Nest Depth Research Articles

Adult Sex-Ratio Bias Does Not Lead to Detectable Adaptive Offspring Sex Allocation Via Nest-Site Choice in a Turtle With Temperature-Dependent Sex Determination.

Sex-ratio theory predicts that parents can optimise their fitness by producing offspring of the rare sex, yet there is a dearth of empirical evidence for adaptive sex allocation in response to the adult sex ratio (ASR). This is concerning, as anthropogenic disruption of the sex ratios of reproductive individuals threatens to cause demographic collapse in animal populations. Species with environmental sex determination (ESD) are especially at risk but may possess the capacity to adaptively influence offspring sex via control over the developmental environment. For example, reptiles with temperature-dependent sex determination (TSD) could conceivably choose nest sites with thermal characteristics that produce offspring of the rare sex. To test this hypothesis, we seeded three secure outdoor ponds with different sex ratios (~M:F 3:1, 1:1, and 1:3) of adult painted turtles (Chrysemys picta), a reptile species with TSD. We then quantified nesting traits that could influence nest temperature and thus offspring sex ratio, including nesting date, nest depth, and nest canopy cover. We found no directional relationship between the ASR treatments and any measured nest traits and thus rejected our hypothesis. Interestingly, increased maternal body size was associated with reduced nest canopy cover, and this trend was more pronounced in the biased ASR treatments. If adaptive sex allocation occurs in this system, it instead may manifest via maternal epigenetic predisposition of offspring sex or in response to a phenomenon other than the ASR.

Design and Experiment of Double-Nest Eye-Type Hole-Wheel Dense-Planting Wheat Dibbler

To address the problems of the inaccurate seeding rate and uneven seeding in the process of dense planting of winter wheat in Xinjiang, according to the physical characteristics of the wheat seeds and the agronomic requirements of the high-yield cultivation techniques for the winter wheat “well” type, a double-hole wheel-type densely planted wheat hole sower was designed and produced. Through theoretical design and research, the structural design of the overall hole seeder and its key components was completed. The findings indicated that 5–7 wheat seeds could be planted in each hole at a 9.2 mm nest depth and 610 mm3 nest volume, which was consistent with the “well”-type high-yield dense-planting cultivation technology’s need for 400,000–500,000 basic seedlings per mu. The rotation speed and the quantity of the wave guide teeth were used as test factors and the qualifying index, replay index, and missed sowing index were used as test indicators to create the two-factor, three-level central composite design center combination test. It was possible to derive the mathematical model connecting the test factors and test indexes. The regression model underwent multi-objective optimization using the Design-Expert 13 program to determine the optimal parameters: the qualifying index was 91.24%, the replay index was 6.14%, and the missed seeding index was 2.62% when the wave guide rail had four teeth and the seed drill rotated at a speed of 40 revolutions per minute. The best parameter combinations were used for a bench verification test, and the test indicated that the qualified index was 90.25%, the replay index was 4.59%, and the missed broadcast index was 5.16%. The results demonstrated that the densely planted wheat hole seeder performs well, satisfies the requirements for winter wheat dense-planting and sowing operations, and serves as a model for the densely planted wheat hole seeders that will be optimized in the future.

Partially non-ergodic ground motion model for the Bucaramanga seismic nest in Northern South America (NoSAm Nest GMM)

The Bucaramanga seismic nest has the highest concentration in volume of intermediate depth seismic events with light and moderate magnitudes (Mb > 4.8) worldwide. Despite the nest depth (Zhypo ≥ 100 km), these events play a crucial role in the seismic hazard assessment for several cities in northern South America (NoSAm), particularly those situated close to their epicenters. Moreover, these earthquakes are widely felt across the country, even hundreds of kilometers away from the nest. This paper assesses the performance of commonly used subduction intraslab Ground Motion Models (GMMs) in predicting the updated nest database gathered and processed by the Colombian Geological Survey. This analysis confirms the necessity of a partially non-ergodic ground motion model for estimating the spectral accelerations produced by Bucaramanga nest earthquakes in northern South America. The GMM presented herein is the first model developed specifically for seismic nests in the region and is conceived as a regionalization of the recent NGA-Sub Abrahamson and Gülerce (Earthq Spectra 38(4):2638−2681, 2022) GMM. Additionally, we provide estimates of the variance components at both the earthquake and station levels and compare the developed GMM with the spectral accelerations recorded for typical earthquakes, for the highest magnitude earthquake in the database, and for a recent Bucaramanga nest earthquake having a moment magnitude over 5.

