Marine turtles are not fussy nesters: a novel test of small-scale nest site selection using structure from motion beach terrain information

BackgroundNest selection is widely regarded as a key process determining the fitness of individuals and viability of animal populations. For marine turtles that nest on beaches, this is particularly pivotal as the nesting environment can significantly control reproductive success.The aim of this study was to identify the environmental attributes of beaches (i.e., morphology, vegetation, urbanisation) that may be associated with successful oviposition in green and loggerhead turtle nests.MethodsWe quantified the proximity of turtle nests (and surrounding beach locations) to urban areas, measured their exposure to artificial light, and used ultra-high resolution (cm-scale) digital surface models derived from Structure-from-Motion (SfM) algorithms, to characterise geomorphic and vegetation features of beaches on the Sunshine Coast, eastern Australia.ResultsAt small spatial scales (i.e., <100 m), we found no evidence that turtles selected nest sites based on a particular suite of environmental attributes (i.e., the attributes of nest sites were not consistently different from those of surrounding beach locations). Nest sites were, however, typically characterised by occurring close to vegetation, on parts of the shore where the beach- and dune-face was concave and not highly rugged, and in areas with moderate exposure to artificial light.ConclusionThis study used a novel empirical approach to identify the attributes of turtle nest sites from a broader ‘envelope’ of environmental nest traits, and is the first step towards optimizing conservation actions to mitigate, at the local scale, present and emerging human impacts on turtle nesting beaches.

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Assessing coastal artificial light and potential exposure of wildlife at a national scale: the case of marine turtles in Brazil

Biodiversity and Conservation ◽

10.1007/s10531-019-01928-z ◽

2020 ◽

Vol 29 (4) ◽

pp. 1135-1152 ◽

Cited By ~ 1

Author(s):

Liliana P. Colman ◽

Paulo H. Lara ◽

Jonathan Bennie ◽

Annette C. Broderick ◽

Juliana R. de Freitas ◽

...

Keyword(s):

Nest Site Selection ◽

Marine Turtle ◽

Conservation Strategies ◽

Brazilian Coast ◽

Light Pollution ◽

Artificial Light ◽

Turtle Species ◽

Marine Turtles ◽

Light Levels ◽

Nesting Beaches

AbstractCoastal areas provide critical nesting habitat for marine turtles. Understanding how artificial light might impact populations is key to guide management strategies. Here we assess the extent to which nesting populations of four marine turtle species—leatherback (Dermochelys coriacea), olive ridley (Lepidochelys olivacea), hawksbill (Eretmochelys imbricata) and two subpopulations of loggerhead (Caretta caretta) turtles—are exposed to light pollution across 604 km of the Brazilian coast. We used yearly night-time satellite images from two 5-year periods (1992–1996 and 2008–2012) from the US Air Force Defense Meteorological Satellite Programme (DMSP) to determine the proportion of nesting areas that are exposed to detectable levels of artificial light and identify how this has changed over time. Over the monitored time-frame, 63.7% of the nesting beaches experienced an increase in night light levels. Based on nest densities, we identified 54 reproductive hotspots: 62.9% were located in areas potentially exposed to light pollution. Light levels appeared to have a significant effect on nest densities of hawksbills and the northern loggerhead turtle stock, however high nest densities were also seen in lit areas. The status of all species/subpopulations has improved across the time period despite increased light levels. These findings suggest that (1) nest site selection is likely primarily determined by variables other than light and (2) conservation strategies in Brazil appear to have been successful in contributing to reducing impacts on nesting beaches. There is, however, the possibility that light also affects hatchlings in coastal waters, and impacts on population recruitment may take longer to fully manifest in nesting numbers. Recommendations are made to further this work to provide deeper insights into the impacts of anthropogenic light on marine turtles.

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Faculty Opinions recommendation of The archaeological record of human impacts on animal populations.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1027566.331635 ◽

2005 ◽

Author(s):

Paul Dayton

Keyword(s):

Human Impacts ◽

Archaeological Record ◽

Animal Populations

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Influence of three artificial light sources on oviposition and half-life of the Black Soldier Fly, Hermetia illucens (Diptera: Stratiomyidae): Improving small-scale indoor rearing

PLoS ONE ◽

10.1371/journal.pone.0197896 ◽

2018 ◽

Vol 13 (5) ◽

pp. e0197896 ◽

Cited By ~ 10

Author(s):

Carina D. Heussler ◽

Andreas Walter ◽

Hannes Oberkofler ◽

Heribert Insam ◽

Wolfgang Arthofer ◽

...

