Eggs In Nests Research Articles

Mobbing behaviour of hosts and non-hosts towards cuckoo Cuculus canorus of different sex

AbstractThe common cuckoo Cuculus canorus is an obligate brood parasite of many Eurasian bird species that exploit the parental care of their hosts. Although only females lay eggs in nests of passerine hosts, male and female cuckoos should cooperate to have a success in nest parasitism. Many bird species mobbing cuckoos as an element of deterrence of cuckoos from the breeding territory of the host. However, mobbing behaviour is costly, although only cuckoo females pose a threat to the dangers of the host. Because only the presence of a female cuckoo is dangerous, due to laying eggs in the nests of hosts, birds should mainly attack cuckoo females. Therefore, we tested for differences in anti-parasite response using field experiments with female and male cuckoo dummies, in 92 breeding sites with prime habitats in Poland. tested for differences in cuckoo responses in anti-parasite response using field experiments and cuckoo dummies (male and female) placed at 92 breeding sites with prime habitats in Poland. The host species that behaved most aggressively towards cuckoos was the barn swallow Hirundo rustica, while the most aggressive behaviour recorded in the non-host group was the great tit Parus major. Generally, host species reacted to cuckoo female dummies with a significantly higher probability than cuckoo males dummies. We conclude that differences in reaction by hosts and non-hosts may have arisen from selection for recognition of danger (parasite female) by reduction of reproductive success.

Percentage of Hatching Success of Olive Ridley Turtle (Lepidochelyis oliviceae) Eggs in Natural and Semi-Natural Nests and the Quality of the Turtle Conservation Community (TCC), Lombok, Indonesia

Sea turtles are internationally and nationally protected marine reptiles. One of the turtle species that can be found in Indonesia is the Olive Ridley turtle or Lepidochelys oliviceae. This study aims to determine the percentage of hatching success of turtle eggs in semi-natural and natural nests at TCC (Turtle Conservation Community), Lombok, determine the physical characteristics of natural and semi-natural nests of turtle eggs, and determine the quality of hatchlings produced in natural and semi-natural nests. The research method used is the descriptive exploration method, including determining the location with purposive sampling, collecting data on the size of Olive Ridley turtle mothers, the number of eggs, the depth and diameter of turtle egg nests, beach slope, nest temperature, substrate grains, beach vegetation, threats to turtle eggs, and locomotor quality of hatchlings. The results of this study are, the percentage of success in natural nests of Olive Ridley turtles is lower at 71.99% and semi-natural nests as much as 59.01%. The average temperature of both nests was 28.67, which is still optimal for turtle egg nesting. The type of grain in the two types of nests is also relatively fine. The slope of the beach is also still relatively gentle. Based on the research conducted by TCC (Turtle Conservation Community), it is suitable to support the success of Olive Ridley turtle hatching.

Hatching success rate of sea turtle in the north coast of Pinrang Regency, South Sulawesi

Background: Turtles are endangered marine reptile species due to various factors, including hunting, habitat loss, and predation. Therefore, practical conservation efforts are essential to protect turtle populations. One effective conservation strategy is to transfer turtle eggs to safe semi-natural nests. Methods: This study was conducted in Turtle Village, Pinrang Regency. Leatherback and Green Turtle eggs were collected from natural nests along the coast and transferred to semi-natural nests. Observations were made to measure the hatching success rate of the eggs, and factors such as temperature, incubation period, predators, microorganism development, and changes in egg position were also recorded and analyzed. Finding: The results showed that the hatching success rate of eggs in semi-natural nests reached 80.23%. The highest hatching percentage was 86.36%, and the lowest was 68.33%. Factors that influenced hatching success included temperature and incubation period while hatching failure was caused by predators, microorganism development, and changes in egg position. Conclusion: This study shows that semi-natural nests in Turtle Village have a high hatching success rate with supportive environmental conditions and proper egg transmission. This indicates that conservation efforts through egg transfer to semi-natural nests can effectively increase turtle populations. Novelty/Originality: This study: It contributes to turtle conservation by demonstrating the effectiveness of semi-natural nests in increasing the hatching success rate of Leatherback and Green Turtle eggs. This approach can serve as a model for turtle conservation programs in other areas facing similar challenges.

