Diversity

20 pages, 809 KiB

Open AccessReview

The Importance of Isotopic Turnover for Understanding Key Aspects of Animal Ecology and Nutrition

by Wales A. Carter, Ulf Bauchinger and Scott R. McWilliams

Diversity 2019, 11(5), 84; https://doi.org/10.3390/d11050084 - 26 May 2019

Cited by 44 | Viewed by 6965

Stable isotope-based methods have proved to be immensely valuable for ecological studies ranging in focus from animal movements to species interactions and community structure. Nevertheless, the use of these methods is dependent on assumptions about the incorporation and turnover of isotopes within animal [...] Read more.

Stable isotope-based methods have proved to be immensely valuable for ecological studies ranging in focus from animal movements to species interactions and community structure. Nevertheless, the use of these methods is dependent on assumptions about the incorporation and turnover of isotopes within animal tissues, which are oftentimes not explicitly acknowledged and vetted. Thus, the purpose of this review is to provide an overview of the estimation of stable isotope turnover rates in animals, and to highlight the importance of these estimates for ecological studies in terrestrial, freshwater, and marine systems that may use a wide range of stable isotopes. Specifically, we discuss 1) the factors that contribute to variation in turnover among individuals and across species, which influences the use of stable isotopes for diet reconstructions, 2) the differences in turnover among tissues that underlie so-called ‘isotopic clocks’, which are used to estimate the timing of dietary shifts, and 3) the use of turnover rates to estimate nutritional requirements and reconstruct histories of nutritional stress from tissue isotope signatures. As we discuss these topics, we highlight recent works that have effectively used estimates of turnover to design and execute informative ecological studies. Our concluding remarks suggest several steps that will improve our understanding of isotopic turnover and support its integration into a wider range of ecological studies. Full article

(This article belongs to the Special Issue Stable Isotopes in Ecological Research)

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18 pages, 950 KiB

Open AccessArticle

Effect of Site Attributes and Matrix Composition on Neotropical Primate Species Richness and Functional Traits: A Comparison Among Regions

by Bayron R. Calle-Rendón, Renato R. Hilário and José Julio de Toledo

Diversity 2019, 11(5), 83; https://doi.org/10.3390/d11050083 - 25 May 2019

Cited by 6 | Viewed by 4858

Abstract

Fragmentation threatens biodiversity and forest-dwelling animals can be especially vulnerable. Neotropical primates inhabit forests and play ecological roles in maintaining forest biodiversity. Currently, many primate communities are restricted to forest fragments. We (1) evaluated the influence of environmental, matrix, and site attributes on [...] Read more.

Fragmentation threatens biodiversity and forest-dwelling animals can be especially vulnerable. Neotropical primates inhabit forests and play ecological roles in maintaining forest biodiversity. Currently, many primate communities are restricted to forest fragments. We (1) evaluated the influence of environmental, matrix, and site attributes on species richness and functional traits of primates in the Neotropics; and (2) evaluated the effect of the sub-region on the relationships between primates and environmental, matrix, and site attributes. We conducted literature searches to find published data on primate communities in forest fragments throughout the Neotropics. Each fragment was assigned to 1 of 11 sub-regions: Mesoamerica, Tumbes-Chocó-Magdalena, Caribbean, Orinoco, Amazon, Atlantic Forest, Cerrado, Chaco, Andes, Caatinga, and Pampa. Based on actual and expected species occurrences, we calculated the proportion of primate species retained in the fragments, the mass retained, and dietary items retained considering reproductive and vegetative plant parts and prey. We used linear mixed models to correlate primate variables with environmental, matrix, and site attributes. Fragment area was more important for primate retention than environmental, matrix, and site attributes, with primate retention being higher in larger fragments. Fragment size was positively correlated with all primate variables, except for retention of prey consumption, whose retention decreased as water bodies and density of buildings in the matrix increased. Fragments within protected areas retained larger species than unprotected fragments. The proportion of extant mass retained and vegetative plant parts in the diet were highest in Mesoamerica and lowest in the Atlantic Forest. Conservation planning of Neotropical primates should consider both the differences among sub-regions, forest restoration to increase fragment size, and the creation of new protected areas, even in fragmented landscapes. Full article

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16 pages, 5729 KiB

Open AccessArticle

Species-Specific Functional Morphology of Four US Atlantic Coast Dune Grasses: Biogeographic Implications for Dune Shape and Coastal Protection

by Sally D. Hacker, Katya R. Jay, Nicholas Cohn, Evan B. Goldstein, Paige A. Hovenga, Michael Itzkin, Laura J. Moore, Rebecca S. Mostow, Elsemarie V. Mullins and Peter Ruggiero

Diversity 2019, 11(5), 82; https://doi.org/10.3390/d11050082 - 24 May 2019

Cited by 53 | Viewed by 6501

Abstract

Coastal dunes arise from feedbacks between vegetation and sediment supply. Species-specific differences in plant functional morphology affect sand capture and dune shape. In this study, we build on research showing a relationship between dune grass species and dune geomorphology on the US central [...] Read more.

