Automatic recognition of bird individuals on an open set using as-is recordings

The most common method used to determine the identity of an individual bird is the capture-mark-recapture technique. The method has several major disadvantages, e.g. some species are difficult to capture/recapture and the capturing process itself may cause significant stress in animals leading even to injuries of more vulnerable species. Some studies introduce systems based on methods used for human identification. An automatic system for recognition of bird individuals (ASRBI) described in this article is based on a Gaussian mixture model (GMM) and a universal background model (GMM-UBM) method extended by an advanced voice activity detection (VAD) algorithm. It is focused on recognizing the bird individuals on an open set, i.e. any number of unknown birds may appear anytime during the identification process as is common in nature. The introduced ASRBI processes the recordings just as if they were recorded by an ornithologist: with durations from seconds to minutes, containing noise and unwanted sounds, as well as masking of the singer, etc. Thanks to the VAD algorithm, the proposed system is fully automatic, no manual pre-processing of recordings is needed, neither by cutting off the songs nor syllables. The overall achieved identification accuracy is 78.5%, the lowest 60.3% and the highest 95.7%. In total, 90% of all experiments reach at least 70% accuracy. The result suggests the application of the GMM-UBM with VAD is feasible for individual identification on the open set processing real-life recordings. The described method is capable of reducing both the time consumption and human intervention in animal monitoring projects.     

Abiotic effects on the distributions of major insect species in agricultural fields

We compared how abiotic factors affect the regional distributions of four insect groups (Dermaptera, Formicidae, Orthoptera and Diptera). Insects were collected using a pitfall trap from 36 agricultural field sites, and 31 933 individuals encompassing 139 species were observed. The distribution pattern of dominant species was not obviously different among the four groups. Species richness (H′) of Orthoptera showed a negative and positive correlation with precipitation and sunlight duration, respectively. Longitudinal zonation was the main distribution pattern of many dominant species. Overall, canonical correspondence analysis showed that temperature and precipitation were closely associated with the distribution of Orthoptera, but not that of Formicidae, implying that Formicidae may be affected less by abiotic factors compared to other taxonomic groups. Some orthopteran species such as Dianemobius nigrofasciatus and Polionemobius mikado showed a negative correlation with temperature. We suggest that these species can be categorized as susceptible to climate change. Our results also implied that the association between climate variables and distribution of insects should be evaluated at a species level.     

Is microclimate important for Orthoptera in open landscapes?

Orthoptera were monitored on field edge public footpaths on the east (leeward) and west (windward) side of hedgerows in Chelmsford, UK, in 2006. A total of 6 species were recorded from footpaths on the leeward side of hedgerows probably due to the shelter from the prevailing westerly winds provided by the trees and shrubs. On the windward side of hedgerows species richness and abundance of Orthoptera were reduced (only 4 species were recorded). It is suggested that shelter from the wind and the exposure to early morning sunlight for Orthoptera on the east side of hedgerows are important factors governing their occurrence on farmland. Many replicates had Environmental Stewardship (ES) scheme field margins adjacent but they did not affect Orthoptera species richness or abundance.     

Comparison of manual and automated methods for identifying target sounds in audio recordings of Pileated, Pale-billed, and putative Ivory-billed woodpeckers

ABSTRACT.   Although offering many benefits over manual recording and survey techniques for avian field studies, automated sound recording systems produce large datasets that must be carefully examined to locate sounds of interest. We compared two methods for locating target sounds in continuous sound recordings: (1) a manual method using computer software to provide a visual representation of the recording as a sound spectrogram and (2) an automated method using sound analysis software preprogrammed to identify specific target sounds. For both methods, we examined the time required to process a 24-h recording, scanning accuracy, and scanning comprehensiveness using four different target sounds of Pileated Woodpeckers ( Dryocopus pileatus ), Pale-billed Woodpeckers ( Campephilus guatemalensis ), and putative Ivory-billed Woodpeckers ( Campehilus principalis ). We collected recordings from the bottomland forests of Florida and the Neotropical dry forests of Costa Rica, and compared manual versus automated cross-correlation scanning techniques. The automated scanning method required less time to process sound recordings, but made more false positive identifications and was less comprehensive than the manual method, identifying significantly fewer target sounds. Although the automated scanning method offers a fast and economic alternative to traditional manual efforts, our results indicate that manual scanning is best for studies requiring an accurate account of temporal patterns in call frequency and for those involving birds with low vocalization rates.     