A new ootype of putative dromaeosaurid eggs from the Upper Cretaceous of southern China

Non-avian maniraptoran eggs are abundant in the Upper Cretaceous of China. Previous studies mainly focused on oviraptorosaur and troodontid eggs which can be classified into the oofamilies Elongatoolithidae and Prismatoolithidae, respectively. Here we report a new possible ootype of dromaeosaurid dinosaur recovered from the Lianhe Formation of the Ganzhou Basin. The new ootaxon, Gannanoolithus yingliangi oogen. et oosp. nov., is remarkable for its symmetrically elliptic shape and two structural layers with an abrupt and straight boundary. It shares a similar elongated shape, interlocked eggshell units, and an angusticanaliculate pore system with those of Deinonychus eggshell-like maniraptoran ootaxa reported from North America, Europe, and East Asia. The new phylogenetic analysis suggests the monophyly of dromaeosaurid and oviraptorosaurian eggs, and troodontid eggs are closely related to bird eggs. Paired eggs of Gannanoolithus might indicate that dromaeosaurid dinosaurs also have paired functional oviducts like oviraptorosaurs and troodontids. In addition, the porosity and EBSD analyses support that these eggs in the mound nests are buried.

Nest predation and climate change as drivers of alternative reproductive tactics in a migratory species

Alternative reproductive tactics enable individuals to choose a reproductive tactic relative to their status and prevailing environmental conditions in a way that increases their fitness. For example, females in many avian species show phenotypic plasticity and employ alternative reproductive tactics to cope with changes in predation risk and climate. Conspecific brood parasitism (CBP), in which females lay eggs in nests of conspecifics, is one example of such behaviour. It has been proposed that when prospects for successful nesting are low and/or costs of reproduction are high, females employ tactics of low effort such as non‐breeding and parasitic laying. When environmental conditions are ideal and prospects for success high, females can increase their reproductive effort above typical nesting by laying parasitic eggs prior to initiating their own nest. Here, I used this flexible life‐history strategy concept and long‐term (1994‒2022) population level data of the common goldeneye Bucephala clangula to study how the rate of parasitic laying varies in relation to variation in nest predation risk and in the timing and length of the breeding season, the latter being measured by the timing of ice breakup. Nest predation rate in the previous year and timing of ice breakup interactively affected parasitic laying, the rate of parasitic laying being particularly high in years with late ice breakup and high nest predation rate in the previous year. Furthermore, the proportion of predated eggs was lower in parasitized nests than in non‐parasitized nests, while the opposite was true for the proportion of eggs that failed in other way. As a consequence, the final number of young produced per nest was higher for parasitized nests. The findings of this study show that changes in environmental conditions affect the dynamics of alternative reproductive tactics in goldeneyes, with consequences to population level reproductive output.

Rewriting The Ugly Duckling tale: a Eurasian tree sparrow reared among great tits

Rewriting The Ugly Duckling Tale: a Eurasian tree sparrow reared among great tits. Competitive relationships between hole-nesting passerine bird species can lead to mixed broods when two or more species lay their eggs in the same nest. On 5 May 2023, during a routine inspection of nest boxes in orange plantations in Sagunto, Eastern Spain, we found a Eurasian tree sparrow (Passer montanus) egg dumped among nine great tit (Parus major) eggs. From this clutch, six great tits and the Eurasian tree sparrow hatched, and four great tits and the sparrow fledged. Using a video camera inside the nest box, we observed that the nestlings, including the sparrow, were fed only by great tit adults. The adults brought caterpillars, moths and spiders, a typical great tit nestling diet in this habitat. To date, great tit eggs have been found in Eurasian tree sparrow nests, but to our knowledge this is the first report of a Eurasian tree sparrow chick successfully raised by great tits.

Research institutes from nest eggs: challenges and the way forward

Research institutes from nest eggs: challenges and the way forward

Pioneer access of the foam nest bacterial community of Leptodactylidae frogs and its biotechnological potential.