Coastal dunes arise from feedbacks between vegetation and sediment supply. Species-specific differences in plant functional morphology affect sand capture and dune shape. In this study, we build on research showing a relationship between dune grass species and dune geomorphology on the US central Atlantic Coast. This study seeks to determine the ways in which four co-occurring dune grass species (Ammophila breviligulata, Panicum amarum, Spartina patens, Uniola paniculata) differ in their functional morphology and sand accretion. We surveyed the biogeography, functional morphology, and associated change in sand elevation of the four dune grass species along a 320-kilometer distance across the Outer Banks. We found that A. breviligulata had dense and clumped shoots, which correlated with the greatest sand accretion. Coupled with fast lateral spread, it tends to build tall and wide foredunes. Uniola paniculata had fewer but taller shoots and was associated with ~42% lower sand accretion. Coupled with slow lateral spread, it tends to build steeper and narrower dunes. Panicum amarum had similar shoot densities and associated sand accretion to U. paniculata despite its shorter shoots, suggesting that shoot density is more important than morphology. Finally, we hypothesize, given the distributions of the grass species, that foredunes may be taller and wider and have better coastal protection properties in the north where A. breviligulata is dominant. If under a warming climate A. breviligulata experiences a range shift to the north, as appears to be occurring with U. paniculata, changes in grass dominance and foredune morphology could make for more vulnerable coastlines. Full article

(This article belongs to the Special Issue Diversity of Ecosystem Engineers in the World Coasts and Oceans)

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19 pages, 292 KiB

Open AccessReview

A Review of the Impacts of Roads on Wildlife in Semi-Arid Regions

by W. Richard J. Dean, Colleen L. Seymour, Grant S. Joseph and Stefan H. Foord

Diversity 2019, 11(5), 81; https://doi.org/10.3390/d11050081 - 19 May 2019

Cited by 50 | Viewed by 9152

Abstract

Roads now penetrate even the most remote parts of much of the world, but the majority of research on the effects of roads on biota has been in less remote temperate environments. The impacts of roads in semi-arid and arid areas may differ [...] Read more.

Roads now penetrate even the most remote parts of much of the world, but the majority of research on the effects of roads on biota has been in less remote temperate environments. The impacts of roads in semi-arid and arid areas may differ from these results in a number of ways. Here, we review the research on the impacts of roads on biodiversity patterns and ecological and evolutionary processes in semi-arid regions. The most obvious effect of roads is mortality or injury through collision. A diversity of scavengers are killed whilst feeding on roadkill, a source of easily accessed food. Noise pollution from roads and traffic interferes with vocal communication by animals, and birds and frogs living along noisy roads compensate for traffic noise by increasing the amplitude or pitch of their calls. Artificial light along roads impacts certain species’ ability to navigate, as well as attracting invertebrates. Animals are in turn attracted to invertebrates at streetlights, and vulnerable to becoming roadkill themselves. Genetics research across taxa confirms a loss of genetic diversity in small populations isolated by roads, but the long-term impact on the fitness of affected populations through a reduction in genetic diversity is not yet clear. Roads may rapidly cause genetic effects, raising conservation concerns about rare and threatened species. We assess mitigation measures and collate methods to identify the impact of roads on wildlife populations and their associated ecosystems, with a particular focus on recent advances. Full article

(This article belongs to the Special Issue Impacts of Linear Infrastructures on Wildlife)

21 pages, 3375 KiB

Open AccessArticle

Plant Part Age and Size Affect Sessile Macrobenthic Assemblages Associated with a Foliose Red Algae Phycodrys rubens in the White Sea

by Alexandra Chava, Anna Artemieva and Eugeniy Yakovis

Diversity 2019, 11(5), 80; https://doi.org/10.3390/d11050080 - 17 May 2019

Cited by 4 | Viewed by 4338

Abstract

Facilitation by foundation species commonly structures terrestrial and marine communities. Intraspecific variation in individual properties of these strong facilitators can affect the whole suite of the dependent taxa. Marine macroalgae often act as ecosystem engineers, providing shelter and substrate for numerous associated organisms. [...] Read more.

