Nesting Birds Research Articles

CS-GA-XGBoost-Based Model for a Radio-Frequency Power Amplifier under Different Temperatures.

Machine learning methods, such as support vector regression (SVR) and gradient boosting, have been introduced into the modeling of power amplifiers and achieved good results. Among various machine learning algorithms, XGBoost has been proven to obtain high-precision models faster with specific parameters. Hyperparameters have a significant impact on the model performance. A traditional grid search for hyperparameters is time-consuming and labor-intensive and may not find the optimal parameters. To solve the problem of parameter searching, improve modeling accuracy, and accelerate modeling speed, this paper proposes a PA modeling method based on CS-GA-XGBoost. The cuckoo search (CS)-genetic algorithm (GA) integrates GA's crossover operator into CS, making full use of the strong global search ability of CS and the fast rate of convergence of GA so that the improved CS-GA can expand the size of the bird nest population and reduce the scope of the search, with a better optimization ability and faster rate of convergence. This paper validates the effectiveness of the proposed modeling method by using measured input and output data of 2.5-GHz-GaN class-E PA under different temperatures (-40 °C, 25 °C, and 125 °C) as examples. The experimental results show that compared to XGBoost, GA-XGBoost, and CS-XGBoost, the proposed CS-GA-XGBoost can improve the modeling accuracy by one order of magnitude or more and shorten the modeling time by one order of magnitude or more. In addition, compared with classic machine learning algorithms, including gradient boosting, random forest, and SVR, the proposed CS-GA-XGBoost can improve modeling accuracy by three orders of magnitude or more and shorten modeling time by two orders of magnitude, demonstrating the superiority of the algorithm in terms of modeling accuracy and speed. The CS-GA-XGBoost modeling method is expected to be introduced into the modeling of other devices/circuits in the radio-frequency/microwave field and achieve good results.

The effect of edible bird's nests on the expression of MHC-II and costimulatory molecules of C57BL/6 mouse splenocytes

The glutinous nest that builds by the saliva secretion of swiftlet is recognizable as an edible bird's nest (EBN). It enriched a medicinal value and was regarded as supplementary food that exerts various beneficial health effects, especially immune boosters. This study's objective was to determine the impact of EBN on the expression of MHC-II and costimulatory molecules (CD86 and CD80) related to the initiation of T-cell activation. Both rEBN and pEBN samples were prepared with simulated gastrointestinal digestion for enhancing the bioaccessibility of bioactive compounds. Our result showed that digested EBN samples slightly influence the upregulation of MHC-II, CD86, and CD80 in gene expression of LPS-stimulated Raw 264.7 cells. The concern of endotoxin contamination in EBN samples, which may cause a false-positive result, was measured by quantitative PCR. We found that the inflammatory genes (IL-1β and TNF-α) were not induced by EBN treatments. Moreover, cell surface protein expression in splenocytes treated with EBN was assessed using flow cytometric analysis. Digested EBN samples demonstrated their capacity to promote the elevation of MHC-II, CD86, and CD80 cell surface protein expression. Finally, the digested-EBN-treated splenocytes only exhibited a specific response in the T-cells population. Thus, EBN is a source of the bioactive compound that has been proposed to exert a role in the stimulation of both MHC-II and costimulatory molecules for TCR/pMHC-II interaction leading to T-cell activation.

