ATTRACTION OF THE EUROPEAN STORM-PETREL TO

ATTRACTION OF THE EUROPEAN STORM-PETREL TO

ATTRACTION OF THE EUROPEAN STORM-PETREL
TO HETEROSPECIFIC CALLS OF OTHER
NORTH ATLANTIC PROCELLARIIFORMES
Eduardo M~NGUEZ*
S~MMARY.-Attraction
of the European Storm-petrel to heterospecijic calls of orher North Atlantic
Procellariilomies. It is known that nocturnal oetrels are stronelv attracted to conscecilic vocaüzations.
Two expe&&& were performed to determin~iiattraction to heíerospmfic calls &urs in the European
Storm-petrel (Hydmbares pelagiw). Five plaring calls oí procellariiíorms were tesled lo lure the birds at
thc Mediterranean
diffemnt sites: the ~ t l a n t i csubsoecies of the Éurowan si&-oetrei.
H. o. oelaaicus.
"
sirbspecies, H. p. melitensis, and vocalizations of three species o1 North Atlantic procellariiíorms, Leach's
Stom-cetrel Oceanodroma leucorhoa. Cory's Shearwater Calonectris diomedea and Manx Shearwater
.%&U>
pu@nus. To compare attraction of the Atlantic storm-petrels. playback tests were periormed at
three breeding wlonies on small barren islands and at two close wastal sites in the Nortb of Spain.
Similar experimental sessions were conducted al a Mediterranean colony. in order to investigate types ol
resoonse. Both at the colonies and on the coast. storm-oetrels resoonded to all tace lures. but attraction
to Lla)back vocalirations o1 shearwatcn was smaller. ~ ; r p n s i n ~ the
l i Leach's ~t6rm-petrelcalls eliciied
behavioural responser Ir ir suggested that heterospecific vowlizations, and not only wwpecific, may acl
as indicators oiquality o í pot&ial breeding habitats.
Key words: Acoustic signals, European Storm-petrel, heterospecilic interaeiion, play-back atlraction.
..
RESUMEN.-Atracci6n del Palfio Eurooeo a cantos Iieteroesnecífieosde otras ~rocelarirormesdel Atldnlico Norre. Es bien conocido que los petreies nocturnos son atialdos fuertemente por la; vocalizaciones de
individuos wnespecficos. Se han realizado dos experimentos con el fin de determrnar si en el Palfio
Eurooeo l~vdrobaresoelnoicus) esta atracci6n ocurre tarabien para cantos heteroesM~cos.Se utilizaron cinco grabaciones de cantos de pr~alariformcspara atracr a las aves: vocalizaciones de la subupecie
atlsntica de Patiro Europeo H. p. pelagicus de la subespeae mediterrhea, H. p. melirensis. y vocalitaciones de tres escecies de ~rocelariformesdel AtlAncico Norte. el Palao Boreal Oceanodroma leucorhoa. la
Pardela ~cniiienta~ a h e c r r i sdiomedea y la Pardela ~ichonetaPuflnus pujinus. Para comparar la
atracci6n por parre de los pafhos atlAnticos se realizaron una serie de pruebas de respuesta a grabaciones
(nplaybackn)en tres colonias de cría en pequenos islotes y en dos lugares de la costa pr6ximos a estos, en
la Costa Cantabrica Espaaola. De forma similar, otro experimento se llevó a cabo en una colonia
Meditemanea para investigar los tipos de respuesta. Tanto en la colonia como en la costa los pafflos
euroceos resuondieron a todos los reclamos. si bien para las vocalizaciones de oardelas la atracción fue
men& ~orp~endentemente.
las grabaciones de cantosdel Pamo Boreal. provocarm respuestas comportamentales. Se sugiere que las vocalizaciones heterocspeclficas. y no solamente las conesp-xliicas, pueden
actuar como indicadores de la calidad de un potencial habitat para la reproducción.
Palabras clave: Atracción a grabaciones, interacciones heteroespecllicas, Paffio Europeo, seaales acbsticas.
