

Population dynamics and life history traits of the ‘giant’ limpet Scutellastra laticostata on intertidal limestone platforms at Rottnest Island, Western Australia, were recorded by interannual (January/February) monitoring of limpet density and size structure, and relocation of marked individuals, at 3 locations over periods of 13-16 yr between 1993 and 2020. Limpet densities ranged from 4 to 9 ind. m-2 on wave-swept seaward margins of platforms at 2 locations and on a rocky notch at the landward margin of the platform at a third. Juvenile recruits (25-55 mm shell length) were present each year, usually at low densities (<1 m-2), but localized pulses of recruitment occurred in some years. Annual survival rates of marked limpets varied among sites and cohorts, ranging from 0.42 yr-1 at the notch to 0.79 and 0.87 yr-1 on the platforms. A mass mortality of limpets on the platforms occurred in 2003, likely mediated by thermal stress during daytime low tides, coincident with high air temperatures and calm seas. Juveniles grew rapidly to adult size within 2 yr. Asymptotic size (L∞, von Bertalanffy growth model) ranged from 89 to 97 mm, and maximum size from 100 to 113 mm, on platforms. Growth rate and maximum size were lower on the notch. Our empirical observations and simulation models suggest that these populations are relatively stable on a decadal time scale. The frequency and magnitude of recruitment pulses and high rate of adult survival provide considerable inertia, enabling persistence of these populations in the face of sporadic climatic extremes.

The Excavation of a Settlement of the Later Bronze Age and Iron Age at Myrehead, Falkirk District

1983 ◽  
Vol 10 (1) ◽  
pp. 41-71 ◽  
Author(s):  
G J Barclay
Keyword(s):  
Bronze Age ◽  
Iron Age ◽  
Farming System ◽  
Activity Period ◽  
Limited Evidence ◽  
Ring Groove ◽  
Domestic Activity ◽  
First Millennium ◽  
First Millennium Bc ◽  
Actual Settlement

SUMMARY Myrehead has revealed the eroded remnants of activity from the Beaker period (Period A) onwards, with actual settlement evinced only from about the early first millennium be. The three houses and the cooking pits of Period B may have been constructed and used sequentially. This open settlement was probably replaced during the mid first millennium bc, possibly without a break, by a palisaded enclosure (Period C), which may have contained a ring-groove house and a four-post structure. Continued domestic activity (Period D) was suggested by a single pit outside the enclosure, dated to the late first millennium bc/early first millennium ad. The limited evidence of the economy of the settlements suggests a mixed farming system.

Antipodean Aftershocks: Group Settlement of Hebridean and non-Hebridean Britons in Western Australia following World War One

2020 ◽  
Vol 11 (2) ◽  
pp. 188-203
Author(s):  
Roy Jones ◽  
Tod Jones
Keyword(s):  
New Zealand ◽  
British Empire ◽  
Western Australia ◽  
The Sun ◽  
World War ◽  
World War One ◽  
A Site

In the speech in which the phrase ‘land fit for heroes’ was coined, Lloyd George proclaimed ‘(l)et us make victory the motive power to link the old land up in such measure that it will be nearer the sunshine than ever before … it will lift those who have been living in the dark places to a plateau where they will get the rays of the sun’. This speech conflated the issues of the ‘debt of honour’ and the provision of land to those who had served. These ideals had ramifications throughout the British Empire. Here we proffer two Antipodean examples: the national Soldier Settlement Scheme in New Zealand and the Imperial Group Settlement of British migrants in Western Australia and, specifically, the fate and the legacy of a Group of Gaelic speaking Outer Hebrideans who relocated to a site which is now in the outer fringes of metropolitan Perth.

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