Landscape factors influencing bird nest site selection in urban green spaces

IntroductionUnderstanding the birds’ breeding strategies in urban habitats is vital for ensuring their continued existence. Therefore, more research must be conducted on bird breeding and urban adaptation strategies in urban green spaces. This study aimed to address this gap by investigating the influence of landscape factors on the selection of bird nest sites. MethodsData on the presence and absence of magpie (Pica pica) and gray magpie (Cyanopica cyana) nests were collected through field surveys conducted in the campus of Nanjing Forestry University during the 2023 breeding season. Generalized additive models (GAMs) incorporating landscape variables were employed to assess the effects of these predictors on nest occurrence. The model with the lowest Akaike’s information criterion value was selected among the candidate GAMs.ResultsBelow is a summary of the main results. Nest tree height (TH), distance from the central lawn (D), and tree coverage (TC) within the sampled area were identified as the primary landscape factors influencing nest site choice. Conversely, factors such as the shortest distance to the water source, herb coverage, shrub coverage, percentage of buildings, and percentage of hard pavement did not significantly impact on nest site selection. Furthermore, the nesting potential of magpies and grey magpies initially increased with tree height, reaching a maximum at ca. TH=25 meters after which it began to decline. The nesting occurrence rate showed an initial decrease tendency with increasing distance from the central lawn, reaching a minimum at D=400 meters, and then increased with further distance. Additionally, nesting potential decreased initially with increasing of TC in the range of 0–20%, fluctuated evenly between 20–60% TC, and decreased rapidly when TC exceeded 60%.DiscussionThis study provides valuable insights into the selection of nest sites by birds in urban habitats, specifically with respect to landscape factors. The understanding of the impact of urban green spaces on urban birds and the underlying mechanisms of their behavior contributes to the conservation of wild birds and promotes the harmonious development of urban areas.

The First Five Mitochondrial Genomes for the Family Nidulariaceae Reveal Novel Gene Rearrangements, Intron Dynamics, and Phylogeny of Agaricales.

The family Nidulariaceae, consisting of five genera including Cyathus, is a unique group of mushrooms commonly referred to as bird's nest fungi due to their striking resemblance to bird's nests. These mushrooms are considered medicinal mushrooms in Chinese medicine and have received attention in recent years for their anti-neurodegenerative properties. However, despite the interest in these mushrooms, very little is known about their mitochondrial genomes (mitogenomes). This study is the first comprehensive investigation of the mitogenomes of five Nidulariaceae species with circular genome structures ranging in size from 114,236 bp to 129,263 bp. Comparative analyses based on gene content, gene length, tRNA, and codon usage indicate convergence within the family Nidulariaceae and heterogeneity within the order Agaricales. Phylogenetic analysis based on a combined mitochondrial conserved protein dataset provides a well-supported phylogenetic tree for the Basidiomycetes, which clearly demonstrates the evolutionary relationships between Nidulariaceae and other members of Agaricales. Furthermore, phylogenetic inferences based on four different gene sets reveal the stability and proximity of evolutionary relationships within Agaricales. These results reveal the uniqueness of the family Nidulariaceae and its similarity to other members of Agaricales; provide valuable insights into the origin, evolution, and genetics of Nidulariaceae species; and enrich the fungal mitogenome resource. This study will help to expand the knowledge and understanding of the mitogenomes in mushrooms.

Individual and population effects of entanglement mortality on ospreys from plastic baling twine in nests

The global production of plastics continues to increase, and most of our knowledge about the negative effects of plastics pollution comes from marine environments. The presence of plastics in nests of terrestrial birds has increased the last century, which can cause adult and nestling mortality through entanglement. Volunteers and I surveyed 600 km of the Yellowstone River, Montana, USA for breeding ospreys and we recorded the presence and amount of polypropylene baling twine in nests, and the number and outcome of nestling and adult entanglements from 2014 to 2022. Each year a mean 44.2 % of nests contained twine and a mean 3.4 % of nestlings became entangled. Entanglement mortality appeared compensatory rather than additive because the local breeding population increased each year and because annual reproductive success exceeded estimates to maintain a stable population. The amount of twine in 35 nests that were either destroyed by weather or removed by electric companies from energized power poles varied substantially (0–227 m). Entanglements occurred at 19 different nests, of which seven (36.8 %) were responsible for multiple entanglements (61.3% of all entanglements). Reducing osprey mortalities and baling twine litter in the environment will take short-term (intensive nest monitoring, bird rescues) and long-term actions (community education, cleanup, recycling).