Keyword(s):

Half Life ◽

Small Scale ◽

Artificial Light ◽

Light Sources ◽

Black Soldier Fly ◽

Hermetia Illucens

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The emergence of tolerance of human disturbance in Neotropical birds

Journal of Tropical Ecology ◽

10.1017/s0266467419000282 ◽

2019 ◽

Vol 36 (1) ◽

pp. 1-5 ◽

Cited By ~ 2

Author(s):

Piotr Tryjanowski ◽

Jakub Z. Kosicki ◽

Martin Hromada ◽

Peter Mikula

Keyword(s):

North America ◽

Human Disturbance ◽

Escape Response ◽

Bird Species ◽

Small Scale ◽

Behavioural Plasticity ◽

Mato Grosso ◽

Animal Populations ◽

History Of ◽

Rapid Emergence

AbstractAnimals living close to human settlements more often experience disturbance, but also reduced predation risk. Because an escape response is costly, behavioural adjustments of animals in terms of increased tolerance of humans occurs and is often reported in the literature. However, most such studies have been conducted in and around long-existing cities in Europe and North America, on well-established animal populations. Here, we investigate the degree of tolerance of human disturbance across 132 bird species occurring in disturbed (small farms) and undisturbed (intact wetlands and grasslands) areas in Pantanal, Mato Grosso (Brazil), a region with only a very recent history of human-induced disturbance. We found a clear across-species trend toward higher tolerance of human disturbance in birds near farms when compared with birds in wild areas. Such a flexible and perhaps also rapid emergence of tolerance when facing small-scale and very recent human disturbance presumably involves learning and might be attributed to behavioural plasticity. The ability of birds to modify their degree of tolerance of human disturbance may play a key role in the facilitation of wildlife–human coexistence.

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Social context alters retreat- and nest-site selection in a globally invasive gecko, Hemidactylus frenatus

Biological Journal of the Linnean Society ◽

10.1093/biolinnean/blz188 ◽

2019 ◽

Vol 129 (2) ◽

pp. 388-397

Author(s):

Benjamin J Muller ◽

Robin M Andrews ◽

Lin Schwarzkopf ◽

David A Pike

Keyword(s):

Invasive Species ◽

Site Selection ◽

Nest Site ◽

Gravid Female ◽

Nest Site Selection ◽

Invasion Success ◽

Ceramic Tiles ◽

Nest Sites ◽

Gravid Females ◽

Hemidactylus Frenatus

Abstract Microhabitat orientation and structure and the presence of conspecifics may strongly influence the choice of habitat. We studied how these variables influence retreat- and nest-site selection in gravid females of a globally successful invasive species, the Asian house gecko (Hemidactylus frenatus). When provided with various substrates (vertical and horizontal ceramic tiles, vertical and horizontal plywood tiles, horizontal bark over leaf litter, vertical bark over a log, and sand) gravid female geckos preferred to retreat to, and nest in, materials with crevices commonly found in urban habitats. When housed alone, gravid females most frequently retreated to vertical ceramic tile or wooden crevices, and 66.7% nested in vertical ceramic tiles. When housed with two other conspecifics, gravid females most frequently retreated to vertical ceramic tiles, but selected a wider range of nest sites. Overall, gravid geckos housed alone typically nested in the same substrates that they used as diurnal retreats; when housed in groups, however, females oviposited in locations different from those they selected as retreats. Thus, H. frenatus females use a wider range of substrates when conspecifics are present. Invasion success in this species might be driven, in part, by preferences for retreat and nest substrates that are common in human-dominated habitats.

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Predicting Geographic Ranges of Marine Animal Populations Using Stable Isotopes: A Case Study of Great Hammerhead Sharks in Eastern Australia

Frontiers in Marine Science ◽

10.3389/fmars.2020.594636 ◽

2020 ◽

Vol 7 ◽

Author(s):

Vincent Raoult ◽

Clive N. Trueman ◽

Kelsey M. Kingsbury ◽

Bronwyn M. Gillanders ◽

Matt K. Broadhurst ◽

...

Keyword(s):

Marine Phytoplankton ◽

Latitudinal Gradients ◽

Marine Animal ◽

Stable Carbon ◽

Population Geography ◽

Geographic Population ◽

Geographic Ranges ◽

The Core ◽

Animal Populations ◽

Eastern Australia

Determining the geographic range of widely dispersed or migratory marine organisms is notoriously difficult, often requiring considerable costs and typically extensive tagging or exploration programs. While these approaches are accurate and can reveal important information on the species, they are usually conducted on only a small number of individuals and can take years to produce relevant results, so alternative approaches may be preferable. The presence of latitudinal gradients in stable carbon isotope compositions of marine phytoplankton offers a means to quickly determine likely geographic population ranges of species that rely on productivity from these resources. Across sufficiently large spatial and temporal scales, the stable carbon isotopes of large coastal or pelagic marine species should reflect broad geographic patterns of resource use, and could be used to infer geographic ranges of marine populations. Using two methods, one based on a global mechanistic model and the other on targeted low-cost latitudinal sampling of fishes, we demonstrate and compare these stable isotope approaches to determine the core population geography of an apex predator, the great hammerhead (Sphyrna mokarran). Both methods indicated similar geographic ranges and suggested that S. mokarran recorded in south-eastern Australia are likely to be from more northern Australian waters. These approaches could be replicated in other areas where coastlines span predictable geographic gradients in isotope values and be used to determine the core population geography of highly mobile species to inform management decisions.

