scholarly journals Biophysical factors influencing the choice of nesting sites by the green turtle (Chelonia mydas) on the Kenyan coast

2019 ◽  
Vol 18 (2) ◽  
pp. 45-55
Author(s):  
Fridah D. Obare ◽  
Robert Chira ◽  
Dorcus Sigana ◽  
Andrew Wamukota
Keyword(s):  
Human Activities ◽  
Vegetation Cover ◽  
Green Turtle ◽  
Chelonia Mydas ◽  
Management Tool ◽  
Factors Influencing ◽  
Biophysical Factors ◽  
Beach Width ◽  
Nesting Sites ◽  
Kenyan Coast

The green turtle (Chelonia mydas) is the most common sea turtle nesting along Kenya’s coastline. Varying biophysical factors influence choice of nesting sites where eggs are laid. This study was conducted between February and November 2016 and was designed to establish the relationship between numbers of C. mydas nests on the beach and biophysical variables such as vegetation cover, organic matter content (OMC), beach width, and beach slope. Multiple regression analysis was employed to assess the factors that contribute to the number of C. mydas nests on a beach. This analysis did not allow prediction of the number of nests in a statistically significant way (F (4, 26) = 0.094, p > 0.05, R = 0.120). However, there was a decrease in the number of nests with increased vegetation cover (b = - 0.013), OMC (b = - 8.114), beach width (b = - 0.089) and slope of the beach (b = - 0.352). Approximately 70% of nests occurred on beaches with medium and fine sand. Beaches with intense human activities were associated with high OMC which significantly affected the number of nests on the beach. It is therefore recommended that existing laws should be enforced to control beach development and human activities along the Kenyan coast to protect nest sites. Additionally, long term monitoring should be put in place to evaluate the impact of human disturbance on the favourable biophysical factors influencing the number of nests on a beach, as a management tool in the conservation of C. mydas. 

CONDITIONS OF HILLING HABITAT OF CHELONIA MYDAS (GREEN TURTLE) IN PANGUMBAHAN BEACH UJUNG GENTENG, SUKABUMI SELATAN

2019 ◽  
Vol 1 (02) ◽  
pp. 64-67
Author(s):  
Meilisha Putri Pertiwi ◽  
Suci Siti Lathifah
Keyword(s):  
Data Collection ◽  
Surface Temperature ◽  
Green Turtle ◽  
Data Retrieval ◽  
Distribution Patterns ◽  
Chelonia Mydas ◽  
Nesting Habitat ◽  
Beach Width ◽  
The Many ◽  
Pandanus Tectorius

Research on the condition of the nesting habitat of Chelonia mydas (green turtle) in Pangumbahan Beach, Ujung Genteng, South Sukabumi has been carried out. Data retrieval is done 6 times for 2 days, 27-28 November 2017 at 3 observation stations. The abiotic parameters measured include surface temperature and depth of 50 cm, surface humidity and depth of 50 cm, beach width, beach slope, and the size of sand grains. While the biotic parameters measured were density, relative density, the frequency of attendance, and distribution patterns of Pandanus tectorius (sea pandanus) vegetation. Based on the results of data processing, the biophysical conditions in Pangumbahan Beach are still suitable for the Chelonia mydas nesting habitat. It also got clear evidence of the many Chelonia mydas landings during the data collection.

Factors Influencing Loggerhead (Caretta caretta) and Green Turtle (Chelonia mydas) Reproductive Success on a Mixed Use Beach in Florida

2016 ◽  
Vol 15 (2) ◽  
pp. 238-248 ◽  
Author(s):  
Rebekah Lindborg ◽  
Emily Neidhardt ◽  
Blair Witherington ◽  
J. Rachel Smith ◽  
Anne Savage
Keyword(s):  
Reproductive Success ◽  
Green Turtle ◽  
Chelonia Mydas ◽  
Caretta Caretta ◽  
Factors Influencing ◽  
Mixed Use

