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Computational Intelligence Applied to Monitor Bird Behaviour

Abstract

The best way to obtain relevant information about the behaviour of animals is direct observation (of individuals). However, traditional close-up observations can interfere on the behaviour, and taking biometric measurements requires the capture of individuals, which also causes stress. This paper describes an automatic motoring system for birds breeding in nest boxes. The main goal is to significantly increase the amount and quality of data acquired on bird behaviour without stressing the individuals or interfering. This system is based in an interconnected embedded sensor network, which permits sharing this valuable information with researchers all over the world through the internet. Each device of the network is a smart nest-box that allows a cross-validation of sensor information and data quality. This system has been evaluated for the specific case of a lesser kestrel breeding colony in Southern Spain. The lesser kestrel is an insectivorous migratory falcon that readily accepts nest-boxes. The system has been named HORUS and the results obtained from a year experiment demonstrate the efficiency of this approach.

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Computational Intelligence Applied to Monitor Bird Behaviour

Author: Larios Marín, Diego Francisco; Rodríguez, C.; Barbancho Concejero, Julio; Baena, M.; Simón, F.; Marín, J.; León de Mora, Carlos; Bustamante, J.
Publisher: ScitePress Digital Library
Year: 2012
DOI: 10.5220/0004068100230032
Source: https://idus.us.es/bitstreams/9d0206c1-eeef-4493-8fe5-02f964d37e2f/download
Compu a ional In elligence Applied o Moni o Bi d Beha iou
D. F. La ios1, C. Rod íguez², J. Ba bancho1, M. Baena3, F. Simón¹,
J. Ma ín2, C. León1 and J. Bus aman e2
1Depa men o Elec onic Technology, Uni e si y o Se ille, Se ille, Spain
2Depa men o We land Ecology, Doñana Biological S a ion (EDB-CSIC), Se ille, Spain
3ICTS, Singula Scien i ic and Technological In as uc u e, Doñana Biological S a ion, Se ille, Spain
Keywo ds: Neu onal Ne wo k, Compu a ional In elligence, Da a Fusion, En i onmen al Moni o ing, Senso Ne wo ks.
Abs ac : The bes way o ob ain ele an in o ma ion abou he beha iou o animals is di ec obse a ion (o
indi iduals). Howe e , adi ional close-up obse a ions can in e e e on he beha iou , and aking
biome ic measu emen s equi es he cap u e o indi iduals, which also causes s ess. This pape desc ibes
an au oma ic mo o ing sys em o bi ds b eeding in nes boxes. The main goal is o signi ican ly inc ease he
amoun and quali y o da a acqui ed on bi d beha iou wi hou s essing he indi iduals o in e e ing. This
sys em is based in an in e connec ed embedded senso ne wo k, which pe mi s sha ing his aluable
in o ma ion wi h esea che s all o e he wo ld h ough he in e ne . Each de ice o he ne wo k is a sma
nes -box ha allows a c oss- alida ion o senso in o ma ion and da a quali y. This sys em has been
e alua ed o he speci ic case o a lesse kes el b eeding colony in Sou he n Spain. The lesse kes el is an
insec i o ous mig a o y alcon ha eadily accep s nes -boxes. The sys em has been named HORUS and he
esul s ob ained om a yea expe imen demons a e he e iciency o his app oach.
1 INTRODUCTION
Fo zoologis s, one o he mos impo an pe iods o
a bi d is he b eeding pe iod, being his pe iod one o
he mos equen ly s udied. Ma e acquisi ion, nes
de ence, ma e eeding, incuba ion, and chick ea ing
(including p o isioning ligh s) a e s udied in he
su oundings o he nes . Many o hese aspec s help
us unde s and key opics in ecology, such as wha
ac o s in luencing li e ime ep oduc i e success
(LRS: New on, 1992), he pa en -o sp ing con lic
(T i e s, 1974; Schlome e al., 2010), o e olu i e
s able s a egies (ESS: Mayna d-Smi h and P ice,
1973) ega ding sex oles in ep oduc ion (Kokko
and Wong, 2007).
Classic moni o ing me hods ha equi e he
cap u ing o indi iduals o close-up obse a ions
limi he amoun and quali y o da a ha can be
ob ained. The e o e, in his pape a emo e
moni o ing sys em based on sma nes -boxes is
p oposed. These sma nes -boxes allow acqui ing
high amoun o da a wi hou s essing he animals,
ga he ing long- e m and highly eliable in o ma ion
on he species.
