scholarly journals North Pacific warming shifts the juvenile range of a marine apex predator

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kisei R. Tanaka ◽  
Kyle S. Van Houtan ◽  
Eric Mailander ◽  
Beatriz S. Dias ◽  
Carol Galginaitis ◽  
...  

AbstractDuring the 2014–2016 North Pacific marine heatwave, unprecedented sightings of juvenile white sharks (Carcharodon carcharias) emerged in central California. These records contradicted the species established life history, where juveniles remain in warmer waters in the southern California Current. This spatial shift is significant as it creates potential conflicts with commercial fisheries, protected species conservation, and public safety concerns. Here, we integrate community science, photogrammetry, biologging, and mesoscale climate data to describe and explain this phenomenon. We find a dramatic increase in white sharks from 2014 to 2019 in Monterey Bay that was overwhelmingly comprised of juvenile sharks < 2.5 m in total body length. Next, we derived thermal preferences from 22 million tag measurements of 14 juvenile sharks and use this to map the cold limit of their range. Consistent with historical records, the position of this cold edge averaged 34° N from 1982 to 2013 but jumped to 38.5° during the 2014–2016 marine heat wave. In addition to a poleward shift, thermally suitable habitat for juvenile sharks declined 223.2 km2 year−1 from 1982 to 2019 and was lowest in 2015 at the peak of the heatwave. In addition to advancing the adaptive management of this apex marine predator, we discuss this opportunity to engage public on climate change through marine megafauna.

2020 ◽  
Vol 8 ◽  
Author(s):  
Sara Bárrios ◽  
José Sustache ◽  
David Goyder ◽  
Martin Hamilton

Thought to be endemic to the Commonwealth of Puerto Rico, Ruehssia woodburyana (Apocynaceae) was recently discovered at a single location on Norman Island in the British Virgin Islands. Despite an increase in the extent of occurrence and area of occupancy, this species meta-population is very limited with a total of 37 individuals known in the wild. The largest subpopulation, on Mona Island, has only 26 individuals. The species suitable habitat is experiencing a continuing decline due to urban development, grazing by feral ungulates and human-induced forest fires. Conservation action is urgently needed and should be directed towards establishing genetically representative ex situ collections, such as seed for long term storage and live material for propagation. This species is evaluated as Critically Endangered (CR), based on Criteria C2a(i)+D, according to the IUCN Red List Categories and Criteria (version 3.1) and guidelines (Subcommittee IUCN Standards and Petitions 2016). Extensive and regular surveys to the region enable the discovery of new plant records for different countries and islands. In this paper, we record a new island record for Ruehssia woodburyana on Norman Island, in the British Virgin Islands and discuss the species conservation status. Marsdenia woodburyana is transferred to the genus Ruehssia to reflect the resurrection of that genus for species of Marsdenia native to the New World.


2021 ◽  
Author(s):  
Sara Stoudt ◽  
Benjamin R Goldstein ◽  
Perry de Valpine

Identifying which species are perceived as charismatic can improve the impact and efficiency of conservation outreach, as charismatic species receive more conservation funding and have their conservation needs prioritized. Sociological experiments studying animal charisma have relied on stated preferences to find correlations between hypothetical "willingness to pay" or "empathy" for a species' conservation and species' size, color, and aesthetic appeal. Recognizing the increasing availability of digital records of public engagement with animals that reveal preferences, an emerging field of "culturomics" uses Google search results, Wikipedia article activities, and other digital modes of engagement to identify charismatic species and traits. In this study, we take advantage of community science efforts as another form of digital data that can reveal observer preferences. We apply a multi-stage analysis to ask whether opportunistic birders contributing to iNaturalist engage more with larger, more colorful, and rarer birds relative to a baseline, from eBird contributors, approximating unbiased detection. We find that body mass, color contrast, and range size all predict overrepresentation in the opportunistic dataset. We also find evidence that, across 473 modeled species, 52 species are significantly overreported and 158 are significantly underreported, indicating a wide variety of species-specific effects. Understanding which birds are charismatic can aid conservationists in creating impactful outreach materials and engaging new naturalists. The quantified differences between two prominent community science efforts may also be of use for researchers leveraging the data from one or both of them to answer scientific questions of interest.


Insects ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 784
Author(s):  
Matthew W. F. Howse ◽  
John Haywood ◽  
Philip J. Lester

Species distribution models (SDMs) are tools used by ecologists to help predict the spread of invasive species. Information provided by these models can help direct conservation and biosecurity efforts by highlighting areas likely to contain species of interest. In this study, two models were created to investigate the potential range expansion of Polistes dominula Christ (Hymenoptera: Vespidae) in the southern hemisphere. This palearctic species has spread to invade North and South America, South Africa, Australia, and more recently New Zealand. Using the BIOCLIM and MAXENT modelling methods, regions that were suitable for P. dominula were identified based on climate data across four regions in the southern hemisphere. In South America areas of central Chile, eastern Argentina, parts of Uruguay, and southern Brazil were identified as climatically suitable for the establishment of P. dominula. Similarly, southern parts of South Africa and Australia were identified by the model to be suitable as well as much of the North Island and east of the South Island of New Zealand. Based on outputs from both models, significant range expansion by P. dominula is possible across its more southern invaded ranges.


