Is the Carpentarian Rock-rat Zyzomys palatalis critically endangered?

2006 ◽  
Vol 12 (2) ◽  
pp. 134 ◽  
Author(s):  
David M. J. S. Bowman ◽  
Daniel L McIntyre ◽  
Barry W. Brook
Keyword(s):  
Conservation Status ◽  
Species Conservation ◽  
Population Viability Analysis ◽  
Critically Endangered ◽  
Isolated Populations ◽  
Forest Habitat ◽  
Viability Analysis ◽  
Area Of Occupancy ◽  
Closed Forest ◽  
Minimum Number

The Carpentarian Rock-rat Zyzomys palatalis is a rare conilurine rodent with a global distribution restricted to a small area of sandstone escarpments in the Gulf of Carpentaria region of the Northern Territory. Previous assessments of its World Conservation Union (IUCN) status in 1996 had classified the species as Critically Endangered based on the restricted area of occupancy and a putative decline in the extent and quality of its closed forest habitat due to uncontrolled landscape fires. A later population viability analysis confirmed that habitat loss was potentially the single most important threatening process. Here we argue that the species should be reclassified as Vulnerable, on the basis of the following new evidence: (1) the assumption that it was a closed forest specialist was not supported by a radiotracking study, which showed that on average 43% of an individual's monitored time was spent in the forest-savannah margin, and (2) analysis of repeat historical aerial photography has shown that the core closed forest habitat has in fact increased by 36% over the last 50 years. This has lead to an increase of 140 in the minimum number of equivalent Z. paJatalis territories, from 387 to 587, when home range overlaps and utilization of the savannah margins are considered. Reclassification of the species' conservation status should be accompanied with: (i) genetic studies of relatedness between isolated populations; (ii) monitoring and maintenance of the integrity of the landscapes, including creeklines that connect patches; and (iii) consideration of the introduction of captive bred specimens into an adjacent unoccupied fragments.

scholarly journals Population status and trend of the Critically Endangered Montserrat Oriole

2013 ◽  
Vol 24 (2) ◽  
pp. 252-261 ◽  
Author(s):  
STEFFEN OPPEL ◽  
ANDREW CASSINI ◽  
CALVIN FENTON ◽  
JAMES DALEY ◽  
GERARD GRAY
Keyword(s):  
Conservation Status ◽  
Population Decline ◽  
Future Trend ◽  
Critically Endangered ◽  
World Population ◽  
Small Range ◽  
Forest Fragments ◽  
Forest Habitat ◽  
Monitoring Design ◽  
The World

SummaryMany island endemics are of great conservation concern due to small range and population sizes. The Montserrat Oriole Icterus oberi is a forest passerine endemic to the Caribbean island of Montserrat, where recent volcanic activity has destroyed a large proportion of suitable forest habitat. From 1997 to 2000 the Montserrat Oriole population declined dramatically even in the remaining forest habitat, leading to its classification as ‘Critically Endangered’. We present trend estimates of the Montserrat Oriole population from 2000 to 2013, and estimate the world population size in 2012 based on repeat point counts and beta-binomial mixture models. Montserrat Orioles recovered between 2003 and 2005, and we found no evidence for a continuing population decline. However, there was large uncertainty around trend estimates, and the power to detect a shallow negative trend was very low. Based on the comparison of count data at 42 points, the Montserrat Oriole population in 2013 was less than half as large as in 1998. To improve future trend estimates a new monitoring design was introduced in 2011, and applied to all subpopulations of the species in 2012. The world population in 2012 was estimated to hold between 307 (95% credible interval 212–503) and 690 birds (476–1131) birds in the two forest fragments on Montserrat, depending on whether the sampling area around each point count was assumed to encompass 100 m or 150 m. Based on these estimates, the Montserrat Oriole currently does not meet the IUCN criteria for ‘Critically Endangered’, and we recommend a revision of the species’ conservation status.

scholarly journals Distribution and status of the Critically Endangered blond titi monkey Callicebus barbarabrownae of north-east Brazil