The p oposed sys em, called HORUS, pe mi s
ga he ing basic in o ma ion on he iden i y o
indi iduals, s udying i s beha iou and he empo al
changes in indi idual body mass. All his
in o ma ion can be made accessible h ough he
in e ne o scien is all o e he wo ld.
Some o he in o ma ion eco ded by he sys em
can be used o s udy, wi hou in e e ence, he
beha iou o species du ing he b eeding pe iod.
One o he mos impo an biome ic pa ame e s in
bi ds is body mass. I allows us o measu e he
impac o pa en al ca e on b eeding indi iduals.
Manually, i is impossible o de elop a con inuous
moni o ing o his pa ame e . Cap u ing causes oo
much s ess on he indi idual in i s mos sensi i e
pe iod. Ano he impo an pa ame e is he
measu emen o he amoun o ood b ough o he
nes by indi iduals o eed hei o sp ing.
The p oposed sys em allows us o pe o m a
con inuous moni o ing o he ep oduc ion wi hou
s essing he indi iduals, e.g. ob aining eliable body
mass measu emen s e e y ime a bi d en e s o
lea es he nes . The main p oblem ob aining he
measu emen s is he mo emen o he animal, which
p oduces uns able alues. These alues ha e been
calib a ed using a neu onal ne wo k p ocessing,
Figu e 1: Pic u e au oma ically aken by he ou side
came a o he moni o ed colony wi h he HORUS ex e nal
senso s. F om op o down i shows a pigeon, a lesse
kes el male and a emale.
ob aining high accu a e measu emen s.
The es o he pape is o ganized as ollows:
Sec ion 2 ocuses on he lesse kes el beha iou
s udy, especially compa ing a adi ional app oach
e sus au oma ed da a eading. Sec ion 3 b ie ly
desc ibes he HORUS sys em in as uc u e. A
de ailed desc ip ion o he in o ma ion ea men
de eloped in his p ojec can be ound in sec ion 4.
The esul s ob ained wi h ou sys em a e shown in
sec ion 5. Finally, sec ion 6 sum-up conclusions and
p o ides ema ks.
2 LESSER KESTREL BREEDING
BEHAVIOR STUDY
habi a s (Pee and Gallo-O si, 2000). The species is
also sensi i e o clima e wa ming (Rod iguez and
Bus aman e, 2003). So i makes o a good model
species o s udy he impac o global change on an
endange ed species.
2.1 T adi ional Moni o ing
The “Es ación Biológica de Doñana” (EDB-CSIC)
has been moni o ing lesse kes el colonies since
1988. I has been eco ding colony occupancy and
b eeding success in e ms o numbe o ledglings
and p opo ion o success ul nes s. Rega ding
indi idual moni o ing, bi ds ha e been ma ked wi h
me al and PVC ings wi h a unique alphanume ic
code ha allows iden i ying indi iduals by using
elescopes. Biome ic measu es we e aken
spo adically o all ma ked indi iduals when
cap u ed. Due o e hical easons, howe e , he
numbe o cap u es in he nes is limi ed ( he cap u e
al e s b eeding beha iou and may jeopa dize he
su i al o he o sp ing) and he majo i y o
esigh ings we e made wi h elescopes. This causes
high di e ences in he equency o ecap u es
among indi iduals mainly due o di e ences in
de ec abili y. In a classic da a base moni o ing,
2,135 bi ds igu ed as ecap u ed (including
esigh ings wi h elescope). On a e age hey we e
cap u ed 3 imes on he same b eeding season
( ange: 1-70). In app oxima ely 45% o cases, body
mass was measu ed and maximum numbe o
measu emen s pe bi d and yea was 4.
Because o ha , he pa e n o body mass
a ia ion o b eeding adul s om a i al o he
colony in mid-Feb ua y o he end o he nes ling
pe iod in mid-July is no well known. Acco dingly,
we ha e no in o ma ion on he pa e n o in aday
a ia ion in body mass.
The p oposed emo e moni o ing sys em aims o
b idge he abo e de ailed logis ic and e hic gaps,
hus allowing us o ge enough in o ma ion o
documen bo h pa e ns.
2.2 Au oma ed Da a Reading
Habi a moni o ing has e ol ed g ea ly e olu ion
due o he boom o senso ne wo ks echnology.