Facilitation by foundation species commonly structures terrestrial and marine communities. Intraspecific variation in individual properties of these strong facilitators can affect the whole suite of the dependent taxa. Marine macroalgae often act as ecosystem engineers, providing shelter and substrate for numerous associated organisms. Epibiosis of foliose red algae, however, remains underexplored, especially in the high latitudes. Here we studied sessile macrobenthic assemblages associated with a foliose red algae Phycodrys rubens in the White Sea (66° N) shallow subtidal, and the effect of individual plant properties on their structure. The blades of P. rubens develop annually, and it is possible to tell the young (usually larger) plant parts from the old ones. We hypothesized that epibenthic community structure depends on plant part age and size. We examined epibiosis on 110 plants at two sites, and the results generally supported our hypotheses. Old plant parts were several times smaller, and had higher total cover than young parts. Sponges strongly dominated the epibiosis on old parts, and young parts were dominated by polychaetes and bryozoans. Plant part surface area negatively correlated with total cover on young parts, while on old parts the relatioship was location-specific. On young parts the relative abundance of a polychaete Circeis armoricana increased with surface area, and the proportion of sponges decreased. The patterns indicate that epibenthic community structure is linked to the demography of an ecosystem engineer. Full article

(This article belongs to the Special Issue Diversity of Ecosystem Engineers in the World Coasts and Oceans)

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26 pages, 6433 KiB

Open AccessArticle

The Influence of Canopy Cover on the Ecological Function of A Key Autogenic Ecosystem Engineer

by Jacqueline B. Pocklington, Michael J. Keough, Tim D. O’Hara and Alecia Bellgrove

Diversity 2019, 11(5), 79; https://doi.org/10.3390/d11050079 - 17 May 2019

Cited by 8 | Viewed by 5221

Abstract

Intertidal fucoid algae can function as ecosystem engineers across temperate marine regions. In this investigation, we assessed the function of the alga dominating rocky reefs in temperate Australia and New Zealand, Hormosira banksii. Invertebrate and algal species assemblages were examined within areas [...] Read more.

Intertidal fucoid algae can function as ecosystem engineers across temperate marine regions. In this investigation, we assessed the function of the alga dominating rocky reefs in temperate Australia and New Zealand, Hormosira banksii. Invertebrate and algal species assemblages were examined within areas of full H. banksii canopy, areas where it was naturally patchy or absent (within its potential range on the shore) and areas where the intact canopy was experimentally disturbed. Differences in species assemblages were detected between areas with natural variation in H. banksii cover (full, patchy, negligible), with defined species associated with areas of full cover. Differences were also detected between experimentally manipulated and naturally patchy areas of canopy cover. Species assemblages altered in response to canopy manipulations and did not recover even twelve months after initial sampling. Both light intensity and temperature were buffered by full canopies compared to patchy canopies and exposed rock. This study allows us to predict the consequences to the intertidal community due to the loss of canopy cover, which may result from a range of disturbances such as trampling, storm damage, sand burial and prolonged exposure to extreme temperature, and further allow for improved management of this key autogenic ecosystem engineer. Full article

(This article belongs to the Special Issue Diversity of Ecosystem Engineers in the World Coasts and Oceans)

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14 pages, 2353 KiB

Open AccessArticle

Do Local Environmental Factors and Lunar Cycle Influence Timing and Synchrony of Oviposition of a Turtle with Strict Nocturnal Nesting?

by Tibisay Escalona, Nicole Valenzuela and Dean C. Adams

Diversity 2019, 11(5), 78; https://doi.org/10.3390/d11050078 - 15 May 2019

Cited by 9 | Viewed by 5214

Abstract

Timing of nesting affects fitness of oviparous animals living in seasonal environments, and females may cue on environmental factors for their nesting behavior, but these relationships are understudied in tropical turtles. Here, the timing and synchrony of egg-laying relative to environmental factors were [...] Read more.

Timing of nesting affects fitness of oviparous animals living in seasonal environments, and females may cue on environmental factors for their nesting behavior, but these relationships are understudied in tropical turtles. Here, the timing and synchrony of egg-laying relative to environmental factors were examined in the South American freshwater turtle Podocnemis unifilis on 11 nesting beaches during three nesting seasons. Daily measurements included number of nests laid, rainfall, river level, air temperature, and the phase of the lunar cycle (full moon, last quarter, new moon and first quarter). Results confirmed that P. unifilis nested at night and revealed that females in our population nest in groups from 2 to 17 females at a time. Nesting was not correlated with rainfall, but a significant relationship was found with river level, such that nesting started at the onset of the dry season when river levels dropped and nesting grounds emerged. Importantly, we found that (1) nesting events concentrated on days with intermediate daily maximum air temperature (although maxima changed annually), and that (2) larger groups of females nested around full moon, suggesting the reliance on visual cues to initiate nesting activities (consistent with social facilitation behavior). Altogether, the timing of nesting in P. unifilis may be shaped by a combination of environmental factors, moon phase and social facilitation, where visual cues play an important role. Full article