Oryx ◽  
2011 ◽  
Vol 45 (3) ◽  
pp. 439-443 ◽  
Author(s):  
Rodrigo C. Printes ◽  
Anthony B. Rylands ◽  
Júlio César Bicca-Marques
Keyword(s):  
Conservation Status ◽  
Iucn Red List ◽  
Red List ◽  
Critically Endangered ◽  
Forest Fragments ◽  
Vegetation Types ◽  
North East ◽  
Area Of Occupancy ◽  
Titi Monkey ◽  
Iucn Red List Assessment

AbstractThe blond titi monkey Callicebus barbarabrownae lives in forest fragments in the caatinga (tropical thorn scrub and forest) of north-east Brazil. In 2004–2005 we carried out five surveys to determine its current distribution and conservation status; surveying forest fragments, interviewing local people, and recording vegetation types and patterns of land use. The blond titi monkey occurs mainly in Dense Arboreal Caatinga and Highland Coastal Rainforest in the state of Bahia, at elevations of 241–908 m. Its range extends over 291,438 km2, with an area of occupancy of 2,636 km2. Estimated minimum population was 260 individuals. It was not recorded in any protected area. Cattle ranching favours the persistence of forest fragments for this species, whereas agriculture, subsistence or commercial, does not. Our findings supported the IUCN Red List assessment of Critically Endangered for this species.

scholarly journals Conservation status of Mascarene Amaranth Aerva congesta Balf.F. Ex Baker (Eudicots: Caryophyllales: Amaranthaceae): a Critically Endangered endemic herb of the Mascarenes, Indian Ocean

2018 ◽  
Vol 10 (8) ◽  
pp. 12056
Author(s):  
Kersley Bruno Pynee ◽  
David Harold Lorence ◽  
Poojanraj Khurun
Keyword(s):  
Conservation Status ◽  
Iucn Red List ◽  
Small Population ◽  
Red List ◽  
Critically Endangered ◽  
Native Vegetation ◽  
Ecological Studies ◽  
Area Of Occupancy ◽  
Mascarene Islands ◽  
Iucn Red List Criteria

Aerva congesta Balf.f. ex Baker (Amaranthaceae), an endemic of Mascarene Islands (Mauritius and Rodrigues) is assessed for its conservation status. Considering its local extinction in Rodrigues and very small population in Mauritius, in Round Island and at Gris Gris, south of Mauritius its area of occupancy (AOO) is estimated at 8km².  Due to its small AOO and threats by increasing native vegetation and alien species, A. congesta is evaluated as Critically Endangered following the latest IUCN Red List criteria.  The species needs an urgent well-defined restoration program and ecological studies to prevent its extinction.  

scholarly journals New island record and conservation status of Puerto Rican Bank endemic plant species, Ruehssia woodburyana (Acev.-Rodr.) Goyder, comb. nov., formally transferred from Marsdenia

2020 ◽  
Vol 8 ◽  
Author(s):  
Sara Bárrios ◽  
José Sustache ◽  
David Goyder ◽  
Martin Hamilton
Keyword(s):  
Forest Fires ◽  
Conservation Status ◽  
Species Conservation ◽  
Virgin Islands ◽  
Ex Situ ◽  
Suitable Habitat ◽  
Endemic Plant ◽  
Conservation Action ◽  
British Virgin Islands ◽  
Area Of Occupancy

Thought to be endemic to the Commonwealth of Puerto Rico, Ruehssia woodburyana (Apocynaceae) was recently discovered at a single location on Norman Island in the British Virgin Islands. Despite an increase in the extent of occurrence and area of occupancy, this species meta-population is very limited with a total of 37 individuals known in the wild. The largest subpopulation, on Mona Island, has only 26 individuals. The species suitable habitat is experiencing a continuing decline due to urban development, grazing by feral ungulates and human-induced forest fires. Conservation action is urgently needed and should be directed towards establishing genetically representative ex situ collections, such as seed for long term storage and live material for propagation. This species is evaluated as Critically Endangered (CR), based on Criteria C2a(i)+D, according to the IUCN Red List Categories and Criteria (version 3.1) and guidelines (Subcommittee IUCN Standards and Petitions 2016). Extensive and regular surveys to the region enable the discovery of new plant records for different countries and islands. In this paper, we record a new island record for Ruehssia woodburyana on Norman Island, in the British Virgin Islands and discuss the species conservation status. Marsdenia woodburyana is transferred to the genus Ruehssia to reflect the resurrection of that genus for species of Marsdenia native to the New World.