Anidación del ave Tolmomyias sulfurescens (Spix, 1825) (Passeriformes: Tyrannidae) asociada a la hormiga Camponotus senex (Smith, 1858) (Hymenoptera: Formicidae) en el Cerrado, Brasil

The nesting of birds associated with social insects has already been documented in different Brazilian biomes, including in the Cerrado, but information about this association in this biome is still scarce. Thus, our objective is to report the nesting association between bird and ants in the Cerrado. In April 2023, in the Grande Sertão Veredas National Park, a colony of the weaver ant Camponotus senex (Smith, 1858) was reported as being 10 cm from an active nest, with eggs, of a Tolmomyias sulphurescens (Spix, 1825), a yellow-olive flatbill, 5 meters from the ground, in a plant substrate. The report brings new information about the nesting behavior of T. sulphurescens and the C. senex ant within the Cerrado, but it is not possible to define whether this association is recurrent or accidental, and further studies are needed to better elucidate this ecological relationship, as well as the advantages for both, especially for the ant.

Anidación del ave Tolmomyias sulfurescens (Spix, 1825) (Passeriformes: Tyrannidae) asociada a la hormiga Camponotus senex (Smith, 1858) (Hymenoptera: Formicidae) en el Cerrado, Brasil

The nesting of birds associated with social insects has already been documented in different Brazilian biomes, including in the Cerrado, but information about this association in this biome is still scarce. Thus, our objective is to report the nesting association between bird and ants in the Cerrado. In April 2023, in the Grande Sertão Veredas National Park, a colony of the weaver ant Camponotus senex (Smith, 1858) was reported as being 10 cm from an active nest, with eggs, of a Tolmomyias sulphurescens (Spix, 1825), a yellow-olive flatbill, 5 meters from the ground, in a plant substrate. The report brings new information about the nesting behavior of T. sulphurescens and the C. senex ant within the Cerrado, but it is not possible to define whether this association is recurrent or accidental, and further studies are needed to better elucidate this ecological relationship, as well as the advantages for both, especially for the ant.

Optimum beverage formulation in terms of pH, viscosity, and DPPH free radical scavenging activity of bird's nest beverage

Optimum beverage formulation in terms of pH, viscosity, and DPPH free radical scavenging activity of bird's nest beverage

Context-guided coarse-to-fine detection model for bird nest detection on high-speed railway catenary

As a critical component of ensuring the safe and stable operation of trains, the detection of bird’s nests on the rail catenary has always been essential. Low-resolution images and the lack of labelled data, however, make it difficult to detect smaller bird’s nests (those occupying small pixels in the input image). Previous solution relies on manual online patrol or offline video playback, which severely limits the detection efficiency. Previously, this challenge was addressed by manual online patrol or offline video playback, which severely limits detection efficiency. We propose in this work a context-guided coarse-to-fine detection model (CG-CFDM) for solving the bird’s nest detection problem. This solution consists of a context reasoning module and a coarse-to-fine detection network. By detecting domains and matching templates, the context reasoning module generates new labelled context bounding boxes, thereby reducing the burden of annotation. As a result of its delicately designed architecture and powerful representation learning ability, this trained coarse-to-fine detection network further facilitates the detection of bird’s nests in an efficient and accurate manner. Extensive experiments demonstrate that the proposed approach is superior to existing methods in terms of performance and has a great deal of potential for detecting bird’s nests.

Morphological evolution and transition at nanoscale in BSTO ceramic materials

Considerable efforts have been devoted since the past three decades for the development of low cost ferroelectric and clean energy storage multifunctional materials. Modification in design and production of a low cost material with well proven process provides pathway for high energy density dielectric energy storage. We studied fluorine doped a commercially well-established material system barium strontium titanate with two different concentrations of dopants and studied the morphological transition and its effect on properties. It was observed that sample with higher concentration transitioned much faster into glassy state, followed by growth of fibers which turned into a self-arranged bird nest type shape. The sample with lower concentration changed slowly into glassy state and only few fibers were farmed. Dielectric was highly dependent on processing methods and shows variation with crystallinity of material, temperature, and cooling conditions during processing. In the higher concentration range, we observed nano-scale interface breakdown very similar to that of solid-liquid interface breakdown during crystal growth.

Songbird nests on the ground as islands of diversity of ptyctimous mites (Acari: Oribatida) in the primeval Białowieża Forest (Poland).

