scholarly journals Conservation and conflict between endangered desert fishes

2008 ◽  
Vol 4 (6) ◽  
pp. 655-658 ◽  
Author(s):  
Jennifer M Gumm ◽  
Jennifer L Snekser ◽  
Murray Itzkowitz

Conservation of naturally sympatric endangered species requires unique considerations. While impacts of invasive species garner much attention, interactions between endangered species must also be managed. The endangered Leon Springs pupfish, Cyprinodon bovinus , has suffered a population decline due to decreasing natural habitat. As breeding habitat is lost, C. bovinus is also adversely affected by the sympatric, endangered Pecos gambusia, Gambusia nobilis . Here, we document interactions between these species, finding significantly more G. nobilis accumulated at pupfish spawning events than randomly distributed on breeding grounds in the absence of spawning. As a known egg predator, our results suggest that G. nobilis presence at spawnings may further decrease pupfish numbers while also altering the evolutionary dynamics of C. bovinus breeding tactics. Habitat restoration may decrease Gambusia concentrations or influence C. bovinus breeding behaviour and increase the number of territorial males resulting in viable population sizes for both critically endangered fishes.

2016 ◽  
Vol 7 (1) ◽  
pp. 237-254 ◽  
Author(s):  
Christopher P. Kofron ◽  
Francis X. Villablanca

AbstractThe Morro Bay kangaroo rat Dipodomys heermanni morroensis occurs in the vicinity of Morro Bay (specifically in and near Los Osos) in western San Luis Obispo County in coastal central California. It was listed as endangered pursuant to the U.S. Endangered Species Conservation Act in 1970 and subsequently the U.S. Endangered Species Act in 1973. Field research from the late 1950s to the mid-1980s has documented a rapid population decline. Despite many efforts, researchers have not captured the Morro Bay kangaroo rat since 1986, and the last captive individual died in 1993. We review the biology and conservation status of the Morro Bay kangaroo rat, including taxonomy and genetics, soil type and burrows, history of decline, primary causes of decline, breeding in the wild and in captivity, habitat restoration, and threats. In particular, there are two primary causes of decline. First, development (urban, agricultural, and industrial) has resulted in direct loss of habitat. Second, in the absence of fire, the early seral stages of coastal dune scrub (optimal habitat) have matured to later successional stages of vegetation, which are denser and with substantially fewer annual food plants, and which negatively impact the locomotion of kangaroo rats and change the diversity of the small mammal community with a likely increase in competition. In 2016 only pockets of habitat remain, with optimal habitat comprising an estimated 1% of the historical geographic range. Although researchers have not demonstrated predation by domestic cats, it is likely a major threat and we suspect it has contributed to the decline based upon a review of the literature. In 2011 we observed potential signs of the Morro Bay kangaroo rat at two historical areas, which suggests it may be persisting at extremely low densities in a few isolated colonies. In addition, we could not obtain permission to survey on four private properties with potential habitat. In consideration of the vast loss and fragmentation of its habitat, along with the continuing and pervasive threats, the Morro Bay kangaroo rat is clearly conservation-reliant. We believe that without urgent human intervention, the Morro Bay kangaroo rat will soon become extinct if it is not already.


Diversity ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 261
Author(s):  
Alexander Cotrina Sánchez ◽  
Nilton B. Rojas Briceño ◽  
Subhajit Bandopadhyay ◽  
Subhasis Ghosh ◽  
Cristóbal Torres Guzmán ◽  
...  

The increasing demand for tropical timber from natural forests has reduced the population sizes of native species such as Cedrela spp. because of their high economic value. To prevent the decline of population sizes of the species, all Cedrela species have been incorporated into Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). The study presents information about the modeled distribution of the genus Cedrela in Peru that aims to identify potential habitat distribution of the genus, its availability in areas protected by national service of protected areas, and highlighted some areas because of their conservation relevance and the potential need for restoration. We modeled the distribution of the genus Cedrela in Peru using 947 occurrence records that included 10 species (C. odorata, C. montana, C. fissilis, C. longipetiolulata, C. angustifolia, C. nebulosa, C. kuelapensis, C. saltensis, C. weberbaueri, and C. molinensis). We aim to identify areas environmentally suitable for the occurrence of Cedrela that are legally protected by the National Service of Protected Areas (PAs) and those that are ideal for research and restoration projects. We used various environmental variables (19 bioclimatic variables, 3 topographic factors, 9 edaphic factors, solar radiation, and relative humidity) and the maximum entropy model (MaxEnt) to predict the probability of occurrence. We observed that 6.7% (86,916.2 km2) of Peru presents a high distribution probability of occurrence of Cedrela, distributed in 17 departments, with 4.4% (10,171.03 km2) of the area protected by PAs mainly under the category of protection forests. Another 11.65% (21,345.16 km2) of distribution covers areas highly prone to degradation, distributed mainly in the departments Ucayali, Loreto, and Madre de Dios, and needs immediate attention for its protection and restoration. We believe that the study will contribute significantly to conserve Cedrela and other endangered species, as well as to promote the sustainable use and management of timber species as a whole.