scholarly journals An estimate of the area of occupancy and population size of Brachycephalus tridactylus (Anura: Brachycephalidae) to reassess its conservation status, with a proposal for conservation measures

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12687
Author(s):  
Marcos R. Bornschein ◽  
Júnior Nadaline ◽  
Luiz Fernando Ribeiro ◽  
Giovanna Sandretti-Silva ◽  
Maria Fernanda Ferreira Rivas ◽  
...  
Keyword(s):  
New Species ◽  
Population Size ◽  
Conservation Status ◽  
Species Conservation ◽  
Type Locality ◽  
Area Of Occupancy ◽  
Conservation Measures ◽  
New Localities ◽  
Species Population ◽  
Surrounding Areas

Background We are experiencing a global crisis in conservation, which has led to the prioritization of targets, such as nations, regions, and animal groups, which are necessary while resources are disputed. Brazil is a priority not only because of its megadiversity, high rates of endemism, and frequent descriptions of new species but also because of its high levels of deforestation. Among the species groups prioritized for conservation is the anurans (Amphibia: Anura), the population of which is severely declining. One group of anurans is the genus Brachycephalus, which includes 37 endemic species in the Brazilian Atlantic Rainforest. Some of these species have highly restricted distributions (<100 ha). Thirty new species have been described since 2000, and 55.3% of all species are threatened with extinction. Brachycephalus tridactylus was only recently described and remains restricted to its type locality. Because of its reduced geographical distribution (0.41 km2), it has been proposed to be considered as Vulnerable. The objective of this study is to reevaluate the conservation status of Brachycephalus tridactylus and propose conservation measures. Methods We searched for new populations during 2016–2020, evaluated in loco impacts and potential impacts on the species’ population, and performed an analysis of the density of this population and estimated its size. International Union for Conservation of Nature (IUCN) criteria were used to assess the conservation status of the species. Results We recorded the species in seven new localities (from 715–1,140 m above sea level) in the state of São Paulo up to 33 km from the type locality of the species (in state of Paraná). We estimated the area of occupancy as 148.44 km2, densities as one calling male per 4.05 m2 and 130.00 m2, and a total population size of 4,429,722 adult individuals. Based on our finding, we proposed three lines of management: (1) formation of fire brigades, (2) management of residents’ mules in the conservation unit and surrounding areas, and (3) management of degraded areas. We recommend changing the species’ conservation status from Vulnerable to Endangered because of its fragmented distribution and decline in the area of occupancy and in the quality of its habitat. Our results have expanded the species previous geographic distribution and delimited areas without previous records. Our estimates of population density and size are in accordance with those verified for congeners. The conservation of this species benefits the environments and other species that inhabit them, being, therefore, strategic for receiving conservation actions that will spread throughout the ecosystem.

scholarly journals New population estimates of a critically endangered species, the Balearic Shearwater Puffinus mauretanicus, based on coastal migration counts

2014 ◽  
Vol 26 (1) ◽  
pp. 87-99 ◽  
Author(s):  
GONZALO M. ARROYO ◽  
MARÍA MATEOS-RODRÍGUEZ ◽  
ANTONIO R. MUÑOZ ◽  
ANDRÉS DE LA CRUZ ◽  
DAVID CUENCA ◽  
...  
Keyword(s):  
Conservation Status ◽  
Population Viability Analysis ◽  
Breeding Population ◽  
Additive Models ◽  
North Coast ◽  
Strait Of Gibraltar ◽  
Viability Analysis ◽  
Critically Endangered Species ◽  
The North ◽  
Breeding Migration

