Breeding Performance and Pond Habitat Management of Critically Endangered Black Soft-Shell Turtle (Nilssonia nigricans) in Bangladesh

2020 ◽  
Vol 73 (4) ◽  
pp. 422-429
Author(s):  
Indrani Kanungo ◽  
M. Shahanul Islam ◽  
Abdullah-Al Mamun
Keyword(s):  
Habitat Management ◽  
Critically Endangered ◽  
Breeding Performance ◽  
Soft Shell

Landscape-level habitat management plan through geometric reserve design for critically endangered Hangul (Cervus hanglu hanglu)

2021 ◽  
pp. 146031
Author(s):  
Tanoy Mukherjee ◽  
Vandana Sharma ◽  
Lalit Kumar Sharma ◽  
Mukesh Thakur ◽  
Bheem Dutt Joshi ◽  
...  
Keyword(s):  
Habitat Management ◽  
Management Plan ◽  
Reserve Design ◽  
Critically Endangered ◽  
Landscape Level

scholarly journals Conservation status and management insights from tracking a cryptic and Critically Endangered species of Orchidaceae

Oryx ◽  
2016 ◽  
Vol 51 (3) ◽  
pp. 441-450
Author(s):  
T. Kraaij ◽  
J. A. Baard ◽  
B. J. Crain
Keyword(s):  
Population Biology ◽  
Habitat Management ◽  
Conservation Status ◽  
Management Strategies ◽  
Growing Season ◽  
Iucn Red List ◽  
Critically Endangered ◽  
Physical Damage ◽  
Beneficial Effects ◽  
Critically Endangered Species

AbstractNinety-five percent of orchid species associated with fynbos shrublands of South Africa's Cape Floristic Kingdom have been assessed for the IUCN Red List, yet aspects of their demography and population biology remain poorly understood. We conducted a 6-year demographic study of the Critically Endangered Disa procera, a cryptic, terrestrial species from South Africa with a global population of c. 50 individuals known from a single location. We aimed to provide management recommendations that would facilitate its persistence. Our findings indicate that the population of D. procera is larger than previously thought, and the species occurs at two distinct locations. These orchids exhibit high interannual variation in population size and turnover of individuals, potentially indicative of a species with a short life span, and still meet the criteria for Critically Endangered status. The species benefits from disturbances, such as brush cutting along trails, or fire, which open up clearances in the vegetation. However, physical damage to plants during their aboveground growing season (September–January) is particularly detrimental and should be avoided in habitat management for the species. Fire had beneficial effects at the population and individual levels and is recommended at 10–25-year intervals, outside the orchid's growing season. The species exhibited comparatively high rates of fruit set (68%), suggesting that pollination limitation does not currently constrain its performance. Its patchy distribution may, however, indicate constraints on dispersal or recruitment. We recommend that management strategies should include continued protection and monitoring of both populations, studies on pollination, habitat requirements and mycorrhizal associates, and a prescribed disturbance regime.

scholarly journals DNA metabarcoding reveals adaptive seasonal variation of individual trophic traits in a critically endangered fish

2021 ◽  
Author(s):  
Kurt Villsen ◽  
Emmanuel Corse ◽  
Emese Meglécz ◽  
Gaït Archambaud-Suard ◽  
Hélène Vignes ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Habitat Management ◽  
Optimal Foraging Theory ◽  
Trophic Niche ◽  
Modelling And Simulation ◽  
Critically Endangered ◽  
Foraging Strategies ◽  
Endangered Fish ◽  
Niche Variation ◽  
Trophic Traits

AbstractDietary studies are critical for understanding foraging strategies and have important applications in conservation and habitat management. We applied a robust metabarcoding protocol to characterize the diet of the critically endangered freshwater fish Zingel asper and conducted modelling and simulation analyses to characterize and identify some of the drivers of individual trophic trait variation in this species. We found that intra-specific competition and ontogeny had minor effects on the trophic niche of Z. asper. Instead, our results suggest that the majority of trophic niche variation was driven by seasonal variation in ecological opportunity (in our case, the seasonal variation in the availability of preferred prey types). Overall, our results are in line with the optimal foraging theory and suggest that Z. asper is specialized on a few ephemeropteran prey species (Baetis fuscatus and Ecdyonurus) but adapts its foraging by becoming more opportunistic as its favoured prey seasonally decline. Despite the now widespread usage of metabarcoding, very few studies have attempted to study inter- and intra-populational individual trophic traits variation with metabarcoding data. This study illustrates how metabarcoding data obtained from feces can be combined with modelling and simulation approaches to test hypotheses in the conventional analytic framework of trophic analysis.

