Realities of rarity: climatically and ecologically restricted, critically endangered Kandian Torrent Toads (Adenomus kandianus) breed en masse

10.7287/peerj.preprints.1575v2 ◽

2015 ◽

Author(s):

Madhava Meegaskumbura ◽

Nayana Wijayathilaka ◽

Nirodha Abayalath ◽

Gayani Senevirathne

Keyword(s):

Natural History ◽

Dna Barcoding ◽

Forest Cover ◽

Developmental Stages ◽

Habitat Associations ◽

Egg Laying ◽

Healthy Population ◽

Rrna Gene ◽

Isolated Populations ◽

Area Of Occupancy

Endemic to Sri Lanka, genus Adenomus contains two torrent-associated toad species whose ecology and natural history in the wild is virtually unknown. Adenomus kelaartii is relatively common, with a wide geographic distribution. Its sister species, A. kandianus, however, is restricted to two isolated populations in fast-disappearing montane and sub-montane forests. Formally declared extinct after not being recorded for over a century, following several years of surveying, a few A. kandianus were found in 2012 and referred to as "the world's rarest toad." However, tadpoles of A. kandianus bearing unique ventral suckers were soon discovered, but the rarity of the adult and the profusion of tadpoles were never explained. Here, using ecological methods, niche modeling and DNA-barcoding, we aim to understand the ecology, natural history and distribution of this rare toad. Following a two-year study of occurrence, habits and habitat associations of adults and larvae, we show this to be a secretive species with a patchy distribution. During non-mating periods female toads (N = 23) were found in primary forests habitat up to 650 m away from the breeding streams, and predominantly males in the riparian zone (12 males, 2 females). Following heavy rain they form large (N = 388) but patchy mating congregations in torrential streams (six sites; range 0−95 mating pairs; mean = 25, SD = 38.16, CV = 152%). Amplexed pairs swim synchronously, enabling them to traverse fast currents. Egg-laying sites remain unknown, but ability to dive, vocalize underwater, and characteristics of the eggs, suggests that they lay eggs in dark recesses of the stream. Quadrat sampling of tadpoles show microhabitat partitioning (in depth, flow-rate and substrate conditions) within the stream: the greatest diversity of larval developmental stages (25-42) in slow-flowing (depth, 0.75−1.5 m) rocky areas; more robust stages (31−39) bearing sucker discs utilise rocky-rapids (depth, 0.25−0.75 m); metamorphic stages (43-45) use stream margins (depth, <0.25 m); slow flowing silt covered areas of the stream were unoccupied, irrespective of the depth. DNA barcoding of the 16S rRNA gene fragment from the two known localities confirms the identity of the Pedro population also as A. kandianus. The uncorrected pairwise genetic distance of 0.1−0.7% suggests historical gene flow between the two populations. Distribution modeling (using MaxEnt), with forest-cover layers added, predicts a very small remaining area of suitable habitats (an area of occupancy of 16 km2 and an extent of occurrence of 128 km2) isolated by habitats that are not conducive to these toads. While the healthy population recorded at one site gives hope for the survival of the species, long-term conservation of this climatically and ecologically restricted species hinges largely on the preservation of cloud and riparian forests and the unpolluted high-flow torrents.

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Realities of rarity: climatically and ecologically restricted, critically endangered Kandian Torrent Toads (Adenomus kandianus) breed en masse

10.7287/peerj.preprints.1575 ◽

2015 ◽

Author(s):

Madhava Meegaskumbura ◽

Nayana Wijayathilaka ◽

Nirodha Abayalath ◽

Gayani Senevirathne

Keyword(s):

