Epimeletic behavior in a free-ranging female Risso’s dolphin (Grampus griseus)

acta ethologica - Here, we describe the epimeletic behavior of an adult Risso’s dolphin towards a deceased newborn calf of the same species across several days with photographs, acoustic...     

Long-term isolation and local adaptation in Palau’s Nikko Bay help corals thrive in acidic waters

The reefs in Palau’s Nikko Bay live in seawater with low pH that is similar to conditions predicted for 2100 because of ocean acidification. Nevertheless, the reefs at Nikko Bay have high coral cover and high diversity. We hypothesize that the low-pH environment in Nikko Bay is caused by low flushing rates, which causes long-term isolation and local adaptation. To test this hypothesis, we modeled the water circulation in and around Nikko Bay. Model results show that average residence time is 71 d, which is ten times the residence time on fore-reef habitats. The long residence time restricts the exchange of coral larvae in the bay with adjacent reefs, allowing persistent selection for tolerant traits and local adaptation. The corals in Nikko Bay are also more susceptible to local pollution because the waters are poorly flushed. Therefore, local management must focus on minimizing human impacts such as dredging, overfishing and pollution in the bay, which would compromise the condition of the corals that have already adapted to low-pH conditions.     

Protected areas in the world’s ecoregions: How well connected are they?

Protected areas (PAs) are the main instrument for biodiversity conservation, which has triggered the development of numerous indicators and assessments on their coverage, performance and efficiency. The connectivity of the PA networks at a global scale has however been much less explored; previous studies have either focused on particular regions of the world or have only considered some types of PAs.Here we present, and globally assess, ProtConn, an indicator of PA connectivity that (i) quantifies the percentage of a study region covered by protected connected lands, (ii) can be partitioned in several components depicting different categories of land (unprotected, protected or transboundary) through which movement between protected locations may occur, (iii) is easy to communicate, to compare with PA coverage and to use in the assessment of global targets for PA systems.We apply ProtConn to evaluate the connectivity of the PA networks in all terrestrial ecoregions of the world as of June 2016, considering a range of median dispersal distances (1–100 km) encompassing the dispersal abilities of the large majority of terrestrial vertebrates.We found that 9.3% of the world is covered by protected connected lands (average for all the world’s ecoregions) for a reference dispersal distance of 10 km, increasing up to 11.7% for the largest dispersal distance considered of 100 km. These percentages are considerably smaller than the global PA coverage of 14.7%, indicating that the spatial arrangement of PAs is only partially successful in ensuring connectivity of protected lands. The connectivity of PAs largely differed across ecoregions. Only about a third of the world’s ecoregions currently meet the Aichi Target of having 17% of the terrestrial realm covered by well-connected systems of PAs. Finally, our findings suggest that PAs with less strict management objectives (allowing the sustainable use of resources) may play a fundamental role in upholding the connectivity of the PA systems.Our analyses and indicator make it possible to identify where on the globe additional efforts are most needed in expanding or reinforcing the connectivity of PA systems, and can be also used to assess whether newly designated sites provide effective connectivity gains in the PA system by acting as corridors or stepping stones between other PAs. The results of the ProtConn indicator are available, together with a suite of other global PA indicators, in the Digital Observatory for Protected Areas of the Joint Research Centre of the European Commission.     

Are important bird areas and special protected areas enough for conservation?: the case of Bonelli’s eagle in a Mediterranean area

The Bonelli’s eagle (BE) is considered by the European Union as a high-priority species for conservation in the Valencian Community (East of Spain). However, in 2006 the European Union opened a legal procedure against the Spanish Kingdom, accused of lacking of an adequate network of special protected areas (SPAs) to preserve the BE in the region. Here we evaluate whether important bird areas (IBAs) and SPAs network is enough to preserve this species, on the basis of a thorough analysis of habitat preferences. A GAP analysis is performed to conduct a revision of current SPAs and BirdLife proposed IBAs. Our results suggest that the current network of SPAs becomes insufficient to protect the BE. The IBAs network, although improves the current network of SPAs, increasing the percentage of BE potential habitat included, also results inadequate. We propose a new SPAs network according to the potential suitable habitat for the species. Given the trade-off between financial investment and the conservation of biodiversity, we propose to maximize the surface of potential habitat included in the protected network minimizing the surface of the region that would be necessary to protect, thus avoiding an unnecessary expense and otherwise unrealistic results.     

Can bison play a role in conserving habitat for endangered sandhills species in Canada?