THE WORD-FORMATION POTENTIAL OF THE WORD-FORMATION NEST WITH THE ORIGINAL WORDS "ZAN"

In this article, the word-formation potential of the word-formation nest with the original word "zan" (law) is determined based on the analysis of the word-formation nest formed from this word. The works of such scientists as N. Oralbai, O. Tokkozhaeva, A. Salkynbai, K. Kurmanaliev, B. Yessimseitov, N. Kokisheva, T. Tokhtarov, D. Kuandykov, who studied the problem of the word-formation nest, are considered. A mandatory element of the word–formation nest is the source word. The original word, it is commonly called the top, plays a very important role in the formation of the word-formation nest, affects its structure, the semantic relations of single-root words in the structure of the nest. It is part of all derived words, determines their meaning. To date, the vertices in the nests can be: nouns, adjectives, numerals, verbs, adverbs. The article analyzes one of the main concepts of legal discourse – the word "law" from the point of view of the word-formation nest. 43 derived words are determined, 24 of them are terms formed in the word-formation nest by synthetic, analytical, lexico-semantic methods of word formation. The identification of synchronous word-formation potential requires the determination of the volume, depth of word–formation nest. At the same time, it was found that the volume of analyzed word-formation nest and their structure depend primarily on the volume of the lexico-semantic space of the source words. The more extensive the system of meanings a word has, the more voluminous its word-formation nest. The dependence of the volume of word-formation nest on the frequency of use of their source words was also revealed. The word-formation potential of the original words is also revealed by the depth of the word-formation nest, which means the number of syntagmatic, paradigmatic units in this particular word-formation nest. Linguistic data are collected from the Explanatory Dictionary of the Kazakh language, the Dictionary of Legal Terms and the Textbook Customs Law of the Republic of

TYPES OF LEXICAL AND GRAMMATICAL TRANSFORMATIONS IN LITERARY TRANSLATION

In this article, the word-formation potential of the word-formation nest with the original word "zan" (law) is determined based on the analysis of the word-formation nest formed from this word. The works of such scientists as N. Oralbai, O. Tokkozhaeva, A. Salkynbai, K. Kurmanaliev, B. Yessimseitov, N. Kokisheva, T. Tokhtarov, D. Kuandykov, who studied the problem of the word-formation nest, are considered. A mandatory element of the word–formation nest is the source word. The original word, it is commonly called the top, plays a very important role in the formation of the word-formation nest, affects its structure, the semantic relations of single-root words in the structure of the nest. It is part of all derived words, determines their meaning. To date, the vertices in the nests can be: nouns, adjectives, numerals, verbs, adverbs. The article analyzes one of the main concepts of legal discourse – the word "law" from the point of view of the word-formation nest. 43 derived words are determined, 24 of them are terms formed in the word-formation nest by synthetic, analytical, lexico-semantic methods of word formation. The identification of synchronous word-formation potential requires the determination of the volume, depth of word–formation nest. At the same time, it was found that the volume of analyzed word-formation nest and their structure depend primarily on the volume of the lexico-semantic space of the source words. The more extensive the system of meanings a word has, the more voluminous its word-formation nest. The dependence of the volume of word-formation nest on the frequency of use of their source words was also revealed. The word-formation potential of the original words is also revealed by the depth of the word-formation nest, which means the number of syntagmatic, paradigmatic units in this particular word-formation nest. Linguistic data are collected from the Explanatory Dictionary of the Kazakh language, the Dictionary of Legal Terms and the Textbook Customs Law of the Republic of Kazakhstan.