Green turtle mitochondrial microsatellites indicate finer-scale natal homing to isolated islands than to continental nesting sites

2020 ◽  
Vol 643 ◽  
pp. 159-171 ◽  
Author(s):  
BM Shamblin ◽  
KM Hart ◽  
KJ Martin ◽  
SA Ceriani ◽  
DA Bagley ◽  
...  
Keyword(s):  
Green Turtle ◽  
National Park ◽  
Mitochondrial Control Region ◽  
Chelonia Mydas ◽  
Great Promise ◽  
Natal Philopatry ◽  
Dry Tortugas ◽  
Key West ◽  
Natal Homing ◽  
Nesting Sites

In highly mobile philopatric species, defining the scale of natal homing is fundamental to characterizing population dynamics and effectively managing distinct populations. Genetic tools have provided evidence of regional natal philopatry in marine turtles, but extensive sharing of maternally inherited mitochondrial control region (CR) haplotypes within regions (<500 km) often impedes identification of population boundaries. Previous CR-based analyses of Florida (USA) green turtle Chelonia mydas nesting sites detected at least 2 populations, but the ubiquity of haplotype CM-A3.1 among southern rookeries decreased the power to detect differentiation. We reassessed population structure by sequencing the mitochondrial microsatellite (short tandem repeat, mtSTR) in 786 samples from 11 nesting sites spanning 700 km from Canaveral National Seashore through Dry Tortugas National Park. The mtSTR marker subdivided CM-A3.1 into 12 haplotypes that were structured among rookeries, demonstrating independent female recruitment into the Dry Tortugas and Marquesas Keys nesting populations. Combined haplotypes provided support for recognition of at least 4 management units in Florida: (1) central eastern Florida, (2) southeastern Florida, (3) Key West National Wildlife Refuge, and (4) Dry Tortugas National Park. Recapture data indicated female nesting dispersal between islands <15 km apart, but haplotype frequencies demonstrated discrete natal homing to island groups separated by 70 km. These isolated insular rookeries may be more vulnerable to climate change-mediated nesting habitat instability than those along continental coasts and should be monitored more consistently to characterize population status. Broader application of the mtSTR markers holds great promise in improving resolution of stock structure and migratory connectivity for green turtles globally.

Green turtle ( Chelonia mydas (L.)) nesting activity at Aldabra Atoll

1979 ◽  
Vol 286 (1011) ◽  
pp. 255-263 ◽  
Keyword(s):  
Green Turtle ◽  
Chelonia Mydas ◽  
Human Settlements ◽  
Southwest Coast ◽  
Annual Variations ◽  
Recent Increase ◽  
Nesting Sites ◽  
Nesting Activity ◽  
Nesting Beaches

Green turtle ( Chelonia mydas ) nesting activity was indirectly monitored at the nesting sites at Aldabra by counting turtle tracks and nest pits during 11 months. Nesting activity took place throughout the year but a prolonged peak season was observed on southwest coast beaches between July and October, and less consistent peaks were observed for other beaches in February and March and from May to August. Estimations based on track and pit counts suggest that about 700 turtles nested at Aldabra during the year. Although annual variations may occur, this is similar to earlier estimates and does not suggest any recent increase. The distribution of turtle emergences among nesting beaches suggests that beaches fall into distinct nesting areas that are utilized to different extents. The distribution of turtle emergences on the largest beach suggests that human settlements may be reducing nesting there.

