宮城教育大学 環境教育研究紀要

第 14 巻 (2012)

Automatic Identification of Animal Species in Miyagi Prefecture,and Its Use in Environmental Education
Lazaro M. ECHENIQUE-DIAZ *要旨 : テクノロジーやデジタル情報処理の発展に伴い，科学者がデータを処理・解析する手法には革新的変化もたらされた．音響生物学の分野では，その場にいなくても遠隔操作で動物の音声を長時間録音することができるようになってきている．得られたデジタル録音には，研究者にとって役立つだけではなく，特定の動物の音声や，学校の周囲を含む特定のハビタットにおけるサウンドスケープを教材にしたいと考える教師にとっても有用な情報が含まれている．そうした目的に適したデータが宮城県内で蓄積され，地域の環境教育に貢献するものとして活用できるようになってきた．

Abstract : Advances in technology and digital information processing have brought about a revolution
in in the way scientist process and analyze their data. In the field of bioacoustics, this advance has
meant the capacity for unattended, remote recording of animal vocalization for extended periods oftime. These digital recordings contain information not only useful for researchers and conservationists,
but also, for teachers and educators interested in letting children know how particulars species
vocalize, or teaching them about soundscape differences along the year in a particular habitat, oraround the school. In Miyagi Prefecture, extensive remote recordings exercises have produced datathat can be purportedly use for this end, contributing to the ongoing environmental education efforts in
the region.
Keywords : animal sounds, automatic identification, Miyagi, environmental education

1. Introduction

in digital signal processing and storage capacity, haveEver since 1925, when Ivan Regen’s experiments

also allowed researchers to deploy their devices forrecording insects marked the beginnings of bioacoustics

long periods in remote areas (days, weeks or months),

as a scientific discipline (Wikipedia, 2012), scientists

widening the impact of biocoustics in fields such as

have been battling the available technologies of theirconservation biology.

times to record and reproduce animal sounds. However,More often than ever, bioacoustic approaches are

it wasn't until the second half of the XX century that

impacting the conservation of vocalizing species that live

portable devices allowed researchers to travel deep into

in remote, isolated areas. However, gathering acoustic

the wilderness with the capacity for recording animal

data for long periods with unattended devices deployedand nature sounds more accurately. More recently, in thein these areas, imply the use of analytical tools thatfirst decade of the XXI century, technological advances

could substitute the trained ear of researchers. This is*Environmental Education Center, Miyagi University of Education－ 41 －Automatic Identification of Animal Species in Miyagi Prefecture, and Its Use in Environmental Education.

due to the fact that listening to days, weeks or months

recording hours, Fig. 4).

of recordings in order to identify vocalizing species canbe very tedious, time consuming, and is not an efficientmode of investigation. Fortunately, in recent years,
sophisticated digital signal processing applications capableof automatically identifying animal species have been
available to wildlife researchers and conservationists.
These applications allow them to analyze long fieldrecordings in a few hours, and provide the capacity toboth, identify species and study the dynamics of sounds

Figure 1． The SM2-Bat recorder.

in space and time, to other professionals that are notnecessarily trained in the identification of species by thesounds they produce. Among these professionals wefound teachers and educators.
Talking about conspicuous animals such as rhinoceros
beetles is always attractive to children, many of whom
may grow to become insect collectionists as adults.
However, even though we use our hearing sense tokeep track of what is going on around us since earlychildhood, most adults living in urban areas may not be

Figure 2． Surveyed area inside the forest.

able to identify forest species by their sounds. Amongthe obvious reason are the fact that we are not actively
taught to listen to nature, and the reality of urban areas,
where not as many animal species live compared toforested places. In this report, we provide 2 examples
of automatically identified animal species, one easily
recognizable by its song, and other that call above thehearing range of humans, but that is very common inplaces where human live. We discuss how this knowledge
Figure 3． Surveyed area along a river.

could be used by teachers and educators to teach children
about animal sounds as an approach to environmental
education.

2. Materials and Methods
For the 2 examples provided in this report, we used
the SM2-Bat recorder from Wildlife Acoustics (http://www.wildlifeacoustics.com/ , Fig. 1). The device was
deployed in different habitats such as inside the forest(74 recording hours, Fig. 2), along a river (65 recordinghours, Fig. 3), at the age of a paddy rice field (87Figure 4． Surveyed area at the age of a paddy rice ﬁeld.