Short-term resilience to climate-induced temperature increases for equatorial sea turtle populations.

Projection models are being increasingly used to manage threatened taxa by estimating their responses to climate change. Sea turtles are particularly susceptible to climate change as they have temperature-dependent sex determination and increased sand temperatures on nesting beaches could result in the 'feminisation' of hatchling sex ratios for some populations. This study modelled likely long-term trends in sand temperatures and hatchling sex ratios at an equatorial nesting site for endangered green turtles (Chelonia mydas) and critically endangered hawksbill turtles (Eretmochelys imbricata). A total of 1078 days of sand temperature data were collected from 28 logger deployments at nest depth between 2018 and 2022 in Papua New Guinea (PNG). Long-term trends in sand temperature were generated from a model using air temperature as an environmental proxy. The influence of rainfall and seasonal variation on sand temperature was also investigated. Between 1960 and 2019, we estimated that sand temperature increased by ~0.6°C and the average hatchling sex ratio was relatively balanced (46.2% female, SD = 10.7). No trends were observed in historical rainfall anomaliesand projections indicated no further changes to rainfall until 2100. Therefore, the sex ratio models were unlikely to be influenced by changing rainfall patterns. A relatively balanced sex ratio such as this is starkly different to the extremely female-skewed hatchling sex ratio (>99% female) reported for another Coral Sea nesting site, Raine Island (~850 km West). This PNG nesting site is likely rare in the global context, as it is less threatened by climate-induced feminisation. Although there is no current need for 'cooling' interventions, the mean projected sex ratios for 2020-2100 were estimated 76%-87% female, so future interventions may be required to increase male production. Our use of long-term sand temperature and rainfall trends has advanced our understanding of climate change impacts on sea turtles.

Nest size parameters of Great Tits and Blue Tits: a long-term study

Nest construction behaviour is widespread among bird species. Causes for the occurrence and great variation in nest characteristics between and within populations are still poorly understood. In this study, we present results concerning nest parameters of Great Tits Parus major and Blue Tits Cyanistes caeruleus over a period of 11 breeding seasons (2012–2022) in two structurally and floristically contrasting study areas in central Poland. The nest depth differed significantly between young (yearlings) and older females (≥ 2 years after hatching) in Blue Tits (but not in Great Tits): younger females tended to build deeper nests. The size and mass of the nest were very variable in both tit species. Blue Tits tended to build deeper and heavier nests than Great Tits. The depth of the nest was positively correlated with nest mass in Great and Blue Tits. In Great Tits, the nest mass (but not nest depth) differed between study sites, with nests being heavier in the forest and the nest depth differed between years; in Blue Tits, there was an interaction between year and study site that affected nest depth. The nest mass (but not depth) from the same nestbox tended to be consistently similar within species in Great Tits and Blue Tits. We argue that the large amount of variation in nest parameters between and within populations of both tit species may be a multi-factorial result of female age, breeding area, breeding season, individual predispositions and the size of the nestbox/natural hole.

Altitudinal Variations in the Mound Nests of Termites <i>Odontotermes Wallonensis</i> and <i>O. obesus</i>

The nesting form of the mound nest of species Odontotermes wallonensis(E. Wasmann) and Odontotermes obesus (Rambur) was studied in hilly and tropical deciduous forest area of Kakoijana Reserved Forest of Abhayapuri (Bongaigaon district). It was compared to the plain village forest area of Baksa district (Bajegaon Pather). The morphometric measurement such as height, circumference, depth of the mound nest and the royal chamber from the surface of the ground was recorded along with weight of fungus garden and queen and their sections were photographed. The outcomes revealed that the location of the nest influences the structure and characteristics of the nest. The young and established mound nests of species O. obesus and O. wallonensis in hilly and plain area had different shape, sizes and colour. The shade of the fungus garden was buff i.e., yellowish brown in young nest whereas it was blackish brown in established nests. The queen termite and the royal chamber unable to be excavated were in hilly area as compared to the plain area. In some of the mound nests, no traces of the queen termites and rest of the castes were observed; and the mound was dead i.e., abandoned after the death of queen termite.