Author(s):  
He Pia He Pia

Abstract In the Mekong Region, the expansion of rubber plantations is a major threat to the remaining natural forests and has led to a considerable degradation of biodiversity. The shift from traditional agriculture to rubber cultivation additionally reduced landscape and agricultural system diversity and with this, the availability of potentially useful habitat types for species originating from natural forest. In most cases, monoculture rubber plantations showed to harbour less than half of the species richness in various plant and animal groups compared with natural forest, and often it was found or being assumed that many of these species are unable to exist permanently in rubber plantations. There is clear evidence that the existence natural forest area is essential for the conservation of large portions of native forest species in rubber-dominated landscapes. Alteration of rubber monoculture land use can only contribute effectively to species conservation if natural forest plots remain. Furthermore, suggested restoration concepts such as the conversion of rubber plantations into forest on marginal sites and land-sharing approaches are currently only vaguely described, and their contribution to the conservation of native forest species remains uncertain. In addition, modalities of stakeholder involvement, economic compensation and ecologically reasonable implementation of such measures are still unexplained. As an ecologically reasonable and economically feasible method to improve species diversity in rubber monoculture plantations, we suggest the promotion of natural undergrowth vegetation to enlarge suitable habitat structures in connection with natural forest. This can be reached through the cease of weeding and herbicide application and potentially through the cultivation of useful wild plants.


2021 ◽  
Vol 8 (3) ◽  
Author(s):  
M. V. Westbury ◽  
K. F. Thompson ◽  
M. Louis ◽  
A. A. Cabrera ◽  
M. Skovrind ◽  
...  

The deep oceans of the Southern Hemisphere are home to several elusive and poorly studied marine megafauna. In the absence of robust observational data for these species, genetic data can aid inferences on population connectivity, demography and ecology. A previous investigation of genetic diversity and population structure in Gray's beaked whale ( Mesoplodon grayi ) from Western Australia and New Zealand found high levels of mtDNA diversity, no geographic structure and stable demographic history. To further investigate phylogeographic and demographic patterns across their range, we generated complete mitochondrial and partial nuclear genomes of 16 of the individuals previously analysed and included additional samples from South Africa ( n = 2) and South Australia ( n = 4), greatly expanding the spatial range of genomic data for the species. Gray's beaked whales are highly elusive and rarely observed, and our data represents a unique and geographically broad dataset. We find relatively high levels of diversity in the mitochondrial genome, despite an absence of population structure at the mitochondrial and nuclear level. Demographic analyses suggest these whales existed at stable levels over at least the past 1.1 million years, with an approximately twofold increase in female effective population size approximately 250 thousand years ago, coinciding with a period of increased Southern Ocean productivity, sea surface temperature and a potential expansion of suitable habitat. Our results suggest that Gray's beaked whales are likely to be resilient to near-future ecosystem changes, facilitating their conservation. Our study demonstrates the utility of low-effort shotgun sequencing in providing ecological information on highly elusive species.


2016 ◽  
Vol 27 (1) ◽  
pp. 96-110 ◽  
Author(s):  
EMMA M. SASS ◽  
JENNIFER L. MORTENSEN ◽  
J. MICHAEL REED

SummaryHabitat suitability models can guide species conservation by identifying correlates of occurrence and predicting where species are likely to occur. We created habitat suitability models for the White-breasted Thrasher Ramphocinclus brachyurus, a narrowly distributed endangered songbird that occupies dry forest in Saint Lucia and Martinique. Eighty-five percent of the global population inhabits two ranges in Saint Lucia, both of which are largely unprotected and threatened by development. We developed three habitat suitability models using Maxent techniques and published occupancy datasets collected from the species’ two Saint Lucian ranges, and used abiotic, land cover, and predator distribution predictors. We built one model with occupancy data from both ranges, and two others with occupancy data specific to each range. The best full-range model included 11 predictors; high suitability was associated with close proximity to Saint Lucia fer-de-lance Bothrops caribbeaus range, moderately low precipitation, and areas near streams. Our assessment of suitable sites island-wide was more restricted than results from a recent model that considered older land cover data and omitted predator distributions. All sites identified in our full-range model as highly suitable were in or adjacent to the species’ current designated range. The model trained on southern range occurrences predicted zero suitable habitat in the northern range, where the population is much smaller. In contrast, the model trained on northern range occurrences identified areas of moderate suitability within the southern range and patches of moderately suitable habitat in the western part of the island, where no White-breasted Thrashers currently occur. We interpret these results as suggesting that White-breasted Thrashers currently occupy virtually all suitable habitat on the island, that birds in the northern range occupy marginal habitat, or that an important correlate of suitability is missing from the model. Our results suggest that habitat management should focus on currently occupied areas.