2021 ◽  
Vol 9 (2) ◽  
pp. 220
Author(s):  
Michele Bertoni Mann ◽  
Janira Prichula ◽  
Ícaro Maia Santos de Castro ◽  
Juliana Mello Severo ◽  
Michelle Abadie ◽  
...  

Melanophryniscus admirabilis (admirable red-belly toad) is a microendemic and critically endangered species found exclusively along 700 m of the Forqueta River, in a fragment of the Atlantic Forest of southern Brazil. One of the greatest concerns regarding the conservation of this species is the extensive use of pesticides in areas surrounding their natural habitat. In recent years, the adaptation and persistence of animal species in human-impacted environments have been associated with microbiota. Therefore, the present study aimed to characterize the oral bacterial community of wild M. admirabilis and to address the question of how this community might contribute to this toad’s adaptation in the anthropogenic environment as well as its general metabolic capabilities. A total of 11 oral samples collected from wild M. admirabilis were characterized and analyzed via high-throughput sequencing. Fragments of the 16S rRNA variable region 4 (V4) were amplified, and sequencing was conducted using an Ion Personal Genome Machine (PGM) System with 316 chips. A total of 181,350 sequences were obtained, resulting in 16 phyla, 34 classes, 39 orders, and 77 families. Proteobacteria dominated (53%) the oral microbiota of toads, followed by Firmicutes (18%), Bacteroidetes (17%), and Actinobacteria (5%). No significant differences in microbial community profile from among the samples were reported, which suggests that the low dietary diversity observed in this population may directly influence the bacterial composition. Inferences of microbiome function were performed using PICRUSt2 software. Important pathways (e.g., xenobiotic degradation pathways for pesticides and aromatic phenolic compounds) were detected, which suggests that the bacterial communities may serve important roles in M. admirabilis health and survival in the anthropogenic environment. Overall, our results have important implications for the conservation and management of this microendemic and critically endangered species.


2014 ◽  
Vol 25 (2) ◽  
pp. 207-219 ◽  
Author(s):  
XIAOPING YU ◽  
XIA LI ◽  
ZHIPING HUO

SummaryReintroduction projects usually attempt to re-establish a self-sustaining population of endangered species within their historical ranges through the release of captive-bred individuals into the wild. We studied the breeding biology and nesting success of a reintroduced population of Crested Ibis Nipponia nippon in Ningshan County on the south slope of the Qinling Mountains of Shaannxi Province, China. From May 2007 to October 2011, 56 captive-bred individuals, composed of 26 females and 30 males, were released into the area and monitored using radio-telemetry. The average age of individuals at release was 5.2 ± 2.5 years for females and 6.4 ± 2.9 years for males. Mean clutch size was 3.14±1.06 (range 1-5). Mean number of fledglings per active nest was 1.57 ± 1.03 and mean number of fledglings per successful nest was 2.00 ± 0.87. Most of the fledglings survived to complete their post-fledging dispersal. Mean annual survival rate was 0.552 ± 0.064 for all released birds, 0.815 ± 0.054 for breeders, and 0.515 ± 0.058 for first year fledglings. The average number of young produced/year/pair was 1.57 ± 1.03 and the growth rate (λ) of the reintroduced population was 1.2193. We confirmed that starvation and predation by King Rat Snake Elaphe carinata were the main causes of death of released individuals, nestlings and fledglings. This is the first attempt to reintroduce captive-bred Crested Ibis to former natural habitat. The ability of captive-bred ibis to survive and breed successfully bodes well for future releases of this and other endangered species.


