scholarly journals Distribution, habitat and status of ‘Endangered’ Sakalava Rail of Madagascar

2009 ◽  
Vol 19 (1) ◽  
pp. 23-32 ◽  
Author(s):  
MARC RABENANDRASANA ◽  
SAMA ZEFANIA ◽  
PETER LONG ◽  
SAM THE SEING ◽  
MARIE CLÉMENTINE VIRGINIE ◽  
...  

SummaryThe ‘Endangered’ Sakalava Rail Amaurornis olivieri is endemic to wetlands in western Madagascar, where it has been recorded between the Betsiboka river in the north and the Mangoky river in the south. Between August 2003 and November 2006, including dry and wet seasons, we surveyed 36 potentially suitable wetlands throughout its known range. We found Sakalava Rails at five sites: Lacs Kinkony, Ampandra, Amparihy, Sahapy and Mandrozo. At each site the population was small (12–39 individuals) and the highest density was 20 individuals km−2. We found up to 67 birds in each field visit and the total number of birds (sum of maxima at each site) seen was 100. We estimate the total population at the five sites to be 215 rails. We cannot confirm that the population lies within the range estimated in the current Red List (250–999 individuals), although this may yet be proven correct. The typical breeding habitat of Sakalava Rail is lotic marshes with a mixture of large areas of open water, reed Phragmites mauritianus and floating Salvinia hastata. The major threats to Sakalava Rail appear to be habitat loss caused by wetland conversion to rice fields and by fires, disturbance by fishermen and people from local villages, and hunting. Other processes that may alter the ecological character of wetlands and so affect their suitability for Sakalava Rails, such as hydrological change or the effects of exotic fish or vegetation, remain to be investigated.

1980 ◽  
Vol 25 (93) ◽  
pp. 425-438
Author(s):  
B. Dey

AbstractThe study reported here illustrates the unique value of NOAA thermal infrared (TIR) images for monitoring the North Water area in Smith Sound and northern Baffin Bay during the periods of polar darkness. Wintertime satellite images reveal that, during the months of December through February, open water and thin ice occur in a few leads and polynyas. However, in March, the areas of open water and thin ice decrease to a minimum with a consequent higher concentration of ice. Two ice dams, in northern Kennedy Channel and in northern Smith Sound, regulate the flow of ice into northern Baffin Bay and also determine the areal variations of open water and thin ice in Smith Sound.


2018 ◽  
Vol 30 (1) ◽  
pp. 89-105
Author(s):  
Jay C. Martin

Boxy and with ‘unseaworthy form’, the sailing scow was not the most aesthetically pleasing of watercraft. Yet the durable hull design based upon European predecessors found a new home in North America where it proliferated on the Atlantic, Gulf, Pacific and Great Lakes coasts because of its practicality for largely unimproved waterways. Scows were widely used on the Great Lakes in the nineteenth century, moving beyond shallow waters and gaining a reputation for reliability in long-distance trade. Late in the century, the technology arrived in New Zealand, where it prospered in a niche market that combined open water voyages and shallow river, port, or beach loading and unloading. The Great Lakes scows presented an alternative for entry into ship ownership on the North American frontier. The development of the New Zealand scow confirmed these findings comparatively in an international context during the late nineteenth and early twentieth centuries.


2009 ◽  
Vol 6 (2) ◽  
pp. 36-38 ◽  
Author(s):  
Zahid Latif

Ireland is the third largest island in Europe and the twentieth largest island in the world, with an area of 86 576 km2; it has a total population of slightly under 6 million. It lies to the north-west of continental Europe and to the west of Great Britain. The Republic of Ireland covers five-sixths of the island; Northern Ireland, which is part of the United Kingdom, is in the north-east. Twenty-six of the 32 counties are in the Republic of Ireland, which has a population of 4.2 million, and its capital is Dublin. The other six counties are in Northern Ireland, which has a population of 1.75 million, and its capital is Belfast. In 1973 both parts of Ireland joined the European Economic Community. This article looks at psychiatry in the Republic of Ireland.