Se e al consequences ha e been caused due o
he inc ease o senso s: Fi s ly he quali y o
in o ma ion g ows in ime and on he spa ial
domain; secondly he possibili y o ansmi ing he
measu ed da a h ough he ne wo k inc eases he
need o ha ing high bandwid h communica ions;
and hi dly, i o he educ ion o he cos o he da a
The lesse kes el (Falco naumanni, igu e 1) is a
small (body mass a ound 150 g ams) mig a o y
alcon inhabi ing open landscapes (C amp and
Simmons, 1980). I is a colonial species ha b eeds
in old buildings, such as chu ches o cas les wi hin
u ban a eas in Wes e n Eu ope. The species
expe ienced a ma ked decline in i s Wes e n
Palea c ic b eeding ange in he middle o he 20 h
cen u y (C amp and Simmons, 1980; Bibe , 1990).
Conside ed p e iously one o he mos abundan
ap o s in Eu ope (Bijle eld, 1974) he lesse kes el
became ex inc in se e al coun ies (e.g. Aus ia,
Hunga y, Poland) and p ac ically disappea ed in
o he s (e.g. F ance, Po ugal, Bulga ia).
Medi e anean Spain cons i u es i s s onghold in
he Wes e n Palea c ic (Bibe , 1990). Howe e , he
Spanish popula ion also su e ed a p ecipi ous
decline, as i d opped om an es ima ed 20,000–
50,000 pai s in he 1970s (Ga zón, 1977) o 4,000–
5,000 b eeding pai s in 1988 (González and Me ino,
1990). This decline has been a ibu ed o he
educ ion in bo h he ex en and quali y o o aging
Figu e 2: HORUS Ne wo k scheme.
s o age makes possible o sa e huge amoun s o
da a.
All hese consequences imply some nega i e
e ec s: an inc ease o da a a ic and inc ease o
powe consump ion.
Some au ho s ha e aken hese e ec s in o
accoun (Cook, 2007; S idha , 2007) and ha e
exp essed he need o employ p ocessing echniques
in o de o educe hese handicaps.
The e a e di e en app oaches o habi a
moni o ing. Some o hem use wi eless senso
ne wo k echnology in o de o acqui e and p ocess
he physical in o ma ion (Ga cía-Sánchez e al,
2010; Handcock e al, 2010; Valen e e al, 2011;
Ca ullo e al, 2009). O he s ocus on he needed
middlewa e ha allows access o he physical
in o ma ion (Hwang e al., 2010; Fa shchi e al.,
2007).
In ou app oach, bo h aspec s a e conside ed.
3 HORUS INFRAESTRUCTURE
The p oposed in as uc u e is a dis ibu ed sys em
as igu e 2 depic s. This igu e shows he mos
impo an de ices o he p oposed a chi ec u e.
These de ices will now beb ie ly desc ibed.
3.1 Ne wo k In as uc u e
The HORUS in as uc u e is made up o di e en
subsys ems in e connec ed h ough a low da a a e
communica ion ne wo k.
This ne wo k has been designed conside ing he
ollowing es ic ions:
The de ices ha p o ided in o ma ion o he
ne wo k a e deployed in a sp ead way wi hou
any p e ious planning.
The da a a e associa ed wi h he da a sou ces is
low (< 250 kbps)
The sys em could be easily scalable.
The ne wo k used in HORUS can be accessible
h ough di e en physical media (wi eless o wi ed
based).
Robus ness o he ne wo k is e y impo an , o
he p oposed applica ion: du ing he b eeding pe iod,
i is no possible o ealize main enance asks,
because i can dis u b and s ess he colony. All
de ec ed ailu es would be epai ed in win e , a e
he bi ds ha e le he colony.
3.2 Base S a ion
The p ocess se e is a sys em ha o e s he
ollowing se ices:
Da abase se e .
Moni o ing and con ol sys em.
Remo e con ol access.
The da abase s o es all he his o ic senso s
in o ma ion ga he ed om he sys em.
The moni o ing con ol sys em is a p og am
esponsible o adding addi ional aluable
in o ma ion o he senso measu emen s, such as
in o ma ion abou he nes sende , a ime s amp
egis e o a con ol sequence, ha pe mi s
Figu e 3: Nes cabine .
de e mining he numbe o loss packe s. This sys em
s o es he in o ma ion in he da abase.
Remo e access con ol o e s he cloud se ices
o emo e use s, such as biologis s. These se ices
pe mi emo e access o he senso s da abase.