Baseline data for automated acoustic monitoring of Orthoptera in a Mediterranean landscape,the Hymettos,Greece

Acoustic emissions of animals serve communicative purposes and most often contain species-specific and individual information exploitable to listeners, rendering bioacoustics a valuable tool for biodiversity monitoring. Recording bioacoustic signals allows reproducible species identification. There is a great need for increased use and further development of automated animal sound recording and identification to improve monitoring efficiency and accuracy for the benefit of conservation. Greece, with its high number of endemic species, represents a hotspot for European Biodiversity, including Orthopteran insects. Songs of many Orthoptera might be employed for the inventorying and monitoring of individual species and communities. We assessed the regional spatio-temporal composition of Orthoptera species at the Hymettos near Athens, which is a Natura 2000 site under constant threat due to the surrounding megacity. Within the framework of the EU Life Plus funded AmiBio project, we documented the Orthopteran species’ habitat characteristics, their co-occurrence and phenology. We found, in total, 20 species with seven to ten Orthoptera at locations characterised by diverse vegetation patterns of perennial herbs and bushes. For the purposes of implementation of an automated remote monitoring scheme, we identified sampling sites with high Orthopteran diversity, allowing the monitoring of all singing Orthoptera within single localities. By analysing sound depositories and adding recordings from new sample individuals, we established a song library as prerequisites for future automatic song detection. Based on our results, acoustic recording units have been placed at remote sites at the Hymettos. We discuss recommendations for further studies to fully employ the potential of automated acoustic monitoring of Orthoptera. A reliable assessment of singing Orthoptera needs recording units covering ultrasound. Due to high attenuation and absorbance by the vegetation, particularly of the high frequencies characterising Orthopteran songs, positioning of microphones at sites is critical: the microphone sensor network has to be an order of magnitude denser than for monitoring birds.     

Aspects of Species Recognition by Sound in Four Species of Damselfishes,Genus Eupomacentrus (Pisces: Pomacentridae)

Members of four sympatric species of Eupomacentrus carry out reproductive activities at the same time of the year and produce similar pulsed courtship sounds. Such sounds are known to facilitate courtship among conspecifics. Consequently, members of the four species in the field and in the laboratory were tested with the various sounds to determine if they could distinguish their own species sounds from those produced by congeners. The differential responses clearly demonstrate species specific recognition by sound and indicate that the pulse interval and the number of pulses per sound are the important parameters for this recognition.     

SILIC: A cross database framework for automatically extracting robust biodiversity information from soundscape recordings based on object detection and a tiny training dataset

