scholarly journals Hatchling sex ratio, body weight and nest parameters for Chelonia mydas nesting on Sugözü beaches (Turkey)

2014 ◽  
Vol 37 (2) ◽  
pp. 177-182
Author(s):  
Ç Kılıç ◽  
◽  
O. Candan ◽  
Keyword(s):  
Body Weight ◽  
Sex Ratio ◽  
Incubation Period ◽  
Green Turtle ◽  
Chelonia Mydas ◽  
Nest Temperature ◽  
Apparent Relationship ◽  
Embryo Sex ◽  
Female Bias ◽  
The Relationship

We investigated the relationship between nest parameters, hatchling body mass, and sex ratio of green turtle, Chelonia mydas, embryos and hatchlings at the temperate nesting rookery of Sugözü Beach (Adana–Turkey). Mean nest temperature and distance from the sea were correlated, while mean nest temperature and incubation period were inversely related. There was no apparent relationship between incubation period and hatchling mass. Hatchling and embryo sex ratios, determined by histological examination, showed a 70.5% and 93.5% female bias, respectively. There was no correlation between sex and body weight of hatchlings,

Natural temperature regimes for loggerhead and green turtle nests in the eastern Mediterranean

1998 ◽  
Vol 76 (4) ◽  
pp. 723-729 ◽  
Author(s):  
Y Kaska ◽  
R Downie ◽  
R Tippett ◽  
R W Furness
Keyword(s):  
Sex Ratio ◽  
Incubation Period ◽  
Green Turtle ◽  
Eastern Mediterranean ◽  
Loggerhead Turtle ◽  
Chelonia Mydas ◽  
Maximum Temperature ◽  
Diel Cycles ◽  
Mean Temperature ◽  
The Mean

Temperatures of green turtle (Chelonia mydas) and loggerhead turtle (Caretta caretta) nests on the beaches of northern Cyprus and Turkey were examined. Electronic continuous-temperature recorders programmed by computer were placed at the top, middle, and bottom of the nests. The sex of 3-7 hatchlings from each level was determined from gonadal histology. The maximum temperature increase during the incubation period was 9.6oC for both species. The mean temperature during the middle third of the incubation period is a good indicator of the sex ratio of the clutch. The percentage of female embryos increased with temperature, 50% being female at 29°C. The mean temperature over the entire incubation period is not a good indicator of sex ratio but can be used to predict the duration of incubation period. The temperature differences within the clutch were larger in loggerhead than in green turtle nests. Eggs at the top of the nest experienced generally warmer (up to 1.4°C) conditions than eggs at the bottom of the same nest, and this caused variation in sex ratio within nests. Over all nests, the sex ratio (percent female) of hatchlings was 91% at the top, 83% at the middle, and 69% at the bottom. There was considerable interbeach thermal variation. Marked diel cycles of up to 1.5°C were detected in loggerhead turtle nests but not in the deeper nests of green turtles.

scholarly journals Sex ratio of the green sea turtle Chelonia mydas (Testudines: Cheloniidae) hatchlings in the Guanahacabibes Peninsula, Cuba

2020 ◽  
Vol 68 (3) ◽  
Author(s):  
Randy Calderón-Peña ◽  
Ryan Betancourt-Avila ◽  
Elizabeth Rodríguez-Fajardo ◽  
Yoel Martínez-González ◽  
Julia Azanza Ricardo
Keyword(s):  
Sex Ratio ◽  
Incubation Period ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Nest Temperature ◽  
Data Loggers ◽  
Incubation Periods ◽  
The Mean ◽  
Study Sites ◽  
Incubation Temperatures

Introduction: Sea turtles have temperature dependent sex determination. The increase in global temperature leads to higher nest temperatures that can cause a prevalence of females, threatening the future of these species. Objective: The present work aims to evaluate the trend of incubation temperatures and the incubation period, as well as to estimate the sex ratio in nests of Chelonia mydas at Antonio and La Barca beaches, Southwestern Cuba, during the seasons from 2012 to 2018. Methods: Temperature data loggers were placed in green turtle nests with a representativeness that varied between the years analyzed. To assess the temporal variation of temperatures and incubation periods, a Kruskal-Wallis test was performed in each case. Sex ratio was estimated from its relation with temperature and incubation duration. Results: At La Barca beach, there was a 1.5 °C increase in the mean nest temperature from 2012 to 2018, although no differences were found in the period from 2015 to 2018. At Antonio beach, there is no trend since no differences were found in the mean nest temperature except for the years 2013 and 2017, which had lower temperatures than the other seasons. In both beaches mean nest temperature exceeded 30 °C in most of the years. As a result, there was a predominance of nests with incubation periods shorter than 55 days. With these values, a female hatchling production over 90 % is expected in both study sites. Conclusions: In correspondence with the registered temperature and incubation period values, most of the years reflect a hatchling production biased towards females in both beaches.