INTRODUC~ON
Various functions have been attributed t o
the calls of nocturnal procellariifonns: sexual
and territorial advertisement (Brooke, 19784
1986; James, 1985; Bretagnolle, 1989; Taoka
& Okumura, 1989; Taoka et al.. 1989; Bretagnolle & Lequette, 1990; Bretagnolle &
Robisson, 1991). species-specifc recognition
(Bretagnolle, 1989; Taoka et al, 1989; BretagnoUe & Lequette, 1990; Bretagnoile & Robinsson, 1991), sex recognition (Bretagnolle, 1989;
Taoka & Okumura, 1989; Taoka et al., 1989;
Bretagnolle & Lequette, 1990), individual recognition (Brooke, 1978a, 1986; Bretagnolle,
1989; Bretagnolle & Lequette, 1990) and as-
* Departamento de Ecologla Evolutiva. Museo Nacional de Ciencias Naturales (CSIC). Jose Gutierra Abascal, 2. E-28D06 Madrid.
ATI'RACTION OF THE EUROPEAN STORM-PETREL
end of the tests (except one night, when it
was also switched on a t first). Each tfiai
lasted 5 minutes. Alternativeiy the tape remained silent or the Eagle Owl recording
was played back during the five minute
intertriai periods. The number of birds
flying or landing in a 1* l * S m3 volurne
around the speaker were noted. Responses
were classified as 'Direct íiight', 'Circle
flight', 'Landed' (Bretagnolle, 1989) and
'Hovering flight' (when a bird flies slowly,
flapping fast and with sort wing beats).
Playback tests with Arlanlic European
Stown-pelreis
As table 1 shows, birds responded to the
úve lures on al1 the trials done within a colony, but on the coast many trials did not elicit
responses, especially for Cd and Pp where the
frequency o í response was lower than at the
colony (two-tail Fisher's exact test, P values
in table 1). On the coast, frequency of respon-
Frequency of responses by Atlantic European Storm-petrels lo playback o1 different vocalizations played
in colonies and on the coast. As a nresoonsen is considered the change o f traiectory uerfonned by at least
one bird flying over the speaker, see iext for more details. P valuecare &en hithe two-tailed Fishers
exact test.
[Frecuencia de respuestas de Palrlos Europeos Atldnlicos a distin~asgrabaciones de vocalizaciones reproducidas en las colonias y en la costa. Como .respuesta. se ha considerado el cambio de trayeeroria realizado
por al menos un ave uolando sobre el altavoz ver el texto para mós detalles. Losvalores de P son dados por la
prueba exacta de dos colas de Fisher.]
COLONY
COAST
Tape-Jure
Response
No response
Response
No response
P
H. p. pelagicus ...........................
H. p. melitensis ..........................
0. Ieucorhoa .............................
P. pufinus .................................
C. diomedea .............................
24
25
10
O
18
17
6
3
2
1
1
2
5
6
n.s.
n.s.
n.s.
0.025
0.009
O
O
O
O
7
6
Time o1 response (in seconds) o1 Atlantic European Stonn-petrels to playback o1 dillerent vocalizations
played in colonies and on the coast. P values are given by the Mann-Whitney U-test.
[Tardanza en la respuesta (en segundos) de Pafños Europeos Atlánticos hacia reclamos hechosfuncionar en
los colonias y en la costa. Los ualores de P son dados por la prueba de la U de Mann-Whitney].
COMNY
Tape-Jure
n
................... 24
.................. 25
O. leucorhoa ...................... 10
P. puflnirs ........................ 7
C. dioniedea ....................... 6
H. p. pelagicus
H. o. melitensis
COAST
mean
standard
deviation
46.95
43.08
68.20
16.71
100.66
51.67
41.00
124.62
15.34
108.38
n
mean
standard
deviarion
18
178.22
110.70
162.00
239.33
272.00
176.90
117.04
63.20
183.74
108.89
17
6
3
2
P
0.001
0.012
0.009
0.03
n.s.
Frequmcy of trials in whicb a response is oblaiwd, frqumcy of responvs $ 0 ~ trials
8
(ooe individual
could show more than one mponx) and mean mponsc-delay times (standard deviaiions io brackets) by
Meditemwan Eurooean Sto&-wtnls to ~lavbackoi dimerent vocalizations daved in the wlonv of
Benidonn Island. ~&snspecificlure results a k iompared with other calls and Sth-silena. P valueian
given by t b Mann-Whitney U-test.
rFremencia de vmebas en los me ha habido al menos una resmesta. frecuencia de resmesas por prueba
ipudiendoun m&mo individuo niornar más de una respuesra) y liempo &dio de tardanza (den<&& tlpico
enrre paréntesis) poro Pelaos Europeas del Mediiewáneo hada disrinras grabaciones de malizacionos
hechnsfincio~ren la colonia de Benidorm. Los resultados con el rechno conespeclfrcose comparan con
otros llamadas y con nsilencior. Las wlores de P son dados por la prueba de lo U de Monn-Whirney].
