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The Ecoacoustic Event Detection and Identification (EEDI) system is a recent methodology to investigate structure and dynamic of soundscapes. In this study, EEDI has been re-engineered by adding to the Acoustic Complexity Index (ACI) calculated for each temporal step ( ACIf t ) and to its evenness ( ACIf t evenness ), the evenness of ACI calculated along each frequency bin ( ACIt f evenness ), and upgrading the ecoacoustic code (EC) from a two-digit to a three-digit code, thus increasing the analytical resolution of EEDI. Furthermore, a new metric, the Acoustic Information (AI) index, is introduced which is obtained by multiplying the value of each EC by the number of Recording Minutes (RM) in which every EC occurs. The EEDI was tested in four localities within a Mediterranean landscape using Soundscape Explorer [Terrestrial] digital recorders. Based on 273,360 RMs, 436 ECs were detected from a field recording system active from December 2015 to November 2016. The number of ECs and AI values increased in late winter and early spring, followed by a reduction in late spring and summer. A second increase was observed in early autumn. Based on bird phenology, non-significant differences in the number of ECs were found between the breeding (395 ECs) and non-breeding season (417 ECs). The sequence of the ECs during night time resulted in significant differences from the sequence of the ECs during daytime, but the number of RMs and of AI values of ECs exclusive of day or night time resulted negligible. Hourly abundance of ECs and the associated AI showed a similar sequence for all the localities, confirming a common daily pattern in soundscape organization. According to the way in which ECs are distributed along the 24 h, the first hundred more frequent ECs were aggregated into seven major patterns: some ECs have a dominant distribution around sunrise, whereas others prevail at midday or at night. EEDI provides a visual representation of each recording day (240 RMs) in an Euclidean space delimited by ACIf t (x), ACIf t evenness (y) and ACIt f evenness (z). An “asymptotical like” distribution that occurs during rain or wind events, and a “shower jet like” distribution that occurs when biophonies are dominant, are the two major patterns that were discovered. The ecoacoustic codes EC000, EC999, EC997, EC476, and EC271, have been utilized after their identification, to classify and analyze ecoacoustic events as an example of the capacity of EEDI. This holistic approach starting with detection of patterns delimited by the combination of ACI metrics associated with the AI, overcomes the usual procedure to first identify the sources and then determine the resulting patterns. The use of EEDI provides the potential to explore and to compare the characteristics of soundscapes with other environmental variables and represents an innovative and flexible ecological indicator. [ABSTRACT FROM AUTHOR]

Abstract: Herein we present one of the first attempts to couple the complexity of vegetation and topographic features with the sonic environment to understand the distribution of bird species and individuals in their habitat. To achieve this, the sonic features of a bird community were studied during the spring and early summer of 2011 in a Mediterranean maqui located on the western slope of a remote hanging valley that is dominated by Erica arborea, Quercus ilex and Arbutus unedo. Species composition, height, vertical foliage profile, canopy density and dispersion of vegetation were utilized as probable proxies for the sonic patterns. The acoustic activity of birds was collected through the use of a regular matrix of 20 audio recorders, spaced 25m apart, which were placed following the topographic isoclines. The sonic complexity of the soundscape was evaluated using the Acoustic Complexity Index (ACI), which is a recently developed metric. The PCA applied to the vegetation parameters revealed two principal distinguishing factors, which we were able to define as “vegetation density and structure” and “species segregation.” Moreover, the results show that, even in the case of sampling sites that are very close together, sonic patterns vary across the season, highlighting the great variability of the soundscape and confirming the adequacy of the sampling scale of 25m adopted in this study. The topographic features do not seem to be connected to the sonic environment. The main sonic complexity was found where the vegetation was taller and denser, especially where E. arborea was the dominant species. Although this proves that acoustic dynamics can be linked to vegetation structure, even on a small scale, a consistent element of sonic variability cannot be explained by vegetation patterns alone, and a soundtope hypothesis must be invoked. [Copyright &y& Elsevier]

The fine-grained mosaic of natural and human-modified patches that characterizes the Mediterranean region has created a multifaceted system that is difficult to investigate using traditional ecological techniques. In this context, sounds have been found to be the optimum model to provide indirect and timely information about the state of ecosystems. The sonic nature of the environment (the soundscape) represents an important component of the landscape, and the new discipline of soundscape ecology has recently been shown to have appropriate tools for investigating the complexity of the environment. In the last decade, technological advances in the acoustic field have led researchers to carry out wide-scale and long-term ecological research using new and efficient tools, such as digital low cost sound recorders, and autonomous software and metrics. Particularly in the Mediterranean region, where land transformation occurs at a very rapid rate, soundscape analysis may represent an efficient tool with which to:1) track transformations in the community balance, 2) indicate the most acoustically complex parts (bioacoustic hotspots) of the land mosaic, 3) prevent environmental degradation, and 4) decide whether protection or restoration actions are most appropriate. Conserving the quality of Mediterranean sounds means preserving the natural dynamics of its animal populations and also involves maintaining the cultural heritage, human identity, and the spiritual values of the area. [ABSTRACT FROM AUTHOR]

Abstract: The soundscape represents the acoustic footprint of a landscape, and may well be a source of a vast amount of information that could be used efficiently in, for example, long-term bird aggregation monitoring schemes. To depict such soundscape footprint, specific indexes are requested. In particular, the aim of this paper was to extensively describe the Acoustic Complexity Index (ACI) and to successively apply it to process the sound files recorded in an ecologically fragile area in a Mediterranean maqui (Eastern Liguria, Italy). Daily acoustic animal activity was sampled in 90 one-minute files between the end of May and the end of July, 2010, using a pre-programmed recording procedure (Songmeter, Wildlife Acoustic). The WaveSurfer software, powered by the Soundscape Metric plug-in, was then utilized to quickly process these data. This approach allows the identification of the compositional changes and acoustic fluctuations activity of a local community (in the proposed case prevalently composed by birds and cicadas). In particular, two distinct patterns emerged during the investigation. From 20 May to 4 July, the soundscape was dominated by birds but, after that period, the onset of the cicadas'' songs completely changed the sound dynamics. The proposed methodology has been demonstrated to be a powerful tool to identify the complex patterns of the soundscape across different temporal scales (hours, days and intraseason). This approach could also be adopted in long-term studies to monitor animal dynamics under different environmental scenarios. [Copyright &y& Elsevier]

The Mediterranean region shows unique environmental and ecological characteristics. The observed ecological complexity is the result of a long-lasting and intense co-evolutionary process between human and non-human organisms. Most of the valuable landscapes at the present time are under serious threat from agricultural intensification, land abandonment and forestation, urban sprawl, and mass tourism. The urgency of conservation clashes against these threats. Such complexity of human–nature interactions is best represented by the “full and empty” world ecological model. Cultural landscape and niche construction theories belong to this framework. In turn, perception and cognition are central themes in the definition of such paradigms. This leads ecological research into the field of eco-semiotics, a new scientific perspective that can provide powerful tools for the study of the Mediterranean ecological complexity, as it addresses the interpretation of signs that human and other evolutionary drivers leave in the environment. Such signs are the expression of mutual interactions that shaped patterns and processes in the region. The eco-field paradigm, derived from the eco-semiotic approach, is a theoretical tool that allows one to intercept a portion of such signals to model the relationship between any species and its environment. [ABSTRACT FROM AUTHOR]