Environmental and Nesting Variables Associated with Atlantic Leatherback Sea Turtle (Dermochelys coriacea) Embryonic and Hatching Success Rates in Grenada, West Indies

Annual monitoring of leatherback sea turtle (Dermochelys coriacea) nesting grounds in Grenada, West Indies has identified relatively low hatch rates compared to worldwide trends. This study investigated the impact of selected environmental variables on leatherback sea turtle embryonic development and hatching success rates on Levera Beach in Grenada between 2015-2019. The mean number of nests per year and eggs per nest were 667.6 ± 361.6 and 80.7 ± 23.0 sd, respectively. Within excavated nests, 35.6% ± 22.0 sd of eggs successfully developed embryos and 30.6% ± 22.6 sd of eggs successfully hatched. The number of eggs per nest, along with embryo and hatching success rates, differed by nesting year. Embryo development success rate was associated with nest location, and both embryo development and hatching success rates were positively associated with nest depth and negatively associated with the percentage of eggs exhibiting microbial growth and with the presence of inspissated yolk. There was no embryo development or hatchling success association with month of the nesting season, distance from the high-water mark, distance from vegetation, nor maternal carapace length. The mean nest temperature was 31.7 °C ± 1.64 sd and mean temperatures during the middle third of egg incubation suggest clutches are highly skewed towards a preponderance of female hatchlings. Histopathologic findings in hatchling mortalities included severe, acute, multifocal, heterophilic bronchopneumonia with intralesional bacteria in 4/50 (8%) hatchlings. Data from this study guide conservation strategies by identifying risk factors and further avenues of research needed to support reproductive success of leatherback sea turtles in Grenada and the greater Caribbean region.

Effect of moisture, temperature, and maternal influence on the hatching, phenotype, and performance of hawksbill turtles Eretmochelys imbricata

Hawksbill turtles are considered Critically Endangered. An understanding of how nest microenvironment (moisture and temperature) and maternal characteristics can influence embryonic development, hatching success, phenotype, and hatchling performance is needed to ensure effective conservation management. We undertook controlled egg incubations at different temperatures and relative humidities. Additionally, we sampled temperatures at natural nests with data loggers, and relative humidity of the sand at nest depth, to determine the conditions that eggs experienced naturally. We varied relative sand humidity (RSH) percentages (30, 50, 75, and 100%) at a constant incubation temperature of 29.5°C. We also assessed constant temperature incubations at 25, 29.5, and 34°C with 75% RSH. Incubation at 29.5°C resulted in successful hatching (73.3%), whereas temperatures of 25 and 34°C prevented hatching. However, hatching in natural nests occurred even between 34 and 36°C, provided that eggs were exposed to these temperatures <20% of the entire period of incubation, and only towards the end of incubation. Controlled incubation at 30% RSH prevented hatching. RSH linearly affected hatching success, phenotype, and performance of hatchlings: eggs incubated at 100% RSH had the greatest hatching success and produced the heaviest, largest, and fastest hatchlings. RSH correlated positively with sand depth on the beach, so that ≥75% RSH is ensured at the average depth of natural nests (~39.2 cm), resulting in successful hatching (74.3 ± 34.7%). The controlled incubation showed that temperature and hydric conditions had the most significant impact on hatching success, hatchling phenotype (size and weight), and hatchling performance. Maternal characteristics, however, were slightly less important. These results suggest that the impact of moisture should be taken into consideration in hawksbill turtle conservation projects. The thermal and hydric environments experienced by developing embryos should also be considered when evaluating how climate change affects marine turtles.

