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

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.

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

2015 ◽  
Author(s):  
Madhava Meegaskumbura ◽  
Nayana Wijayathilaka ◽  
Nirodha Abayalath ◽  
Gayani Senevirathne
Keyword(s):  
Forest Cover ◽  
High Elevation ◽  
Habitat Associations ◽  
Egg Laying ◽  
Primary Forest ◽  
Isolated Populations ◽  
In The Wild ◽  
Suitable Habitats ◽  
Wide Geographic Distribution ◽  
Forest Habitats

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, a few A. kandianus were rediscovered in 2012 and redescribed as "the world's rarest toad". Here we report the results of a two-year study of the occurrence, habits and habitat associations of adult and larval A. kandianus using both general surveys and quadrat sampling. We show this to be a secretive species with a patchy distribution. Non-breeding female toads dwell in primary-forest habitats, but after heavy and sudden downpours they form large mating congregations in large streams. Amplexed pairs swim synchronously, enabling them to traverse fast currents. Egg-laying sites remain unknown, but the ability to dive and vocalize underwater, and characteristics of the eggs, suggest that they lay eggs in dark recesses of the stream. Tadpoles show microhabitat partitioning within the stream, with the greatest diversity of stages in slow-flowing rocky areas. The more robust stages possessing sucker discs exploit rocky-rapids, while metamorphic stages inhabit stream margins. We use DNA-barcoding to show the existence of two disparate toad populations. Distribution modeling with forest-cover layers added, predict a very small remaining area of suitable habitats. Conservation of this climatically and ecologically restricted species hinge largely on the preservation of high-elevation primary and riparian forests and unpolluted torrents.

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

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.

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

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.

scholarly journals High Survivorship of First-Generation Monarch Butterfly Eggs to Third Instar Associated with a Diverse Arthropod Community

Insects ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 567
Author(s):  
Misty Stevenson ◽  
Kalynn L. Hudman ◽  
Alyx Scott ◽  
Kelsey Contreras ◽  
Jeffrey G. Kopachena
Keyword(s):  
Host Plants ◽  
First Generation ◽  
Danaus Plexippus ◽  
Monarch Butterfly ◽  
Conservation Strategies ◽  
North Texas ◽  
Ecological Processes ◽  
Area Of Occupancy ◽  
Predator Abundance ◽  
A Site

Based on surveys of winter roost sites, the eastern migratory population of the monarch butterfly (Danaus plexippus) in North America appears to have declined in the last 20 years and this has prompted the implementation of numerous conservation strategies. However, there is little information on the survivorship of first-generation monarchs in the core area of occupancy in Texas, Oklahoma, and Louisiana where overwinter population recovery begins. The purpose of this study was to determine the survivorship of first-generation eggs to third instars at a site in north Texas and to evaluate host plant arthropods for their effect on survivorship. Survivorship to third instar averaged 13.4% and varied from 11.7% to 15.6% over three years. The host plants harbored 77 arthropod taxa, including 27 predatory taxa. Despite their abundance, neither predator abundance nor predator richness predicted monarch survival. However, host plants upon which monarchs survived often harbored higher numbers of non-predatory arthropod taxa and more individuals of non-predatory taxa. These results suggest that ecological processes may have buffered the effects of predators and improved monarch survival in our study. The creation of diverse functional arthropod communities should be considered for effective monarch conservation, particularly in southern latitudes.

scholarly journals Estimating change in the geographical range and population size of Hinde's Babbler Turdoides hindei

2003 ◽  
Vol 13 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Philip Shaw ◽  
John Musina ◽  
Patrick Gichuki
Keyword(s):  
Protected Areas ◽  
Population Size ◽  
Geographical Range ◽  
Population Estimates ◽  
Extent Of Occurrence ◽  
Area Of Occupancy ◽  
Species Area ◽  
Gains And Losses ◽  
Global Population