• 1.Passive acoustic monitoring (PAM) offers many advantages comparing with other survey methods and gains an increasing use in terrestrial ecology, but the massive effort needed to extract species information from a large number of recordings limits its application. The convolutional neural network (CNN) has been demonstrated with its high performance and effectiveness in identifying sound sources automatically. However, requiring a large amount of training data still constitutes a challenge.
• 2.Object detection is used to detect multiple objects in photos or videos and is effective at detecting small objects in a complex context, such as animal sounds in a spectrogram and shows the opportunity to build a good performance model with a small training dataset. Therefore, we developed the Sound Identification and Labeling Intelligence for Creatures (SILIC), which integrates online animal sound databases, PAM databases and an object detection-based model, for extracting information on the sounds of multiple species from complex soundscape recordings.
• 3.We used the sounds of six owl species in Taiwan to demonstrate the effectiveness, efficiency and application potential of the SILIC framework. Using only 786 sound labels in 133 recordings, our model successfully identified the species' sounds from the recordings collected at five PAM stations, with a macro-average AUC of 0.89 and a mAP of 0.83. The model also provided the time and frequency information, such as the duration and bandwidth, of the sounds.
• 4.To our best knowledge, this is the first time that the object detection algorithm has been used to identify sounds of multiple wildlife species. With an online sound-labeling platform embedded and a novel data preprocessing approach (i.e., rainbow mapping) applied, the SILIC shows its good performance and high efficiency in identifying wildlife sounds and extracting robust species, time and frequency information from a massive amount of soundscape recordings based on a tiny training dataset acquired from existing animal sound databases. The SILIC can help expand the application of PAM as a tool to evaluate the state of and detect the change in biodiversity by, for example, providing high temporal resolution and continuous information on species presence across a monitoring network.

     

Adaptations to the acoustic environment by the squirrelfishes Myripristis violaceus and M. Pralinius

Three sounds naturally produced by squirrelfish of the genus Myripristis were recorded and analyzed sonographically. Captive Myripristis violaceus responded acoustically and behaviorally to playbacks of calls by conspecifics. Acoustic characteristics (velocity and pressure levels, and their attenuation as a function of frequency and distance) of grunt sounds, produced by hand held fish, were determined for M. violaceus and M. pralinius. Background noise components were analyzed for four different environments of these fish. Background noise and grunt sounds had high velocity levels, relative to pressure levels, expected in acoustic near fields, but attenuated at rates characteristic of acoustic far fields. Electrophysiological recordings from the lateral line organs of M. violaceus indicated that the lateral line system is directionally sensitive to a vector component (e.g., displacement or velocity) of the sound field, and is capable of mediating the observed behavioral responses.     

SOUNDS OF A PYGMY RIGHT WHALE (CAPEREA MARGINATA)

Abstract: This is the first report of recordings of sounds from the pygmy right whale, Caperea marginata . The recordings were obtained in the presence of a juvenile in the harbor at Portland, on the southeastern corner of the Australian continent. Only one type of sound was heard-a short thump-like pulse or tone burst with a downsweep in frequency and decaying amplitude, with most energy between 60 and 120 Hz. The pulses occurred predominantly in pairs and once in a trio. The sounds are simpler than those of most baleen whales, but they show some similarity in characteristics. Source levels are in the lower end of the range determined for other species. There was no evidence to indicate the purpose of these sounds.     

The impact of grazing management on Orthoptera abundance varies over the season in Mediterranean steppe-like grassland

As semi-natural grassland has a high level of biological diversity, understanding the effects of grazing and its variation over time is important in order to identify sustainable grazing practices. We measured temporal variation in Orthoptera abundance and spatial vegetation structure during seasonal grazing in an extensive sheep-farming system. We studied five grazed pasture areas (pre-grazing and post-grazing) and two adjacent ungrazed grasslands. We recorded the total abundance of Orthoptera and described the vegetation structure of 175 replicate plots (25 per pasture/grassland) during six field sampling sessions. We demonstrated that the impact of grazing on Orthoptera abundance is species-specific and greatly varies over the grazing season. The decrease of phytovolume is significant after 4–7 weeks of sheep grazing. Total Orthoptera abundance was higher in pre-grazed plots than in ungrazed plots, and higher in ungrazed plots than in post-grazed plots. These differences were particularly high during the peak of adult abundance. No difference in species richness was observed between grazing intensities. Total Orthoptera abundance positively correlated to phytovolume only when grazing pressure was high. However, the relationship between abundance and phytovolume differed between species. Extensive grazing by sheep tends to homogenize spatial vegetation structure and to temporarily reduce total Orthoptera abundance at pasture scale. However, rotational grazing allows spatial and temporal heterogeneity in vegetation structure to be maintained at farm scale, heterogeneity that is beneficial for Orthoptera. In contrast, absence of grazing has a negative impact on Orthoptera abundance as it favours the accumulation of litter, which is detrimental for a high proportion of xerothermophilic Orthoptera associated with bare ground and short vegetation.     