龙凤保护区普通鸬鹚巢特征与巢址选择

PDF HTML阅读 XML下载 导出引用 引用提醒 龙凤保护区普通鸬鹚巢特征与巢址选择 DOI: 10.5846/stxb202008062047 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 第三次新疆综合科学考察项目(2021xjkk1200);教育部中央高校基本科研业务费(2572019BE04);大学生创新计划项目(201910225314) Nests characteristics and nest-site selection of Common Cormorant in Longfeng Reserve, China Author: Affiliation: Fund Project: The Third Xinjiang Comprehensive Scientific Investigation Program(2021XJKK1200); Fundamental Research Funds for the Central Universities of the Ministry of Education(2572019BE04); Innovation Program for College Students(201910225314) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:巢址选择作为鸟类繁殖的重要环节,是动物生态学关注的热点问题。为探究中等体型湿地鸟类普通鸬鹚的巢址选择偏好及主要影响因子,2019年4-10月运用秩和检验、主成分分析等方法对黑龙江龙凤保护区内普通鸬鹚巢特征、巢址特征、巢址选择进行了分析。结果表明:(1)普通鸬鹚偏好选择巢树乔木相对较矮(P<0.05)、周围灌木相对较矮(P<0.01)、植被盖度较低(P<0.01)、人为干扰距离较远(P<0.01)、距水面距离较远(P<0.05)的区域筑巢;(2)影响普通鸬鹚巢址选择的因子为隐蔽因子(20.634%)、巢稳定因子和干扰因子(27.614%)、植被因子(13.901%)、水因子(5.782%)和巢忠诚度(5.069%)。进一步分析表明:(1)普通鸬鹚倾向选择粗细适中的巢材,巢材来源于优势植被,巢深随纬度增高而增大;(2)巢区植被特征符合普通鸬鹚对能量支配的权衡,巢区粪便对该特征有强化作用。基于上述结果,建议龙凤保护区在巢区内加种高大乔木。 Abstract:Nest site selection, as an important part of bird breeding, is a hot issue in animal ecology. In order to explore the nest site selection preference and the main influencing factors of Common Cormorant, a medium-sized wetland bird, we analyzed the nest characteristics, nest site characteristics and nest site selection of Common Cormorant in Longfeng Reserve of Heilongjiang Province from April to October in 2019 by Mann-Whitney U test and principal component analysis. The results showed that: (1) Common Cormorants preferred to nest in the areas where the trees were relatively short (P<0.05), surrounding shrubs were relatively short (P<0.01), vegetation coverage was low (P<0.01), the distance from human disturbance was far (P<0.01), and the distance from water surface was far (P<0.05). (2) The influencing factors of nest site selection were concealment factor (20.634%), nest stability factor and disturbance factor (27.614%), vegetation factor (13.901%), water factor (5.782%) and nest loyalty factor (5.069%). Further analysis showed that: (1) The Common Cormorants tended to choose nest materials of moderate thickness, which came from dominant vegetation, and nest depth increased with increasing latitude. (2) The characteristics of Common Cormorants nest vegetation were consistent with the trade-offs of energy domination, and the feces in nest enhanced the characteristics. Based on above results, it is suggested that the tall trees should be planted in the nest area of Longfeng Reserve. 参考文献 相似文献 引证文献

NESTING ECOLOGY, TERRITORIALITY AND BROOD CARE IN RED-VENTED BULBUL, Pycnonotus cafer stanfordi DEIGNAN AT LUMAMI, ZUNHEBOTO DISTRICT, NAGALAND