1995 ◽  
Vol 52 (2) ◽  
pp. 416-424 ◽  
Author(s):  
James W. LaBaugh

Algal chlorophyll a is commonly used as a surrogate for algal biomass. Data from three lakes in western Nebraska, five wetlands in north-central North Dakota, and two lakes in north-central Minnesota represented a range in algal biovolume of over four orders of magnitude and a range in chlorophyll a from less than 1 to 380 mg∙m−3. Analysis of these data revealed that there was a linear relation, log10 algal biovolume = 5.99 + 0.09 chlorophyll a (r2 = 0.72), for cases in which median values of chlorophyll a for open-water periods were less than 20 mg∙m−3. There was no linear relation in cases in which median chlorophyll a concentrations were larger than 20 mg∙m−3 for open-water periods, an occurrence found only in shallow prairies lakes and wetlands for years in which light penetration was the least.


2004 ◽  
Vol 1 (3) ◽  
pp. 16-17
Author(s):  
Fuad Ismayilov

Azerbaijan is a nation with a Turkic population which regained its independence after the collapse of the Soviet Union in 1991. It has an area of approximately 86 000 km2. Georgia and Armenia, the other countries comprising the Transcaucasian region, border Azerbaijan to the north and west, respectively. Russia also borders the north, Iran and Turkey the south, and the Caspian Sea borders the east. The total population is about 8 million. The largest ethnic group is Azeri, comprising 90% of the population; Dagestanis comprise 3.2%, Russians 2.5%, Armenians 2% and others 2.3%.


2018 ◽  
Vol 9 (2) ◽  
pp. 402-414 ◽  
Author(s):  
Max Post van der Burg ◽  
Neil Chartier ◽  
Ryan Drum

Abstract “Strategic habitat conservation” refers to a process used by the U.S. Fish and Wildlife Service to develop cost-efficient strategies for conserving wildlife populations and their habitats. Strategic habitat conservation focuses on resolving uncertainties surrounding habitat conservation to meet specific wildlife population objectives (i.e., targets) and developing tools to guide where conservation actions should be focused on the landscape. Although there are examples of using optimization models to highlight where conservation should be delivered, such methods often do not explicitly account for spatial variation in the costs of conservation actions. Furthermore, many planning approaches assume that habitat protection is a preferred option, but they do not assess its value relative to other actions, such as restoration. We developed a case study to assess the implications of accounting for and ignoring spatial variation in conservation costs in optimizing conservation targets. We included assumptions about habitat loss to determine the extent to which protection or restoration would be necessary to meet an established population target. Our case study focused on optimal placement of grassland protection or restoration actions to influence bobolink Dolichonyx oryzivorus populations in the tallgrass prairie ecoregion of the north central United States. Our results show that not accounting for spatially variable costs doubled or tripled the cost of meeting the population target. Furthermore, our results suggest that one should not assume that protecting existing habitat is always a preferred option. Rather, our results show that the balance between protection and restoration can be influenced by a combination of desired targets, assumptions about habitat loss, and the relative cost of the two actions. Our analysis also points out how difficult it may be to reach targets, given the expense to meet them. We suggest that a full accounting of expected costs and benefits will help to guide development of viable management actions and meaningful conservation plans.


2010 ◽  
Vol 124 (2) ◽  
pp. 179
Author(s):  
Jean-François Ouellet ◽  
Pierre Fradette ◽  
Isabel Blouin

We report the first observations of Barrow's Goldeneyes south of the St. Lawrence estuary in typical breeding habitat during the breeding season. Until recently, the confirmed breeding locations for the species in Eastern North America were all located on the north shore of the Estuary and Gulf of St. Lawrence.


