Comparison of beach profiles conducive for turtle nesting in Andaman

The present study was undertaken to compare beach characteristics associated with turtle nesting in the Andaman group of islands. Karmatang, Kalipur, Ramnagar, Chidiyatapu, Carbyn’s Cove, and Wandoor were chosen as study sites. Beach slope, sand grain characteristics, and general vegetation patterns were analysed. The angle of inclination of the beach slope ranged from 2.06 to 8.3 degrees. Beaches with a higher angle had a comparatively higher number of nesting sites. The study shows that a single factor does not make a beach more conducive for nesting. Chidiyatapu has the widest beach but lacks other features and so it is not a preferred nesting site. The grain size of sand in Wandoor is highly favourable, but the intertidal region is not long and there are streams that can drown the nests. Karmatang has a long beach and a higher slope angle. Ramnagar has a moderate beach length and a high slope angle. The dominant grains at both the beaches were found to be granules. The absence of streams and artificial light, fewer number of anthropogenic activities, lack of obstacles, the presence of bordering vegetation, and a conducive beach slope with granular sand grains make Ramnagar, Karmatang, and Kalipur ideal for turtle nesting.

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Factors influencing the occurrence of negative interactions between people and crocodilians in Mexico

Oryx ◽

10.1017/s0030605319000668 ◽

2021 ◽

pp. 1-9

Author(s):

Giovany Arturo González-Desales ◽

Luis Sigler ◽

Jesús García-Grajales ◽

Pierre Charruau ◽

Martha Mariela Zarco-González ◽

...

Keyword(s):

Anthropogenic Activities ◽

Biosphere Reserve ◽

Rigorous Evaluation ◽

Caiman Crocodilus ◽

Crocodylus Acutus ◽

American Crocodile ◽

Nesting Sites ◽

The Relationship ◽

Nesting Season ◽

Negative Interactions

Abstract Negative interactions between people and crocodilians have increased worldwide, but in Mexico there have been few systematic reports and no rigorous evaluation of this problem. We compiled information on negative interactions between people and the spectacled caiman Caiman crocodilus and American crocodile Crocodylus acutus from the Worldwide Crocodilian Attack Database for 1993–2018, and we investigated interactions in greater depth, through interviews with people in La Encrucijada Biosphere Reserve. We examined the relationship between the occurrence of negative interactions between people and C. acutus and the species' nesting season and abundance, and presence records. In Mexico, the frequency of negative interactions increases when anthropogenic activities occur close to nesting sites (< 30 km) and during the nesting season (February–September). In La Encrucijada, following negative interactions with crocodiles, the local inhabitants killed 30 crocodiles measuring > 2.5 m long in 2011–2012. The frequency of negative human–crocodilian interactions was not correlated with the abundance of crocodilians but was correlated with the number of presence records of crocodiles. Strategies to minimize these interactions include warnings at nesting sites, increased monitoring of anthropogenic activities during the nesting season, and management of nests to prevent them being destroyed by people.

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Floral diversity assessment of the buffer zones and vicinity of the Mt. Hamiguitan Range Wildlife Sanctuary (MHRWS), Davao Oriental: basis for inclusion to protected area zone

10.26757/pjsb.2018b12004 ◽

2019 ◽

Vol 12 (2) ◽

Keyword(s):

Protected Area ◽

Anthropogenic Activities ◽

Buffer Zones ◽

Floral Diversity ◽

Diversity Assessment ◽

Study Support ◽

Study Sites ◽

Trees And Shrubs ◽

Sampling Plot ◽

Ferns And Lycophytes

In 2016, municipal ordinances to expand the protected area of the MHRWS were issued with the aim of protecting and preserving the remaining biodiversity of the buffer zones and to strengthen the core zone. The municipal ordinances however, have limitations and do not guarantee legal promulgation. Hence, this study is on the gathering of complete and concrete floral data so that these expansion sites will become part of the protected area and encompassed in legal promulgations. Botanical fieldworks conducted from Oct to Dec 2017 were carried out in five study sites of the MHRWS expansion sites using 40 20 x 20 m sampling plot with a distance of 20 m between plots and opportunistic transect walk techniques. The study disclosed 228 taxa of plants, of these, 74 species were ferns and lycophytes, 6 species of gymnosperms, 30 species of herbs and vines and 118 species were trees and shrubs. There were three new records of ferns and lycophytes increasing the number of species to 155. There are 13 (5.7%) threatened species, 22 (9.6%) and endemic species. Findings suggest that species in each site are unique and maybe attributed to the vegetation present, elevation variations of the different sampling sites and anthropogenic activities. The proposed expansion sites harbor diverse threatened and plants deserving protection and conservation efforts. Results of this study support the contention that the expansion sites, which are included in the municipal ordinances, be part of the official protected area.