scholarly journals Vertical structure use by the Stout Iguana (Cyclura pinguis) on Guana Island, BVI

2013 ◽  
Vol 20 (3) ◽  
pp. 112-118
Author(s):  
Christopher A. Cheek ◽  
Shay Hlavaty ◽  
Krista Mougey ◽  
Rebecca N. Perkins ◽  
Mark A. Peyton ◽  
...  
Keyword(s):  
Puerto Rico ◽  
Endangered Species ◽  
Habitat Management ◽  
Vertical Structure ◽  
Virgin Islands ◽  
Critically Endangered ◽  
British Virgin Islands ◽  
Critically Endangered Species ◽  
Free Ranging ◽  
Important Habitat

The Stout Iguana (Cyclura pinguis) is a critically endangered species endemic to the Puerto Rico Bank and currently restricted to the British Virgin Islands (BVI). Our study on Guana Island, BVI, focused on vertical structure use by adult (n = 4) and juvenile (n = 11) iguanas with tracking bobbins. We recorded structure types used, heights attained on structures, distances between structures, and structure sizes. We found that Stout Iguanas used vertical structure more than previously documented. Trees comprised a significantly greater (P <  0.001) proportion of structures used by juveniles than by adults, whereas rocks comprised the greatest proportion of structures used by adults. In addition to differential structure use, juveniles climbed significantly higher (2.4 vs. 0.9 m on average; P < 0.001) than adults. We found no difference in the diameter or distance between structures used by adults and juveniles. Our results suggest that vertical structure use may be an important habitat element for free-ranging juvenile Stout Iguanas. Habitat management that provides vertical structure may be advantageous for the conservation of this species.

scholarly journals Small pelagic fish, trawling discards and breeding performance of the critically endangered Balearic shearwater: improving conservation diagnosis

2006 ◽  
Vol 318 ◽  
pp. 247-254 ◽  
Author(s):  
M Louzao ◽  
JM Igual ◽  
M McMinn ◽  
JS Aguilar ◽  
R Triay ◽  
...  
Keyword(s):  
Pelagic Fish ◽  
Critically Endangered ◽  
Breeding Performance ◽  
Small Pelagic Fish

scholarly journals Conservation of Critically Endangered Olive Barb Puntius sarana (Hamilton, 1822) through Artificial Propagation

Our Nature ◽  
2014 ◽  
Vol 11 (2) ◽  
pp. 96-104 ◽  
Author(s):  
Muhammad Abu Bakar Siddik ◽  
Ashfaqun Nahar ◽  
Ferdous Ahamed ◽  
Zubia Masood ◽  
Md. Yeamin Hossain
Keyword(s):  
Body Weight ◽  
Critically Endangered ◽  
Hatching Rate ◽  
Breeding Performance ◽  
Endangered Fish ◽  
Artificial Propagation ◽  
Special Diet ◽  
The Family ◽  
Puntius Sarana ◽  
Experimental Ponds

The Olive barb Puntius sarana (Hamilton, 1822) is a member of the family Cyprinidae and its conservational status has been referred as critically endangered in Bangladesh and vulnerable in India. An experiment on artificial propagation of the critically endangered fish P. sarana was carried out to determine the suitable dose of pituitary gland (PG) hormone as well as to determine the effective breeding season for the conservation of this critically endangered fish species. Three breeding trials (April 2010, June 2010 and July 2010) have been taken into consideration with PG doses in three different treatments (4.5, 5.5, 6.5 mg/kg body weight, respectively) having three replications of each. Brood fishes were collected from the Kangsha River (Netrokona) and reared in the experimental ponds, providing special diet upto their maturation. A total of 18 broods (9 female and 9 male) were selected for induced breeding in each trial. To observe the effective dose for induced breeding, the females were first injected at the rate of 4.5, 5.5 and 6.5 mg PG/kg body weight in T1, T2 and T3, respectively in each trial. On the other hand, the males were administrated at the rate of 2 mg PG/kg body weight. The breeding performance in terms of ovulation, fertilization and hatching rate were studied. Induced breeding, in trial-2 obtained the better result in terms of ovulation, fertilization and hatching rate compared to other two trials. In trial-2 among the treatments, T2 with doses of 5.5 mg/kg body weight showed better result than other two treatments where 4.5 and 6.5 mg/kg body weight PG doses were used in T1 and T3, respectively. The findings of the present study can be used in induced breeding of P. sarana for the development of hatchery propagation as well as to conserve this valuable critically endangered species.DOI: http://dx.doi.org/10.3126/on.v11i2.9534 Our Nature 2013, 11(2): 96-104