Natural History ◽

Dna Barcoding ◽

Forest Cover ◽

Developmental Stages ◽

Habitat Associations ◽

Egg Laying ◽

Healthy Population ◽

Rrna Gene ◽

Isolated Populations ◽

Area Of Occupancy

Endemic to Sri Lanka, genus Adenomus contains two torrent-associated toad species whose ecology and natural history in the wild is virtually unknown. Adenomus kelaartii is relatively common, with a wide geographic distribution. Its sister species, A. kandianus, however, is restricted to two isolated populations in fast-disappearing montane and sub-montane forests. Formally declared extinct after not being recorded for over a century, following several years of surveying, a few A. kandianus were found in 2012 and referred to as "the world's rarest toad." However, tadpoles of A. kandianus bearing unique ventral suckers were soon discovered, but the rarity of the adult and the profusion of tadpoles were never explained. Here, using ecological methods, niche modeling and DNA-barcoding, we aim to understand the ecology, natural history and distribution of this rare toad. Following a two-year study of occurrence, habits and habitat associations of adults and larvae, we show this to be a secretive species with a patchy distribution. During non-mating periods female toads (N = 23) were found in primary forests habitat up to 650 m away from the breeding streams, and predominantly males in the riparian zone (12 males, 2 females). Following heavy rain they form large (N = 388) but patchy mating congregations in torrential streams (six sites; range 0−95 mating pairs; mean = 25, SD = 38.16, CV = 152%). Amplexed pairs swim synchronously, enabling them to traverse fast currents. Egg-laying sites remain unknown, but ability to dive, vocalize underwater, and characteristics of the eggs, suggests that they lay eggs in dark recesses of the stream. Quadrat sampling of tadpoles show microhabitat partitioning (in depth, flow-rate and substrate conditions) within the stream: the greatest diversity of larval developmental stages (25-42) in slow-flowing (depth, 0.75−1.5 m) rocky areas; more robust stages (31−39) bearing sucker discs utilise rocky-rapids (depth, 0.25−0.75 m); metamorphic stages (43-45) use stream margins (depth, <0.25 m); slow flowing silt covered areas of the stream were unoccupied, irrespective of the depth. DNA barcoding of the 16S rRNA gene fragment from the two known localities confirms the identity of the Pedro population also as A. kandianus. The uncorrected pairwise genetic distance of 0.1−0.7% suggests historical gene flow between the two populations. Distribution modeling (using MaxEnt), with forest-cover layers added, predicts a very small remaining area of suitable habitats (an area of occupancy of 16 km2 and an extent of occurrence of 128 km2) isolated by habitats that are not conducive to these toads. While the healthy population recorded at one site gives hope for the survival of the species, long-term conservation of this climatically and ecologically restricted species hinges largely on the preservation of cloud and riparian forests and the unpolluted high-flow torrents.

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Forest cover reduces thermally suitable habitats and affects responses to a warmer climate predicted in a high-elevation lizard

Oecologia ◽

10.1007/s00442-014-2882-1 ◽

2014 ◽

Vol 175 (1) ◽

pp. 25-35 ◽

Cited By ~ 23

Author(s):

Shu-Ping Huang ◽

Warren P. Porter ◽

Ming-Chung Tu ◽

Chyi-Rong Chiou

Keyword(s):

Forest Cover ◽

High Elevation ◽

Suitable Habitats

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Assessing spatial dispersion, abundance, and conservation perspectives of Military Macaw Ara militaris populations in Mexico

Bird Conservation International ◽

10.1017/s0959270920000702 ◽

2021 ◽

pp. 1-19

Author(s):

TIBERIO C. MONTERRUBIO-RICO ◽

JUAN F. CHARRE-MEDELLÍN ◽

YAMEL RUBIO-ROCHA ◽

CARLOS BONILLA-RUZ ◽

CLAUDIA CINTA-MAGALLÓN ◽

...

Keyword(s):