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A review on crocodilian nesting habitats and their characterisation via remote sensing

Amphibia-Reptilia ◽

10.1163/15685381-20191159 ◽

2019 ◽

Vol 40 (4) ◽

pp. 403-423 ◽

Cited By ~ 1

Author(s):

Gabriela Banon ◽

Eduardo Arraut ◽

Francisco Villamarín ◽

Boris Marioni ◽

Gabriel Moulatlet ◽

...

Keyword(s):

Remote Sensing ◽

Forest Canopy ◽

Open Water ◽

Site Distribution ◽

Nesting Site ◽

Nesting Sites ◽

Conservation Actions ◽

Key Variables ◽

Reproductive Females ◽

Remote Sensing Methods

Abstract Crocodilians usually remain inside or near their nests during most vulnerable life stages (as eggs, neonates and reproductive females). Thus, protection of nesting sites is one of the most appropriate conservation actions for these species. Nesting sites are often found across areas with difficult access, making remote sensing a valuable tool used to derive environmental variables for characterisation of nesting habitats. In this study, we (i) review crocodilian nesting habitats worldwide to identify key variables for nesting site distribution: proximity to open-water, open-water stability, vegetation, light, precipitation, salinity, soil properties, temperature, topography, and flooding status, (ii) present a summary of the relative importance of these variables for each crocodilian species, (iii) identify knowledge gaps in the use of remote sensing methods currently used to map potential crocodilian nesting sites, and (iv) provide insight into how these remotely sensed variables can be derived to promote research on crocodilian ecology and conservation. We show that few studies have used remote sensing and that the range of images and methods used comprises a tiny fraction of what is available at little to no cost. Finally, we discuss how the combined use of remote sensing methods – optical, radar, and laser – may help overcome difficulties routinely faced in nest mapping (e.g., cloud cover, flooding beneath the forest canopy, or complicated relief) in a relevant way to crocodilians and to other semiaquatic vertebrates in different environments.

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How size and trigger matter: analyzing rainfall- and earthquake-triggered landslide inventories and their causal relation in the Koshi River basin, Central Himalaya

10.5194/nhess-2018-109 ◽

2018 ◽

Cited By ~ 2

Author(s):

Jianqiang Zhang ◽

Cees J. van Westen ◽

Hakan Tanyas ◽

Olga Mavrouli ◽

Yonggang Ge ◽

...

Keyword(s):

River Basin ◽

Causal Relation ◽

Anthropogenic Activities ◽

Slope Angle ◽

Central Himalaya ◽

Triggering Mechanism ◽

Susceptibility Maps ◽

Triggering Mechanisms ◽

Koshi River Basin ◽

Frequency Area

Abstract. Inventories of landslides caused by different triggering mechanisms, such as earthquakes, extreme rainfall events or anthropogenic activities, may show different characteristics in terms of distribution, causal factors and frequency-area relationships. This research aims to study such differences in landslide inventories, and the effect they have on landslide susceptibility assessment. Koshi River basin in central Himalaya was taken as study area. Detailed landslide inventories were generated based on visual interpretation of remote sensing images and field investigation for different time periods and triggering mechanisms. Maps and images from the period 1992 to 2015 were used to map 5,858 rainfall-triggered landslides and after the 2015 April 25 Gorkha earthquake, an additional 1138 co-seismic landslides were mapped. A set of topographic, geological and land cover factors were employed to analyze their correlation with different types and sizes of landslides. The results show that the frequency – area distributions of rainfall and earthquake–triggered landslides varied considerably, with the former one having a larger frequency of small landslides. Also topographic factors varied considerably for the two triggering events, with both elevation and slope angle showing significantly different patterns for earthquake-triggered and rainfall-triggered landslides. Landslides were classified into two size groups, in combination with the main triggering mechanism (rainfall- or earthquake-triggered). Susceptibility maps for different combinations of landslide size and triggering mechanism were generated using logistic regression analysis. The different triggers and sizes of landslide data were used to validate the models. The results showed that susceptible areas for small and large size rainfall- and earthquake-triggered landslides differed substantially, while susceptibility maps for different size of earthquake-triggered landslides were similar.