Relative to their cultivated surroundings, sandhills of the Canadian prairies represent intact, heterogeneous ecosystems. These extensive tracts of sand dunes and native prairie are biodiversity hotspots, which act as refugia for a variety of specialized wildlife species. However, due to changes in climate and suppression of natural disturbance, the dunes have experienced drastic rates of stabilization over the past 200 years, such that the proportion of open sand in the region is currently less than 1%. This continuing trend is resulting in a gradual loss of sparsely vegetated, sandy habitat for many uncommon, specialist species, including a number that are considered to be at risk of extirpation or extinction by COSEWIC (Canada’s list agency). Without management to conserve active sandhill habitat the future long-term survival of rare and imperilled dune-dependent plants and animals is questionable. In this article we propose that the re-introduction of disturbance to southern Canadian prairie sandhills, specifically sandhill use by bison, might be effective in restoring and sustaining actively-eroding sandhill habitat to support some threatened and endangered species. We outline several lines of evidence (geological, geomorphological, archaeological, and historical accounts) indicating bison occupied sandhills and actively modified these ecosystems until European settlement of the prairies. We argue that bison were attracted to sandhills for a number of reasons, and that in great numbers they had considerable influence on sandhills ecosystem functions. Behaviours such as grazing, trailing, wallowing, horning, and trampling created a patchwork mosaic of disturbance effects. We hypothesize that it may be beneficial to reintroduce bison to sandhills ecosystems in the Canadian prairies to restore biodiversity at all levels.     

Can numerical modeling help understand the fate of tau protein in the axon terminal?

In this paper, we used mathematical modeling to investigate the fate of tau protein in the axon terminal. We developed a comprehensive model of tau transport that accounts for transport of cytosolic tau by diffusion, diffusion transport of microtubule (MT)-bound tau along the MT lattice, active motor-driven transport of MT-bound tau via slow axonal transport mechanism, and degradation of tau in the axon due to tau's finite half-life. We investigated the effect of different assumptions concerning the fate of tau in the terminal on steady-state transport of tau in the axon. In particular, we studied two possible scenarios: (i) tau is destroyed in the terminal and (ii) there is no tau destruction in the terminal, and to avoid tau accumulation we postulated zero flux of tau at the terminal. We found that the tau concentration and percentage of MT-bound tau are not very sensitive to the assumption concerning the fate of tau in the terminal, but the tau's flux and average velocity of tau transport are very sensitive to this assumption. This suggests that measuring the velocity of tau transport and comparing it with the results of mathematical modeling for different assumptions concerning tau's fate in the terminal can provide information concerning what happens to tau in the terminal.     

Can switches in disturbance type improve habitat for grassland birds in semi-arid grasslands of South-Eastern Australia?

Grasslands are one of the most endangered and degraded ecosystems globally. Switches in disturbance type can restore grassland function and improve conservation outcomes for fauna, but land-use legacies can limit the capacity of biota to respond positively to shifts in disturbance type, making it difficult to predict ecological outcomes. In semi-arid grasslands of South-Eastern Australia, habitat for grassland birds is managed using livestock grazing, a practice that has continued for >150 years. It is unknown if outcomes for birds can be improved by a switch in disturbance type as alternatives to livestock grazing have not been explored. We compare the effects of status-quo livestock grazing with alternative biomass management tools (no management, ‘crash’ grazing, planned fire) on birds, vegetation structure, and food resources using a BACI design across 3 years (2017–2019). We found crash grazing and fire produced more open, shorter grassy swards, with less exotic grass cover, compared to status-quo grazing or disturbance exclusion. Preferred habitat structure for the critically endangered plains-wanderer (Pedionomus torquatus) was maximized by status-quo grazing. Grassland birds responded in opposing ways to a disturbance switch. Brown songlarks (Megalurus cruralis) and Horsfield's bushlarks (Mirafra javanica) responded positively to disturbance exclusion, while stubble quail (Coturnix pectoralis) responded negatively to crash grazing. Australasian pipits (Anthus novaeseelandiae) were more frequent in response to status-quo grazing. Our findings suggest that multiple disturbance types should be used if the aim is to promote the spectrum of vegetation structures and food sources required to support a diverse grassland bird community in semi-arid grasslands of Australia.     

Are protected areas working for endangered frogs in the Peruvian Andes?

Biodiversity and Conservation - Assessments of the performance of protected-area (PA) networks for aquatic biodiversity conservation are rare yet essential for successful conservation of species....     

