Replacement of Procambarus acutissimus (Girard) by non-indigenous Procambarus clarkii (Girard) in a disturbed wetland

2015 ◽  
Vol 21 (1) ◽  
pp. 153-157
Author(s):  
Kayla M. Coble ◽  
Amanda L. Hall ◽  
Cody C. Meshes ◽  
Joell A. Zalatan ◽  
George E. Stanton ◽  
...  
Keyword(s):  
Procambarus Clarkii ◽  
Conservation Status ◽  
Pit Lake ◽  
Population Status ◽  
Isolated Populations ◽  
Isolated Wetland ◽  
Wetland Complex ◽  
Surface Dwelling ◽  
Crayfish Species ◽  
Wetland Habitats

Abstract Of the nearly 600 crayfish species worldwide, more than half are native to North America. The southeastern USA is the epicenter of global crayfish species richness. There is concern about the conservation status of many crayfish species and the viability of their populations. Procambarus acutissimus is a surface dwelling crayfish that is native in Mississippi and Alabama and has isolated populations in west Georgia. Its limited distribution in Georgia prompted this re-assessment of a previously surveyed population in a wetland complex near Columbus, Georgia. To assess the population status of P. acutissimus, we used baited Gee minnow traps to survey crayfish in 2014 following similar protocols used in a 1994 survey. Catches from the littoral zone of a borrow pit lake shifted from only P. acutissimus in 1994 to only Procambarus clarkii, a non-indigenous, invasive species in 2014. Trapping in 2014 documented P. acutissimus in only one of five isolated wetland depressions sampled. Procambarus clarkii appears to be replacing P. acutissimus in this wetland complex. Our results suggest that P. clarkii may displace other crayfish, particularly those that share its affinity for wetland habitats.

scholarly journals Dramatic decline of François' langur Trachypithecus francoisi in Guangxi Province, China

Oryx ◽  
2007 ◽  
Vol 41 (1) ◽  
pp. 38-43 ◽  
Author(s):  
Youbang Li ◽  
Chengming Huang ◽  
Ping Ding ◽  
Zheng Tang ◽  
Chris Wood
Keyword(s):  
Population Size ◽  
Conservation Status ◽  
Guangxi Province ◽  
Isolated Populations ◽  
Term Survival ◽  
Management Planning ◽  
Management Measures ◽  
Species Survival ◽  
Dramatic Decline ◽  
Trachypithecus Francoisi

Interviews with local people and a survey were carried out in 23 counties of south-west Guangxi Province from April 2002 to June 2003 to evaluate the conservation status of François' langur Trachypithecus francoisi and assess the extent and nature of threats to the species' survival. François' langurs were found in only 10 counties compared with their presence in 23 counties before 1990. The total population size is estimated to be 307 individuals in 14 isolated populations. This represents a 90% decrease in population size since the early 1980s and an 85% decrease since the mid 1990s. The primary threat to the langur is hunting, mainly for traditional medicine. Our results suggest that conservation efforts for the species have been ineffectual during the last decade and, even within reserves, few direct management measures seem to have been taken to protect and conserve the langurs. Without the instigation of such measures it seems likely that François' langur will disappear both inside and outside reserves. To ensure the long-term survival of Francois' langur in Guangxi Province increased investment and improved management, planning, and training of reserve managers and staff is required, with a particular focus on the key remaining reserves and sites for the langur. Some of this work is now underway.

Genetic Structure is Inconsistent with Subspecies Designations in the Western Massasauga Sistrurus tergeminus

2015 ◽  
Vol 6 (2) ◽  
pp. 350-359 ◽  
Author(s):  
Wade A. Ryberg ◽  
Johanna A. Harvey ◽  
Anna Blick ◽  
Toby J. Hibbitts ◽  
Gary Voelker
Keyword(s):  
New Mexico ◽  
Conservation Status ◽  
Genetic Research ◽  
Peripheral Populations ◽  
Isolated Populations ◽  
North Central ◽  
Sistrurus Catenatus ◽  
Central Texas ◽  
Difficult Challenge ◽  
Incomplete Sampling