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Soil Erosion on Mountain Trails in Eastern Iberian Peninsula

Proceedings ◽

10.3390/proceedings2019030080 ◽

2020 ◽

Vol 30 (1) ◽

pp. 80

Author(s):

Artemi Cerdà ◽

David Salesa ◽

Jesús Rodrigo-Comino ◽

Gaspar Mora-Navarro ◽

Enric Terol ◽

...

Keyword(s):

Soil Erosion ◽

Slope Angle ◽

Parent Material ◽

Rock Outcrops ◽

Erosion Rates ◽

Soil Erosion Rates ◽

Mountain Terrains ◽

Study Sites ◽

Coastal Land ◽

Clear Relation

A review on trial erosion shows that soil erosion rates are one to three orders of magnitude higher than the ones recommended as sustainable. This is threatening the sustainable managements of mountain terrains, mainly in the popular hiking paths. The warm temperatures characterize Eastern Spain in winter, which results in visitors from northern Europe to walk in the coastal land mountainous terrain. This increases the pressure to the currently highly visited most popular paths. We selected representative transects of the trails of Serra de Bérnia, Puigcampana, Penyagolosa, Montcabré, Serra del Sit, Aitana, Les Tres Creus, Caroig, Cupurutxo and Circ de la Safor. All the selected study sites have Limestone parent material, and a scrubland as vegetation cover and the selected slope angle ranged in average between 5 and 10%. The surveys showed that soil erosion rates measured with a topographical method range from 13 till 450 Mg ha−1 y−1. There is a clear relation between the number of users and the damage done on the trails; and we found that short cuts are the areas that contribute with fresh sediment. Rock outcrops are found in 34% of the measured trail sections and this is a good example how the complete soil can be lost as a consequence of recreational activities.

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Deciding Where to Sleep: Spatial Levels of Nesting Selection in Chimpanzees (Pan troglodytes) Living in Savanna at Issa, Tanzania

International Journal of Primatology ◽

10.1007/s10764-020-00186-z ◽

2020 ◽

Vol 41 (6) ◽

pp. 870-900 ◽

Cited By ~ 1

Author(s):

R. Adriana Hernandez-Aguilar ◽

Trond Reitan

Keyword(s):

Pan Troglodytes ◽

Site Selection ◽

Spatial Scales ◽

Tree Height ◽

Important Variable ◽

Physical Characteristics ◽

Individual Tree ◽

Trunk Diameter ◽

Nesting Site ◽

Nesting Sites

AbstractTo understand how animals select resources we need to analyze selection at different spatial levels or scales in the habitat. We investigated which physical characteristics of trees (dimensions and structure, e.g., height, trunk diameter, number of branches) determined nesting selection by chimpanzees (Pan troglodytes) on two different spatial scales: individual nesting trees and nesting sites. We also examined whether individual tree selection explained the landscape pattern of nesting site selection. We compared the physical characteristics of actual (N = 132) and potential (N = 242) nesting trees in nesting sites (in 15 plots of 25 m × 25 m) and of all trees in actual and potential nesting sites (N = 763 in 30 plots of 25 m × 25 m). We collected data in May and June 2003 in Issa, a dry and open savanna habitat in Tanzania. Chimpanzees selected both the site they used for nesting in the landscape and the trees they used to build nests within a nesting site, demonstrating two levels of spatial selection in nesting. Site selection was stronger than individual tree selection. Tree height was the most important variable for both nesting site and tree selection in our study, suggesting that chimpanzees selected both safe sites and secure trees for sleeping.