2013 ◽  
Vol 280 (1768) ◽  
pp. 20131087 ◽  
Author(s):  
D. T. Tyler Flockhart ◽  
Leonard I. Wassenaar ◽  
Tara G. Martin ◽  
Keith A. Hobson ◽  
Michael B. Wunder ◽  
...  

Insect migration may involve movements over multiple breeding generations at continental scales, resulting in formidable challenges to their conservation and management. Using distribution models generated from citizen scientist occurrence data and stable-carbon and -hydrogen isotope measurements, we tracked multi-generational colonization of the breeding grounds of monarch butterflies ( Danaus plexippus ) in eastern North America. We found that monarch breeding occurrence was best modelled with geographical and climatic variables resulting in an annual breeding distribution of greater than 12 million km 2 that encompassed 99% occurrence probability. Combining occurrence models with stable isotope measurements to estimate natal origin, we show that butterflies which overwintered in Mexico came from a wide breeding distribution, including southern portions of the range. There was a clear northward progression of monarchs over successive generations from May until August when reproductive butterflies began to change direction and moved south. Fifth-generation individuals breeding in Texas in the late summer/autumn tended to originate from northern breeding areas rather than regions further south. Although the Midwest was the most productive area during the breeding season, monarchs that re-colonized the Midwest were produced largely in Texas, suggesting that conserving breeding habitat in the Midwest alone is insufficient to ensure long-term persistence of the monarch butterfly population in eastern North America.


2021 ◽  
Vol 50 (1) ◽  
pp. 69-77
Author(s):  
Tengfei Shen ◽  
Youmiao Zheng ◽  
Zimou Sun ◽  
Meng Xu

With its unique square-shaped culm, Chimonobambusa hirtinoda C.S. Chao & K.M. Lan is a critically endangered species, and its natural habitat is solely restricted to Doupeng Mountain in Guizhou, China. Two small-insert libraries from C. hirtinoda were constructed and sequenced. Approximately 127.83 Gb of highquality reads were generated and assembled into 9,320,997 contigs with a N50 length of 213bp, thereby producing 8,867,344 scaffolds with total length of 2.01 Gb. An estimated genome size of C. hirtinode was 2.86 Gb on the basis of k-mer frequency analysis, with the GC content of 45.40%. The repeat rate and heterozygous ratio were 74.11 and 1.48% in C. hirtinoda genome, respectively. Finally, 65,398 SSR loci were identified in the assembled contigs, including 58.66% tri-nucleotide, 27.42% di-nucleotide, 7.94% tetranucleotide, 3.67% penta-nucleotide, and 2.31% hexa-nucleotide. Results of this study are useful not only for ecological conservation of C. hirtinoda, but also for phylogenetic studies.


2021 ◽  
Author(s):  
Ilan N. Rubin ◽  
Iaroslav Ispolatov ◽  
Michael Doebeli

AbstractOne of the oldest and most persistent questions in ecology and evolution is whether natural communities tend to evolve toward saturation and maximal diversity. Robert MacArthur’s classical theory of niche packing and the theory of adaptive radiations both imply that populations will diversify and fully partition any available niche space. However, the saturation of natural populations is still very much an open area of debate and investigation. Additionally, recent evolutionary theory suggests the existence of alternative evolutionary stable states (ESSs), which implies that some stable communities may not be fully saturated. Using models with classical Lokta-Volterra ecological dynamics and three formulations of evolutionary dynamics (a model using adaptive dynamics, an individual-based model, and a partial differential equation model), we show that following an adaptive radiation, communities can often get stuck in low diversity states when limited by mutations of small phenotypic effect. These low diversity metastable states can also be maintained by limited resources and finite population sizes. When small mutations and finite populations are considered together, it is clear that despite the presence of higher-diversity stable states, natural populations are likely not fully saturating their environment and leaving potential niche space unfilled. Additionally, within-species variation can further reduce community diversity from levels predicted by models that assume species-level homogeneity.Author summaryUnderstanding if and when communities evolve to saturate their local environments is imperative to our understanding of natural populations. Using computer simulations of classical evolutionary models, we study whether adaptive radiations tend to lead toward saturated communities in which no new species can invade or remain trapped in alternative, lower diversity stable states. We show that with asymmetric competition and small effect mutations, evolutionary Red Queen dynamics can trap communities in low diversity metastable states. Moreover, limited resources not only reduces community population sizes, but also reduces community diversity, denying the formation of saturated communities and stabilizing low diversity, non-stationary evolutionary dynamics. Our results are directly relevant to the longstanding questions important to both ecological empiricists and theoreticians on the species packing and saturation of natural environments. Also, by showing the ease evolution can trap communities in low diversity metastable stats, we demonstrate the potential harm in relying solely on ESSs to answer questions of biodiversity.