scholarly journals Sex Ratio and Growth Pattern of Coconut Crabs Birgus latro (Crustacea, Decapoda, Cianobitidae) in North Moluccas Province, Indonesia

Omni-Akuatika ◽  
2019 ◽  
Vol 15 (1) ◽  
pp. 1
Author(s):  
Rugaya Serosero ◽  
Sulistiono Sulistiono ◽  
Nurlisa A. Butet ◽  
Etty Riani
Keyword(s):  
Body Weight ◽  
Sex Ratio ◽  
Growth Pattern ◽  
B Value ◽  
Strongly Correlated ◽  
Thorax Length ◽  
Large Size ◽  
Cephalothorax Length ◽  
Relationship Of ◽  
The Relationship

Coconut crab (Birgus latro) is a crustacean that has a large size until four kilograms. The study  aimed to analyze sex ratio and growth pattern including the relationship of thorax length - body weight, thorax width - body weight and cephalothorax length plus rostrum - body weight in Daeo (Morotai Island), Laigoma (South Halmahera District) and Fitako (North Halmahera District). The sex ratio was determined using χ2 test and the growth pattern was tested by the b value through t test. The results showed sex ratio of 1: 0.9 in Daeo (n = 581), 1: 0.6 in Laigoma (n = 24), and 1: 2 in Fitako (n = 31). The relationship of thorax length, thorax width and cephalothorax length plus rostrum with body weight were strongly correlated (R2> 70%). The growth pattern of coconut crab in Daeo was negative allometric, while in Laigoma and Fitako were negative allometric and isometric.

scholarly journals Reproductive seasonality and environmental effects in green turtle (Chelonia mydas) nesting at Penang Island, Malaysia

2020 ◽  
Vol 100 (4) ◽  
pp. 645-650
Author(s):  
Sarahaizad Mohd Salleh ◽  
Hideaki Nishizawa ◽  
Shahrul Anuar Mohd Sah ◽  
Ahmed Jalal Khan Chowdhury
Keyword(s):  
Green Turtle ◽  
Annual Variation ◽  
Temporal Distribution ◽  
Chelonia Mydas ◽  
Monthly Basis ◽  
Fundamental Information ◽  
Higher Temperature ◽  
Lower Temperature ◽  
Response To Environmental Change ◽  
The Relationship

AbstractFor species with environmental sex determination, understanding the relationship between reproduction and environmental factors is important for predicting their reproductive output. Here, we study intra-annual variation in green turtle nesting during the 2010–2016 seasons at Penang Island (5°16′28″–5°28′15″N 100°10′52″–100°11′55″E), Malaysia. The additive modelling on a monthly-basis number of nests shows that fluctuation in the number of nests relates to temperature in addition to month of year, rather than precipitation. The number of nests tended to be higher in response to higher temperature during March–July, whereas the lower temperature during August–February also tended to result in a relatively higher number of nests. Concentration of nests during March–July resulted from a shorter inter-nesting interval during warm temperatures, whereas relatively low temperatures may homogenize the temporal distribution of the number of nests. This study provides fundamental information for green turtle nesting seasonality in response to environmental change.

The Relationship between Body Weight, Egg Weight, Incubation Period, Nestling Period and Nest Site in the Psittaciformes, Falconiformes, Strigiformes and Columbiformes.

1984 ◽  
Vol 32 (1) ◽  
pp. 57 ◽  
Author(s):  
DA Saunders ◽  
GT Smith ◽  
NA Campbell
Keyword(s):  
Body Weight ◽  
Incubation Period ◽  
Nest Site ◽  
Egg Weight ◽  
Incubation Periods ◽  
Nestling Period ◽  
The Relationship

The theory that landbirds which nest in holes tend to have larger clutches, longer incubation periods and longer nestling periods than those which nest in the open was tested by comparing the Psittaciformes, Columbiformes, Falconiformes and Strigiformes. It was found that among the graminivore-frugivores, the hole-nesting Psittaciformes produce larger clutches, have longer incubation and nestling periods than the open-nesting Columbiformes. Among the carnivore-insectivores, the Strigiformes (which predominantly nest in holes) produce larger clutches and have longer nestling periods than the open-nesting Falconiformes but there is no difference in incubation periods.