(This article belongs to the Special Issue Advances in the Biology and Conservation of Turtles)

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19 pages, 5531 KiB

Open AccessArticle

Impacts of Elevated CO₂ Levels on the Soil Bacterial Community in a Natural CO₂-Enhanced Oil Recovery Area

by Jing Ma, Zhanbin Luo, Fu Chen, Run Chen, Qianlin Zhu and Shaoliang Zhang

Diversity 2019, 11(5), 77; https://doi.org/10.3390/d11050077 - 11 May 2019

Cited by 11 | Viewed by 3775

Abstract

Knowledge of the interactions among different microorganisms is important to understand how ecological function transformation is affected by elevated CO₂ levels in CO₂-enhanced oil recovery (CO₂-EOR) sites. Molecular ecological networks were established to reveal the interactions among different [...] Read more.

Knowledge of the interactions among different microorganisms is important to understand how ecological function transformation is affected by elevated CO₂ levels in CO₂-enhanced oil recovery (CO₂-EOR) sites. Molecular ecological networks were established to reveal the interactions among different microbes of the soil bacterial community with the high-throughput sequencing data of 16S rRNA genes. The results showed that these networks are a powerful tool to identify and explain the interactions and keystone species in the communities under elevated CO₂ pressure. The structures of networks under different CO₂ leakage concentrations were different as a result of the networks’ topology properties, such as node numbers, topological roles of individual nodes, and network hubs. These indicators imply that the interactions among different groups were obviously changed. Moreover, changes in the network structure were significantly correlated with soil pH value, which might suggest that the large CO₂ leakage affected the soil ecosystem functions by changing the network interactions. Additionally, the key microbial populations such as Bacteroidetes and Proteobacteria were distinguished based on network topology to reveal community structure and ecosystem functioning. The work developed in this study could help microbiologists to address some research questions that could not be approached previously, and, hence, might represent a new area of research for microbial ecology. Full article

(This article belongs to the Special Issue Microbial Diversity in Extreme Environments: Implications for Ecological and Applicative Perspectives)

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11 pages, 1219 KiB

Open AccessArticle

Evaluation of Gonadal Tissue to Validate Size at Reproductive Maturity in Kemp’s Ridley Sea Turtles Found Stranded in Texas, USA

by Kathryn Stephenson Craven, Jay York Seabright Hodgson, Donna Jill Shaver, Jennifer Shelby Walker, Martha Ramona Villalba-Guerra and David William Owens

Diversity 2019, 11(5), 76; https://doi.org/10.3390/d11050076 - 9 May 2019

Cited by 6 | Viewed by 3610

Abstract

The Kemp’s ridley, Lepidochelys kempii, is the most endangered sea turtle in the world. Anthropogenic mortality of Kemp’s ridleys has been well documented in the Gulf of Mexico (GOM), USA. We evaluated the reproductive maturity of 75 Kemp’s ridley sea turtles found [...] Read more.

The Kemp’s ridley, Lepidochelys kempii, is the most endangered sea turtle in the world. Anthropogenic mortality of Kemp’s ridleys has been well documented in the Gulf of Mexico (GOM), USA. We evaluated the reproductive maturity of 75 Kemp’s ridley sea turtles found dead on GOM beaches on Mustang Island and North Padre Island, Texas, USA, 1994–1999. Straight carapace length (SCL) ranged from 40.8 to 68.7 cm. Preserved gonads and associated tissues were examined and measured. Gonadal measurements were then compared with SCL. Adults and juveniles shared a larger range of carapace measurements than expected, supporting the idea that juveniles spend several years in a pubertal state. Our results suggest caution when using SCL, tail length, or curved front claws alone as indicators of sexual maturity. In fact, SCL can be used to discern adults from juveniles with more predictive power when coupled with testis length or oviduct length measurements, thus allowing endangered species managers to more clearly identify demographic shifts in the number of mature animals, which can precede population changes. This study shows that information gained from the examination of stranded sea turtles allows wildlife managers to make more informed decisions regarding conservation priorities. Full article

(This article belongs to the Special Issue Advances in the Biology and Conservation of Turtles)

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13 pages, 3433 KiB

Open AccessArticle

Biogeographical Patterns of Endolithic Infestation in an Invasive and an Indigenous Intertidal Marine Ecosystem Engineer

by Aldwin Ndhlovu, Christopher D. McQuaid, Katy Nicastro, Nathalie Marquet, Marcos Gektidis, Cristián J. Monaco and Gerardo Zardi

Diversity 2019, 11(5), 75; https://doi.org/10.3390/d11050075 - 7 May 2019

Cited by 14 | Viewed by 5799

Abstract

By altering the phenotypic properties of their hosts, endolithic parasites can modulate the engineering processes of marine ecosystem engineers. Here, we assessed the biogeographical patterns of species assemblages, prevalence and impact of endolithic parasitism in two mussel species that act as important ecosystem [...] Read more.