Due to specific microclimatic conditions and accumulation of organic matter, bird nests are microhabitats that are often inhabited by various invertebrates, including mites (Acari). We tested whether nests of the ground-nesting passerinePhylloscopus sibilatrix (Bechstein) (Passeriformes: Phylloscopidae)[wood warbler] were associated with an increased local diversity of ptyctimous mites (Acari: Oribatida) on the forest floor in the Białowieża National Park, East Poland. In 2019-2020, we analysed 150 warbler nests shortly after they had been vacated by the birds, and additionally we sampled mites in leaf litter at 1 and 6m distances from 21 of the collected nests. We found on average more mite species in nests sampled in 2020 than in nests sampled in 2019. Although the species composition largely overlapped between bird nests and the litter, bird nests contained a greater average number of mite species than litter samples, including species found only - Microtritia minima (Berlese) and Phthiracarus crenophilus Willmann - or mostly - Euphthiracarus cribrarius (Berlese) and Phthiracarus globosus (C.L. Koch) - in bird nests. The results suggest that the presence of bird nests may increase the local diversity of the invertebrate species assemblage.

Bird nest building: visions for the future.

Successful reproduction for most birds requires them to have built 'good' nests. The remarkable diversity of nests across approximately 10 000 species of living birds suggests that 'good' nest design depends critically on a species' microhabitat, life history and behaviour. Unravelling the key drivers of nest diversity remains a key research priority-bolstered by renewed appreciation for nest museum collections and increasing correlational field and experimental laboratory data. Phylogenetic analyses-coupled with powerful datasets of nest traits-are increasingly shedding light on the evolution of nest morphology and there are functional questions yet to be addressed. For birds, at least, developmental and mechanistic analyses of building (behaviour, hormones, neuroscience) itself, rather than measurements and analyses of nest morphology, are already becoming the next major challenge. We are moving towards a holistic picture in which Tinbergen's four levels of explanation: evolution, function, development, and mechanism, are being used to explain variation and convergence in nest design-and, in turn, could shed light on the question of how birds know how to build 'good' nests. This article is part of the theme issue 'The evolutionary ecology of nests: a cross-taxon approach'.

Cavity-breeding birds create specific microhabitats for diverse arthropod communities in boreal forests

The nests of secondary cavity-nesters located in tree cavities may form specific microhabitats of conservation importance due to their limited accessibility and availability. Species-specific nesting materials in nests of different secondary cavity-nesters may furthermore provide very different microhabitats for arthropods. The potential differences in arthropod communities inhabiting nests of different bird species in excavated cavities or nest boxes have, however, rarely been studied despite their relevance for conservation. Here we investigated the diversity and composition of arthropod communities in these different cavity types and bird species’ nests in managed boreal forests. We identified morphologically and by DNA-metabarcoding arthropods in nest materials that were collected in and compared between (i) woodpecker-size cavities from seven different combinations of cavity type (nest box or excavated cavity), tree species (aspen or pine) and accumulation history of nest materials (single-season cleaned or uncleaned nest boxes that accumulated nests of passerines or an owl species); and (ii) nests of two different passerine species in small nest boxes. We identified 64 arthropod taxa in ten orders, from which Diptera, Coleoptera, Siphonaptera, and Lepidoptera were the most abundant. Shannon diversity index was similar among the cavity-nest-type combinations, but taxa richness was the highest in the owl nests. The arthropod communities (especially Histeridae beetles) deviated most from the other types of nests in owl and aspen cavity nests with more advanced decomposition of nest material (soil or wet environment related taxa). The differences in arthropod communities between the different nest types point out the importance of the ecological chain “tree cavities—bird nests—arthropod communities”.