In the present study we have examined nesting ecology, territorial integrity and brood care strategy in red-vented bulbul, Pycnonotus cafer stanfordi Deignan at Lumami (26oN). Observations recorded on 300 nests from 2017-2021 showed that birds prepared loose textured cup-shaped nests between spring equinox and autumnal equinox with a seasonal peak appearing during May/June. Nests were made using locally available grasses within 4.50±0.25 (Table 1) days lurking into deep foliage of host plants/trees. Prior to fixing their nest, mates were seen ascertaining suitability of the site by eliciting motions of building a nest without nesting material. Entry and egress routes to the nesting sites were not common. Clutch size consisted of 2-3 pinkish-brown eggs which appeared to be regulated during nest construction. At rim level, an average diameter of nest with 3 eggs measured at 67.62±0.42 mm (n=240) which was significantly more (p&lt;.001) as compared with nest with only 2 eggs (62.83±0.24 mm; n=60). Conversely, mean depth of nest with 3 eggs measured at 37.39±0.11 mm (n=240) and was significantly less (p&lt;.001) as compared with nest holding only 2 eggs (42.40±0.23 mm; n=60). Basement area of nest with 2 eggs measured at 117.80±1.05 cm2 which was significantly less (p&lt;.001) as compared to basement area of nest with 3 eggs (150.34±3.15 cm2). The bird was noticed to exhibit a strong tendency to safeguard its nest and brood against predators. Brood care began with deposition of first egg which grew progressively with completion of clutch size, incubation and hatching. Persistent predation pressure amidst incubation has led to the heightening of security concerns of mates and a consequent decline in foraging timings had triggered rejection of eggs and hatchlings appearing late. Fledglings were nourished and cared by parent birds until they had learnt to fetch nourishment for themselves and evade predation. It is suggested that red-vented bulbul is highly territorial and has a strong tendency to defend its brood vis-à-vis extending its territorial boundary.

Sex ratio estimation for Green Turtle, Chelonia mydas, hatchlings at Akyatan Beach, Turkey

Marine turtles have temperature-dependent sex determination and the increase in global temperature could cause female predominance due to higher nest temperatures. The temperatures of 163 Green Turtle nests were measured with temperature data loggers at Akyatan beach, Turkey. The mean entire incubation duration (EID) and the sexdetermination period (SPD) temperatures of the Green Turtle nests were 31.03°C and 30.81°C respectively. The mean incubation duration (ID) was 51.94 days. Significant differences were found in terms of ID among nesting seasons, and ID had a negative relationship with the nesting seasons. The mean ID for the nesting seasons had a statistically significant negative correlation with EID temperature. The mean female ratio estimation for the nesting seasons was 89%. Significant differences were found among the female ratio estimations for the nesting seasons. The mean female ratio estimation for the nesting seasons showed a statistically significant negative correlation with ID and nest depth. Long-term temperature increase may pose a threat to the Green Turtle populations.

Reproductive Dynamics of an Isolated Population of American Crocodiles (Crocodylus acutus) Based on Long-term Monitoring Data

The American Crocodile (Crocodylus acutus) is still considered Vulnerable, with some populations remaining depressed and showing little evidence of recovery. An understanding of the reproductive dynamics and parameters of C. acutus is essential for its conservation and management. Although the knowledge of C. acutus reproductive ecology has greatly increased during recent years, some critical parameters such as breeding effort (i.e., proportion of adult females that nest each year in a population) remain poorly known. Herein we analyzed 14 yr of reproductive data from a C. acutus population in a Mexican atoll to better understand its reproductive dynamics in space and time. We estimated the number of reproductive females in the population and in each nesting area, compared nest characteristics and clutch parameters among nesting areas, and determined female breeding effort and breeding frequency (i.e., proportion of years that an adult female nested). We estimated that 35 reproductive female C. acutus inhabit the main island of the atoll, distributed among 12 nesting areas. The annual female breeding effort ranged from 27.3–60.6% and the breeding frequency of 15 selected females ranged from 57.1–92.3%. Breeding effort depends on the breeding effort in preceding years. We also found significant differences in reproductive attributes (i.e., number of nests, nest–water distance, nest depth, clutch size, and nesting success) among nesting areas that we explain by the quality of those habitats for crocodile nesting and by territorial behavior of females.

Breeding ecology of the Asian pied starling (Gracupica contra) at Jahangirnagar University campus, Bangladesh