Abstract The massasauga Sistrurus catenatus was historically divided into three subspecies, but this long-standing taxonomy has recently been called into question. Genetic research now recognizes a split of the species into the eastern massasauga S. catenatus and western massasauga S. tergeminus, with the latter split into two subspecies, the desert massasauga S. t. edwardsii and the prairie massasauga S. t. tergeminus. Although the distinction between geographically isolated populations of S. catenatus and S. tergeminus is well-supported genetically, the geographic relationships among populations of S. t. tergeminus and S. t. edwardsii remain unresolved because of incomplete sampling throughout the species’ range. This poses a difficult challenge for conservation and management of this species. Sistrurus t. tergeminus does not have state or federal conservation status, but S. t. edwardsii has been petitioned for listing under the U.S. Endangered Species Act. In this study, we used nuclear and mitochondrial DNA from 52 individuals from 7 states to explore the taxonomic and geographic relationships between S. t. tergeminus and S. t. edwardsii populations. Maximum likelihood and Bayesian inference frameworks for both nuclear and mtDNA genes indicated that S. t. tergeminus and S. t. edwardsii populations were genetically indistinguishable. However, at the species level, we did find eight well-supported mtDNA clades within S. tergeminus, including individuals from five peripheral populations in 1) Arizona and western New Mexico, 2) Colorado and Kansas, 3) Missouri, 4) Oklahoma, and 5) southern Texas. These peripherally isolated populations surrounded a larger population of individuals from north-central Texas, New Mexico, and Oklahoma that was contiguous with three additional genetically distinct populations. We conclude that the putative subspecies S. t. tergeminus and S. t. edwardsii, as currently defined, most likely represent polytypic phenotypes of S. tergeminus rather than discrete taxonomic entities. Instead, we suggest that S. tergeminus existed historically as a large, contiguous collection of populations that only recently became fragmented into several, as opposed to two, potentially discrete taxonomic entities.

Detection of the eastern pygmy-possum Cercartetus nanus (Marsupialia: Burramyidae) at Barren Grounds Nature Reserve, New South Wales.

2005 ◽  
Vol 27 (1) ◽  
pp. 85 ◽  
Author(s):  
JM Harris ◽  
RL Goldingay
Keyword(s):  
New South ◽  
Survey Methods ◽  
Conservation Status ◽  
New South Wales ◽  
Detection Methods ◽  
Isolated Populations ◽  
South Eastern ◽  
Nest Boxes ◽  
South Wales ◽  
Cercartetus Nanus

THE eastern pygmy-possum (Cercartetus nanus) has an extensive distribution, from south-eastern Queensland to south-eastern South Australia, and also into Tasmania (Strahan 1995). Despite this it is rarely detected in fauna surveys (Bowen and Goldingay 2000). This rarity in detection suggested that the species may be characterised by small and isolated populations, and therefore vulnerable to extinction. Consequently, it became listed as a 'Vulnerable' species in New South Wales (NSW) in 2001. Unless resolved, the low rate of detection of C. nanus will continue to hinder the acquisition of basic ecological information that is needed to more clearly define its conservation status and that is fundamental to the development of a recovery plan. An extensive body of survey data for NSW involving C. nanus has been reviewed by Bowen and Goldingay (2000). Among a range of survey methods aimed at detecting this species, trapping within flowering banksias and checking installed nest-boxes had the highest rates of detection. Indeed, one study in northern NSW captured 98 individuals over a 3- year period from within nest-boxes (Bladon et al. 2002). All other studies detected fewer than 15 C. nanus. It is clear that further research is required to investigate the effectiveness of a range of detection methods.

scholarly journals Integrating Multiple Lines of Evidence to Explore Intraspecific Variability in a Rare Endemic Alpine Plant and Implications for Its Conservation

Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1160
Author(s):  
Martino Adamo ◽  
Stefano Mammola ◽  
Virgile Noble ◽  
Marco Mucciarelli
Keyword(s):  
Conservation Status ◽  
Intraspecific Variability ◽  
Leaf Traits ◽  
Species Range ◽  
Distribution Area ◽  
Nominal Species ◽  
Peripheral Populations ◽  
Isolated Populations ◽  
Distribution Models ◽  
Precipitation Seasonality

We studied the ecology, distribution, and phylogeography of Tephroseris balbisiana, a rare plant whose range is centered to the South-Western Alps. Our aim was to assess the extent of intraspecific variability within the nominal species and the conservation status of isolated populations. We studied genetic diversity across the whole species range. We analyzed leaf traits, which are distinctive morphological characters within the Tephroseris genus. A clear pattern of genetic variation was found among populations of T. balbisiana, which clustered according to their geographic position. On the contrary, there was a strong overlap in the morphological space of individuals across the species’ range, with few peripheral populations diverging in their leaf morphology. Studying habitat suitability by means of species distribution models, we observed that T. balbisiana range is primarily explained by solar radiation and precipitation seasonality. Environmental requirements could explain the genetic and morphological uniformity of T. balbisiana in its core distribution area and justify genetic, morphological, and ecological divergences found among the isolated populations of the Apennines. Our findings emphasize the need to account for the whole diversity of a species, comprising peripheral populations, in order to better estimate its status and to prioritize areas for its conservation.

