PERÍODO DE DESOVA E SUCESSO REPRODUTIVO DO TRACAJÁ Podocnemis unifilis TROSCHEL 1848 (TESTUDINES: PODOCNEMIDIDAE) NA VÁRZEA DA RDSM – MÉDIO SOLIMÕES, BRASIL

2008 ◽  
Vol 2 (1) ◽  
pp. 63-75
Author(s):  
Augusto Fachín Terán ◽  
Eduardo Matheus Von Mülhen
Keyword(s):  
Hatching Success ◽  
Management Program ◽  
Nesting Biology ◽  
Sand Beach ◽  
Podocnemis Unifilis ◽  
Turtle Population ◽  
Nesting Beaches ◽  
Conservation And Management ◽  
Tegu Lizard ◽  
Solimões River

In this study the nesting biology of Podocnem is unifilis was investigated from July to November 1998 at the Mamirauá Sustainable Development Reserve, located in the Solimões river, near Tefé, Amazonas, Brazil. Podocnemis unifilis nested in August and September, with the hatching event occurring in October and November. Nests were excavated in clay soils (67.5%), sand (25%), and leaf litter (7.5%). Hatching success was highest in the sand beach nests and lowest in the clay banks nests. Humans and the tegu lizard (Tupinambis) were the main egg predators. This turtle population can recover only by the protection of nesting beaches, educational programs for the in habitants of the Reserve, participation of the community in the conservation and management program , and permanent guarding of the nesting beaches by Instituto Brasileiro do Meio Ambiente e Dos Recursos Naturais Renováveis-IBAMA authorities.

The effect of on-shore light pollution on sea-turtle hatchlings commencing their off-shore swim

2017 ◽  
Vol 44 (2) ◽  
pp. 127 ◽  
Author(s):  
Zoe Truscott ◽  
David T. Booth ◽  
Colin J. Limpus
Keyword(s):  
Environmental Conditions ◽  
Green Turtle ◽  
Sea Turtle ◽  
Swimming Behaviour ◽  
Light Pollution ◽  
The World ◽  
Near Shore ◽  
Turtle Population ◽  
Nesting Beaches ◽  
Nesting Season

Context Off-shore recruitment impairment of sea-turtle hatchlings because of light pollution is a growing concern to conservation of sea-turtle population throughout the world. Studies have focussed on sea-turtle hatchling sea-finding behaviour, and ignored the possible effect that on-shore lighting might have on hatchlings after they have entered the sea. Aims We experimentally evaluated the effect that on-shore light pollution has on the swimming behaviour of green turtle hatchlings once they have entered the sea and begun swimming off-shore. We also estimated the decrease in off-shore recruitment of hatchlings as a result of light pollution disruption of the off-shore swim. Methods Hatchling misorientation rates were quantified by releasing marked hatchlings to the sea from different land-based locations adjacent to light-polluted beach areas under a variety of environmental conditions. The beach in light-polluted regions was then searched for marked hatchlings returning to shore from the sea. Key results Misorientation rates were highest in trials conducted during moonless nights (66.7% of trials had some hatchlings return to shore) and lowest during trials conducted during moonlit nights (no trials had hatchlings return to shore). Green turtle hatchling off-shore recruitment for the entire 2014–15 nesting season at Heron Island was estimated to decrease 1.0 –2.4% as a result of on-shore lights disrupting hatchling off-shore swimming behaviour. Conclusions On moonless nights, sea-turtle hatchlings after having successfully completed their journey from nest to sea and entered the sea can be lured back to shore again by shore-based light pollution and, this will decrease their off-shore recruitment success. Implications To ensure maximum off-shore recruitment of sea-turtle hatchlings, on-shore light pollution adjacent to nesting beaches needs to be minimised so as to minimise misorientation and disorientation of hatchlings while on the beach and in near-shore waters.

scholarly journals Impact of the fire ant pesticide AMDRO on loggerhead turtle nest productivity and seafinding orientation