Habitat Restoration ◽

Forest Cover ◽

Climatic Conditions ◽

Conservation Strategies ◽

Primary Forest ◽

Isolated Populations ◽

Extent Of Occurrence ◽

Area Of Occupancy ◽

Conservation Organizations ◽

Conservation Corridors

Summary The preservation of Military Macaw Ara militaris in Mexico required the implementation of a nationwide assessment evaluating its vulnerability using IUCN criteria. With the combined effort of several institutions, the abundance, location, dispersion, habitat availability, and climatic conditions of areas occupied by the species were determined. Although the species’ extent of occurrence is extensive (263,919 km2) only 29% of this constitutes area of occupancy. Published estimates indicate a series of isolated populations containing from four macaws to 215. Macaws occurred in 35 populations in four regions of 16 states containing an estimated 1,563–3,263 macaws; lower than required for long-term viability. Within regions, neighbouring populations were separated by an average of 68 km. The extent of occurrence is heterogeneous, and macaws inhabit areas that differ in elevation, precipitation, temperature, and forest cover. Higher local abundances occur in landscapes where annual precipitation is ≥1,100 mm, and primary forest availability ≥1,800 km2. Although the existence of undetected macaw groups in Mexico is possible, these are likely to contain only small numbers of individuals, as most detected areas with macaws contain less than 40 individuals, and larger concentrations are more likely to be noticed due to their conspicuous behaviour. The species is threatened primarily by its low overall abundance, fragmented distribution, and forest loss around populations with the highest abundance. With the information generated, it is possible to design and implement specific management and conservation strategies at different geographic scales for the recovery and maintenance of the species in Mexico. It is necessary to strengthen collaborative programmes among conservation organizations, government agencies, and local communities in each region of the country to organize and finance community-based actions such as monitoring, habitat restoration, protection from poaching and the creation of a network of conservation corridors and macaw reserves focused on conservation.

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Status and range decline of two galliform species in South-East Asia

Bird Conservation International ◽

10.1017/s0959270917000168 ◽

2017 ◽

Vol 28 (3) ◽

pp. 423-438

Author(s):

NGUYEN TRAN VY ◽

DUSIT NGOPRASERT ◽

STEPHEN BROWNE ◽

TOMMASO SAVINI

Keyword(s):

Deciduous Forest ◽

Anthropogenic Activities ◽

Habitat Associations ◽

Distribution Range ◽

Deciduous Forests ◽

Primary Forest ◽

Population Declines ◽

Historical Distribution ◽

Suitable Habitats

SummaryThe South-East Asian ranges of two narrow-geographical range species, Germain’s Peacock Pheasant Polyplectron germaini (GPP) and Orange-necked Partridge Arborophila davidi (ONP) have been shrinking due to pressures from anthropogenic activities. To improve our knowledge of population densities of Germain’s Peacock Pheasant and the Orange-necked Partridge in their remaining habitats, their current and historical distribution range, and the contraction of their distribution range as a surrogate for population declines, we carried out line and point transect surveys in protected areas in southern Vietnam to estimate their density and subsequently model their habitat associations. Our results consistently showed that the density of the GPP was not significantly different among mosaic, evergreen, or mixed deciduous forests, but appeared to be notably lower in bamboo forest, while the density of the ONP was highest in evergreen and mosaic forests and lower in bamboo, with no detections in mixed-deciduous forest. GPP was mostly found close to water sources in mosaic, evergreen and mixed-deciduous forests. The presence of ONP was positively associated with elevation, evergreen and mosaic forest. Primary forest loss, mainly in the lowlands, within the ranges of both species was at least 70% over the last 70 years, suggesting that suitable habitats within the range of both species may have shrunk by at least 60–70%. In addition, a number of threats still occur in their remaining suitable habitats, making them increasingly vulnerable in the long-term, if conservation interventions, such as increased protection, are not implemented.

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The recent distribution of endemic, disjunct and globally uncommon birds in the forests of Kerala State, south-west India

Bird Conservation International ◽

10.1017/s0959270900003415 ◽

1999 ◽

Vol 9 (3) ◽

pp. 191-225 ◽

Cited By ~ 3

Author(s):

V. J. Zacharias ◽

Anthony J. Gaston

Keyword(s):