Factors Influencing the Breeding Distribution of the Peregrine Falcon in Victoria, Australia

1997 ◽  
Vol 24 (4) ◽  
pp. 433 ◽  
Author(s):  
W. B. Emison ◽  
C. M. White ◽  
V. G. Hurley ◽  
D. J. Brimm
Keyword(s):  
Volcanic Activity ◽  
Human Activities ◽  
Peregrine Falcon ◽  
Factors Influencing ◽  
Tree Hollows ◽  
Peregrine Falcons ◽  
Large Trees ◽  
Breeding Distribution ◽  
Nesting Sites ◽  
Water Vegetation

Since 1950, 199 nesting sites of peregrine falcons (Falco peregrinus) have been found in Victoria. Over half (51%) are on natural cliffs, 37% in trees and 12% on human-made structures and stone quarry faces. Most eyries on natural cliffs occur in the uplands (>200 m elevation) or along the coast. Tree eyries are located in hollows and in stick nests of other birds; most of these are within the distributions of red gums and belahs. Human-made structures (other than quarries) supporting nests include dam walls, silos, electricity pylons and buildings. Factors believed to influence the breeding distribution of peregrine falcons in Victoria are discussed; these include volcanic activity, landform and elevation, water, vegetation, climate, other birds and humans. The influence of human activities on the distribution of nesting peregrine falcons appears to have been positive. However, the future of the population of peregrine falcons nesting in tree hollows is of concern: it is likely that large trees with nest hollows will be destroyed or will fall from decay long before sufficient numbers of replacement trees are available.

scholarly journals SEBARAN LOKASI PENELURAN PENYU HIJAU (Chelonia mydas) DI PULAU SANGALAKI KEPULAUAN DERAWAN KABUPATEN BERAU

2016 ◽  
Vol 18 (2) ◽  
pp. 39
Author(s):  
Andi Ibrahim ◽  
Djumanto Djumanto ◽  
Namastra Probosunu
Keyword(s):  
Green Turtle ◽  
Sandy Beach ◽  
Environmental Parameters ◽  
Chelonia Mydas ◽  
Lunar Phase ◽  
The West ◽  
Conservation Area ◽  
Border Line ◽  
Spawning Frequency ◽  
Beach Width

Population of green turtle (Chelonia mydas) that laid their eggs in the Derawan Islands conservation area was declined due to various factors. The aim of this study was to determine the number of egg that was laid down into the nest for each green turtle parent and its correlation to shade, sandy beach width, and moon phase. The study was conducted from 24 January to 31 March 2015 in the Sangalaki Island. The observation of the broods stock was done by walking down the beach in the night to find out the broodstock that laid the eggs and counted the number. A sign was given to the nest of broodstock that finished laying the eggs. On the following day, nest excavation, egg collection, and the environmental measurement were conducted. Environmental conditions were measured include the depth of the nest, substrate temperature, the distance of the nest site to the shading trees and the border line of lowest tide. Data analysis was done descriptively by counting the number of eggs and environmental parameters. The results show that the average number of egg per nest was 97 items with the range of 45 - 127 items, the length of the carapace was 96 cm with a range of 86 - 107 cm, the average depth of the nest hole was 73 cm with a range of 56 - 87 cm. Broods stock of green turtle that laid more eggs would dig nest hole deeper, but there was no correlation between the carapace length and the number of the laid eggs. The average number of green turtle broods stock that lay eggs in the Sangalaki Island was 486 individual/ month with the range of 168 - 1085 individu/month. The west and east seasons affect the frequency of nesting and the laid eggs. The frequency of spawning occured throughout the year and the highest spawning frequency occured in August which coincides with the peak of the East Season. The frequency of spawning during the East Season was four times higher than during the West season. The frequency of green turtle landing was not affected by the lunar phase. Based on the location of laying egg, the beaches that were selected for laying egg are located in the northwest, northeast, and south parts of the Sangalaki Island. The Green turtle nests were commonly found in the vegetation shading areas (64%) than open sand areas (36%).