3.3 Sma Nes -Boxes
The sma nes -boxes a e he main componen s o
he moni o ing sys ems. I consis s o he nex wo
blocks:
The nes cabine .
The elec onic sys em
The nes cabine (Figu e 3) is di ided in o wo
pa s: a co ido and he incuba ion chambe . This
nes cabine has a sma design o ensu e ha he
bi ds pass he co ido each ime hey en e o lea e
he nes . The ad an age o his is o allow he
dis ibu ion he senso s in a small a ea ( he co ido )
whe e he animal is o ced o pass and, he e o e, i
ensu es ob aining he senso in o ma ion.
The elec onic sys em (Figu e 4) o each sma
nes -box is accomplished wi h he nex subsys ems:
3.3.1 Mic ocon olle Boa d
This boa d is based on he ATmega2560, an
economic, low powe and obus mic ocon olle . I
con ols and p ocesses he nes ’s senso in o ma ion.
This boa d communica es wi h senso s and o he
componen s, and p ocesses he collec ed in o ma ion
ha is sen o he p ocess se e o e he
communica ion in e ace.
The p og am implemen ed in he mic ocon olle
pe o ms he ollowing asks:
Communica es wi h he p ocess se e o e a
communica ion in e ace, and synch onize
clock ime wi h his.
Figu e 4: A chi ec u e o he elec onic sys em.
Checks in a- ed ba ie s. Each nes -box has
wo in a- ed ba ie s a bo h ex emes o he
co ido . The sequence in which hey a e
ac i a ed indica es whe he bi ds en e o
lea e he nes -box.
Checks i he RFID eade has ead a code om
inged kes els.
Ob ains he body mass measu emen om a
digi al balance.
Reads he empe a u e and humidi y o he nes .
Con ols he RFID eade o iden i y
indi iduals.
3.3.2 Senso s Boa d
A senso boa d adap s he logic le els om he nes
senso s o he mic ocon olle boa d’s equi emen s.
All he nes ’s senso s a e sp ead on o he
co ido o he nes . Posi ions o senso s a e
designed o ensu e ha e e y ime he bi ds pass he
co ido he sys em egis e s a leas one eco d pe
senso .
The deployed senso s a e:
A digi al balance. I allows a maximum weigh
o 600 g . and an accu acy o 0.01 g , o e ing
16 measu es pe second. I pe mi s ge ing an
es ima e o he body mass o he indi iduals in
mo emen . Al hough he pan is ound, i has
been modi ied o be ec angula in o de o i
he shape o he co ido .
(a)
(b)
(c)
(d)
Figu e 5: Di e en weigh pa e n Y-axis, weigh in g ams. X-axis, samples.
An in eg a ed empe a u e senso loca ed in he
window. I is calib a ed o ope a e in
en i onmen al empe a u e ange. I is used o
measu e he nes empe a u e.
An in eg a ed humidi y senso . I is used o
measu e he nes humidi y.
Two in a- ed ba ie s, used o ace he
di ec ion o bi ds’ mo emen s.
A RFID eade . I communica es ia RS-232C
and o e s a eading on he unique ID o a
agged bi d, when i is passing h ough he nes
en ance. This sys em has mechanisms o a oid
collisions, pe mi ing ope a ion e en when
he e a e se e al bi ds a ound he en ance.
A Se omechanism. I is used o emo ely
cap u e bi ds when hey en e in he nes -box.
4 TREATMENT OF THE
INFORMATION
As desc ibed be o e, e e y nes -box p o ides he
ollowing in o ma ion:
Measu emen s o body mass: The digi al
balance used o e s 16 measu emen s pe
seconds wi hou calib a ion and classi ies
measu emen s as s able o uns able.
IR in o ma ion: These senso s pe mi
de e mining i he bi ds go in o o go ou o he
nes .
RFID in o ma ion: I pe mi s a ibu ing he
in o ma ion o o he senso s o an indi idual
bi d.
All his in o ma ion is ob ained om he senso s
deployed in e e y nes -box. The senso s o e
ele an in o ma ion on he indi idual b eeding a
he colony o he biologis s ha s udy hem. This
in o ma ion, excep he body mass, canno be added,
as hey in o m abou disc e e e en s. The e o e, his
in o ma ion is sen di ec ly o he da abase wi hou
any local p ocessing o ea men .