SummaryThe Balearic Shearwater Puffinus mauretanicus is considered one of the most threatened seabirds in the world, with the breeding population thought to be in the range of 2,000–3,200 breeding pairs, from which global population has been inferred as 10,000 to 15,000 birds. To test whether the actual population of Balearic Shearwaters is larger than presently thought, we analysed the data from four land-based census campaigns of Balearic Shearwater post-breeding migration through the Strait of Gibraltar (mid-May to mid-July 2007–2010). The raw results of the counts, covering from 37% to 67% of the daylight time throughout the migratory period, all revealed figures in excess of 12,000 birds, and went up to almost 18,000 in two years. Generalised Additive Models were used to estimate the numbers of birds passing during the time periods in which counts were not undertaken (count gaps), and their associated error. The addition of both counted and estimated birds reveals figures of between 23,780 and 26,535 Balearic Shearwaters migrating along the north coast of the Strait of Gibraltar in each of the four years of our study. The effects of several sources of bias suggest a slight potential underestimation in our results. These figures reveal the urgent need to reformulate the population viability analysis for the species, and then if necessary reconsider its conservation status.

scholarly journals Distribution, status, and conservation of Camellia changii Ye (Theaceae), a Critically Endangered plant endemic to southern China

Oryx ◽  
2014 ◽  
Vol 48 (3) ◽  
pp. 358-360 ◽  
Author(s):  
Hai Ren ◽  
Shuguang Jian ◽  
Yongju Chen ◽  
Hong Liu ◽  
Qianmei Zhang ◽  
...  
Keyword(s):  
Nature Reserve ◽  
Sandy Loam ◽  
Southern China ◽  
Conservation Status ◽  
Species Conservation ◽  
Iucn Red List ◽  
Critically Endangered ◽  
Ex Situ ◽  
Flowering Rate ◽  
In The Wild

AbstractThe distribution of the endemic threatened plant Camellia changii Ye (Family Theaceae) is restricted to a small area in southern China, and little else is known about its status in the wild. To provide information for the conservation of C. changii we investigated its distribution, population size and structure, and habitat, and assessed its conservation status. Surveys confirmed that the species grows in a narrow band along both sides of a 4 km long segment of a stream in Ehuangzhang Nature Reserve, under the discontinuous canopy of a secondary evergreen broadleaved forest on well-drained, acidic sandy loam soil. We found a total of 1,039 individuals of C. changii. The population has a high flowering rate but a low seed-setting rate. The population appears to be in decline because no seedlings and few young plants were evident. Our findings indicate that C. changii should be categorized as Critically Endangered on the IUCN Red List. We have recommended an integrated species-conservation plan for the species that includes patrolling the Ehuangzhang Nature Reserve to prevent plant removal, establishing an ex situ living collection that contains the entire wild genetic diversity (accomplished by grafting of short cuttings from all wild individuals), facilitating propagation for commercial use, and implementing reintroduction to augment the wild population.

scholarly journals Species versus within-species niches: a multi-modelling approach to assess range size of a spring-dwelling amphibian

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Forough Goudarzi ◽  
Mahmoud-Reza Hemami ◽  
Mansoureh Malekian ◽  
Sima Fakheran ◽  
Fernando Martínez-Freiría
Keyword(s):  
Species Distribution ◽  
Conservation Status ◽  
Species Conservation ◽  
Landscape Scale ◽  
Species Level ◽  
Environmental Data ◽  
Similar Species ◽  
Fine Scale ◽  
Distribution Models ◽  
Area Of Occupancy

AbstractSpecies Distribution Models (SDMs) can be used to estimate potential geographic ranges and derive indices to assess species conservation status. However, habitat-specialist species require fine-scale range estimates that reflect resource dependency. Furthermore, local adaptation of intraspecific lineages to distinct environmental conditions across ranges have frequently been neglected in SDMs. Here, we propose a multi-stage SDM approach to estimate the distributional range and potential area of occupancy (pAOO) of Neurergus kaiseri, a spring-dwelling amphibian with two climatically-divergent evolutionary lineages. We integrate both broad-scale climatic variables and fine-resolution environmental data to predict the species distribution while examining the performance of lineage-level versus species-level modelling on the estimated pAOO. Predictions of habitat suitability at the landscape scale differed considerably between evolutionary level models. At the landscape scale, spatial predictions derived from lineage-level models showed low overlap and recognised a larger amount of suitable habitats than species-level model. The variable dependency of lineages was different at the landscape scale, but similar at the local scale. Our results highlight the importance of considering fine-scale resolution approaches, as well as intraspecific genetic structure of taxa to estimate pAOO. The flexible procedure presented here can be used as a guideline for estimating pAOO of other similar species.

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