Sound-producing mechanisms and recordings in<Emphasis Type="Italic"> Carapini</Emphasis> species (Teleostei,Pisces)

Carapus boraborensis, C. homei and Encheliophis gracilis are three species of Carapidae that display the ability to penetrate and reside in the holothurian Bohadschia argus. This study describes both the particular morphology of the sound-producing structures and, for the first time, the sounds produced by each species. The study of the structures composing the sound-producing system seems to indicate that the action made by the primary sonic muscles (i.e. the pulling and releasing of the front of the swim bladder) might be responsible for the sound emissions of these three species by provoking a vibration of a thinner zone in front of the swim bladder (swimbladder fenestra). The sounds were only emitted and recorded when several individuals of the same species were inside the same sea cucumber. They were composed of serially repeated knocks and were heard as drum beats or drum rolls. Their specific differences were mainly defined as variations in the timing or grouping of the knocking sounds. The recordings of these sound productions demonstrate a vocal ability for the three species, linked with the presence of particular organs associated with sound production. Moreover, the ecological significance of the sounds and of the sound apparatus system is discussed.     

基于线粒体ND2基因的直翅目部分种类分子系统发育分析

测定了39种直翅目昆虫线粒体ND2基因全长序列,联合GenBank中41种直翅目昆虫的ND2基因序列,探讨ND2基因在解决直翅目系统发育分析上的功效,为建立直翅目的主要类群之间稳定的系统发育关系提供更多的数据。研究结果表明,直翅目昆虫的ND2基因序列全长为996～1 029 bp,平均长度为1 020 bp,A+T含量平均为73%。用贝叶斯法(Bayesian,BI)、最简约法(maximum parsimony,MP)和最大似然法(maximum likelihood,ML)构建系统树,SH检验显示,RAxML法构建的ML树似然值最大,与PAUP*的ML法构建的ML树差异显著,而与贝叶斯树和简约树没有明显差异。所有系统树都显示直翅目为单系群;而蝗亚目的剑角蝗科、网翅蝗科、槌角蝗科和斑腿蝗科均不是单系群,锥头蝗科与瘤锥蝗科亲缘关系较近,这与Otte分类系统一致。螽亚目基本由两大分支构成,一支是蝼蛄总科和蟋蟀总科聚集而成,且具有很高的置信度;另一大分支由螽斯总科独自构成。     

An evaluation of manual and automated methods for detecting sounds of maned wolves (Chrysocyon brachyurus Illiger 1815)

Although bioacoustics is increasingly used to study species and environments for their monitoring and conservation, detecting calls produced by species of interest is prohibitively time consuming when done manually. Here we compared four methods for detecting and identifying roar-barks of maned wolves (Chrysocyon brachyurus) within long sound recordings: (1) a manual method, (2) an automated detector method using Raven Pro 1.4, (3) an automated detector method using XBAT and (4) a mixed method using XBAT's detector followed by manual verification. Recordings were done using a song meter installed at the Serra da Canastra National Park (Minas Gerais, Brazil). For each method we evaluated the following variables in a 24-h recording: (1) total time required analysing files, (2) number of false positives identified and (3) number of true positives identified compared to total number of target sounds. Automated methods required less time to analyse the recordings (77–93 min) when compared to manual method (189 min), but consistently presented more false positives and were less efficient in identifying true positives (manual = 91.89%, Raven = 32.43% and XBAT = 84.86%). Adding a manual verification after XBAT detection dramatically increased efficiency in identifying target sounds (XBAT+manual = 100% true positives). Manual verification of XBAT detections seems to be the best way out of the proposed methods to collect target sound data for studies where large amounts of audio data need to be analysed in a reasonable time (111 min, 58.73% of the time required to find calls manually).     