Can systems biology approach help in finding more effective treatment for acute myeloid leukemia?

Acute myeloid leukemia (AML) is a hematological cancer comprising of cancer stem cells (CSCs) that are responsible for the disease progression, drug resistance and post treatment relapses. Advances in genomic technologies have identified AML as a genetically heterogenous disease with dysregulated gene expression networks. Furthermore, observation of intracellular signaling in individual CSCs by mass cytometry has demonstrated the dysregulation of the mitogen associated protein kinase (MAPK) pathways. It has been envisaged that the future treatment for AML would entail upon formulating individualized treatment plans leading to decreased drug related toxicities for patients. However the emerging role of signaling pathways as dynamic molecular switches influencing the cell cycle process, thereby leading to varying stages of cell differentiation, is making community rethink about the current strategies used for the treatment of AML. This commentary will focus on discovering novel biomarkers and identifying new therapeutic targets, to analyze and treat AML, on a platform enabled by systems biology approach.     

Can the source–sink hypothesis explain macrofaunal abundance patterns in the abyss? A modelling test

Low food availability is a major structuring force in deep-sea benthic communities, sustaining only very low densities of organisms in parts of the abyss. These low population densities may result in an Allee effect, whereby local reproductive success is inhibited, and populations are maintained by larval dispersal from bathyal slopes. This slope–abyss source–sink (SASS) hypothesis suggests that the abyssal seafloor constitutes a vast sink habitat with macrofaunal populations sustained only by an influx of larval ‘refugees'' from source areas on continental slopes, where higher productivity sustains greater population densities. Abyssal macrofaunal population densities would thus be directly related to larval inputs from bathyal source populations. We evaluate three predictions derived from the SASS hypothesis: (i) slope-derived larvae can be passively transported to central abyssal regions within a single larval period, (ii) projected larval export from slopes to the abyss reproduces global patterns of macrofaunal abundance and (iii) macrofaunal abundance decreases with distance from the continental slope. We find that abyssal macrofaunal populations are unlikely to be sustained solely through influx of larvae from slope sources. Rather, local reproduction probably sustains macrofaunal populations in relatively high-productivity abyssal areas, which must also be considered as potential larval source areas for more food-poor abyssal regions.     

Utility of mesohabitat features for determining habitat associations of subadult sharks in Georgia’s estuaries

We examined the affects of selected water quality variables on the presence of subadult sharks in six of nine Georgia estuaries. During 231 longline sets, we captured 415 individuals representing nine species. Atlantic sharpnose shark (Rhizoprionodon terranovae), bonnethead (Sphyrna tiburo), blacktip shark (Carcharhinus limbatus) and sandbar shark (C. plumbeus) comprised 96.1% of the catch. Canonical correlation analysis (CCA) was used to assess environmental influences on the assemblage of the four common species. Results of the CCA indicated Bonnethead Shark and Sandbar Shark were correlated with each other and with a subset of environmental variables. When the species occurred singly, depth was the defining environmental variable; whereas, when the two co-occurred, dissolved oxygen and salinity were the defining variables. Discriminant analyses (DA) were used to assess environmental influences on individual species. Results of the discriminant analyses supported the general CCA findings that the presence of bonnethead and sandbar shark were the only two species that correlated with environmental variables. In addition to depth and dissolved oxygen, turbidity influenced the presence of sandbar shark. The presence of bonnethead shark was influenced primarily by salinity and turbidity. Significant relationships existed for both the CCA and DA analyses; however, environmental variables accounted for <16% of the total variation in each. Compared to the environmental variables we measured, macrohabitat features (e.g., substrate type), prey availability, and susceptibility to predation may have stronger influences on the presence and distribution of subadult shark species among sites.     

Can tourism make a major contribution to the conservation of protected areas in Madagascar?

The authors review the anticipated benefits from tourism for protected areas in Madagascar, the mechanisms that have been adopted, and how these are working at national and local levels. The contribution of tourism to the maintenance of Protected Areas in Madagascar is assessed. The anticipated benefits of tourism envisaged by the 1991 National Environmental Action Plan are considered to be over-optimistic. The growth rate in tourist arrivals is found to be smaller than previously anticipated as a result of infrastructural constraints at national and local scales. It is suggested that revenues from tourism are inadequate in meeting park management costs although the local transfer of entrance fee revenues to development projects is found to be more beneficial. It is also argued that the benefits of revenue sharing can be effective only for a limited number of protected areas until unfrastructure is improved and protected areas become more accessible to tourists.