The breeding ecology of the Asian pied starling (Gracupica contra) was studied between 2015 and 2016 at Jahangirnagar University (JU) campus to document the breeding period, nests and nest-site selection, clutch size, egg morphology, hatching and breeding success. Breeding activities of starling in JU campus started in late February and continued to early September. A total of 105 nests were recorded in two breeding seasons. The nests were loosely constructed out of straw into the shape of a dome with an entrance on the side. The average nest depth was 18±4.5 cm (n=21, range =12-29 cm) with a mean entrance diameter of 7.6±1.3 cm (n=21, range= 6-10 cm). Most of the nests (98%) were found in trees (98%), only 2% of them were found on the electric poles (2%). Overall, 17 tree species were utilized by the starlings for nesting and majority of the nests were found in Albizia procera (n=25), Gmelina arborea (n=17), and Swietenia mahagoni (n=13). The Asian pied starling nested between 3 and 18 meters (mean =10.3±3.5m) above the ground. Clutch size varied from 2 to 6 eggs with a mean size of 3.8±1.2 (n=21). Eggs were glossy blue with an average dimension of 26.6±1.6 mm×19.3±0.33 mm (n=35). Both sexes took part in incubation by rotation and fed the young. The average incubation and nestling period were 17.3±3.6 days (n=19, range=14-30) and 23±1.5 days (n=16, range=20-25), respectively. Out of the 80 eggs monitored, 63 eggs successfully hatched and 52 chicks reached their fledgeling stage, resulting in a breeding success of 65%.&#x0D; Jahangirnagar University J. Biol. Sci. 10(1 &amp; 2): 49-57, 2021 (June &amp; December)

Karakteristik dan Preferensi Habitat Penyu dalam Membuat Sarang Alami untuk Peneluran

This study aims to examine the characteristics and environmental factors of turtles' preferences in making their natural nests. The method used is the descriptive quantitative method. The results showed that there were two types of turtles found during the observation, namely the green turtle (Chelonia mydas) and the hawksbill turtle (Eretmochelys imbricata). Measurements and observations of the characteristics of the 14 nesting points showed that the diameter and depth of the green turtle's nest were larger than those of the hawksbill turtle. Both types of turtles have a preference for nesting areas on sloping beaches with temperatures of 28-30ºC and humidity of 76-89%, as well as being around vegetation in the form of sea pine (Casuarina equisetifolia), sea oyster (Gynura sp), sea pandanus (Pandanus odorifer), sea kangkung (Ipomea peltate) and sea hibiscus (Thespesia populnea). In conclusion, temperature, humidity and types of vegetation around the nest determine the turtle's preference in making natural nests for laying eggs.&#x0D; Keywords: Nest Characteristics, Conservation, Turtle, Habitat Preference

Tingkah Laku Bertelur Burung Maleo (Macrochepalon maleo S. Muller) di Taman Nasional Lore Lindu (TNLL) Blok Saluki

Knowledge of behavior is very important to maintain the habitat of the maleo as an endemic animal to Sulawesi that must be preserved. Research takes place in March-December 2021. The research location is in the Saluki Lore Lindu National Park, Central Sulawesi Province. The study took place in March-December 2021. The findings targeted in the study are: (1) Information on egg-laying behavior, (2). When laying eggs, (3) After laying eggs, (4) Determining the length of time for laying eggs, (5) Physical characteristics of the nest and vegetation. The research method used the survey method. Observations of maleo bird activity were carried out every day for 3 months in the egg-laying season from May to July. The results showed that the physical condition of the average nest depth was 67.78 cm, the average nest width was 52.78 cm, the average nest temperature was 33.44°C, the nest humidity was 76.11% and, the soil acidity (pH) with an average of 6.35. The vegetation found at the nesting site consisted of 18 species. The maleo maleo bird's egg-laying behavior activities are playing, snooping (observation), and making a trick hole. There were four activities of female maleo bird laying behavior, namely playing, digging holes for laying eggs, lurking, making trick holes and laying eggs. The duration of time needed by male maleo birds when playing, snooping, making holes, until the female finishes laying eggs, which takes 92 minutes. While the female takes 84 minutes.

Do soil density and humidity affect nest‐founding in leaf‐cutting ant queens?