By altering the phenotypic properties of their hosts, endolithic parasites can modulate the engineering processes of marine ecosystem engineers. Here, we assessed the biogeographical patterns of species assemblages, prevalence and impact of endolithic parasitism in two mussel species that act as important ecosystem engineers in the southern African intertidal habitat, Perna perna and Mytilus galloprovincialis. We conducted large-scale surveys across three biogeographic regions along the South African coast: the subtropical east coast, dominated by the indigenous mussel, P. perna, the warm temperate south coast, where this species coexists with the invasive Mediterranean mussel, M. galloprovincialis, and the cool temperate west coast dominated by M. galloprovincialis. Infestation increased with mussel size, and in the case of M. galloprovincialis we found a significantly higher infestation in the cool temperate bioregion than the warm temperate region. For P. perna, the prevalence of infestation was higher on the warm temperate than the subtropical region, though the difference was marginally non-significant. On the south coast, there was no significant difference in infestation prevalence between species. Endolith-induced mortality rates through shell collapse mirrored the patterns for prevalence. For P. perna, endolith species assemblages revealed clear grouping by bioregions. Our findings indicate that biogeography affects cyanobacteria species composition, but differences between biogeographic regions in their effects are driven by environmental conditions. Full article

(This article belongs to the Special Issue Diversity of Ecosystem Engineers in the World Coasts and Oceans)

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16 pages, 942 KiB

Open AccessArticle

Comparative Analysis of Mollusc Assemblages from Different Hard Bottom Habitats in the Central Tyrrhenian Sea

by Edoardo Casoli, Andrea Bonifazi, Giandomenico Ardizzone, Maria Flavia Gravina, Giovanni Fulvio Russo, Roberto Sandulli and Luigia Donnarumma

Diversity 2019, 11(5), 74; https://doi.org/10.3390/d11050074 - 6 May 2019

Cited by 25 | Viewed by 4149

Abstract

Composition, trophic structure, and species-substrate relationships of molluscan assemblages inhabiting different hard bottom habitats (Sabellaria alveolata reef, photophilic bottoms, Phyllophora crispa sciaphilic assemblage, and coralligenous bioconstruction) were studied in two different sites of the Tyrrhenian Sea. In particular, molluscs from the Sabellaria [...] Read more.

Composition, trophic structure, and species-substrate relationships of molluscan assemblages inhabiting different hard bottom habitats (Sabellaria alveolata reef, photophilic bottoms, Phyllophora crispa sciaphilic assemblage, and coralligenous bioconstruction) were studied in two different sites of the Tyrrhenian Sea. In particular, molluscs from the Sabellaria alvevolata (Linnaeus, 1767) reef and coralligenous concretion were investigated, testing the hypothesis that bioconstructions increase the diversity and abundance of associated biota compared to the surrounding habitats. A total of 3134 individuals belonging to the classes of Polyplacophora (5 species, 24 individuals), Bivalvia (39 sp., 2734 ind.), and Gastropoda (53 sp., 376 ind.) were identified. These three taxonomic groups showed different distribution patterns in the studied habitats. Multivariate analyses revealed significant inter-habitat differences in the composition of mollusc assemblages, especially between bioconstructions and the other habitats. S. alveolata and coralligenous host the highest rich molluscan fauna when compared to the neighboring hard bottom habitats characterized by photophilic and sciaphilic assemblages. The first ones were dominated by bivalve suspension feeders, mainly represented by sessile and sedentary organisms, which act as bio-constructors, bio-eroders, or simply inhabit the several microhabitats provided by the bioconstructions, while the second ones host a rich molluscan fauna dominated by gastropod grazers and predators. The present study increases the comparative knowledge of molluscan assemblages inhabiting habitats of littoral plans of the Mediterranean Sea, providing pivotal information regarding biodiversity of coastal zones. Full article

(This article belongs to the Section Marine Diversity)

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15 pages, 1343 KiB

Open AccessArticle

Lichen Responses to Disturbance: Clues for Biomonitoring Land-use Effects on Riparian Andean Ecosystems

by Leiddy Chuquimarca, Fernando P. Gaona, Carlos Iñiguez-Armijos and Ángel Benítez

Diversity 2019, 11(5), 73; https://doi.org/10.3390/d11050073 - 5 May 2019

Cited by 24 | Viewed by 5346

Abstract

The transformation of natural ecosystems due to anthropogenic land use is considered one of the main causes of biodiversity loss. Lichens, due to their poikilohydric nature, are very sensitive to natural and anthropogenic disturbances. Therefore, lichen communities have been widely used as bioindicators [...] Read more.