An Image Recognition Method Based on Dynamic System Synchronization

Abstract: At present, image recognition technology first classifies images and outputs category information through the neural network. The next step involves the search. Before retrieval, the feature database needs to be established, followed by one-to-one correspondence. This method is tedious, time-consuming and has low accuracy. In computer vision research, researchers have proposed various image recognition methods to be applied in various fields and made many research achievements. However, at present, the accuracy, stability and time efficiency cannot meet the needs of practical work. In terms of UAV image recognition, high accuracy and low consumption are required. Previous methods require huge databases, which increases the consumption of UAVs. Taking aerial transmission and line images as the research object, this paper proposes a method of image recognition based on chaotic synchronization. Firstly, the image is used as a function to construct a dynamic system, and the function structure and parameters are adjusted to realize chaos synchronization. In this process, different types of images are identified. At the same time, we research this dynamic system characteristics and realize the mechanism of image recognition. Compared with other methods, the self-built aerial image data set for bird's nest identification, iron frame identification and insulator identification has the characteristics of a high identification rate and less calculation time. It is preliminarily proven that the method of synchronous image recognition is practical, and also worthy of further research, verification and analysis.

ASSESSMENT OF THE NATURAL RESOURCE POTENTIAL OF THE IMPORTANT BIRD AREAS OF THE NORTH KAZAKHSTAN REGION FOR THE DEVELOPMENT OF ORNITHOLOGICAL TOURISM

To assess the potential of the allocated Important Bird Areas (IBA) of the North Kazakhstan region for the development of ecological tourism in the region. The work uses the materials of field research of domestic and international ornithological expeditions, cartographic method, statistical and mathematical processing of the data obtained. The territory of the North Kazakhstan region is of interest for the development of ornithological tourism. This is facilitated by the natural resource potential of the allocated promising IBA. The borders of these territories coincide with lake ecosystems located in the forest-steppe and steppe zones of the region. The selected ornithological areas are confined to lake ecosystems that are on the way of migrations and nesting of birds. IBA are characterized by floristic and faunal diversity, insignificant human development. The habitation of rare and endangered species has been noted. The presence of roads ensures accessibility to the studied territories of tourists and wildlife lovers from Kazakhstan, near and far abroad. The allocated territories may be used not only for ornithological, but also for recreational and educational tourism, as well as amateur fishing. The results of the resource potential assessment confirm the prospects for the development of ornithological tourism in the territory of the North Kazakhstan region in the implementation of environmental measures aimed at preserving the uniqueness of ecosystems. The selected IBA have significant natural resource potential and uniqueness. Key territories associated with lake ecosystems can serve for the development of ornithological and recreational tourism. The comprehensive assessment made it possible to identify the weighting coefficient of the studied properties of the territories. This confirms the fact about the prospects of their use as unique natural objects for scientific research, amateur fishing, various types of tourism on the territory of the North Kazakhstan region.

Effect of light intensity in the nest site on eggshell pigmentation in a hole-nesting passerine

Daylight is an important factor necessary for the proper embryonic development of birds, which raises the question, what happens when birds nest in relatively dim sites? The study experimentally tested whether there is a relationship between light conditions at the nesting site and the protoporphyrin-based pigmentation in the eggshell of the Great Tit (Parus major). We hypothesised that at lower light levels, eggs are less pigmented to increase the amount of light reaching the embryo. Our study system consisted of two types of nest boxes: "dark", in which the only source of light was the entrance hole, and "bright", which had two additional side windows. Photographs of clutches taken during the incubation period were used to quantify eggshell pigmentation. Multispectral image analyses were performed to measure variables correlating with protoporphyrin content, such as spot brightness, average spot size, spotting coverage, and spot red chroma. Repeatability analysis indicated that eggshell colouration characteristics were significantly and moderately repeatable between eggs from a single clutch, which suggests that they are under genetic and environmental control. However, none of the pigmentation traits differed significantly between the two types of nest boxes. We speculate about other ecological aspects that might have influenced the observed variability in eggshell pigmentation.

Oribatid Mites (Oribatida) Associated with Nests of Hollow-Nesting Birds, on the Example of a Model Species, the European Pied Flycatcher (Ficedula hypoleuca), in the Taiga Forests of the European North-East of Russia