AbstractThe habitat choice of nest sites by founding queens of leaf‐cutting ants varies with abiotic factors such as temperature, soil density, and soil humidity. In this study, we tested the hypothesis that soil density and moisture affect excavation effort (i.e., excavation period, excavated soil amount, initial nest depth, initial chamber volume, and mortality) in queens of the leaf‐cutting ant Atta sexdens (L.) (Hymenoptera: Formicidae). Queens were placed in experimental areas in three natural soils in Brazil with varying density and moisture content. The excavated soil was collected, dried, and weighed, and digging period, nest depth, chamber volume, and queen mortality were evaluated after nest establishment. In artificially shaded habitats (less dense and more humid soil), the establishment of queens was greater, the period of nest foundation was shorter, and excavated soil amount, nest depth, and volume of the initial chamber were greater than in forest and pasture habitats (denser and drier soils). Also, queen mortality was lower in less dense, more humid soil. This indicates a trade‐off between maximizing the depth of the nest, to increase protection against inadequate environmental conditions, and minimizing energy expenditure during excavation, affecting their survival.

The ideal habitat for leaf-cutting ant queens to build their nests

Queens of Atta sexdens Forel (Hymenoptera: Formicidae) face biotic and abiotic environmental factors in the environment while establishing their nests. Biotic factors such as predation, microbial pathogens, successful symbiotic fungus regurgitation, excavation effort and abiotic factors such as radiant sunlight, temperature, density, and soil moisture exert selection pressures on ant queens. Biotic factors such as temperature and solar irradiation affect the survival of the initial colony differently, in different environments in the field. Queens of the leaf-cutting ant A. sexdens, were installed in sunny and shaded conditions to test this hypothesis. Two hundred A. sexdens queens were collected and individualized in two experimental areas (sunny and shaded), each in an experimental area (25 m2) in the center of a square (50 × 50 cm). Temperature, irradiance, nest depth, rainfall and queen mortality were evaluated. Atta sexdens colony development was better in the shaded environment, and the depth and volume of the initial chamber, fungus garden biomass and number of eggs, larvae, pupae and workers were greater. The queen masses were similar in both environments but mortality was higher in the sunny environment. The worse parameter values for A. sexdens nests in the sunny environment are due to the greater solar irradiance, increasing the variation range of the internal temperature of the initial chamber of the nest. On the other hand, the more stable internal temperature of this chamber in the shaded environment, is due to the lower incidence of solar irradiance, which is also more advantageous for queen survival and the formation and development of A. sexdens colonies. Shaded environments are a better micro habitat for nesting A. sexdens than sunny ones.

Macro- and Microhabitat Predictors of Nest Success and Hatchling Survival in Eastern Box Turtles (Terrapene carolina carolina) and Spotted Turtles (Clemmys guttata) in Oak Savanna Landscapes

Differing selection pressures on stationary nest contents compared to mobile offspring mean that the nest-site characteristics resulting in the highest nest success may not be the same characteristics that result in the highest survival of juveniles from those nests. In such cases, maternal nest-site choice may optimize productivity overall by selecting nest sites that balance opposing pressures on nest success and juvenile survival, rather than maximizing survival of either the egg or the juvenile stage. Determining which macro- and microhabitat characteristics best predict overall productivity is critical for ensuring that land management activities increase overall recruitment into a population of interest, rather than benefiting one life stage at the inadvertent expense of another. We characterized nest-site choice at the macro- and microhabitat scale, and then quantified nest success and juvenile survival to overwintering in two declining turtle species, eastern box turtles and spotted turtles, that co-occur in oak savanna landscapes of northwestern Ohio and southern Michigan. Nest success in box turtles was higher in nests farther from macrohabitat edges, constructed later in the year, and at greater total depths. In contrast, survival of juvenile box turtles to overwintering was greater from nests under less shade cover and at shallower total depths. Spotted turtle nest success and juvenile survival were so high that we were unable to detect relationships between nest-site characteristics and the small amount of variation in survival. Our results demonstrate, at least for eastern box turtles, a tradeoff in nest depth between favoring nest success vs. juvenile survival to overwintering. We suggest that heterogeneity in microhabitat structure within nesting areas is important for allowing female turtles to both exercise flexibility in nest-site choice to match nest-site characteristics to prevailing weather conditions, and to place nests in close proximity to habitat that will subsequently be used by hatchlings for overwintering.