The Auk ◽  
2019 ◽  
Author(s):  
Émile Brisson-Curadeau ◽  
Kyle H Elliott ◽  
Pascal Côté

Abstract The phenology of migrating birds is shifting with climate change. For instance, short-distance migrants wintering in temperate regions tend to delay their migration in fall during spells of warmer temperature. However, some species do not show strong shifts, and the factors determining which species will react to temperature changes by delaying their migration are poorly known. In addition, it is not known whether a slower migration or a postponed departure creates the observed delays in fall migration because most studies occur far south of the boreal breeding areas making it difficult to separate those 2 mechanisms. We used 22 yr of data at a northern observatory in eastern North America, at the southern edge of the boreal forest, to examine how 21 short-distance migrants responded to changing temperatures. We investigated if those species responding to temperature share life-history features (i.e. diet, size, total migration distance, breeding habitat, timing of migration). The period of migration in each species was, by far, the most important factor predicting the response of a species to temperature. Eight of the 13 species migrating in October changed their migration onset with temperature (usually by delaying migration by 1–2 days/°C), while the migration timing of none of the 8 species migrating in September was dependent on temperature. Furthermore, the absence of a greater migration delay by birds breeding farther from the study site (i.e. Arctic-breeding birds) suggests the mechanism is a postponed departure rather than a slower migration. We conclude that temperature variations in late fall influence the conditions on the breeding grounds, so that birds still present at that time benefit more from postponing their departure in warm weather.


2019 ◽  
Vol 93 (11) ◽  
Author(s):  
Rowena Chong ◽  
Mang Shi ◽  
Catherine E. Grueber ◽  
Edward C. Holmes ◽  
Carolyn J. Hogg ◽  
...  

ABSTRACT The Tasmanian devil is an endangered carnivorous marsupial threatened by devil facial tumor disease (DFTD). While research on DFTD has been extensive, little is known about viruses in devils and whether any are of potential conservation relevance for this endangered species. Using both metagenomics based on virion enrichment and sequence-independent amplification (virion-enriched metagenomics) and metatranscriptomics based on bulk RNA sequencing, we characterized and compared the fecal viromes of captive and wild devils. A total of 54 fecal samples collected from two captive and four wild populations were processed for virome characterization using both approaches. In total, 24 novel marsupial-related viruses, comprising a sapelovirus, astroviruses, rotaviruses, picobirnaviruses, parvoviruses, papillomaviruses, polyomaviruses, and a gammaherpesvirus, were identified, as well as known mammalian pathogens such as rabbit hemorrhagic disease virus 2. Captive devils showed significantly lower viral diversity than wild devils. Comparison of the two virus discovery approaches revealed substantial differences in the number and types of viruses detected, with metatranscriptomics better suited for RNA viruses and virion-enriched metagenomics largely identifying more DNA viruses. Thus, the viral communities revealed by virion-enriched metagenomics and metatranscriptomics were not interchangeable and neither approach was able to detect all viruses present. An integrated approach using both virion-enriched metagenomics and metatranscriptomics constitutes a powerful tool for obtaining a complete overview of both the taxonomic and functional profiles of viral communities within a sample. IMPORTANCE The Tasmanian devil is an iconic Australian marsupial that has suffered an 80% population decline due to a contagious cancer, devil facial tumor disease, along with other threats. Until now, viral discovery in this species has been confined to one gammaherpesvirus (dasyurid herpesvirus 2 [DaHV-2]), for which captivity was identified as a significant risk factor. Our discovery of 24 novel marsupial-associated RNA and DNA viruses, and that viral diversity is lower in captive than in wild devils, has greatly expanded our knowledge of gut-associated viruses in devils and provides important baseline information that will contribute to the conservation and captive management of this endangered species. Our results also revealed that a combination of virion-enriched metagenomics and metatranscriptomics may be a more comprehensive approach for virome characterization than either method alone. Our results thus provide a springboard for continuous improvements in the way we study complex viral communities.


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