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宮城教育大学 環境教育研究紀要

Recordings were stored in 8 GB flash cards, class 6

第 14 巻 (2012)

Cettia diphone （ウグイス）． Fig. 5.

(Transcend Inc.), and later transferred to a desktop

Known as the“spring bird”, it is distributed throughout

Apple computer. Before analyzing our data, we hadJapan and adjacent regions. It is very easily recognizable

compiled a database with the sounds of several species

by their songs, but given their habits of hiding in treethat we had previously recorded. We used 2 species calls

foliages, is also difficult to spot.

from the database to build“recognizers”, a reference
against which vocalizing species could be automatically

Pipistrellus abramus （アブラコウモリ）． Fig. 6.

recognized in SM2-Bat recordings. These reference calls,A very common bat species in urban and suburban

and the automatic recognition of species was done withareas, and probably the most noticeable bat species

Song Scope 4.0.3, a software designed to be easy to use,

in Japan. This bat feeds on small insects, including

and does not require the user to be an expert in digital

mosquitoes, and is known to roost only in human-madesignal processing (http://www.wildlifeacoustics.com/).

structures such as houses, temples, and schools. It is not

Recognizers were builded for the following species:

uncommon to hear stories of school children excited atFigure 5. The sonogram of Cettia diphone as displayed by Song Scope 4.0.3. Note that in this particular recording there wasno other birds songs that could mask the call of C. diphone.

Figure 6. The sonogram of P. abramus. The species was easily recognized by Song Scope 4.0.3. Note that only pulses A, B, C,and D were recognized as being from this species. The pulses between A and B were not automatically recognized, but they
are known to represent a change in behavior of the species (feeding approach and buzz).

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Automatic Identification of Animal Species in Miyagi Prefecture, and Its Use in Environmental Education.

the presence of this species flying inside the classroom,

This process provides meaningful data of the day

probably as a result of the school building being used as aand time the species of interest has been around theroost by the bat.

recorders, and can also give an idea of their behavior,as observed in fig. 6 for P. abramus, where a series of3. Results and Discussion

search and approach pulses, and then a buzz indicate

The bat P. abramus was recognized in recordingsthat the animal was feeding. Similarly, from theseobtained at the edge of the paddy rice field (as expected),calls we can know whether the animal is vocalizing forwhile C. diphone was recognized in all other habitats. The

their territories, to attract a female, etc. By actively

recognition process was rather easy, given the existence

involving children in reading this data, they can developof reference calls and the software especially designed

an appreciation of the value of animal and nature sounds infor this task, and confirmed that it can be easily carried

their surroundings, because it teaches them that animalout by researchers and non-experts alike.

sounds do have a message they can easily read. At thesame time, because sonograms in these recordings show

The software used in this exercise (Sound Scope 4.0.3)

the dynamics of sounds along days and weeks, teachers

is mainly known to field biologist interested in the study

can show children how sound levels and properties areof population density, migration patterns and behavior

structured through time, highlighting the differencesof specific animal species, especially those consideredbetween“noisy”and“quiet”. This are important concepts

threatened or endangered (Wildlife Acoustics, 2012).

that may have not been properly addressed in environmental

However, teachers that wish to involve children in theeducation programs where visual materials are dominant.

study of nature and animal sounds by means of thismethod, can easily master the procedures needed forReferences

this end. The critical point is to gather the sounds ofEchenique-Dia, L.M., and Saito, C. 2010. Bioacoustics asdifferent species, which can be easily done from many
internet sources (Echenique-Diaz and Saito, 2009), anda tool for environmental education.
Res. Bull. Environ. Educ. Cent., Miyagi Univ. Educ., 12,build“recognizers”in Sound Scope 4.0.3. Once this has

41-48.

been done, recordings obtained at the school yard orother sites of interest can be scanned to see if species for

Wildlife Acoustics 2012.

which recognizers has been built are present.

(http://www.wildlifeacoustics.com/).
Wikipedia 2012.
(http://en.wikipedia.org/wiki/Bioacoustics)－ 44 －