The transformation of natural ecosystems due to anthropogenic land use is considered one of the main causes of biodiversity loss. Lichens, due to their poikilohydric nature, are very sensitive to natural and anthropogenic disturbances. Therefore, lichen communities have been widely used as bioindicators of climatic and environmental changes. In this study, we evaluated how the species richness and community composition of epiphytic lichens respond to land-use intensity in riparian ecosystems of the Andes in southern Ecuador. Additionally, we evaluate how the richness of six functional traits (photobiont type, growth form, and reproductive strategy) changed across the different land-use intensity. We selected 10 trees in twelve sites for a total de 120 trees, equally divided into four riparian land-use intensities (forest, forest-pasture, pasture and urban). We recorded a total of 140 lichen species. Species richness was highest in the forest sites and decreased towards more anthropogenic land uses. Lichen community composition responded to land-use intensity, and was explained by microclimate variables (e.g., precipitation, percentage forested area) and distance to the forest. Richness of functional traits of lichens also differed significantly among the four land-use intensity and decreased from forests to urban land-use. Taxonomic diversity and functional traits can be effectively applied as bioindicators to assess and monitor the effects of land-use changes in the riparian ecosystems of tropical montane regions. Full article

(This article belongs to the Special Issue Lichen Diversity and Biomonitoring)

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13 pages, 3333 KiB

Open AccessArticle

Assessing the Impacts of Urbanization on Sex Ratios of Painted Turtles (Chrysemys picta)

by John P. Vanek and Gary A. Glowacki

Diversity 2019, 11(5), 72; https://doi.org/10.3390/d11050072 - 2 May 2019

Cited by 17 | Viewed by 5493

Abstract

Turtles are particularly susceptible to the negative impacts of urbanization due to low mobility and a life history strategy emphasizing long generation times and high adult survival. In addition to declines directly through habitat loss, urbanization has been hypothesized to limit populations of [...] Read more.

Turtles are particularly susceptible to the negative impacts of urbanization due to low mobility and a life history strategy emphasizing long generation times and high adult survival. In addition to declines directly through habitat loss, urbanization has been hypothesized to limit populations of aquatic turtles through changes in population structure, as adult females are disproportionally killed on and near roads, leading to male-biased populations, which can lead to population declines or local extirpations. The purpose of this study was to better understand how urbanization impacts the sex ratios of painted turtles (Chrysemys picta) in an urban ecosystem, as empirical results linking male-biased turtle populations to roads and urbanization are mixed. Using eight years of trapping data from a long-term monitoring program in a suburb of Chicago, IL, USA, we report one of the most male-biased populations (

\bar{x}

= 75% male) of turtles in the USA, consistent with prevailing road mortality hypotheses. However, we found no evidence that male-biased populations were related to road density or the amount of protected area around a sampling location and found that impervious surface (a metric of urbanization) was weakly related to less male-biased populations. Our results highlight the importance of replicating ecological studies across space and time and the difficulty in assessing population structure in aquatic turtles. We suggest that active conservation measures may be warranted for the continued persistence of urban turtle populations. Full article

(This article belongs to the Special Issue Advances in the Biology and Conservation of Turtles)

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15 pages, 944 KiB

Open AccessArticle

Utility of Condition Indices as Predictors of Lipid Content in Slimy Sculpin (Cottus cognatus)

by Adrian R. Hards, Michelle A. Gray, Sophia C. Noël and Rick A. Cunjak

Diversity 2019, 11(5), 71; https://doi.org/10.3390/d11050071 - 29 Apr 2019

Cited by 10 | Viewed by 4155

Abstract

Slimy sculpin (Cottus cognatus) are increasingly being used as indicator species. This has primarily entailed measuring their condition, the assumption being that condition can be used as a surrogate for lipid content. While there is evidence to suggest this assumption is [...] Read more.

Slimy sculpin (Cottus cognatus) are increasingly being used as indicator species. This has primarily entailed measuring their condition, the assumption being that condition can be used as a surrogate for lipid content. While there is evidence to suggest this assumption is applicable to some fish, it has yet to be validated for C. cognatus. Further, there are several means by which one may calculate condition, the most commonly employed of which are indirect measurements of lipid content (namely, Fulton’s K, somatic K (Ks), and Le Cren’s relative condition factor (Kn)). We compared the ability of each of these morphometric indices to predict whole-body lipid content in C. cognatus. There was a moderate degree of evidence that Fulton’s K, Ks, and Kn are reliable predictors (Ks and Kn in particular). Of the latter we recommend Kn be used because, unlike Ks, it does not require that fish be killed. And while Fulton’s K did not perform quite as well, we consider it a sufficient substitute if the data necessary to calculate Kn are unavailable. Full article

(This article belongs to the Special Issue Aquatic Environmental Monitoring and Assessment)

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19 pages, 2384 KiB

Open AccessArticle

Effects of Land Use Intensification on Avian Predator Assemblages: A Comparison of Landscapes with Different Histories in Northern Europe

by Michael Manton, Per Angelstam and Vladimir Naumov

Diversity 2019, 11(5), 70; https://doi.org/10.3390/d11050070 - 29 Apr 2019

Cited by 12 | Viewed by 5231

Abstract

Land use and landcover change alter the ability of habitat networks to maintain viable species populations. While their effects on the quality, amount and patterns of landcover patches are commonly studied, how they affect ecological processes, such as predation on focal species remains [...] Read more.