On he o he hand, he digi al balance o e s a
high amoun o in o ma ion. I s equency o
measu emen is much highe han he body mass
e olu ion o he animal. i.e., he animal body mass
e olu ion has mo e ine ia han he weigh p o ided
by he balance. Due o his, i is possible o pe o m
a da a p e-p ocessing abou weigh in o ma ion,
educing wi h ha he amoun o in o ma ion send o
he cen al p ocessing.
4.1 Weigh P e-p ocessing
The algo i hm desc ibed in his pape , is ocused on
locally p e-p ocessing he weigh in o ma ion, o
educe he amoun o unnecessa y in o ma ion and
inc ease i s accu acy. I is designed o be execu ed in
each nes -box, in he mic ocon olle boa d. I has
been designed o ul il he nex goals:
To educe he amoun o useless in o ma ion in
he da abase using local p e-p ocessing.
To inc ease he accu acy o he measu emen s,
calib a ing he esul s ob ained.
To inc ease accu acy o he communica ion
ne wo k, educing he amoun o packe loss,
he delays and he collisions.
To inc ease he amoun o use ul in o ma ion in
he da abase, es ima ing a body mass om
each pa e n wi h non-s able measu emen s.
To pe mi i s execu ion on de ices wi h low
esou ces.
To inc ease he accu acy a a e calib a ion is
necessa y. The balance used o e s measu emen s
wi hou a a e calib a ion. This calib a ion would be
ob ained consul ing he body mass measu ed by he
balance, when he e is no animal on he pan i.e.,
when he measu ed weigh is below a ce ain

es ima ed h ough a compu a ional in elligence
algo i hm. In bo h cases, only one selec ed weigh
pe pa e n is sen o he da abase. These selec ed
weigh s a e calib a ed wi h he a e, be o e sending
hem.
The p oposed algo i hm is summed-up in he
nex pseudo-code:
while 1:
wai new(meas_weigh );
i meas_weigh >= h eshold
weigh [i]:=meas_weigh – a e;
inc ease I;
i s able(meas_weigh )==1
s able :=1;
end i
else
i i!=0
i s able==1
es _weigh :=a e age(
s able_weigh );
s able:=0;
else
es _weigh :=model(weig h);
end i
send_se e (es _weigh );
i:=0;
else
new_ a e:=meas_weigh ;
a e:=I e _RMS(p e _ a es,
new_ a e);
end i
end i
end while
4.1.1 Applying Machine Lea ning o
Weigh Recogni ion
Fo his applica ion, an algo i hm has been
e alua ed. Ini ially, an algo i hm wi hou machine
lea ning based on he di e ences be ween
consecu i es measu emen s has been conside ed.
This algo i hm conside s a weigh s able i he e a e
mo e han a ce ain numbe o measu emen s o he
same weigh . This is simila o he in e nal algo i hm
o he balance o agging measu emen s as s able o
uns able, bu i is less es ic i e: he balance
equi es a high numbe o measu emen s wi h he
same alue o conside a measu emen s able. I
pe mi s he e ie al o some weigh s om he
uns able pa e ns, bu i ails wi h complex pa e ns.
Ou p oposal o using compu a ional in elligence
(machine lea ning) inc eases he pe cen age o
success.
Machine lea ning is widely used in pa e n
ecogni ion, bu i s use in animal moni o ing is less
widesp ead. O he supe ised lea ning echniques
apa o he neu onal ne wo k ha e been conside ed.
h eshold. This h eshold can be ob ained as a
unc ion o he body mass o he animals o moni o .
In ou deploymen o he Lesse Kes el (wi h a
body mass ange o 100-190 g) a h eshold o 100
g ams o has been used.
In he eal deploymen we ha e p o en ha he
a e does no change signi ican ly du ing a yea .
The e o e, measu ing he a e only once pe day
o e s enough accu acy o he p oposed sys em.
On he o he hand, as desc ibed be o e, he
balance o e s 16 weigh measu emen s agging
hem e e y second by i sel as s able (i.e.,
measu emen s ha emain a same alue du ing a
long pe iod o ime) o uns able. Bu bi ds usually
do no pass o e he balance slow enough o ob ain
s able measu emen s. This causes he da abase o
ha e a high amoun o he in o ma ion as uns able
measu es. In he eal p o o ype only abou 15.25%
o he measu ed pa e ns had a s able measu emen ,
conside ing a pa e n as he collec ion o
measu emen s ob ained om he ime he bi d ge s
on he balance (i.e., when he balance acqui es a
weigh o e he h eshold) un il he animal ge s ou
o balance (i.e., when he balance acqui es du ing 5
seconds weigh s below he h eshold). Fig. 5 shows
di e en examples o weigh pa e ns ob ained in he
eal deploymen wi h hese condi ions.