Hinde's Babbler Turdoides hindei is a globally threatened Kenyan endemic, which during the 1990s, was known from just seven localities. Based mainly on surveys undertaken in 2000–2001, we estimate the species's global population size and compare recent changes in its “extent of occurrence” and “area of occupancy”. Historically, Hinde's Babbler has been recorded from c. 40 10 × 10 km squares; 27 pre-1980 and 19 subsequently, suggesting that its area of occupancy has declined by about 30%. In contrast, its extent of occurrence has declined by only 8%, this measure being less sensitive to the balance of gains and losses occurring near the centre of its range. During surveys in 1994 and 2000–2001, 157 groups were located, containing 665 birds, 75% of which were found at two intensively cultivated sites. Some 97% of birds were located in, or adjacent to, five Important Bird Areas, but only 8% were found within legally protected areas. Two extrapolated population estimates are presented, based on the number of birds likely to have been missed at survey sites, and the species' area of occupancy. These suggest that the global population of Hinde's Babbler is likely to fall within the range of 1,500–5,600 birds.

scholarly journals An assessment of the distribution, population size and conservation status of the Santa Marta Foliage-gleaner Automolus rufipectus: a Sierra Nevada de Santa Marta endemic

2015 ◽  
Vol 25 (4) ◽  
pp. 451-465 ◽  
Author(s):  
ESTEBAN BOTERO-DELGADILLO ◽  
NICHOLAS BAYLY ◽  
CAMILA GÓMEZ ◽  
PAULO C. PULGARÍN-R. ◽  
CARLOS ANDRÉS PÁEZ
Keyword(s):  
Population Size ◽  
Sierra Nevada ◽  
Forest Cover ◽  
Conservation Status ◽  
Bird Species ◽  
Environmental Niche ◽  
Coffee Plantations ◽  
Habitat Transformation ◽  
Elevation Range ◽  
Area Of Occupancy

SummaryThe Santa Marta Foliage-gleaner Automolus rufipectus is one of 19 endemic bird species found in the Sierra Nevada de Santa Marta (SNSM) in northern Colombia but until recently it was considered a sub-species of the Ruddy Foliage-gleaner Automolus rubiginosus. Consequently, published information on its distribution and ecology is lacking, and while it is classified as near- threatened, this designation was based on limited quantitative data. To improve our knowledge of the Santa Marta Foliage-gleaner’s geographical distribution, elevation range, population density, habitat use and conservation status, we analysed both historical and recent site locality records and carried out variable distance transects within forested habitats and shade coffee plantations. We modelled the environmental niche of the species and subsequently estimated its extent of occurrence and area of occupancy, as well as population size. Our results consistently showed that the distribution of the Santa Marta Foliage-gleaner is more restricted than previously considered, both geographically and by elevation (we redefine elevation range as 600–1,875 m). This suggests that the species is more at risk of habitat transformation and combined with our estimates of population size (< 10,000 individuals), it is likely that the species will be uplisted to a higher threat category. More positively, and contrary to published accounts, we found that approximately 40% of the species’ range lies within protected areas. Nevertheless, we recommend the implementation of strategies to maintain forest cover on the western flank of the SNSM and further research to better define the species’ habitat needs and population dynamics.

The speciation continuum and species relations between populations: in search of agreement between the theory and practice of systematics

2021 ◽  
pp. 173-179
Author(s):  
Oleksandr Zinenko
Keyword(s):  
Reproductive Isolation ◽  
Species Concept ◽  
Climatic Conditions ◽  
Point Of View ◽  
Theory And Practice ◽  
Hybrid Origin ◽  
Isolated Populations ◽  
As Species ◽  
Mitochondrial Cytochrome B ◽  
Traditional Taxonomy

From an evolutionary point of view, the achievement of species status by a group of populations is an ongoing process (except for rare cases of instantaneous speciation), during which isolated populations acquire traits and adaptations that minimize gene flow between them. However, depending on the group, the ways and timing of the gaining of reproductive isolation may be different. In such a complex group for systematics as small vipers (genus Vipera, subgenus Pelias), there are a number of problematic situations for species delimitation: the ability to form hybrids and hybrid populations between species, adaptive hybridization and hybrid speciation, and possible traces of reversed speciation, which indicate that complete and irreversible reproductive isolation may not be achieved at all. The effectiveness of reproductive isolation largely depends on external factors, mostly related to the range spatial structure, ecology of species in areas of sympatry, as well as climatic conditions and their changes, landscape dynamics, etc. The only species concept that allows to describe new species in the absence of reproductive isolation, recognizes the possibility of hybrid and reverse speciation — de Queiroz unified species concept — is practically unsuitable due to the need to consider as species a large number of isolated populations. Therefore, the solution is a conservative approach in practical taxonomy, which takes into account as a species criterion the ecological divergence of species, the possibility of their sympatric existence, which is usually achieved at 5% divergence of the mitochondrial cytochrome b gene. Stabilized hybrid populations occupying distinct ecological niche different from those of parental species also deserve recognition as species of hybrid origin. Not only species deserves to be protected, but also a distinguishable and diverged group of populations — Evolutionary Significant Unit (ESU) or subspecies in traditional taxonomy.