Many anuran amphibians deposit their eggs in foam nests, biostructures that help protect the eggs and tadpoles from predators. Currently, there are no other identification and description studies of the cultivable microbiota role in the nests of the Leptodactylid frogs such as Physalaemus cuvieri, Leptodactylus vastus and Adenomera hylaedactyla. This study aimed to isolate and identify the culturable bacteria from these three anuran species' nests, as well as to prospect enzymes produced by this microbiota. Foam nests samples and environmental samples were diluted and viable cell count was determined. Bacterial morphotypes from foam nest samples were isolated through spread plate technique. Isolates' DNAs were extracted followed by rRNA 16S gene amplification and Sanger sequencing. To evaluate their enzymatic potential, the isolates were cultured in ATGE medium supplemented with starch (0.1% w/v), gelatin (3% w/v) and skimmed milk (1% w/v), to verify amylase and protease activity. A total of 183 bacterial morphotypes were isolated, comprising 33 bacterial genera. Proteobacteria phylum was the most abundant in all the three nests (79%). The genera Pseudomonas and Aeromonas were the most abundant taxon in P. cuvieri and L. vastus. In A. Hylaedactyla, were Enterobacter and Bacillus. Regarding enzymatic activities, 130 isolates displayed protease activity and 45 isolates were positive for amylase activity. Our results provide unprecedented information concerning culturable bacterial microbiota of the foam nests of the Leptodactylid frogs, as well as their potential for biomolecules of biotechnological interest.

Nesting Ecology of Lepidochelys olivacea in Lobito, Angola.

The scarcity on the Atlantic coast of the African sea turtle population and its dynamics data is well known. This article discusses the nesting ecology methods and analysis of a nascent Angolan project aimed at preserving the nesting female population of the Olive Ridley turtle (Lepidochelys olivacea) on the coast of Lobito. This study examines the nesting ecology of this species from 2020 to 2023. Females had an average CCL of 70.2 cm and CCW of 68.5 cm. These females laid 127 eggs in nests that averaged 47.0 cm deep. The ex situ nest incubation period averaged 60 days, and the hatchling success was 82.1%. Some techniques used in this project require modifications and enhancements. The utilization of photo identification did not yield the anticipated outcomes, prompting the adoption of passive integrated transponders (PITs) in the last season. However, due to limited funding, the success of this method is contingent upon an augmented field effort, allowing for the recapture of a larger number of females. The continuity of this project hinges upon collaboration between higher authorities and the local community. Together, it is possible to deepen the understanding of the nesting ecology of this species and address pivotal issues for its conservation, thereby implementing the most effective preservation measures.

The Role of Riverine Bed Roughness, Egg Pocket Location, and Egg Pocket Permeability on Salmonid Redd‐Induced Hyporheic Flows

AbstractSalmon spawning activities alter streambed morphology, forming a dune‐shaped egg nest called a redd. The spawning process increases redd sediment hydraulic conductivity, KD, by removing fines, creating an egg pocket with larger sediment grains such that egg pocket hydraulic conductivity, KEP, may be higher than KD. Salmon females may create one or more egg pockets within a single redd. Although the impact of redd shape and KD on redd‐induced hyporheic fluxes has been studied, the effects of streambed roughness, R, egg pocket permeability, and egg pocket location on egg pocket hyporheic fluxes, , (downwelling flows from the stoss side of the redd which may enter egg pockets) have not yet been quantified. This study investigates this knowledge gap with a set of numerical simulations supported by flume experiments. We simulated hyporheic flows for five egg pocket locations, five KEP values from 0.0025 to 0.02 m/s, and 12 rough streambed surfaces. Surface roughness was scaled from a measured streambed surface in two ways—only vertically (R1) and both vertically and horizontally (R2)—with scaling coefficients ranging from 0.5 to 3. The measured streambed surface had a median diameter, D50, of 1 cm and a standard deviation (σD) of 0.77 cm. The results indicate that the dimensionless flux into the egg pocket, increases noticeably with the downstream distance of egg pockets from the redd pit, and less strongly with . The near‐surface downwelling fluxes significantly increase with R1, but only negligibly with R2, and for deeper egg pockets, is minimally impacted by surface roughness. Our results suggest that the typical simplification of a smooth redd surface with a single redd hydraulic conductivity provides a good representation of the interstitial flow within the redd, and the effects of surface roughness and egg pocket hydraulic conductivity on fall within the uncertainty of the egg pocket location.