This igu e shows di e en eal weigh pa e ns
ob ained om he same animal in di e en days.
Only pa e n (a) has some s able measu emen .
These s able measu emen s ha e been compa ed
wi h measu emen s o he animal done manually
cap u ing he bi d. The s able a e measu emen s a e
co ec , bu no equen enough o ob ain a long
e m sequence o body mass empo al change o he
bi ds a he colony.
To sol e his, a compu a ional in elligence
algo i hm o es ima e he body mass o animals om
he pa e ns wi h non-s able weigh s has been
de eloped, inc easing he amoun o use ul
in o ma ion. This neu onal ne wo k algo i hm is
desc ibed below.
Ini ially, he sys em has been designed o s o e,
in he cen al se e , all weigh measu emen s o he
pa e n acqui ed by he balance, s able o uns able,
bu i causes high bandwid h consump ion in he
communica ions in e ace.
To educe he amoun o useless in o ma ion, he
p oposed algo i hm only sends one es ima ed weigh
o he da abase o each measu ed pa e ns. I he
pa e n has some s able measu emen s, he es ima ed
weigh sen o he cen al se e will be he a e age
o he ob ained s able measu emen s. I no
measu emen s o he pa e n a e s able, he weigh is
Non supe ised echniques, such as Sel -O ganized
maps (SOM, Kohonen, 1990) o Suppo Vec o
Machine (SVM, Co es 1995) we e disca ded,
because we ha e some s able measu emen s ha
pe mi pe o ming aining.
One example o he conside ed supe ised
machine lea ning echniques is he use o A i icial
Neu o-Fuzzy In e ence Sys ems (ANFIS; Jang,
1993). ANFIS has many applica ions in he
e alua ion o complex sys ems, bu i equi es a
p e ious knowledge o he sys em o design he ules
and he ini ial sys em. This sys em was disca ded;
due o he complex o ms o he pa e ns ha do no
easily pe mi acqui e his ini ial sys em.
Expe sys ems o case based expe s sys em
we e no conside ed, due o he amoun o p e ious
in o ma ion ga he ed om he sma nes -box was
no su icien o hese kinds o sys ems.
Fo hese easons, a neu onal ne wo k model was
inally chosen. The a iables used as inpu s o he
model a e as ollows:
Max_1: The mos epea ed weigh in a pa e n
( he la ges i mul iple).
N_1: Numbe o epe i ions o he p e ious
a iable in a pa e n.
Max_2: The second mos epea ed weigh in a
pa e n ( he la ges i mul iple).
N_2: Numbe o epe i ions, in a pa e n, o he
p e ious a iable.
Max_C1: The mos consecu i ely epea ed
weigh in a pa e n.
NC_1: Numbe o epe i ions o he p e ious
a iable in a pa e n,
Max_C2: The second mos epea ed weigh ,
consecu i ely, in a pa e n.
NC_2: Numbe o epe i ions, in a pa e n, o
he p e ious a iable.
N_EL: To al numbe o weigh measu es in a
pa e n.
In o de o ob ain hese pa ame e s, a pa e n
wi h a leas 5 weigh measu emen s is needed. As
Table 1: Analysis o he da abase.
Cap ion
Value
Measu emen weigh
2583565
Numbe o pa e n
51517
Pa e ns wi h s able weigh s
7856
A e age pa e n ime
23,18 seconds
Days o es
399 days
an alue ou pu , he neu onal ne wo k model o e s a
alue, called “Ou pu weigh ”. This ou pu e lec s
he es ima ed weigh o he neu on model and i is
he in o ma ion sen h ough he ne wo k o he
se e da abase.
The s eps execu ion o his neu onal ne wo k
model is summed-up in he nex pseudo-code, whe e
he neu onal ne wo k is he execu ion o a h ee
laye ne wo k.
Neu onal ne wo k needs a se o pa ame e s o
i s aining. These se s ha e been ob ained o each
pa e n wi h s able measu es, by execu ing he
ollowing s eps:
S ep 1: A a iable name “Ta ge weigh ” was
de ined o e e y pa e n. This a iable s o es he
a e age alue o all s able weigh s. This is he a ge
esul o he aining o he neu onal ne wo k.