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

2018 ◽  
Vol 115 (46) ◽  
pp. 11850-11855 ◽  
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.

scholarly journals Drivers and distribution of forest fires in Sikkim Himalaya: A maximum entropy-based approach to spatial modelling.

2020 ◽  
Author(s):  
Polash Banerjee
Keyword(s):  
Forest Fire ◽  
Forest Fires ◽  
Forest Cover ◽  
Spatial Modelling ◽  
Climatic Conditions ◽  
Mitigation Measures ◽  
Sikkim Himalaya ◽  
Environmental Features ◽  
Validation Criteria ◽  
Forest Fire Model

Abstract The recent episodes of forest fire in Brazil and Australia of 2019 are tragic reminders of the hazards of the forest fire. Globally incidents of forest fire events are in the rise due to human encroachment into wilderness and climate change. Sikkim with a forest cover of more than 47%, suffers seasonal instances of frequent forest fire during the dry winter months. To address this issue, a GIS-aided and MaxEnt machine learning-based forest fire prediction map has been prepared using forest fire inventory database and maps of environmental features. The study indicates that amongst the environmental features, climatic conditions and proximity to roads are the major determinants of the forest fire. Model validation criteria like ROC curve, correlation coefficient and Cohen’s Kappa show a good predictive capability (AUC = 0.95, COR = 0.78, κ = 0.78). The outcomes of this study in the form of a forest fire prediction map can aid the stakeholders of the forest in taking informed mitigation measures.

scholarly journals Increasing accuracy: The advantage of using open access species occurrence database in the Red List assessment

2020 ◽  
Vol 21 (8) ◽  
Author(s):  
Iyan Robiansyah ◽  
Wita Wardani
Keyword(s):  
Open Access ◽  
Extinction Risk ◽  
Conservation Status ◽  
Iucn Red List ◽  
Red List ◽  
Suitable Habitat ◽  
Herbarium Specimens ◽  
Species Occurrence ◽  
Extent Of Occurrence ◽  
Area Of Occupancy

Abstract. Robiansyah I, Wardani W. 2020. Increasing accuracy: The advantage of using open access species occurrence database in the Red List assessment. Biodiversitas 21: 3658-3664. IUCN Red List is the most widely used instrument to assess and advise the extinction risk of a species. One of the criteria used in IUCN Red List is geographical range of the species assessed (criterion B) in the form of extent of occurrence (EOO) and/or area of occupancy (AOO). While this criterion is presumed to be the easiest to be completed as it is based mainly on species occurrence data, there are some assessments that failed to maximize freely available databases. Here, we reassessed the conservation status of Cibotium arachnoideum, a tree fern distributed in Sumatra and Borneo. This species was previously assessed by Praptosuwiryo (2020, Biodiversitas 21 (4): 1379-1384) which classified the species as Endangered (EN) under criteria B2ab(i,ii,iii); C2a(ii). Using additional data from herbarium specimens recorded in the Global Biodiversity Information Facility (GBIF) website and from peer-reviewed scientific papers, in the present paper we show that C. arachnoideum has a larger extent of occurrence (EOO) and area of occupancy (AOO), more locations and different conservation status compared to those in Praptosuwiryo (2020). Our results are supported by the predicted suitable habitat map of C. arachnoideum produced by MaxEnt modelling method. Based on our assessment, we propose the category of Vulnerable (VU) C2a(i) as the global conservation status for C. arachnoideum. Our study implies the advantage of using open access databases to increase the accuracy of extinction risk assessment under the IUCN Red List criteria in regions like Indonesia, where adequate taxonomical information is not always readily available.

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