scholarly journals Inter- and Intra-Beach Thermal Variation for Green Turtle Nests on Ascension Island, South Atlantic

1995 ◽  
Vol 75 (2) ◽  
pp. 405-411 ◽  
Author(s):  
Graeme C. Hays ◽  
Colin R. Adams ◽  
Jeanne A. Mortimer ◽  
J.R. Speakman
Keyword(s):  
Green Turtle ◽  
Chelonia Mydas ◽  
South Atlantic ◽  
Nest Temperature ◽  
Long Beach ◽  
Thermal Variation ◽  
Green Turtles ◽  
North East ◽  
Ascension Island ◽  
East Bay

Nest temperatures for green turtles (Chelonia mydas) nesting on Ascension Island, South Atlantic (7°57'S 14°22'W), were examined. Temperature probes were placed into nests on two beaches, Long Beach (26 nests) and North East Bay (8 nests). Within these beaches there was relatively little thermal variation (SD of nest temperature was 0.32°C for Long Beach and 0.30°C for North East Bay). To examine inter-beach thermal variation temperature probes were buried at 55 cm on 12 beaches. Inter-beach thermal variation was large and was related to the beach albedo with the darkest beach (albedo, 016) being 4.2°C warmer than the lightest coloured beach (albedo, 0.73).

The relationship between hunting methods and sex, age and body weight in a non-trophy animal, the red fox

2009 ◽  
Vol 36 (2) ◽  
pp. 106 ◽  
Author(s):  
Piotr Tryjanowski ◽  
Tim H. Sparks ◽  
Robert Kamieniarz ◽  
Marek Panek
Keyword(s):  
Body Weight ◽  
Body Size ◽  
Sex Ratio ◽  
Vulpes Vulpes ◽  
Red Fox ◽  
Seasonal Differences ◽  
Evolutionary Changes ◽  
Potential Sources ◽  
The Relationship ◽  
Game Animals

Recently, hunting has represented a major source of mortality in game animals, including red fox, Vulpes vulpes, populations. Data from hunting studies have been used to explain evolutionary changes (body size, dental structure) in fox populations; however, knowledge of potential sources of bias in these kinds of data is lacking. Moreover, nature and game managers as well as conservationists have recently been seeking methods to limit European fox populations, which are increasing. In the present study in Polish farmland, we show that three different hunting methods (individual – lying in wait, with dogs at dens, with beating undergrowth to flush out foxes) resulted in differences in the age, sex ratio and body size of shot foxes. Taking account of seasonal differences in hunting methods used, shooting assisted by beating gave a higher proportion of male foxes, whereas individual hunting resulted in smaller foxes in shot samples. Hunting with dogs resulted in heavier female foxes, with the results being skewed towards females. Thus, this method may help limit the breeding capacity of a population and is recommended to assist in the control of red fox populations, at least in farmland areas.

scholarly journals KARAKTERISTIK SARANG PENYU HIJAU (CHELONIA MYDAS) DI PULAU KASIAK KAWASAN KONSERVASI PENANGKARAN PENYU PARIAMAN, SUMATERA BARAT

2018 ◽  
Vol 46 (2) ◽  
pp. 42
Author(s):  
Desi Nova Sari ◽  
Muhammad Fauzi ◽  
Eni Sumiarsih
Keyword(s):  
Green Turtle ◽  
High Tide ◽  
Chelonia Mydas ◽  
Nest Temperature ◽  
Thespesia Populnea ◽  
Quality Of Water ◽  
Substrate Texture ◽  
Water Edge ◽  
The Common

The research aimed to understand the nesting area characteristic of C. mydas in the Kasiak Island was conducted from March-April 2017, coincidence with the nesting time of green turtle. Observation of the nesting area of green turtle was conducted in the Northern, Southern, Western and Eastern parts of the island. Parameters studied were the slope of the beach, the distance between the water edge during the high tide and the nest, sand texture, types of vegetations around the nest, number of nests present and the quality of water around the island.  Results shown that the coast’s slope ranged from 1.74 to 2.890, the distance between the water edge during the high tide and the nest ranged from 1.17 to 1.70 m, the substrate texture was dominated by sand (> 90%), silt (3.4-7.25%) and clay (2-8%).  The nest temperature was 25-320C, nest humidity was 30-40% and the common vegetation was Thespesia populnea.  Quality of the water  around the Kasiak Island are as follows: temperature was 29-300C, salinity was from 33-34 ‰, current speedwas 0.4-0.5 m / s and pH was 8.

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