S ep 2: Fo e e y pa e n, a new pa e n has been
c ea ed, elimina ing all s able measu emen s.
S ep 3: The inpu s ha e been ob ained om his
new pa e n wi hou s able alues.
S ep 4: The inpu alues o each pa e n we e
s o ed, oge he wi h hei espec i e Ta ge weigh
in o a able, named “T aining in o ma ion”
Wi h hese ables wo se s o in o ma ion we e
ob ained, one o aining and he o he o
e alua ing he accu acy o he sys em. In o al, he
aining in o ma ion able has 1163 se s o alues.
50% o hese alues ( andomly selec ed) we e used
o aining, and he o he 50 % we e used o
alida ion.
5 SIMULATION, TESTS AND
RESULTS
The esul s ob ained wi h his sys em can be
classi ied in wo ypes: analysis o he ne wo k
pe o mance and weigh es ima ion accu acy
ob ained wi h he eal deploymen .
This sec ion summa izes hese wo ypes o
esul s.
5.1 Ne wo k Pe o mance
Du ing he i s yea o he deploymen (2010), he
p o o ype was sending in o ma ion om all senso s,
e en he 16 eco ds pe second o he balance, o he
da abase o he cen al se e . The main
cha ac e is ic o he ga he ed in o ma ion in he
da abase is summa ized in able 1.
A e a yea o deploymen , he analysis o da a
allowed us o de ec some ne wo k con lic s. Fo
example, i di e en nes -boxes a e acqui ing
weigh s om indi iduals a he same ime, hey a e
compe ing o con ol o he bus, causing da a
collisions and delays in ansmi ing in o ma ion.
Table 2: Cos pe message wi h CC2420 Radio
anscei e .
Cap ion
Ene gy (J)
Wi hou da a usion
255.3
Wi h da a usion
0.608
The p oposed sys em allows a oiding hese
con lic s, using he p oposed da a usion.
In his sec ion we a e going o quan i y he
ad an age o da a usion agains he classical
cen alized sys ems. Due o ha , in his kind o
applica ions i is impo an o educe he use o
bandwid h as much as possible.
The analysis o da abase in o ma ion has been
summed-up in he able 1. I shows ha only a
15.25% o he acqui ed pa e ns ha e any s able
measu emen .
Knowing ha he balance o e s 16 Samples Pe
Second (SPS), he a e age payload o he
applica ion laye pe pa e n o he sys em wi hou
da a usion can be ob ained wi h he equa ion 1.
,16 · · ·
T aw SPS T By es msg
N P N N
(1)
Whe e
,T aw
N
is he numbe o by es o send
pe day a applica ion laye ;
T
P
is he leng h o he
pa e n in seconds;
By es
N
is he numbe o by es o
send. 16 by es in his case and
msg
N
is he numbe
o messages pe day.
On he o he hand, wi h he p oposed algo i hm,
only one message pe pa e n is sen . In his case, he
payload pe pa e n can be ob ained acco ding o
equa ion 2.
,·
T aw By es msg
N N N
(2)
This shows ha he amoun o in o ma ion sen
o he da abase a ies in unc ion o he numbe o
pa e ns and he leng h (in ime) o he pa e n.
Figu e 6 depic s hese esul s.
Concluding, he local p ocessing pe mi s one o
d as ically educe he used h oughpu o he
ne wo k, especially in days wi h a high numbe o
pa e ns.
This da a usion and agg ega ion scheme is
especially impo an o i s use in low bandwid h
sys ems, due o i pe mi ing one o sa e ene gy.
Wi h he p oposed sys em, only one message pe
pa e n is sen , ins ead o 16 measu emen s pe
second du ing he cap u e o he pa e n. These
esul s a e summed-up in able 2. They conside he
a e age pa e n leng h o 23.18 seconds, i.e. he
a e age ime while he bi d is on he balance.
Wi h hese condi ions and wi h he CC2420
adio anscei e , widely used in wi eless senso
ne wo k, pe mi sa ing 99.76 % o he ene gy used
in da a ansmissions, conside ing a powe
consump ion o 38mW in ansmission mode
(Polas e e al, 2005.
Using all weigh pa e ns ob ained in he yea
2010, he p oposed body mass es ima ion algo i hm
pe mi s he e ie al o a ound 56.21% o he
pa e ns wi hou s able measu emen s.
This is a good esul ha pe mi s us o ob ain an
a e age o 4 body mass es ima ions pe day and
nes , which is 4 imes highe han using only
pa e ns wi h s able measu emen s. I pe mi s o
ha e a con inuous acing o body mass in
indi iduals.