Keunikan Struktur Anatomi dan Morfologi Burung Maleo (Macrochepalon maleo) sebagai Fauna Endemik Indonesia dan Upaya Konservasinya

Maleo bird is one of the unique animals of the aves class which is included in endemic animals in Indonesia. The Maleo bird is almost endangered due to predators and irresponsible behavior of local people. One of the conservation efforts carried out by the government is contained in Law No. 5 of 1990 and Government Regulation No. 7 of 1999 concerning the protection or conservation of Maleo birds. The purpose of this paper is to analyze the morphological and physiological characteristics of the Maleo bird (Macrochepalon maleo), the anatomy of the Maleo bird (Macrochepalon maleo), the relationship of the uniqueness of the behavior of the Maleo bird (Macrochepalon maleo) with the morphology, anatomy, and physiology of the Maleo bird, as well as conservation efforts of the Maleo bird (Macrochepalon maleo). The method used is a literature review by reading various books, journals and papers and other publications in accordance with the research topic. The results of research that have been conducted show that the morphology, anatomy, and physiology of the Maleo bird are closely related to the behavior of the Maleo bird. The Maleo bird uses a crest located on its head to detect heat when digging an egg nest. Maleo bird legs equipped with sharp hooves can make Maleo birds able to survive in coastal forests. Maleo birds are monogamous animals, namely animals that are loyal to their partners. The advice that can be given through this literature review is that the community must have awareness to take care of the Maleo bird as a form of accountability for the mandate given by God to humans. Key words: Aves; endemic; conservation; maleo; morphology

Nest Egg

Nest Egg

Food Provisioning and Body Mass of Nestling Meadow Pipits and Cuckoos

Common Cuckoos Cuculus canorus are obligate brood parasites, laying eggs in nests of other species. Cuckoo nestlings are often thought to be insatiable, compared to host broods. However, in Reed Warblers Acrocephalus scirpaceus and a few other species, cuckoo nestlings are fed at most only as frequently as a host brood. To add to the small body of knowledge on feeding frequencies and body mass development of Cuckoo nestlings, I studied Cuckoos using another host, the Meadow Pipit Anthus pratensis, in the Dutch dunes (2019–2021). By filming feeding parents (hosts) I determined the provisioning frequency for broods of Pipits and for nestling Cuckoos. I found that nestling Cuckoos receive on average fewer feeds per hour than broods of Meadow Pipits. Furthermore, overall Cuckoos received as many feeds during their 22-day nestling period as a brood of Pipits during their 13 days in the nest. At 13 days of age (day 1 is the day of hatching), the single Cuckoo was as heavy as a brood of four Meadow Pipits. At 22 days, the maximum weights of the nestling Cuckoos were greater than the Meadow Pipit broods and varied between 91 and 105 g. Thus, although Cuckoos are being fed less frequently, young Cuckoos are heavier at fledging than a whole brood of Pipits. This could be because Cuckoos are fed larger prey. Alternatively, Cuckoos may require less food because their thermoregulatory costs could be smaller: they have almost black skin which absorbs solar radiation efficiently, do not have to compete with siblings in the nest and, once older and feathered, have a smaller surface-to-volume ratio than a Pipit brood of four nestlings.

Effect of Surface Hydraulics and Salmon Redd Size on Redd‐Induced Hyporheic Exchange