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 Distribution and conservation status of the Endangered pepperbark tree Warburgia salutaris (Canellaceae) in Swaziland

Oryx ◽  
2016 ◽  
Vol 51 (3) ◽  
pp. 451-454 ◽  
Author(s):  
Meshack N. Dludlu ◽  
Priscilla S. Dlamini ◽  
Gugu F. Sibandze ◽  
Vusumuzi S. Vilane ◽  
Cliff S. Dlamini
Keyword(s):  
Conservation Status ◽  
Conservation Strategy ◽  
Population Status ◽  
Field Surveys ◽  
Area Of Occupancy ◽  
Conservation Effort ◽  
Fragmented Distribution ◽  
Physiographic Regions ◽  
Unprotected Area ◽  
Conservation Interventions

AbstractThe Endangered Warburgia salutaris (Bertol. f.) Chiov. (Canellaceae), a sought-after medicinal plant in southern Africa, is on the verge of extinction as a result of overexploitation for illegal trade. As part of formulating a conservation strategy for the species in Swaziland we sought to determine its distribution and population status and to revise its national conservation status. Field surveys were conducted in all physiographic regions of Swaziland. Eighteen locations of species presence were found, of which 14 were new records. Three were within protected areas, and seven were in areas worthy of protection. The largest subpopulations occurred in two of the latter areas, Ngudzeni and Sitsatsaweni (351 and 230 individuals, respectively), and one unprotected area, Bulunga (250 individuals). Warburgia salutaris has a severely fragmented distribution and an area of occupancy of 192 km2. Of 700 mature individuals 38% were ring-barked and 7% felled, and some subpopulations had ring-barked juveniles. This indicates a plausible decline in number of mature individuals. Most localities in unprotected areas are eroded and invaded by alien plants, indicating a decline in habitat quality. Our findings indicate that W. salutaris should be categorized as Endangered nationally based on criteria B2ab (iii,v). Although this status implies a lower level of threat than the previous national categorization as Critically Endangered, it does not imply an improved conservation effort in the country, but rather a more accurate assessment based on more data. We have clarified the conservation status of W. salutaris in Swaziland, discovered some previously undocumented subpopulations and identified potential conservation interventions. We recommend that this information be used in setting priorities to ensure conservation of the species.

Vulnerability of Southwest Iberian amphibians to an introduced crayfish, Procambarus clarkii

2005 ◽  
Vol 26 (3) ◽  
pp. 293-303 ◽  
Author(s):  
Rui Rebelo ◽  
Maria João Cruz
Keyword(s):  
Procambarus Clarkii ◽  
Larval Survival ◽  
Bufo Bufo ◽  
Microhabitat Use ◽  
Amphibian Species ◽  
Embryo Survival ◽  
Breeding Habitats ◽  
Mesocosm Experiments ◽  
Native Crayfish ◽  
Crayfish Species

AbstractThe introduction of predators in amphibian breeding habitats may contribute to the decline or extinction of amphibian populations. Procambarus clarkii, a North American crayfish, was recently introduced in the Iberian Peninsula, being now quite abundant in the southwest, a region with no native crayfish species and where 13 amphibian species may be found. We performed mesocosm experiments to evaluate the vulnerability of amphibian embryos and larvae from those species to P. clarkii. Despite the presence of alternative food (vegetation and leaf litter), embryo survival in the presence of P. clarkii was low for all species except Bufo bufo. However, newly hatched B. bufo tadpoles were readily consumed. P. clarkii reduced larval survival in all species, with those species that in nature have few contacts with predators at the larval stage suffering the highest mortalities. Most larvae reduced their activity and/or altered microhabitat use in the presence of P. clarkii, but these behavioural modifications did not lead necessarily to a low vulnerability to predation.

Ephemeral wetlands as significant habitat for threatened crayfish in Alabama, USA

2015 ◽  
Vol 21 (1) ◽  
pp. 147-152
Author(s):  
Michael R. Kendrick ◽  
Alexander D. Huryn
Keyword(s):  
United States ◽  
Southeastern United States ◽  
The State ◽  
Large Rivers ◽  
Undescribed Species ◽  
Freshwater Biodiversity ◽  
Ephemeral Wetlands ◽  
Crayfish Species ◽  
Wetland Habitats ◽  
Imperiled Species