2020 ◽  
Vol 41 ◽  
pp. 339-347
Author(s):  
HE Smith ◽  
SR Hoover ◽  
M Salmon ◽  
H Seaman ◽  
CM Coppenrath ◽  
...  
Keyword(s):  
Nest Site ◽  
Hatching Success ◽  
Loggerhead Turtle ◽  
Sea Turtle ◽  
Fire Ants ◽  
Fire Ant ◽  
Typical Application ◽  
Ghost Crabs ◽  
Emergence Success ◽  
Nesting Beaches

Invasive fire ants prey on a variety of organisms in the southeastern USA, including the pipped eggs and hatchlings within sea turtle nests. The granular fire ant bait AMDRO® (active ingredient hydramethylnon) is currently used at some rookeries to protect nests, but no studies have been conducted to determine if the pesticide negatively impacts the eggs or the hatchlings. We examined the pesticide’s effect on loggerhead (Caretta caretta) nests at Juno Beach, Florida, USA, specifically targeting how exposure affected hatching success, hatchling emergence success, and the ability of the turtles to orient visually from the nest to the sea. Pesticide granules were placed within a 30 cm diameter circle on the sand directly above the nest during the final 5-10 days of incubation, representative of its typical application at nesting beaches. Cornmeal granules in soybean oil and untreated natural nests served as controls. AMDRO had no significant effect on hatching success or emergence success, nor did it result in any deficiencies in hatchling orientation accuracy. However, the pesticide and cornmeal control attracted other predators (Atlantic ghost crabs and avian species), in addition to fire ants, to the nest site, thus revealing the nest’s location and potentially increasing its vulnerability. Consequently, we suggest that its usage may not be beneficial at sites where predators other than ants are especially abundant.

scholarly journals Nesting biology of the Hooded Crow Corvus corone cornix in a mixed residential–agricultural area in southern Sweden

Ornis Svecica ◽  
2010 ◽  
Vol 20 (2) ◽  
Author(s):  
Rebecca Hessel ◽  
Johan Elmberg
Keyword(s):  
Hatching Success ◽  
Canopy Cover ◽  
Forest Edge ◽  
Southern Sweden ◽  
Land Area ◽  
Nesting Biology ◽  
Significant Bias ◽  
Corvus Corone ◽  
Pine Trees ◽  
Hooded Crows

We studied 11 active and 29 old nests of Hooded Crows Corvus corone cornix in a mixed residential-farmland landscape (3.6 km2) in southern Sweden in 2009. The density of active nests was 3.06/km2 land area and 7.33/km2 forest area. Thirty-eight nests were in pine-dominated forest and two in private gardens. All nests (active and old) were in pine trees Pinus sylvestris, and sample plots around nest trees had the following characteristics (means): 350 tree stems/hectare, 1,487 bushes/ hectare, and canopy cover 8%. Distance to the nearest active Crow nest averaged 234 m, but variation was large. Mean distance from nests to nearest forest edge was 19 m and to the nearest inhabited building 68 m. Nests were placed near the tree top (mean height 11 m) in all cardinal directions but with a significant bias towards the south. Seven out of 11 (64%) active nests produced fledglings (mean 1.2 nestling/successful nest). Breeding success was higher in nests that were close to another crow nest. Compared with previous studies, hatching success was high but final fledgling production was low.

scholarly journals Olive Ridley Sea Turtle Hatching Success as a Function of Microbial Abundance and the Microenvironment ofIn SituNest Sand at Ostional, Costa Rica

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Vanessa S. Bézy ◽  
Roldán A. Valverde ◽  
Craig J. Plante
Keyword(s):  
Organic Matter ◽  
Costa Rica ◽  
Hatching Success ◽  
Quantitative Polymerase Chain Reaction ◽  
Organic Matter Content ◽  
Sea Turtle ◽  
High Density ◽  
Microbial Abundance ◽  
Olive Ridley ◽  
Nesting Beaches