Land use and landcover change alter the ability of habitat networks to maintain viable species populations. While their effects on the quality, amount and patterns of landcover patches are commonly studied, how they affect ecological processes, such as predation on focal species remains neglected. This macroecological study tests the hypothesis that predator assemblages are affected by land use intensity linked to different socio-economic contexts. We measured the distribution and abundance of two avian predator groups (generalist corvid birds and specialist raptors), and proxy variables that mirror their food resources, at three spatial scales in northern Europe’s West and East. In total, we made 900 survey counts for avian predators and their resources in six landcover strata throughout five landscapes and analyzed their relationships. The abundance of omnivorous corvid birds was associated with the number of anthropogenic food resources. Thus, corvid birds were most common in the urban and agricultural landcovers, and where forest cover was low. Corvid bird abundance, and availability of their resources, increased with increasing land use intensity. Raptors were less abundant than corvid birds and most common in semi-natural grasslands. The number of raptor species increased with decreasing land use intensity. This study shows that the abundance and composition of avian predator species must be understood to maintain functional habitat networks. Full article

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12 pages, 1550 KiB

Open AccessArticle

The Polyextreme Ecosystem, Salar de Huasco at the Chilean Altiplano of the Atacama Desert Houses Diverse Streptomyces spp. with Promising Pharmaceutical Potentials

by Carlos Cortés-Albayay, Johanna Silber, Johannes F. Imhoff, Juan A. Asenjo, Barbara Andrews, Imen Nouioui and Cristina Dorador

Diversity 2019, 11(5), 69; https://doi.org/10.3390/d11050069 - 28 Apr 2019

Cited by 22 | Viewed by 6003

Abstract

Salar de Huasco at the Chilean Altiplano of the Atacama Desert is considered a polyextreme environment, where solar radiation, salinity and aridity are extremely high and occur simultaneously. In this study, a total of 76 bacterial isolates were discovered from soil samples collected [...] Read more.

Salar de Huasco at the Chilean Altiplano of the Atacama Desert is considered a polyextreme environment, where solar radiation, salinity and aridity are extremely high and occur simultaneously. In this study, a total of 76 bacterial isolates were discovered from soil samples collected at two different sites in the east shoreline of Salar de Huasco, including H0 (base camp next to freshwater stream in the north part) and H6 (saline soils in the south part). All isolated bacteria were preliminarily identified using some of their phenotypic and genotypic data into the genera Streptomyces (86%), Nocardiopsis (9%), Micromonospora (3%), Bacillus (1%), and Pseudomonas (1%). Streptomyces was found dominantly in both sites (H0 = 19 isolates and H6 = 46 isolates), while the other genera were found only in site H0 (11 isolates). Based on the genotypic and phylogenetic analyses using the 16S rRNA gene sequences of all Streptomyces isolates, 18% (12 isolates) revealed <98.7% identity of the gene sequences compared to those in the publicly available databases and were determined as highly possibly novel species. Further studies suggested that many Streptomyces isolates possess the nonribosomal peptide synthetases-coding gene, and some of which could inhibit growth of at least two test microbes (i.e., Gram-positive and Gram-negative bacteria and fungi) and showed also the cytotoxicity against hepatocellular carcinoma and or mouse fibroblast cell lines. The antimicrobial activity and cytotoxicity of these Streptomyces isolates were highly dependent upon the nutrients used for their cultivation. Moreover, the HPLC-UV-MS profiles of metabolites produced by the selected Streptomyces isolates unveiled apparent differences when compared to the public database of existing natural products. With our findings, the polyextreme environments like Salar de Huasco are promising sources for exploring novel and valuable bacteria with pharmaceutical potentials. Full article

(This article belongs to the Special Issue Microbial Diversity in Extreme Environments: Implications for Ecological and Applicative Perspectives)

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12 pages, 883 KiB

Open AccessArticle

A Surfeit of Studies: What Have We Learned from All the Box Turtle (Terrapene carolina and T. ornata) Home Range Studies?

by Christopher W. Habeck, Miranda P. Figueras, Jean E. Deo and Russell L. Burke

Diversity 2019, 11(5), 68; https://doi.org/10.3390/d11050068 - 28 Apr 2019

Cited by 16 | Viewed by 4960

Abstract

Home range (HR) studies are a particularly common approach to investigations of animal habitat use, resource availability, and response to management manipulation such as relocations. Terrapene carolina (Eastern box turtle) and its sister taxon T. ornata (Ornate box turtle) are especially popular subjects [...] Read more.