As a conclusion, he local p ocessing pe mi s us
o d as ically educe he used h oughpu o he
ne wo k, especially in he days wi h a high numbe
o pa e ns.
5.2 Body Mass Es ima ion Accu acy
Based on he aining and e i ica ion se desc ibed
in sec ion 4.1.1, some analysis has been done o he
p oposed algo i hm o body mass es ima ion.
Wi h he e alua ion se , he sys em o e s an
accu acy o 98.7%, i.e., an e o in he o de o 2
(a)
(b)
Figu e 6: By es pe day send, a applica ion laye , o he cen al se e . (a) Wi hou da a usion. B) Wi h da a usion.
Figu e 7: Neu al ne wo k model: impo ance o he
a iables in he calcula ion o he es ima ed weigh s.
Figu e 8: G ain ele a o used o he p o o ype
ins alla ion.
g ams, which is qui e small conside ing he ypical
body mass o hese animals (150 g ams).
This accu acy pe mi s analysis o a long se ies
o he e alua ion o empo al changes in body mass,
and some imes o de e mine he body mass o p ey,
when bi ds b ing medium-sized animals o he nes
o eed he nes lings.
F om he aining p ocedu e, an analysis o he
impo ance o he inpu pa ame e s in ela ionship
wi h he a ge body mass can be ob ained. Figu e 7
shows hese esul s. This analysis concludes ha he
selec ed pa ame e s a e alid o e ec i ely es ima e
he body mass o animals.
5.3 Real Deploymen
A p o o ype, o a eal alida ion o he p oposed
sys em, has been deployed in he g ain ele a o o
“La Palma del Condado (Huel a P o ince, SW
Spain” ( igu e 8). A his si e, esea che s o he
Es ación Biológica de Doñana ha e been s udying
he lesse kes el colony since 1994. A his colony,
kes els nes ed on he windowsills o he g ain
ele a o ha a e shel e ed and su icien ly enclosed
o make a sui able nes ing si e.
Fo he p o o ype ins alla ion we selec he
windows on he 6 h loo o he building whe e
sma nes -boxes we e ins alled, and eadily
accep ed, by kes els du ing p elimina y checking (3
and 4 nes -boxes du ing 2008 and 2009,
espec i ely) and also when he de ini i e p o o ype
ins alla ion was made in 2010.
Nes -boxes a e placed in all he windows along
he six h loo . They a e named “6XY”, whe e X
e e s o he ca dinal poin and Y is an o dinal
numbe . Each box has wo sepa a e en ances and
wo incuba ion chambe s (I. le and D: igh ) in a
symme ical dis ibu ion. En ances a e placed a he
ex emes o he box o a oid po en ial agg essions
be ween neighbou s, hus maximizing he numbe o
po en ial b eeding pai s. None heless, he igh pa
has no been opened ye .
The esul s p o ided by he sys em a e s ill being
analysed by biologis s. Howe e , in i s cu en s a e,
i is possible o ob ain some conclusions:
18 o he 20 ins alled nes s-boxes we e used by
b eeding kes els. This leads o he conclusion
ha he p oposed sys em e ec i ely allows one
o ga he a high amoun o in o ma ion abou
he beha iou o b eeding indi iduals wi hou
s essing hem. I he nes and i s senso s we e
hos ile, i would no ha e been chosen by lesse
kes els b eeding pai s.
A p elimina y esul o he con inuous
weigh ing o indi iduals will allow he
esea che s o es ima e he cos o b eeding in
e ms o body mass. This cos is di ec ly
associa ed wi h he o aging ips o eed he
nes lings.
The lesse kes el mainly eeds on insec s, bu
some imes can ca ch sligh ly bigge p ey, such
as small oden s, bi ds o liza ds (wi h a ound a
dozen o g ams). The p oposed sys em would
pe mi an analysis o he equency o big p ey
cap u es.
6 CONCLUSIONS
The main goal o he p oposed sys em is o use
cu en echnological ad ances in a eal-wo ld
applica ion in he a ea o Biodi e si y Conse a ion
o s udy how global clima e change could a ec a
colonial and endange ed bi d species.
The esul s ob ained conclude ha he p oposed
sys em would pe mi i s use in a sys em wi h low
esou ces and wi h a low bandwid h usage.
The p o o ype deployed in Spain o e alua ion