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Abundance and genetic diversity responses of a lizard (Eulamprus heatwolei) to logging disturbance

Australian Journal of Zoology ◽

10.1071/zo17051 ◽

2017 ◽

Vol 65 (6) ◽

pp. 362

Author(s):

Francesca Lyndon-Gee ◽

Joanna Sumner ◽

Yang Hu ◽

Claudio Ciofi ◽

Tim S. Jessop

Keyword(s):

Genetic Diversity ◽

Forest Management ◽

Management Practices ◽

Forest Disturbance ◽

Population Level ◽

Landscape Scale ◽

Population Abundance ◽

Animal Populations ◽

Eastern Australia ◽

Logging Disturbance

Rotational logging practices are used with the goal of reducing forest disturbance impacts on biodiversity. However, it is poorly understood whether such forest management practices conserve the demographic and genetic composition of animal populations across logged landscapes. Here we investigated whether rotational logging practices alter patterns of landscape-scale population abundance and genetic diversity of a forest-dwelling lizard (Eulamprus heatwolei) in south-eastern Australia. We sampled lizards (n = 407) at up to 48 sites across a chronosequence of logging disturbance intervals (<10 to >60 years after logging) to assess site-specific population changes and genetic diversity parameters. Lizard abundances exhibited a significant curvilinear response to time since logging, with decreased numbers following logging (<10 years), increased abundance as the forest regenerated (10–20 years), before decreasing again in older regenerated forest sites (>30 years). Lizard genetic diversity parameters were not significantly influenced by logging disturbance. These results suggest that logging practices, whilst inducing short-term changes to population abundance, had no measurable effects on the landscape-scale genetic diversity of E. heatwolei. These results are important as they demonstrate the value of monitoring for evaluating forest management efficacy, and the use of different population-level markers to make stronger inference about the potential impacts of logging activities.

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Ocean-finding in marine turtles: the importance of low horizon elevation as an orientation cue

Behaviour ◽

10.1163/1568539x-00003083 ◽

2013 ◽

Vol 150 (8) ◽

pp. 863-893 ◽

Cited By ~ 17

Author(s):

Col Limpus ◽

Ruth L. Kamrowski

Keyword(s):

Effective Means ◽

Sea Turtle ◽

Current Theory ◽

Light Reduction ◽

Artificial Lighting ◽

Marine Turtles ◽

Nest Sites ◽

Reduction Strategies ◽

Horizon Line ◽

Nesting Beaches

Sea finding behaviour in hatchling sea turtles is widely believed to be guided by orientation towards the brightest horizon and away from high silhouettes. We propose that the horizon profile at the lowest angle of elevation is a more important cue for ocean finding than light intensity. Examples of hatchling orientation occurring at natural nest sites, at preselected beach release sites, and within a walled wooden arena under various conditions in the field, are presented. We conclude that hatchlings orient as follows: (1) Hatchlings move towards the horizon line at the lowest angle of elevation; (2) Hatchlings move away from high silhouettes, in a direction that remains close to the horizon line at the lowest angle of elevation; (3) Should a conflict exist regarding the direction of lowest horizon elevation, hatchlings move towards the brightest lowest horizon. This refinement to current theory explains numerous instances of natural non-ocean-finding behaviour in marine turtles, which occur both by day and by night, and in the absence of artificial lighting. We propose that the disruption caused to hatchling orientation by artificial lighting close to nesting beaches occurs because bright lights mask the horizon line as a cue by making it impossible to discern, causing the hatchlings to move towards the only visible “horizon” — the artificial lights. Consequently, we recommend that managers of sea turtle rookeries where turtles have an ocean-finding problem should manipulate the beach profile to ensure the direction of the ocean matches the lowest angle of elevation, in combination with light reduction strategies — as the most effective means of preventing disrupted orientation.

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Nest-site selection in the barn swallow, Hirundo rustica: What predicts seasonal reproductive success?

Canadian Journal of Zoology ◽

10.1139/z06-176 ◽

2006 ◽

Vol 84 (11) ◽

pp. 1533-1539 ◽

Cited By ~ 17

Author(s):

Rebecca Jo Safran

Keyword(s):

Reproductive Success ◽

Site Selection ◽

Nest Site ◽

Individual Characteristics ◽

Nest Site Selection ◽

Hirundo Rustica ◽

Barn Swallow ◽

Nest Location ◽

Nest Sites ◽

Site Characteristics

Despite hundreds of studies, we know very little about the causes and fitness-related consequences of nest-site selection. For example, it is not typically known whether the rarely reported fitness consequences of site selection are the result of nest, individual, or nest-site variables or combinations of these factors. Reuse of previously constructed nest sites is a prevalent behavior in many animals and offers the opportunity to experimentally tease apart whether seasonal reproductive success is a function of nest, individual, or nest-site characteristics. I used observational and experimental data to test three hypotheses related to these factors in association with barn swallow ( Hirundo rustica L., 1758) nest reuse. While both nest and individual characteristics explain variation in seasonal reproductive success, nest location per se is not an important factor defining the outcome of nest-site selection. Whereas traits related to habitat and individual characteristics are likely confounded in correlational studies, my experiments demonstrate a causal relationship between seasonal reproductive success and aspects of the nest and individual, the latter explaining more variation in the model than nest characteristics. Knowledge of the relative roles of individual, nest, and nest-site attributes are important for understanding the causes and consequences of habitat selection behavior.

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