1986 ◽  
Vol 32 (112) ◽  
pp. 383-390 ◽  
Author(s):  
Konrad Steffen

AbstractThe surface condition of the North Water was investigated during two winters (i.e. the three polynyas: Smith Sound polynya, Lady Ann Strait polynya, and Barrow Strait polynya). Since no detailed information was available on ice conditions and the extent of open water during winter, radiometric temperature measurements of the sea surface had to be taken along a flight line of 2650 km from an altitude of 300 m. From November to March 1978-79 and 1980-81, 14 remote-sensing flights were carried out. On the basis of the radiometric measurements, the following ice types were identified: ice-free, dark nilas, light nilas, grey ice, grey-white ice, and white ice. A comparison between the thermal and the visual ice classification (the latter being based on grey tones of the aerial images) showed a deviation of 3%. The analysis showed that in November, December, and January more than 50% of the Smith Sound polynya was covered by young ice, nilas, and ice-free, whereas in February and March white ice was dominant. Moreover, it was found that the two polynyas in Smith Sound and Lady Ann Strait were much smaller than previously believed. In Barrow Strait, a semi-permanent polynya was observed in the winter of 1980-81. The occurrence of polynyas in Barrow Strait seems to be connected with the location of the fast-ice edge. On the basis of the calculated ice-type distribution and heat-flux rates for different ice types, an energy loss of 178 W m-2was found on the surface of the Smith Sound polynya due to open water and thin ice for the winter months November to March. Compared with other ice-covered sea surfaces in the Arctic, the heat release by the sea-water in the Smith Sound polynya is about 100 W m-2larger.


Oryx ◽  
2007 ◽  
Vol 41 (1) ◽  
pp. 44-50 ◽  
Author(s):  
Peter S. Harlow ◽  
Martin Fisher ◽  
Marika Tuiwawa ◽  
Pita N. Biciloa ◽  
Jorge M. Palmeirim ◽  
...  

The endemic Fijian crested iguana Brachylophus vitiensis, categorized as Critically Endangered on the IUCN Red List, has been recorded from several islands in western Fiji. We conducted a survey for the crested iguana on 12 uninhabited and five inhabited islands in the Yasawa and Mamanuca archipelagos of western Fiji in September 2000. Night searches for sleeping iguanas along a total of 11.2 km of forest transects suggest that crested iguanas are either extremely rare or extinct on all of these islands. Although we collectively searched a total of 44 km of transect over 123 person hours, we located crested iguanas on only four islands: three small uninhabited islands (all <73 ha) and one large inhabited island (22 km). In July 2003 we resurveyed two islands identified as having the best potential for the long-term conservation of crested iguanas, and found that populations were continuing to decline. We suggest that the scarcity of crested iguanas on all islands surveyed is due to the combination of habitat loss and the introduction of exotic predators. All islands surveyed have free ranging goats, forest fires have occurred repeatedly over the last few decades, and feral cats are established on many islands. To reverse the population decline of this species immediate intervention is required on selected islands to halt continuing forest degradation and to clarify the effects of introduced predators.


1958 ◽  
Vol 49 (2) ◽  
pp. 273-285 ◽  
Author(s):  
C. C. Scheepers ◽  
D. L. Gunn

SummaryA method is described of estimating the total numbers and frequency distributions of adults of the Red Locust, Nomadacris septemfasciata (Serv.), in outbreak areas of hundreds of square miles, based upon counting the numbers that fly up in a two-yard strip in front of a moving vehicle. The method has proved itself valuable for indicating both immediate and future requirements for killing the locusts, but it requires refining for some research purposes.By this method, the importance has been clearly shown of the process of congregation of scattered adult locusts in forming emigrant swarms that could start a plague. The locusts do not congregate but actually disperse just before laying eggs.The total population in part (189 sq. miles) of the North Rukwa Outbreak Area (a self-contained area of 253 sq. miles) in Tanganyika Territory has been followed for four years. There are indications that a small migrant swarm contains 5–10 million locusts, that a total population in the whole of the North Rukwa Outbreak Area of 20 million locusts is unlikely to yield a migrant swarm, but that 50 million locusts could readily do so.In 1953, after poor rains, no natural mortality was detected between July and October by the assessment methods described. In 1957, after good rains, natural mortality of 70–90 per cent. was revealed by the same methods, although the dry season was not fully covered by the assessments.


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