Sea turtle hatching success at mass nesting beaches is typically lower than at solitary nesting beaches, presumably due in part to high rates of microbial metabolism resulting from the large input of organic matter from turtle eggs. Therefore, we tested the hypothesis that hatching success varies across areas of the beach in conjunction with differences in the physical nest environment and microbial abundance of in situ olive ridley sea turtle nests at Ostional, Costa Rica. We marked natural nests in high-density, low-density, and tidal-wash nesting areas of the beach and monitored clutch pO2and temperature throughout the incubation period. We quantified hatching success and collected samples of nest sand during nest excavations. We quantified microbial abundance (bacteria and fungi) with a quantitative polymerase chain reaction (qPCR) analysis. Hatching success was lower in nests with lower pO2, higher temperatures, higher organic matter content, and higher microbial abundance. Our results suggest that the lower oxygen within the nest environment is likely a result of the high microbial abundance and rates of decomposition in the nest sand and that these factors, along with increased temperature of clutches in the high-density nesting area, are collectively responsible for the low hatching success at Ostional.

scholarly journals CHARACTERISTIC INFLUENCE OF SAND BEACH ABOUT PERCENTAGE HATCHING SUCCESS OLIVE RIDLEY SEA TURTLE EGG ON CONSERVATION EFFORT SEA TURTLE IN BALI

2018 ◽  
Vol 5 (1) ◽  
pp. 36
Author(s):  
I Nyoman Yoga Parawangsa ◽  
I Wayan Arthana ◽  
Rani Ekawaty
Keyword(s):  
Hatching Success ◽  
Sea Turtle ◽  
Olive Ridley ◽  
Sand Beach ◽  
Lepidochelys Olivacea ◽  
Conservation Effort

Enam dari tujuh spesies penyu laut ditemukan di Indonesia dan tiga diantaranya melakukan proses peneluran di beberapa pantai di Bali, salah satunya adalah Penyu Lekang (Lepidochelys olivacea) yang masuk kedalam kategori terancam punah oleh IUCN. Penelitian ini bertujuan untuk mempelajari pengaruh perbedaan karaktertistik pasir pantai terhadap persentase penetasan telur Penyu Lekang pada media sarang semi alami. Keberhasilan penetasan pada sampel telur dilihat melalui variabel suhu pasir, suhu udara, kelembaban pasir, kelembaban udara, besar ukuran pasir, dan warna pasir. Persentase tertinggi dari keberhasilan penetasan sampel telur terjadi pada media penetasan pasir Pantai Pulau Serangan sebesar 97% dengan masa inkubasi 49 hari dan rentang suhu pasir berkisar antara 27,50o C, sampai 30,40o C. Sedangkan media pasir Pantai Saba dan Pantai Perancak memiliki persentase keberhasilan penetasan 87% dan 67% dengan masa inkubasi 46 hari. Perbedaan masa inkubasi tersebut dipengaruhi oleh variabel suhu pasir. Sementara perbedaan persentase keberhasilan penetasan dipengaruhi oleh perbedaan karakteristik pasir pada media penetasan. Dengan meningkatkan persentase keberhasilan penetasan yang tinggi, maka akan diperoleh tukik hidup yang lebih banyak untuk pemulihan populasi penyu dalam upaya untuk mendukung kegiatan konservasi penyu.

scholarly journals Geological control of Podocnemis expansa and Podocnemis unifilis nesting areas in Rio Javaés, Bananal Island, Brazil

2003 ◽  
Vol 33 (3) ◽  
pp. 445-468 ◽  
Author(s):  
Paulo Dias Ferreira Júnior ◽  
Paulo de Tarso Amorim Castro
Keyword(s):  
Grain Size ◽  
Hatching Success ◽  
Coarse Sand ◽  
Turtle Species ◽  
Podocnemis Unifilis ◽  
Topographical Distribution ◽  
Podocnemis Expansa ◽  
Point Bars ◽  
The Moment ◽  
Geological Control