National Parks ◽

Forest Cover ◽

Bird Species ◽

High Elevation ◽

Western India ◽

Large Network ◽

Isolated Populations ◽

Bird Populations ◽

Disjunct Populations ◽

Kerala State

SummarySurveyed the avifaunas of 24 forest areas in Kerala State, south-western India, over the period 1973–1997, recording 309 species. We give details here of distributions and status for all species endemic to South Asia and all those having isolated populations, disjunct from conspecifics in northern India (disjunct species). Most bird species found in Kerala that are endemic to southern India, or form disjunct populations, occur in forest habitats. Those species endemic to the Western Ghats (passerines), or constituting disjunct populations (raptors) tend to have more restricted occurrence than other forest birds. For the passerines this is because they are mainly confined to high elevation forests and grasslands: rather restricted habitats in Kerala. The raptors may be more dependent than other species on large areas of forest and hence may have suffered from recent reductions in forest cover. Current trends in forest clearance for agriculture and plantations and encroachment by settlers, threaten especially the birds of low and middle altitude forests. The present status of such birds as Malabar Pied Hornbill Anthracoceros coronatus, Great Eared Nightjar Eurostopodus macrotis, Lesser Coucal Centropus bengalensis and White-bellied Blue Flycatcher Cyornis pallipes seems to be markedly worse than that described by Ali (1969) for the 1930s. These species, as well as Dollarbird Eurystomus orientalis and Black-crested Baza Aviceda leuphotes, are patchily distributed at low densities and may be vulnerable to extirpation from local areas. Higher altitude habitats, where many endemics occur, cover smaller areas, but are less threatened. However, some species occurring at low densities (Rufous-bellied Eagle Hieraaetus kienerii, White-bellied Shortwing Brachypteryx major, Black-and-orange Flycatcher Ficedula nigrorufa, Broad-tailed Grassbird Schoenicola platyura) may be vulnerable to extirpation or extinction in the long term. Kerala has a large network of protected areas (National Parks, Sanctuaries). Effective protection of those areas should be sufficient to maintain most species, although the coverage of low altitude forest is poor and remaining fragments should be carefully protected. There is continuous pressure on all habitats and bird populations will need to be carefully monitored in future if Kerala's endemic and disjunct populations are to be maintained.

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Haiti’s biodiversity threatened by nearly complete loss of primary forest

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1809753115 ◽

2018 ◽

Vol 115 (46) ◽

pp. 11850-11855 ◽

Cited By ~ 9

Author(s):

S. Blair Hedges ◽

Warren B. Cohen ◽

Joel Timyan ◽

Zhiqiang Yang

Keyword(s):

Tropical Forests ◽

National Parks ◽

Mass Extinction ◽

Forest Cover ◽

Secondary Growth ◽

Complete Loss ◽

Primary Forest ◽

The Difference ◽

Primary Forests ◽

Agricultural Organization

Tropical forests hold most of Earth’s biodiversity. Their continued loss through deforestation and agriculture is the main threat to species globally, more than disease, invasive species, and climate change. However, not all tropical forests have the same ability to sustain biodiversity. Those that have been disturbed by humans, including forests previously cleared and regrown (secondary growth), have lower levels of species richness compared with undisturbed (primary) forests. The difference is even greater considering extinctions that will later emanate from the disturbance (extinction debt). Here, we find that Haiti has less than 1% of its original primary forest and is therefore among the most deforested countries. Primary forest has declined over three decades inside national parks, and 42 of the 50 highest and largest mountains have lost all primary forest. Our surveys of vertebrate diversity (especially amphibians and reptiles) on mountaintops indicates that endemic species have been lost along with the loss of forest. At the current rate, Haiti will lose essentially all of its primary forest during the next two decades and is already undergoing a mass extinction of its biodiversity because of deforestation. These findings point to the need, in general, for better reporting of forest cover data of relevance to biodiversity, instead of “total forest” as defined by the United Nation’s Food and Agricultural Organization. Expanded detection and monitoring of primary forest globally will improve the efficiency of conservation measures, inside and outside of protected areas.

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Methods of Landscape Valorization and Possibilities of Its Application in Hunting Area Categorisation

10.5772/intechopen.94048 ◽

2020 ◽

Author(s):

Szewczyk Grzegorz ◽

Krzysztof Lipka ◽

Piotr Wężyk ◽

Karolina Zięba-Kulawik ◽

Monika Winczek

Keyword(s):

Natural Environment ◽

Functional Role ◽

Large Scale ◽

Forest Cover ◽

Agricultural Landscape ◽

Environmental Changes ◽

Environmental Values ◽

Small Game ◽

Forest Habitats

As a result of environmental changes, assessment indexes for the agricultural landscape have been changing dramatically. Being at the interface of human activity and the natural environment, hunting is particularly sensitive to environmental changes, such as increasing deforestation or large-scale farming. The classical categorisation of hunting grounds takes into account the area, forest cover, number of forest complexes, fertility of forest habitats, lack of continuity of areas potentially favourable to wild animals. Landscape assessment methods used in architecture often better reflect the actual breeding and hunting value of a given area, especially in relation to fields and forests. The forest-field mosaic, large spatial fragmentation as well as interweaving of natural environment elements with buildings do not have to be the factors that limit the numbers of small game. Identification of the constituents of architectural-landscape interiors: content and significance assessment, determination of the functional role or assessment based on the general environmental values being represented take into account factors important for the existence of game, in particular small game.