What determines Orthoptera species distribution and richness in temperate semi-natural dry grassland remnants?

Wide-spread fragmentation and isolation of habitats with high nature conservation value lends increasing importance to a better understanding of the factors which determine species richness in isolated habitat patches. Using data of one of the most abundant invertebrate groups in grasslands, Orthoptera, we analysed how species richness and distribution in 60 isolated semi-natural grassland remnants in Austria were affected by five environmental variables (altitude, habitat and land use diversity within each patch, habitat diversity of areas adjacent to each patch, patch size), and related to diversity of their main food source, i.e. vascular plants. We found a significant positive correlation between Orthoptera and vascular plant species richness, with threatened Orthoptera species having the lowest correlation coefficients. Life form diversity of plants was only moderately positively correlated with Orthoptera species richness. Habitat diversity within and adjacent to the grassland patch had by far the highest loadings on the first two axes of the principal component analysis, which jointly explained 99?% of the variance, and proved to be significant for total, threatened and not threatened Orthoptera, as well as for the two Orthoptera orders occurring in Central Europe (Caelifera, Ensifera). Additionally, the distribution of the majority of those 14 Orthoptera species analysed individually was mainly correlated with habitat diversity within and adjacent to the grassland patch. However, the distribution of a significant proportion of species was associated with other factors: five species were closely related to on-site land use diversity and patch size, and the distribution of three Ensifera species was not significantly correlated to any of the explanatory variables. We conclude that a surrogate taxa approach, i.e. the use of well-known taxonomic groups (e.g. vascular plants), may indeed deliver good results for capturing total, but less so for threatened, Orthoptera species richness in semi-natural grassland remnants. Small scale habitat diversity may be crucial to allow for the co-existence of a large number of Orthoptera species and has to be taken equally into account as patch size in nature conservation.     

Calling Behavior and Morphology of the Stridulatory Apparatus in Neotropical Grasshoppers (Aleuas Stål; Orthoptera)

The sound production and sound producing apparatus of two species of grasshoppers, A. lineatus Stål, 1878 and A. vitticollis Stål, 1878 (Orthoptera, Acrididae, Copiocerinae) have been studied. For both species oscillograms and other physical data on sounds are presented for the first time. The sound producing behavior is described and the stridulation apparatus mechanism is illustrated. In the case of A. vitticollis these data are the first known on its sound production and general acoustic behavior.     

Acoustic identification and measurement of activity patterns of white grubs in soil

Activity patterns of Phyllophaga crinita (Burmeister), Phyllophaga congrua (LeConte), Phyllophaga crassissima (Blanchard), and Cyclocephala lurida (Bland) grubs were monitored with acoustic sensors in small pots of bluegrass, Poa arachnifera Torr, at varying and constant temperatures over multiple-day periods. Experienced listeners readily distinguished three types of sound with distinct differences in frequency and temporal patterns, intensities, and durations. Of approximately 3,000 sounds detected from P. crinita larvae, 7% were identifiable as snaps, with large amplitudes and short durations typically associated with root breakage or clipping activity. Approximately 60% were identifiable as rustles, suggestive of surfaces sliding or rubbing past each other during general movement activity. Another 2% of sounds contained patterns of repeated pulses suggestive of surfaces scraping across a pointed ridge. The remaining 31% had spectral or temporal patterns that fell outside the ranges of easily recognizable sound types. Because the behavioral significance of the different sound types has not yet been fully established, the classified and unclassified sounds were pooled together in analyses of the effects of species, temperature, weight, and time of day. Grubs of all four species produced detectable sounds at rates that increased with temperature [0.45 sounds/((min)(degrees C))] and larval weight [6.3 sounds/((min)(g))]. Mean sound rates were independent of species and time of day. At temperatures <9 degrees C, mean sound rates fell below the typical levels of background noise observed under field conditions. This reduced activity at low temperatures is likely to reduce the effectiveness of acoustic monitoring in the field in cold weather. The consistency of results obtained in these tests over multiple-day periods suggests that acoustic systems have potential as tools for nondestructive monitoring of the efficacy of insect management treatments as well as for biological and ecological studies.     