The distribution of the nests of Podocnemis expansa (Amazon turtle) and Podocnemis unifilis (yellow-spotted side neck turtle) along the point bars of the Javaés River in Bananal Island, demonstrates a clear preference of these chelonians for differentiated geological environments, in respect to the morphology, grain size or height of the nests in relation to the level of the river. The topographical distribution and the differences in the grain size of the sediments that compose the point bars of the river, originated from the multiple sedimentary processes, and make possible the creation and separation of different nesting environments. Each turtle species takes advantage of the place that presents physiographic characteristics appropriate to the hatching success of their eggs. The superposition of the P. expansa and P. unifilis nest placement areas is rare. The P. expansa nests are concentrated on the central portion of the beaches where successive depositional sedimentary events produced sandy banks more than 3.3 m above the river water level. The P. unifilis nests are distributed preferentially in the upstream and downstream portions along the point bars where the sandy deposits rarely surpass 1.5 m at the moment of laying. P. expansa nests located on the beaches of fine to medium sized sand hatch in a mean of 68 days, while those incubated on beaches of medium to coarse sand size take a mean of 54 days to hatch.

Crocodylus johnstoni in the McKinlay River Area N. T, VI.* Nesting Biology

1983 ◽  
Vol 10 (3) ◽  
pp. 607 ◽  
Author(s):  
GJW Webb ◽  
SC Manolis ◽  
R Buckworth
Keyword(s):  
Clutch Size ◽  
Incubation Temperature ◽  
Management Program ◽  
Alligator Mississippiensis ◽  
Sensitive Period ◽  
Temperature Sensitive ◽  
Nesting Biology ◽  
Crocodylus Johnstoni ◽  
Hatching Time ◽  
Potential Strategy

In the McKinlay River area most female C. johnstoni mature at 74-78 cm snout-vent length (SVL), and 11-14 years of age, whereas maies are about 87 cm SYL and 16-17 years of age. Adult sex ratios in the field are lM:3-4F. There is a well defined, brief nesting period in late August and early September, and the nests are typical 'hole' nests excavated in sand or other friable substrates close to permanent water. Mean clutch size is 13.2 � 3.2 eggs (� SD) and mean egg dimensions are: length 6.64 � 0.26 cm, breadth 4.19 � 0.19 cm and weight 68.2 � 8.0 g. There is a variable but significant increase in egg size with clutch size, and large clutches of large eggs tend to be laid earlier in the nesting season than small clutches of small eggs. From 2 to 4% of eggs are infertile. Nest temperatures show considerable daily variation and baseline levels differ between shaded and exposed nest sites. Incubation times are temperaturedependent and range from 9 to 14 weeks. Females excavate nests at hatching time, but attend the nests little, ifat all, during incubation. Hatchlings are 11.2 � 0.5 cm SVL and weigh 42.0 � 6.1 g. Formulae for predicting egg and hatchling dimensions from each other are presented. A preliminary method for aging C. johnstoni embryos is described. Artificial incubation at 26�, 30� and 34�C, respectively, resulted in 0, 63% and 21% survival; at 26 and 34�C physically deformed embryos were common. Hatching success is correlated with the age at which eggs are transported to incubators. Sex determinantion is influenced by incubation temperature, and at temperatures we tested between 26 and 34�C, females predominated; males were produced at 31-32�C. Histological examination of females from high-temperature incubation (34�C) indicated slight hermaphroditic tendencies in two of 35 animals examined; their status remains to be clarified. The temperature-sensitive period for sex determination appears to be between 20 and 57 days of age (30�C equivalent ages), but this may well vary with incubation temperature, as in Alligator mississippiensis. Egg losses due to predators (particular varanid lizards) were estimated as 64%, although they may have been increased by our interference with nests. Eggs are also lost to flooding and overheating, and a 60-70% annual egg mortality may be common. In one experiment, hatchling mortality was estimated at 98% within the first year. An egg and/or hatchling harvest balanced by a proportional return to the wild of raised 1-year-olds (5% and 10% of eggs and hatchlings collected respectively) is a potential strategy through which sustained-yield harvesting could be introduced into a conservation-management program.

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