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Conservation biology of the critically endangered salamander, Paradactylodon persicus gorganensis (Clergue-Gazeau & Thorn, 1979) (Amphibia: Hynobiidae) in northeastern Iran

Animal Biology ◽

10.1163/15707563-bja10057 ◽

2021 ◽

pp. 1-12

Author(s):

Seyyed Saeed Hosseinian Yousefkhani

Keyword(s):

High Elevation ◽

Quality Parameters ◽

Critically Endangered ◽

Ex Situ ◽

Conservation Action ◽

Agriculture Industry ◽

Negative Effect ◽

In The Wild ◽

Future Viability ◽

Anthropogenic Threats

Abstract Paradactylodon persicus gorganensis is a critically endangered salamander found in northeastern Iran which faces increasing major anthropogenic threats such as agriculture, industry and mining. The aim of the current study is to identify key environmental variables associated with the species’ presence. Also, measuring and comparing the water quality parameters in habitats where P. p. gorganensis is present and absent are the other aims of the study. The results indicate that high pH and dissolved oxygen values have a negative effect on the species’ presence, while its presence was strongly correlated with low mean water temperatures. The species’ range in response to the climate change will shift to the south and east, where areas of high elevation occur, because the species favors cold habitats. This study indicates that it will be particularly important to evaluate the whole range where P. p. gorganensis exists when preparing conservation action plans. It is recommended that ex-situ conservation programs are incorporated into conservation planning for the species, because the number of individuals in the wild is so low and their future viability is fragile.

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Ecology of the Atlantic Forest

Ecology ◽

10.1093/obo/9780199830060-0233 ◽

2021 ◽

Author(s):

Elise Damstra ◽

Cristina Banks-Leite

Keyword(s):

Atlantic Forest ◽

Forest Cover ◽

Time Lag ◽

Native Forest ◽

Important Species ◽

Habitat Transformation ◽

Golden Lion Tamarin ◽

Palm Heart ◽

In The Wild ◽

Unique Domain

Extending along the southern coast of Brazil, into Argentina and Paraguay, the Atlantic Forest is a domain that once covered 150 Mha and includes many distinct forest subtypes and ecosystems. Its large latitudinal (29˚) and altitudinal (0–2,800 m above sea level) range, as well as complex topography in the region, has created microclimates within forest subtypes, which has led to biodiversity specifically adapted to narrow ecological ranges. The region is incredibly species-rich and is home to charismatic or economically important species such as the black and golden lion tamarin, the red-browned Amazon parrot, and the highly prized palm heart from Euterpe edulis. Through widespread human-driven change dating back to the arrival of European settlers in 1500, this realm has been extensively reduced, fragmented, and modified. Nowadays, this region is home to about 130 million people (60 percent of the Brazilian population) and is responsible for producing 70 percent of Brazil’s GDP, putting a strain on natural resources and providing challenges to conservation. Due to its high levels of endemic species coupled with a high threat of habitat loss and fragmentation, the Atlantic Forest has been identified as a “biodiversity hotspot.” Numerous studies have assessed the effects of habitat transformation on biodiversity and the consensus is that the majority of species are negatively affected. It is puzzling however that few species have actually gone extinct in the wild, even if some extinctions might have gone undetected. Extinctions do not immediately follow habitat change, there is often a time lag of many decades between habitat transformation and extinction. This may suggest that many species in the Atlantic Forest are “living deads,” as despite their presence the available habitat no longer supports their requirements. It also suggests that there is a window of opportunity to restoring the domain to avert extinctions before they are realized. Current research and policy actions are geared toward optimizing restoration and increasing the extent of native forest cover, bringing hope to the conservation of this unique domain.

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