Home range (HR) studies are a particularly common approach to investigations of animal habitat use, resource availability, and response to management manipulation such as relocations. Terrapene carolina (Eastern box turtle) and its sister taxon T. ornata (Ornate box turtle) are especially popular subjects of HR studies because they are relatively easily tracked. Terrapene HR studies have revealed a wide variation in HR sizes within and between populations, due to factors such as differences in ecoregion and analytical approach (e.g., minimum convex polygons, kernel analysis, bivariate normal, multivariate Ornstein–Uhlenbeck stochastic process, harmonic means). We performed a meta-analysis of the available literature, including unpublished work to avoid bias due to under-publication, to explore the causes for variation in HR size. We found 19 studies reporting T. carolina HR sizes and seven studies reporting T. ornata HR sizes; the resulting meta-analysis revealed patterns that are not visible in the individual studies. We found important differences between the species: female T. ornata had smaller HRs than males, whereas the opposite is true for T. carolina, and T. ornata HRs were influenced by ecoregion, while T. carolina HRs were not similarly influenced. Not surprisingly, we found that choice of analysis technique affected HR estimate; analyses using ellipses resulted in larger HR estimates than all the other techniques, while kernels were smaller than minimum convex polygons. Although not indicated by individual studies, our meta-analysis showed that the HRs of relocated T. carolina females were significantly larger than those of non-relocated females. Although the number of individual turtles in studies varied from three to 25, the sample size did not significantly affect HR size. Full article

(This article belongs to the Special Issue Advances in the Biology and Conservation of Turtles)

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19 pages, 1781 KiB

Open AccessArticle

Latitudinal and Cross-Shelf Patterns of Size, Age, Growth, and Mortality of a Tropical Damselfish Acanthochromis polyacanthus on the Great Barrier Reef

by Michael J. Kingsford, David Welch and Mark O’Callaghan

Diversity 2019, 11(5), 67; https://doi.org/10.3390/d11050067 - 26 Apr 2019

Cited by 10 | Viewed by 3968

Abstract

Patterns of age and growth of a sedentary damsel fish Acanthochromis polyacanthus were tested over a latitudinal range of approximately 10 degrees (1200 km) on the Great Barrier Reef (GBR), Australia. Within latitudes, these patterns were also compared on reefs in distance strata [...] Read more.

Patterns of age and growth of a sedentary damsel fish Acanthochromis polyacanthus were tested over a latitudinal range of approximately 10 degrees (1200 km) on the Great Barrier Reef (GBR), Australia. Within latitudes, these patterns were also compared on reefs in distance strata (inner, mid, and outer) across a continental shelf that ranged in width from 52 to 128 km. Although variation in length-max (SLMAX), growth, age-max (AMAX), and the von Bertalanffy metrics of L_inf and K were found within and among latitudes, the greatest variation in some demographic characteristics was found among distance strata across the shelf regardless of latitude. Fish were always relatively smaller at inner shelf reefs and grew more slowly when compared to mid and outer shelf reefs; this was true regardless of the color morph of fish. The oldest fish collected was 11 years old, and there was no consistent variation in age-max among distances from shore. On outer reefs, there was a negative linear relationship with age-max and latitude. This “tropical gradient” of age only explained 34% of the variation; furthermore, this was not found when only the oldest group of fish was considered (top 10%). Fish only reached an age-max of six years on the southernmost reefs. There was a trend for a smaller L_inf with latitude but it was not significant and L_inf did not vary predictably with water temperature. The sampling of marine protected areas (MPAs) and fished zones did not confound the resultant patterns in that fish were not consistently larger or older in MPAs or fished zones. Instantaneous mortality rates were 0.245–0.685; they were highest at inner reefs and also showed no consistent MPA-related patterns. Our study suggested that the mid and outer shelf waters of the GBR appeared best suited for growth of A. polyacanthus. In conclusion, the position on continental shelves dominated other geographical patterns and needs to be considered in spatial models of growth. We suggest that local environmental conditions such as turbidity and the quality and quantity of plankton likely have a strong influence on distance across the shelf-based demographic patterns of planktivores. Full article

(This article belongs to the Special Issue Cross-shelf Variation in the Structure and Function of Coral Reef Assemblages)

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Diversity, Volume 11, Issue 5 (May 2019) – 18 articles

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