AbstractSalmonids create an egg nest, called a redd, in hyporheic streambed gravel to bury their eggs, characterized by a pit and a hump topography, resembling a dune. Embryos' survival depends on downwelling oxygen‐rich stream water fluxes, influenced by the redd shape, stream hydraulics, and the hydraulic conductivity of the redd sediment, K. We hypothesize that downwelling fluxes increase with stream discharge and redd aspect ratio (AR = A/L, with A, the redd amplitude and L, its length), and they can be predicted using a set of dimensionless numbers, which include the stream flow Reynolds (Re) and Froude (Fr) numbers, AR, and the redd relative submergence (A/Y0, with Y0, the water depth). We address our goal by simulating the surface and subsurface flows with numerical hydraulic models linked through the near‐bed pressure distribution quantified with a two‐phase (air‐water) two‐dimensional surface water computational fluid dynamics model, validated with experiments. We apply the modeling approach to five redd sizes, which span the field observed range (from ∼1 to ∼4 m long), and by increasing discharge from shallow (0.1 m) and slow (0.15 m/s) to deep (8 m) and fast (3.3 m/s). Results confirm that downwelling fluxes increase with discharge and redd aspect ratio due to the increased near‐bed head gradient over the redd. Averaged downwelling fluxes are a function of Re, Fr, AR, and hydraulic conductivity of the redd and not of the undisturbed streambed material. The derived regression equation may help evaluate regulated and unregulated flow impacts on hyporheic flows during embryo incubation.

Fledgling discrimination in the hoopoe, a potential host species of the great spotted cuckoo

Obligate brood parasites lay their eggs in nests of other species, with host parents bearing the cost of raising their offspring. These costs imposed on hosts select for the evolution of host defenses against parasitism at all stages of the reproductive cycle. The most effective defense is egg rejection at early stages of the breeding cycle, with later-stage defenses (nestling and fledgling discrimination) being less common. In this study, we tested whether the hoopoe (Upupa epops), a potential host of the great spotted cuckoo (Clamator glandarius) without egg rejection ability, presents defenses after the egg stage. We experimentally parasitized hoopoe nests with great spotted cuckoo nestlings creating mixed broods (with hoopoe and cuckoo nestlings) and broods with only cuckoo nestlings and measured parental feeding behavior and survival of nestlings and fledglings of both species. Cuckoo fledglings were fed fewer often than hoopoe fledglings in mixed broods, and adults approached more often to feed hoopoe fledglings than cuckoo fledglings. Consequently, the survival of cuckoo fledglings in both mixed and only-cuckoo-broods, was significantly lower than that of hoopoe fledglings. These results suggest that hoopoes would discriminate great spotted cuckoo fledglings, with or without direct comparison with their own fledglings. However, the survival of some cuckoos suggests that hoopoes have not reached highly efficient defenses so, other life history traits hindering parasitism by cuckoos may explain low parasitism rates and low levels of defenses in this species.Significance statementBrood parasites lay their eggs in nests of other species, tricking hosts into raising their parasitic offspring. However, hosts may fight back impeding successful parasitism by developing defences at any of the stages of their breeding cycle. We investigated why the hoopoe is not parasitized by the great spotted cuckoo despite this potential host apparently does not show such anti-parasitic defenses. We found that hoopoes have evolved the less common host defense: discrimination of parasite fledglings, even in the absence of their own fledgling for comparison. Our study supports the idea that discrimination during the later stages of the nesting cycle (i.e. nestling and fledgling periods) may be more common that previously assumed.

Investing in a nest egg: intraspecific variation in the timing of egg laying across a latitudinal gradient.

Avian reproductive strategies vary widely, and many studies of life-history variation have focused on the incubation and hatching stages of nesting. Birds make proximate decisions regarding reproductive investment during the laying stage, and these decisions likely constrain and tradeoff with other traits and subsequent behaviors. However, we know relatively little about egg-laying stage behaviors given the difficulty of locating and monitoring nest sites from the onset of laying. We used non-invasive continuous video recording to quantify variation in the egg-laying behaviors of burrowing owls (Athene cunicularia) along a 1400-km latitudinal gradient in western North America. Burrowing owls laid eggs disproportionately in the morning hours, and that tendency was strongest among first eggs in a clutch. However, selection appeared to act more strongly on laying intervals (the time between laying of consecutive eggs) than on the diel time of laying, and laying intervals varied widely among and within clutches. Laying intervals declined seasonally and with increasing clutch size but increased with increasing burrow temperature and as a function of laying stage nest attentiveness, which may be a strategy to preserve egg viability. Laying interval was positively correlated with the duration of hatching intervals, suggesting that laying interval duration is one mechanism (along with timing of incubation onset) that generates variation in hatching asynchrony. Our results lend support to two general hypotheses to explain laying schedules; selection favors laying eggs in the morning, but other selective pressures may override that pattern. These conclusions indicate that allocation decisions during laying are an important part of avian life-history strategies which are subject to energetic constraints and tradeoffs with other traits.