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The persistence of moles in nesting at the same site as indicated by mushroom fruiting and nest reconstruction

Canadian Journal of Zoology ◽

10.1139/z93-237 ◽

1993 ◽

Vol 71 (8) ◽

pp. 1690-1693 ◽

Cited By ~ 7

Author(s):

Naohiko Sagara ◽

Hisashi Abe ◽

Hiroaki Okabe

Keyword(s):

Nesting Site ◽

Nesting Sites

Evidence is presented to show that under certain conditions, three species of Japanese talpine mole, Euroscaptor mizura, Mogera wogura, and Mogera kobeae, persistently use the same nest or nesting site. The moles' nesting sites were detected by the fruiting of an agaric species, Hebeloma radicosum, which specifically colonizes a mole's latrines near its nest. The nests were removed to observe the moles' response. During excavation, the moles often returned to the disturbed sites in search of their nests. The nests were soon reconstructed, followed by refruiting of the mushroom. Thus, one nesting site of E. mizura was used for more than 15 years, despite removal of the nest seven times, and another for more than 5 years, a period ended by the capture of the occupant. Similar results were also obtained with M. wogura and M. kobeae. The occupants may have changed generationally at each site. These persistently used sites seem to be associated with well-drained soil and appropriate vegetation.

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The effect of vegetation dynamics on erosion processes, sediment dynamics, and landscape evolution in semiarid areas with sparse plant cover

10.5194/egusphere-egu2020-9027 ◽

2020 ◽

Author(s):

Patricia Saco ◽

Juan Quijano ◽

Mariano Moreno-de las Heras ◽

Garry Willgoose ◽

Jose Rodriguez

Keyword(s):

Anthropogenic Activities ◽

Plant Cover ◽

Northern Territory ◽

Vegetation Patterns ◽

Hydrologic Connectivity ◽

Sparse Vegetation ◽

Erosion Processes ◽

Modelling Framework ◽

Sediment Redistribution ◽

Linear Behaviour

Vegetation not only controls but is also controlled by erosion processes. This tight feedback effect leads to the coevolution of vegetation and erosion patterns that modulate landform shape, and regulate many other landscape processes. These tight interactions are particularly important in semiarid landscapes. We have studied these interactions using a landform evolution model that accounts for the effect (and feedbacks) of spatially and temporally varying hydrologic and vegetation patterns.We apply the modelling framework to improve our understanding of the coevolution of landforms and vegetation patterns in different semiarid landscapes in Australia. The vegetation of the selected sites is Acacia Aneura (Mulga) which covers vast areas of Australia. &#160;These sites display a sparse vegetation cover and strong patterns of water redistribution, with sources located in the bare areas and sinks in the vegetation patches which characterize the observed hydrologic connectivity. This effect triggers high spatial variability of erosion/deposition rates that affects the evolving topography and induces feedbacks to the dynamic vegetation patterns. We run simulations for 1000 years using local rainfall and erosion and vegetation parameters previously calibrated for similar sites in the Northern territory. Our numerical modelling results are validated by comparing simulated and observed patterns of vegetation and landforms obtained from satellite, airborne remote sensing and field data. We further investigate the effect of alterations in hydrologic connectivity induced by climate change and/or anthropogenic activities, which affect water and sediment redistribution and can be linked to loss of resources leading to degradation.Our simulations are able to reproduce observed banded vegetation and landform patterns for the Northern territory in Australia. We show that an increase in hydrologic connectivity can trigger changes in vegetation patterns inducing feedbacks with landforms leading to degraded states. These transitions display non-linear behaviour and in some cases can lead to thresholds with an abrupt reduction in productivity. Critical implications for effective long-term restoration efforts are discussed.

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Abundance and Distribution of Odonates (Dragonflies and Damselflies) In Akwa Ibom State, Nigeria

Pan African Journal of Life Sciences ◽

10.36108/pajols/8102/10(0160) ◽

2018 ◽

Vol 1 (1) ◽

pp. 33-38

Author(s):

Kehinde A. Kemabonta ◽

Rosemary Essien ◽

Babasola W. Adu ◽

Sylvester U. Ogbogu ◽

Abdussalam Iysa ◽

...