Offspring recognition by mother crab spiders with extreme maternal care

Maternal care is provided by several spider species, but there are no reports of mother spiders recognizing their young, which suggests that maternal care can be exploited by unrelated individuals. Diaea ergandros, a crab spider with extreme, sacrificial maternal care, does accept unrelated spiderlings (ca. 43.9% of spiderlings) into its nest in areas of high nest density. However, a field and a laboratory experiment with mother spiders and natural and adoptive spiderlings demonstrated that mothers did recognize their own offspring. Recognition was not expressed in survival as adopted (unrelated) spiderlings had similar survival rate to that of natural offspring. Instead it was displayed in growth; mother D. ergandros caught large prey items for their own offspring, but not for adopted spiderlings, and so natural offspring grew more than adopted spiderlings. Also, mothers produced trophic oocytes, which are important for the sacrificial care that influences spiderling survival, only when they lived with their own offspring.     

Disentangling the role of management,vegetation structure,and plant quality for Orthoptera in lowland meadows

Seminatural grasslands provide habitats for various species and are important for biodiversity conservation. The understanding of the diverse responses of species and traits to different grassland managenient methods is therefore urgently needed. We disentangled the role of grassland management (fertilization and irrigation), vegetation structure (biomass, sward height) and plant quality (protein and fiber content) for Orthoptera communities in lowland hay meadows in Germany. We found vegetation structure to be the most important environmental category in explaining community structure of Orthoptera (species richness, total individuals, fiinctional diversity and species composition). Intensively used meadows (fertilized, irrigated, high plant biomass) were characterized by assemblages with few species, low functional diversity, and low conservation value. Thereby, the relatively moderate fertilizer inputs in our study system of up to -75 kg N/ha/year reduced functional diversity of Orthoptera, while this negative effect of fertilization was not detectable when solely considering taxonomic aspects. We found strong support for a prominent role of plant quality in shaping Orthoptera communities and especially the trait composition. Our findings demonstrate the usefulness of considering both taxonomic and functional comp on ents (functio nal diversity) in biodiversity research and we suggest a stronger involvement of plant quality measures in Orthoptera studies.     

Applications of bioacoustics in animal ecology

In communication animals use a full range of signals: acoustic, visual, chemical, electrical and tactile. The processes involved in how and why animals communicate have long held veritable fascination for scientists. A branch of science concerned with the production of sound and its effects on living organisms is bioacoustics.The main purpose of the present study is to raise and discuss some issues related to the relationship between animals, their sounds and ecology, including presentation of methods of analysis of sound recordings. A better understanding of the relationship between the studied animals will allow for development of a better framework for future research, as well as a better grasp of interactions between different organisms, including humans. The paper discusses the significance of acoustic research in animal ecology and its possible applications in the future. The author also summarizes previous research in the field of sound communication of various animal species.The paper proves that vocalizations of every acoustically communicating animal are threatened by climate change. For marine animals, the source of changes in vocalization abilities is ocean acidification and increased ambient noise, which can affect communication and foraging behavior. For terrestrial animals, changes in precipitation and temperature may result in modifications of the sounds emitted, as well as certain modifications to the auditory system. Together with changes in species distribution due to environmental parameters, cumulatively these factors can cause changes in the entire landscape of acoustics ecosystems. Thanks to acoustic biomonitoring, we can understand how the sounds of entire habitats and acoustic ecosystems will change in response to the changing climate and how it will affect bioacoustics on a global scale.