The authors have obtained original material on the fauna and population structure of oribatid mites inhabiting nests of the European Pied Flycatcher (Ficedula hypoleuca, Passeriformes, hollow-nesting bird) on the territory of the taiga zone of the European North-East of Russia. Long-term research and the collection of nests were carried out in the green zone of Syktyvkar in 2017–2022. Observations were made for artificial nests (hollows) of a box type with a bottom area of 100 cm2. The material of the tray was collected completely. In 135 studied nests of Pied Flycatchers, 1762 specimens were found and identified for 22 species of oribatid mites from 19 genera and 16 families. In the nests of the Pied Flycatcher, a complex of species was found that is known as an arboricolous species for this region; these are Oribatula (Zygoribatula) propinqua, Oribatula (Z.) exilis, Trichoribates (T.) berlesei, and Ameronothrus oblongus. We suggested that arboricolous species, as well as eurytopic species, can actively inhabit bird nests. Highly numerous in our collections were representatives of the Oribatulidae and Scheloribatidae families; they are Oribatula (Z.) propinqua, Oribatula (Z.) exilis, Oribatula (O.) tibialis, and Scheloribates laevigatus. Epigeic species are dominated by the species number. The fauna of oribatid mites mainly included widespread Holarctic species (54.54%).

The determination of epidermal growth factor in Edible bird's nest by enzyme-linked immunosorbent assay

Edible bird's nest (EBN) is a traditional food which was nourishing and functional. Particularly, there is the epidermal growth factor (EGF) in EBN, which is thought to play an important role in promoting skin repair. However, the type and content of EGF in EBN were not determined yet. In this study, the type of EGF in EBN was identified as bird EGF by enzyme-linked immunosorbent assay and this method was validated to be accurate and precise. Moreover, it was found that the content of EGF in raw-unclean EBN, raw-clean EBN and stewed EBN was 3000 pg/g–4000 pg/g and there were no significant differences, which suggested that the batches, origins, forms, stewing temperatures and stewing times of EBN had no effect on the content of EGF in EBN. However, it was due to that enzyme destroyed the primary structure of EGF, the EGF content of neutral protease and trypsin hydrolysates of EBN was lower than that of flavor enzymes, alkaline protease and pepsin hydrolysates of EGF. This study was the first to determine the type and content of EGF in EBN, and provided a theoretical basis for the selection and processing of EBN and using EBN as a source of EGF.

Recognition of bird nests on transmission lines based on YOLOv5 and DETR using small samples

The safety and reliability of transmission line operations are critical to the delivery of electricity. Bird nests are one of the frequent potential factors affecting the safety of transmission lines. The main objective of this paper is to propose a small-sample learning method to detect bird nests on transmission lines. The method combines the two latest deep learning models, YOLOv5 and detection transformer (DETR). Inspired by biological vision, this method transfers the learning of bird nests in daily scenes to the recognition of bird nests on transmission lines. The proposed method is evaluated by two public datasets. The test on the first one presents a recognition rate of 95.50%, whereas the training set only contains ten homologous data and 80 non-homologous data. The second test shows that 85.54% of the samples are recognized by generalization without homologous training data. The results show that our method provides a way to identify bird nests on transmission lines with the help of bird nests of daily scenes under small sample conditions.

Good neighbors? Does aggregation of nests in an Arctic-breeding shorebird influence daily survival rates?

Our current understanding of the factors that influence where birds nest is incomplete, yet such information is important for accurate demographic assessments. To address questions related to spatial distributions of shorebird nests and to evaluate factors that may affect nest distribution in these species, during 2017 and 2019, we studied a small population of semipalmated sandpiper Calidris pusilla breeding in the Central Canadian Arctic, near the Karrak Lake Research Station, in Nunavut. The spatial distribution of semipalmated sandpiper nests at this site suggested loose aggregation, with median nearest neighbor distances of 73.8 m and 92.0 m in 2017 and 2019, respectively, while no nests were detected on mainland areas in the vicinity. Evidence for the influence of nesting distribution on the daily survival rate of nests, however, was mixed. Neither nearest neighbor distance nor local nest density had a significant effect on daily nest survival in 2017, but in 2019, the best approximating model included an effect of local nest density, which indicated that nests in areas of high density had reduced survival rates. Contrary to other studies assessing settlement and nest site selection in semipalmated sandpipers, the spatial distribution of nests in this population demonstrates aggregation in an otherwise territorial species, but suggests that aggregated nesting can impose a cost on nest survival under certain conditions.