Differences in mutualistic or predatory interactions between tree and rodent species as revealed by using a double-duplex passive integrated transponder tagging technique

2021 ◽  
Vol 112 ◽  
pp. 103747
Author(s):  
Haifeng Gu ◽  
Xifu Yang ◽  
Rodolfo Dirzo ◽  
Zhibin Zhang
2020 ◽  
Vol 6 (2) ◽  
Author(s):  
Wen Wang ◽  
Xian-Dan Lin ◽  
Hai-Lin Zhang ◽  
Miao-Ruo Wang ◽  
Xiao-Qing Guan ◽  
...  

Abstract To better understand the genetic diversity, host associations and evolution of coronaviruses (CoVs) in China we analyzed a total of 696 rodents encompassing 16 different species sampled from Zhejiang and Yunnan provinces. Based on reverse transcriptase PCR-based CoV screening of fecal samples and subsequent sequence analysis of the RNA-dependent RNA polymerase gene, we identified CoVs in diverse rodent species, comprising Apodemus agrarius, Apodemus chevrieri, Apodemus latronum, Bandicota indica, Eothenomys cachinus, Eothenomys miletus, Rattus andamanensis, Rattus norvegicus, and Rattus tanezumi. CoVs were particularly commonplace in A. chevrieri, with a detection rate of 12.44 per cent (24/193). Genetic and phylogenetic analysis revealed the presence of three groups of CoVs carried by a range of rodents that were closely related to the Lucheng Rn rat CoV (LRNV), China Rattus CoV HKU24 (ChRCoV_HKU24), and Longquan Rl rat CoV (LRLV) identified previously. One newly identified A. chevrieri-associated virus closely related to LRNV lacked an NS2 gene. This virus had a similar genetic organization to AcCoV-JC34, recently discovered in the same rodent species in Yunnan, suggesting that it represents a new viral subtype. Notably, additional variants of LRNV were identified that contained putative non-structural (NS)2b genes located downstream of the NS2 gene that were likely derived from the host genome. Recombination events were also identified in the open reading frame (ORF) 1a gene of Lijiang-71. In sum, these data reveal the substantial genetic diversity and genomic complexity of rodent-borne CoVs, and extend our knowledge of these major wildlife virus reservoirs.


2021 ◽  
Vol 41 (1) ◽  
pp. 187-195
Author(s):  
Timothy W. D’Amico ◽  
Dana L. Winkelman ◽  
Tyler R. Swarr ◽  
Christopher A. Myrick

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1186
Author(s):  
Francisco Javier Bravo-Córdoba ◽  
Juan Francisco Fuentes-Pérez ◽  
Jorge Valbuena-Castro ◽  
Andrés Martínez de Azagra-Paredes ◽  
Francisco Javier Sanz-Ronda

With the aim of building more compact fishways and adapting them to field conditions to improve their location by fish, it is common to use turning pools, reducing the longitudinal development of the construction. However, depending on their design, turning pools may affect the hydraulic performance of the fishway and consequently the fish passage. To study these phenomena, turning pools in a vertical slot and in different configurations of submerged notches with bottom orifice fishway types were assessed. Both types of fishways were studied using numerical 3D models via OpenFOAM, a computational fluid dynamics software, in combination with fish responses, assessed with PIT (Passive Integrated Transponder) tag telemetry for three different species of potamodromous cyprinids in several fishways. Results show differences between the hydrodynamics of straight and turning pools, with lower values in the hydrodynamic variables in turning pools. Regarding fish behavior, the ascent was slower in turning pools but with no effect on passage success and without being a problem for fish migration. This information validates the use of turning pools as a key design component for fishways for studied species.


2016 ◽  
Vol 73 (1) ◽  
pp. 94-104 ◽  
Author(s):  
Elsa Goerig ◽  
Theodore Castro-Santos ◽  
Normand Émile Bergeron

Culverts can restrict access to habitat for stream-dwelling fishes. We used passive integrated transponder telemetry to quantify passage performance of >1000 wild brook trout (Salvelinus fontinalis) attempting to pass 13 culverts in Quebec under a range of hydraulic and environmental conditions. Several variables influenced passage success, including complex interactions between physiology and behavior, hydraulics, and structural characteristics. The probability of successful passage was greater through corrugated metal culverts than through smooth ones, particularly among smaller fish. Trout were also more likely to pass at warmer temperatures, but this effect diminished above 15 °C. Passage was impeded at higher flows, through culverts with steep slopes, and those with deep downstream pools. This study provides insight on factors influencing brook trout capacity to pass culverts as well as a model to estimate passage success under various conditions, with an improved resolution and accuracy over existing approaches. It also presents methods that could be used to investigate passage success of other species, with implications for connectivity of the riverscape.


2004 ◽  
Vol 20 (2) ◽  
pp. 225-228 ◽  
Author(s):  
Marcos de Souza Lima Figueiredo ◽  
Fernando Antonio dos Santos Fernandez

Habitat fragmentation causes a sharp increase in the forested area affected by edge effects (Murcia 1995). Compared with the core of the forest, edges present higher litterfall rates, air and soil humidity reduction, higher temperature and increased wind incidence (Bierregaard et al. 1992, Didham & Lawton 1999, Laurance et al. 1998, Matlack 1993). These features of edges may increase the probability of fire occurrence, especially if the surrounding vegetation is composed of grasses (D'Antonio & Vitousek 1992, Freifelder et al. 1998). After a fire, the damaged edge will grow substantial amounts of herbaceous vegetation, extending the inflammable area into the forest, and thereby creating a positive feedback system of fire susceptibility and intensity (Cochrane & Schulze 1999, Cochrane et al. 1999). Fires may affect the structure and composition of the vegetation (Cochrane & Schulze 1999, Didham & Lawton 1999, Sanaiotti & Magnusson 1995), favouring, in the long-term, the dominance of the community by species characteristic of disturbed habitats and making the habitat unsuitable to primary forest species (Malcolm 1994, Possingham et al. 1994). Unfortunately, there are few studies on the effects of fires on neotropical small-mammal populations (Borchert & Hansen 1983, Ojeda 1989, Vieira & Marinho-Filho 1998). The objective of this study was to analyse the influence of a fire on populations of two rodent species, Akodon cursor (Winge) and Oecomys concolor (Wagner) in two fragments of Atlantic Forest in Brazil.


Mammalia ◽  
2004 ◽  
Vol 68 (2-3) ◽  
Author(s):  
Helena Godoy Bergallo ◽  
William E. Magnusson

The main purpose of this study was to determine whether the maximum distance traveled and home range area of


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