Status and conservation of the rodents of Victoria

2000 ◽  
Vol 27 (4) ◽  
pp. 357 ◽  
Author(s):  
John Seebeck ◽  
Peter Menkhorst
Keyword(s):  
Native Species ◽  
Habitat Management ◽  
Coastal Dunes ◽  
Critically Endangered ◽  
Sciurus Carolinensis ◽  
Isolated Populations ◽  
Extinct Species ◽  
North West ◽  
The North ◽  
Extant Species

Nineteen species of rodents, in two families, have been recorded from Victoria in the modern era. Eighteen are of the family Muridae, represented by 15 native and 3 introduced species. The other species, now extinct in Victoria, was the introduced Sciurus carolinensis. Six of the native species are extinct, one is classified Critically Endangered, one Endangered and four Lower Risk – near threatened. Four of the extinct species were restricted to the semi-arid far north-west; these were Leporillus apicalis, L. conditor, Pseudomys bolami and P. desertor. The two other extinct species, Conilurus albipes and Pseudomys australis, inhabited open forest/woodland, and grassy ecosystems. Extant species include Rattus fuscipes and R. lutreolus, both in the sub-family Murinae; both are widespread and common, particularly in southern Victoria. The remaining seven species are in the sub-family Hydromyinae. Hydromys chrysogaster is widespread in waterbodies throughout the state. Notomys mitchellii and Pseudomys apodemoides occur in dry habitats in the north-west of Victoria; they are uncommon, but most of their habitat is reserved. Mastacomys fuscus, found in higher-rainfall areas of southern and eastern Victoria, from coastal dunes to alpine snowfields, is uncommon. The distribution of Pseudomys fumeus is disjunct, in four widely separated areas. It is classified as Endangered. P. shortridgei is restricted to the Grampians and south-western Victoria, where it may be locally common. The most geographically restricted rodent species in Victoria, Pseudomys novaehollandiae, is Critically Endangered and is the subject of special conservation measures. The most critical threats to rodent populations in Victoria are considered to be (1) the lack of active habitat management for those species that require early seral stages in vegetation, (2) predation by introduced carnivores, and (3) the fragmentation of species into small genetically isolated populations.

Changes in nesting numbers and breeding success of African White-backed Vulture Gyps africanus in north-central Botswana

2020 ◽  
Vol 30 (3) ◽  
pp. 456-473
Author(s):  
LEUNGO B. L. LEEPILE ◽  
GLYN MAUDE ◽  
PETE HANCOCK ◽  
RICHARD P. READING ◽  
BRIAN BRIDGES ◽  
...  
Keyword(s):  
Breeding Success ◽  
Population Viability Analysis ◽  
Population Viability ◽  
Breeding Birds ◽  
Critically Endangered ◽  
Breeding Performance ◽  
North Central ◽  
Viability Analysis ◽  
Aerial Surveys ◽  
Local Breeding

SummaryAfrican White-backed Vultures were recently uplisted to ‘Critically Endangered’ by IUCN due to declines across their range. Poisoning is widely accepted as the major reason for these declines. Botswana supports a high number of this species (breeding pairs > c.1,200), but as yet no published information exists on their breeding success in the country. However, mass poisonings within Botswana and neighbouring countries have killed thousands of White-backed Vultures in recent years. We therefore expected that nesting numbers may have declined in this region if these poisoning events killed local breeding birds. We used information from aerial surveys conducted between 2006 and 2017 in Khwai and Linyanti, two important breeding areas for this species in north-central Botswana, to determine if there was any change in nesting numbers and breeding success of White-backed Vultures. Results showed an overall 53.5% decline in nesting numbers, with a greater decline in Linyanti than in Khwai. In both areas, breeding success was significantly lower in 2017 than it was 10 ten years earlier. We recommend that similar repeat surveys are continued to provide greater confidence in the trends of both nesting numbers and breeding performance. Population viability analysis suggested that if the productivity levels detected in 2017 were a true indication of current productivity levels for this population, and if recent high poisoning rates continue, this population could be extirpated from the area in the next 13 years.

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