Abstract While ephemeral wetlands contribute significantly to regional freshwater biodiversity, their role in supporting threatened and imperiled species of crayfish is not widely recognized. As the center of global crayfish biodiversity, the southeastern United States (US), and the state of Alabama (AL) in particular, are important focal areas where information is needed to develop understanding of habitat constraints determining the distributions of crayfish species. To this end, we documented crayfish species associated with ephemeral wetlands and associated wetland habitats that have been traditionally under sampled. Fifteen species of crayfish were documented among 96 survey sites. This assemblage included three Alabama state-listed Priority 1 species [Cambarellus diminutus Hobbs, Fallicambarus burrisi Fitzpatrick, Procambarus viaeviridis (Faxon)] and five Priority 2 species [Hobbseus prominens (Hobbs), Orconectes lancifer (Hagan), Procambarus evermanni (Faxon), P. leconti (Hagan), P. marthae Hobbs]. An undescribed species of Cambarellus (“sp. A”) was also documented, and will presumably be eventually designated a Priority 1 species in Alabama due to its restricted distribution and apparent endemism. Ten species of crayfish were documented from ephemeral wetlands, including four Priority 1 and 2 species [Cambarellus sp. A (presumed Priority 1 species), H. prominens, P. marthae, P. viaeviridis]. Most populations of Priority 1 and 2 species we documented are within the 100-year floodplain of the Black Warrior River. Ephemeral wetlands and associated wetland habitats within the floodplains of large rivers thus appear to be vital habitat for threatened and imperiled crayfish in Alabama. Our results suggest that future crayfish surveys should include sampling of these important but often overlooked habitats.

Elusive but widespread? The potential distribution and genetic variation of Hyalosaurus koellikeri (Günther, 1873) in the Maghreb

2011 ◽  
Vol 32 (3) ◽  
pp. 385-397 ◽  
Author(s):  
Juan M. Pleguezuelos ◽  
Elisa Mora ◽  
Philip de Pous ◽  
Daniel Escoriza ◽  
Margarita Metallinou ◽  
...  
Keyword(s):  
Potential Distribution ◽  
Conservation Status ◽  
Species Distribution Modelling ◽  
Deciduous Forests ◽  
Annual Rainfall ◽  
Isolated Populations ◽  
Distribution Modelling ◽  
The Core ◽  
Mitochondrial Nd1 ◽  
Genetic Results

AbstractThe genetic variability and the potential distribution under past (Last Glacial Maximum; LGM (MIROC and CCSM simulations)) and present conditions were studied for the anguid Hyalosaurus koellikeri, using analyses of two mitochondrial (ND1 and ND2) and one nuclear (PRLR) gene and species distribution modelling (SDM) including 19 geographical coordinates, covering most of its distribution range. Unexpectedly, the genetic results show that H. koellikeri presents a very low level of variability both in the mitochondrial and nuclear genes studied. The present predicted distribution of H. koellikeri revealed a large potential distribution in both north and eastwards directions, with suitable areas predicted in places where the species has never been reported before, as for instance the Rif Mountains in Morocco, as well as into most parts of northern Algeria and Tunisia. The LGM distribution is even larger compared to the present, with a continuous predicted distribution from Morocco to Tunisia, and even into Libya under the MIROC simulation. The results of the genetic and SDM analyses suggest that the now isolated populations from Debdou and Tlemcen have probably been in contact during the LGM, but its absence from both present and past predicted suitable areas is still a mystery. Hyalosaurus koellikeri depends mainly on closed deciduous forests (typically Cedrus atlantica and Quercus sp.) and open deciduous shrubland with high amounts of annual rainfall. The results of this study and the absence of recent sightings of the species outside the core distribution might indicate a regression of the species. Hence, a reevaluation of the conservation status of the species seems warranted.

scholarly journals Status of Nahan’s Partridge Ptilopachus nahani (Dubois, 1905) (Aves: Galliformes: Odontophoridae) in Uganda

2020 ◽  
Vol 12 (15) ◽  
pp. 17063-17076
Author(s):  
Eric Sande ◽  
Sisiria Akoth ◽  
Ubaldo Rutazaana ◽  
William Olupot
Keyword(s):  
National Parks ◽  
Tropical Rainforest ◽  
Conservation Status ◽  
The Other ◽  
Population Status ◽  
Density Estimates ◽  
Point Count ◽  
Forest Reserves ◽  
High Incidence ◽  
Point Count Method

We carried out a survey of Nahan’s Partridge Ptilopachus nahani in the Ugandan forests of Mabira, Bugoma, and Budongo from December 2016 to December 2017, using a point count method employing a call playback technique.  The aim was to establish the population status of this globally threatened species, which was last surveyed in 2003.  Separate analyses of the number of groups per point and those involving use of the Distance Program yielded the same density estimates, indicating that either method reliably estimates the density of the species.  The density estimates for the three reserves were 31.6, 25.2, and 13.3 groups per km2 for Bugoma, Budongo, and Mabira forest reserves, respectively.  In the last 14 years, it appears that the density of the species for Uganda has increased from 16.3 to 23.4 groups per km2, which when extrapolated translates to 16,000 and 23,000 groups, respectively.  This represents a 44% increase in density, or a group growth rate of 450 per year.  The lowest density and population increment was registered in Mabira and we attribute this to the apparently high incidence of disturbance and degradation of this forest compared to the other two.  Since Mabira, Bugoma, and Budongo are the only remaining large tropical rainforest reserves in Uganda, strengthening their conservation or upgrading their conservation status to national parks is required to save the species.

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