An Efficient Hybrid Job Scheduling Optimization (EHJSO) approach to enhance resource search using Cuckoo and Grey Wolf Job Optimization for cloud environment.

Cloud computing has now evolved as an unavoidable technology in the fields of finance, education, internet business, and nearly all organisations. The cloud resources are practically accessible to cloud users over the internet to accomplish the desired task of the cloud users. The effectiveness and efficacy of cloud computing services depend on the tasks that the cloud users submit and the time taken to complete the task as well. By optimising resource allocation and utilisation, task scheduling is crucial to enhancing the effectiveness and performance of a cloud system. In this context, cloud computing offers a wide range of advantages, such as cost savings, security, flexibility, mobility, quality control, disaster recovery, automatic software upgrades, and sustainability. According to a recent research survey, more and more tech-savvy companies and industry executives are recognize and utilize the advantages of the Cloud computing. Hence, as the number of users of the Cloud increases, so did the need to regulate the resource allocation as well. However, the scheduling of jobs in the cloud necessitates a smart and fast algorithm that can discover the resources that are accessible and schedule the jobs that are requested by different users. Consequently, for better resource allocation and job scheduling, a fast, efficient, tolerable job scheduling algorithm is required. Efficient Hybrid Job Scheduling Optimization (EHJSO) utilises Cuckoo Search Optimization and Grey Wolf Job Optimization (GWO). Due to some cuckoo species' obligate brood parasitism (laying eggs in other species' nests), the Cuckoo search optimization approach was developed. Grey wolf optimization (GWO) is a population-oriented AI system inspired by grey wolf social structure and hunting strategies. Make span, computation time, fitness, iteration-based performance, and success rate were utilised to compare previous studies. Experiments show that the recommended method is superior.

Application of portfolio optimization using pension and other 6 stocks

This paper uses the Capital Asset Pricing Model and Fama-French Three-Factor Model (FF3F) to construct optimal portfolios with maximized Sharpe ratio, aiming to help retired firefighters decide between the pension’s annual benefits and the lump sum of the pension. Firstly, this paper selects six well-diversified assets from different industries. Secondly, this study estimates the expected return of each asset using the CAPM and FF3F Model, respectively. Thirdly, this paper constructs two ‘With Pension Portfolio’s using the expected return from the two models. Fourthly, this paper also builds two portfolios using the same results from the two models but keeping the pension’s weight to zero. By comparing the maximized Sharpe ratios from ‘With Pension Portfolio’s and ‘Without Pension Portfolio’s, we conclude that the firefighter should choose to take the benefits of the pension. The results in this paper can serve as a reference for retired people when they want to allocate their nest egg and pension better.

Cracking the Nest Egg: Comparing Pension Politics in Post-Communist Russia and Hungary – ERRATUM

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Molecular characterisation and additional morphological descriptions of Eimeria spp. (Apicomplexa: Eimeriidae) from brown kiwi (Apteryx mantelli Bartlett)

Brown kiwi (Apteryx mantelli Bartlett), a ratite endemic to New Zealand, is currently listed as “Vulnerable” under the IUCN classification system due to predation by introduced mammals. Operation Nest Egg (ONE) raises chicks and juveniles in predator-proof enclosures until they are large enough to defend themselves. These facilities experience an environmental accumulation of coccidial oocysts, which leads to severe morbidity and mortality of these kiwi. Four species of coccidia have been morphologically described from sporulated oocysts with additional opportunistic descriptions of endogenous stages. This research continues the morphological descriptions of these species of Eimeria with an additional novel morphotype also morphologically described. It also provides the first genetic characterisation targeting the mitochondrial cytochrome c oxidase I (COI) gene. Based on these findings, it was determined there are at least five morphotypes of Eimeria that infect brown kiwi and co-infections are common at the ONE facilities surveyed. The COI amplicon targeted for this study was sufficient to provide differentiation from other members of this genus. Sanger sequencing yielded ambiguous bases, indicating the need for more in-depth sequencing.