2019 ◽  
Vol 11 (24) ◽  
pp. 7047 ◽  
Author(s):  
Mohammad Rajab Houmsi ◽  
Mohammed Sanusi Shiru ◽  
Mohamed Salem Nashwan ◽  
Kamal Ahmed ◽  
Ghaith Falah Ziarh ◽  
...  

Expansion of arid lands due to climate change, particularly in water stressed regions of the world can have severe implications on the economy and people’s livelihoods. The spatiotemporal trends in aridity, the shift of land from lower to higher arid classes and the effect of this shift on different land uses in Syria have been evaluated in this study for the period 1951–2010 using high-resolution monthly climate data of the Terrestrial Hydrology Research Group of Princeton University. The trends in rainfall, temperature and potential evapotranspiration were also evaluated to understand the causes of aridity shifts. The results revealed an expansion of aridity in Syria during 1951–1980 compared to 1981–2010. About 6.21% of semi-arid land was observed to shift to arid class and 5.91% dry-subhumid land to semi-arid land between the two periods. Analysis of results revealed that the decrease in rainfall is the major cause of increasing aridity in Syria. About 28.3% of agriculture land located in the north and the northwest was found to shift from humid to dry-subhumid or dry-subhumid to semi-arid. Analysis of results revealed that the shifting of drylands mostly occurred in the northern agricultural areas of Syria. The land productivity and irrigation needs can be severely affected by increasing aridity which may affect food security and the economy of the country.


2021 ◽  
Vol 55 (1) ◽  
pp. 29-37
Author(s):  
Craig P. O'Connell ◽  
David Dayan ◽  
Christian Healy ◽  
Pingguo He

AbstractUnderstanding if a discrete region fits three key criteria for shark nursery area designation is of utmost importance. Such a designation within United States territorial waters could result in the implementation of an Essential Fish Habitat (EFH) classification, a determination facilitating species protection. In this study, baited remote underwater video systems (BRUVS) were used to determine if they could effectively confirm a previously identified white shark (Carcharodon carcharias) nursery area south of Montauk, New York, so that the technique may be applied in other potential nursery areas. During experimentation, 1,348.32 h of video data were collected between Region A (Block Island Sound; 674.16 h), outside of the previously identified nursery area, and Region B (Atlantic Ocean; 674.16 h), within the identified nursery area. From the video data, 35 sightings of C. carcharias were recorded, with 31 unique individuals identified. Data associated with Region B fit all three nursery area criteria: (a) young-of-the-year (YOY) and juvenile sharks were more commonly found in this region over Region A (p < 0.001), (b) several YOY and juvenile sharks (n = 4) were resighted in this region within a given year (e.g., average resighting duration: 10.5 days), and (c) YOY and juvenile sharks exhibited repeated use of this region over multiple years. We conclude that BRUVS can be used for fine-scale analyses to help designate a discrete area(s) as a shark nursery, even in turbid New York waters. Therefore, using BRUVS to identify shark nursery areas is a viable and noninvasive approach that can contribute to species conservation.


2014 ◽  
Vol 24 (3) ◽  
pp. 379-388 ◽  
Author(s):  
MARTIN GILBERT ◽  
RUTH TINGAY ◽  
JAMBAL LOSOLMAA ◽  
NADIA SUREDA ◽  
COLIN GILBERT ◽  
...  

SummaryPallas’s Fish Eagle Haliaeetus leucoryphus (PFE) is sparsely distributed across a vast swathe of central, eastern and southern Asia, and is classified as ‘Vulnerable’ by IUCN on the basis of population size and reports of declines in many areas. Mongolia has long been considered a breeding stronghold for the species, but evidence to support this is unclear. Our objective was to assess the current distribution and status of the PFE in Mongolia to enable a more accurate assessment of the species’ conservation status, through collation of existing information from the historical literature, and a contemporary survey of historical sites and potential PFE breeding habitat. Thirty-four traceable locations were identified in the historical literature, of which breeding activity had been recorded in seven. Field surveys were conducted at a total of 77 sites throughout the study period (2005–2011) between April and October, including 21 of the historical PFE locations. PFE were observed at eight sites, all of which were historical PFEs locations, and no evidence of breeding activity was recorded. These findings suggest that Mongolia is not (and may never have been) a breeding stronghold for the PFE. The lack of eagles at 13 of 21 historical sites surveyed, coupled with a lack of sightings of birds at alternative locations is suggestive of a decline in site occupancy. Observations of juvenile eagles within one month of the spring thaw suggests that at least a proportion of Mongolian PFEs are breeding at southern latitudes, and future studies to establish these migratory linkages are warranted. These findings, coupled with evidence of declines in other parts of the PFE range indicate a need to re-evaluate the species’ conservation status, and in particular to determine the number of mature PFEs present in suitable habitat in the Indian Subcontinent and Myanmar between November and March.


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