Structural description of sea turtle fibropapilloma

2020 ◽  
Vol 13 (3) ◽  
pp. 585-591
Author(s):  
Luana Melo ◽  
Isabel Velasco ◽  
Julia Aquino ◽  
Rosangela Rodrigues ◽  
Edris Lopes ◽  
...  
Keyword(s):  
Green Turtle ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Tumor Formation ◽  
Neoplastic Disease ◽  
Structural Description ◽  
Chemical Carcinogens ◽  
Epidermal Proliferation ◽  
Turtle Population ◽  
Bulky Mass

Fibropapillomatosis is a neoplastic disease that affects sea turtles. It is characterized by multiple papillomas, fibropapillomas and cutaneous and/or visceral fibromas. Although its etiology has not been fully elucidated, it is known that there is a strong involvement of an alpha - herpesvirus, but the influence of other factors such as parasites, genetics, chemical carcinogens, contaminants, immunosuppression and ultraviolet radiation may be important in the disease, being pointed out as one of the main causes of a reduction in the green turtle population. Thus, the objective of this article was to describe the morphology of cutaneous fibropapillomas found in specimens of the green turtle (Chelonia mydas), using light and scanning electron microscopy in order to contribute to the mechanism of tumor formation. Microscopically, it presented hyperplastic stromal proliferation and epidermal proliferation with hyperkeratosis. The bulky mass was coated with keratin, with some keratinocyte invaginations, that allowed the keratin to infiltrate from the epidermis into the dermis, forming large keratinized circular spirals. Another fact that we observed was the influence of the inflammation of the tumors caused by ectoparasites.

Discovery of a Major East Pacific Green Turtle (Chelonia mydas) Nesting Population in Northwest Costa Rica

2018 ◽  
Vol 17 (2) ◽  
pp. 169
Author(s):  
Luis G. Fonseca ◽  
Pilar Santidrián Tomillo ◽  
Wilbert N. Villachica ◽  
Wagner M. Quirós ◽  
Marta Pesquero ◽  
...  
Keyword(s):  
Costa Rica ◽  
Green Turtle ◽  
Chelonia Mydas ◽  
East Pacific

The Effect of Invertebrate Infestation on Green Turtle (Chelonia mydas) Nests on Kazanlı Beach, Mersın, Turkey

2020 ◽  
Vol 27 (5) ◽  
pp. 245-256
Author(s):  
Cemil Aymak ◽  
Aşkın Hasan Uçar ◽  
Yusuf Katılmış ◽  
Eyup Başkale ◽  
Serap Ergene
Keyword(s):  
Green Turtle ◽  
Hatching Success ◽  
Negative Relationship ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Faunal Composition ◽  
Independent Variables ◽  
Invertebrate Species ◽  
First Time ◽  
Nesting Season

In this study invertebrate infestation in green turtle (Chelonia mydas) nests were recorded for the first time for Kazanlı beach, Mersin, Turkey. For this aim, in 2006 nesting season, 294 natural intact green turtle nests were sampled to examine their contents and invertebrate infestation was found in 76 (25.85% of the total sampling green turtle nests). These infested nests were examined in terms of the invertebrate faunal composition. The specimens found in the green sea turtle nests were identified to order, family or genus levels and they were represented in 5 orders. These invertebrate groups are Elater sp. larvae (Elateridae; Coleoptera), Pimelia sp. larvae (Tenebrionidae; Coleoptera), Enchytraeidae (Oligochaeta), Cyrptostigmata (Acari), Oniscidae (Isopoda), Formicidae (Hymenoptera). Elater sp. was the most common invertebrate group in the green turtle nests. According to student t test, we found statistically significant differences between 7 independent variables and invertebrate species presence. Furthermore, logistic regression analysis explained that there is a negative relationship between hatching success rate and invertebrate species presence.

Pulmonary Blood Flow at Rest and during Swimming in the Green Turtle, Chelonia mydas

1992 ◽  
Vol 65 (2) ◽  
pp. 287-310 ◽  
Author(s):  
Nigel H. West ◽  
Patrick J. Butler ◽  
Richard M. Bevan
Keyword(s):  
Blood Flow ◽  
Green Turtle ◽  
Pulmonary Blood Flow ◽  
Chelonia Mydas
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