Keyword(s):

Species Diversity ◽

Statistical Difference ◽

Habitat Degradation ◽

Anthropogenic Activities ◽

Ongoing Research ◽

Management Techniques ◽

Study Sites ◽

Abundance And Distribution ◽

Number Of Individuals ◽

Sweep Net

Introduction: Odonates are used as bio-indicators for monitoring habitat degradation both on terrestrial and aquatic ecosystem because of their sensitivity to anthropogenic activities. They serve an important role in the ecological food chain by consuming aquatic larvae and being in turn consumed by birds and various amphibians. This study is part of the ongoing research on the diversity of Odonate species of Nigeria. The objective is to determine the abundance and distribution of odonates in Akwa Ibom State and to compare the species diversity across the various sites in Akwa Ibom State. Methodology: Akwa Ibom state was divided into six areas namely Ikot Akpaden, Obio Akpa, Ikot Okoro, Ikot Udofia, Urua Udofia and Obio Ndot using biotypes and a study site was randomly selected in each area. Adult members were captured using a sweep net and were preserved for identification using morphological features. Results: A total of 767 odonates were collected at the six study sites representing 24 species, 16 genera and four families namely Libellulidae (77%), Coenagrionidae (21%), Calopterygidae (>1%) and Chlorocyphidae (>1%). Most of the species collected were members of family Libellullidae (77%) with Palpopleura lucia having the highest occurrence (41%) and found in all the sites. Family Calopterygidae and Chlorocyphidae had less than 1% population of the total individuals collected. Ikot Okoro had the highest number of individuals (238) and the least evenness (e^H/S=0.3292) while Ikot Akpaden, which had the least effect of anthropogenic intrusion had the largest diversity of Odonata species (H’=2.387). Obio Ndot had the most evenly distributed Odonata species (e^H/S=0.8028). There was no statistical difference in the occurrence of dragonflies across all study sites (p= 0.238). Conclusion: The high occurrence of family Libellulidae which are anthropogenic tolerant, and the absence of more highly localized species indicate that most of the study sites have been degraded and may not be fit for species with narrow niches. It is therefore vital to conserve the Odonata community by implementing proper forest management techniques.

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How size and trigger matter: analyzing rainfall- and earthquake-triggered landslide inventories and their causal relation in the Koshi River basin, central Himalaya

Natural Hazards and Earth System Science ◽

10.5194/nhess-19-1789-2019 ◽

2019 ◽

Vol 19 (8) ◽

pp. 1789-1805 ◽

Cited By ~ 4

Author(s):

Jianqiang Zhang ◽

Cees J. van Westen ◽

Hakan Tanyas ◽

Olga Mavrouli ◽

Yonggang Ge ◽

...

Keyword(s):

Causal Relation ◽

Anthropogenic Activities ◽

Slope Angle ◽

Field Investigation ◽

Central Himalaya ◽

Visual Interpretation ◽

Triggering Mechanism ◽

2015 Gorkha Earthquake ◽

Triggering Mechanisms ◽

Frequency Area

Abstract. Inventories of landslides caused by different triggering mechanisms, such as earthquakes, extreme rainfall events or anthropogenic activities, may show different characteristics in terms of distribution, contributing factors and frequency–area relationships. The aim of this research is to study such differences in landslide inventories and the effect they have on landslide susceptibility assessment. The study area is the watershed of the transboundary Koshi River in the central Himalaya, shared by China, Nepal and India. Detailed landslide inventories were generated based on visual interpretation of remote-sensing images and field investigation for different time periods and triggering mechanisms. Maps and images from the period 1992 to 2015 were used to map 5858 rainfall-triggered landslides, and after the 2015 Gorkha earthquake, an additional 14 127 coseismic landslides were mapped. A set of topographic, geological and land cover factors were employed to analyze their correlation with different types and sizes of landslides. The frequency–area distributions of rainfall- and earthquake-triggered landslides (ETLs) have a similar cutoff value and power-law exponent, although the ETLs might have a larger frequency of a smaller one. In addition, topographic factors varied considerably for the two triggering events, with both altitude and slope angle showing significantly different patterns for rainfall-triggered and earthquake-triggered landslides. Landslides were classified into two size groups, in combination with the main triggering mechanism (rainfall- or earthquake-triggered). Susceptibility maps for different combinations of landslide size and triggering mechanism were generated using logistic regression analysis. The different triggers and sizes of landslide data were used to validate the models. The results showed that susceptible areas for small- and large-size rainfall- and earthquake-triggered landslides differed substantially.

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