Type of Tape-hre
Numbers of pleybacks
Frequency
of responses
during trials
P
of response
P
8.29 (6.07)
-
31.14 (23.96)
-
3.45 (5.43)
0.006
127.11 (84.72)
0.04
1.94 (1.81)
0.0002
129.75 (99.43)
0.002
123 (1.01)
<0.0001
101.77 (97.99)
0.09
8 (SO)
0.81 (1.11)
<0.0001
165.13 (93.88)
0.001
7 (5385)
1.0 (1.15)
<O.0001
152.42 (95.64)
0.01 1
Response
(%)
H. p. melitensis ................. 7 (100)
n=7
O. leucorhou .................... 9 (81.82)
n=ll
P. pf@Enw ....................... 12 (75)
n=16
C. diomedea ..................... 9 (69.23)
TTme
n=13
Bubo inibo .......................
n = 16
No caü
played back. n= 13 ..........
ses of Hpm and OI were similar to Hpp (two- island in order to establish different types of
tail Fisher's exact test, m.), but not to Cd responses towards the calls. The total num(two-tail Fisher's exact test, P=0.0006) or to ber of responding birds and times of response
P p (two-tail Fisher's exact test, P=0.003). shows that, as was expected, the Hpm lure
Dunng the five minutes intertrial penod was clearly more attractive than the rest of
when no cal1 is played back, no birds were the caUs (Table 3). Comparing types of ressighted above the silent speaker.
ponse, the direct flight response (Table 4, fint
Responsedelay time was longer at the column) shows no significant difference for
coast stations than within the wlony (Ta- al1 the caUs played back when compared to
ble Z),except for Cd (Mann-Whitney U-test, the silent control (Mann-Whitney U-test, al1
P=0.28b In ail of these, response times to cdls compared with no cal1 played, Pz0.05
calls of other spenes did not diier significan- for a11 tests). However, the number of birds
tly hom those to calls of Hpp, both at the flying in loops ('circle flight') is higher during
colonies and on the wast (Mann-Whitney trials than for control with the Hpm lure
U-test, P>0.05 for al1 tests, not signilicant). (Mann-Whitney U-test, U = 7.0, P=0.001) and
perhaps also with the 0 1 recording, although
the difference is not significant (Mann-WhitPlayback tests with Mediterronean European ney U-test, U=42.5, P=O.W). If only the behavioural responses are taken into account
Stom-peirel (types o í response)
(without 'direct íüght'), sign~ficantdifferences
Tables 3 and 4 summarize the results of the appear while Hpm cal1 or O1 calls are played
expenments done at the coiony oí Benidorm back (Mann-Wtney U-test, U=7.0, P=O.Wl
FIG.I . - S o n o m s oI the Euro~eauStorm-cetrel calls uxd in olav-back exoenmeals íobtaiued Irom
o1 H. pe¡aginrs pelogicus (above): ~urr-caila i d ~ l i ~ h l i a(Irom
l l i300 ms) oí H.
Roche -19901~~urriall
pelagims melirensls @elow).Noted thal thc purring ir overlapped by the flightaill ol another individual.
[Sonogramas de los cantos de PafAo Europeo utilizados e n h s experimentos de respuesta, obtenidos de
Roch6 (1990). nPurr-callr de H . pelagicus pelagicus (arriba): .Purr-callr y rFlighr-callr ( a partir de 1300
ms) de H . pelagicus melitensis (abajo). Ndtese que el rpurr-callu se solapa con el nflight-callr de otro
individuo.j
were some circle fiights when the 01 calls
were broadcasted flable 4). On the wast,
where there were also circle füghts (not a u n ted) in response to Hp, 01 and Pp, the majority of responses were 'direct ilights'. At the
colony of Benidonn, the number of birds giving the direct flight response did not vary
according to the cal1 played back. Similarly,
Bretagnolle (1989) lound that in Wilsons Petrel (Oceanites oceanicus) the direct ilight
response was not different for the three types
olconspecific calls played by him, and he did
not consider these as positive responses. However, the presence of these flights at a site
outside of the colony islet, where no liying
birds were sighted when the tape-lure was
swiched off during the 5 minutes inter-tnal
time, suggests that these ilights could be a
form of positive response as birds changed
their trajectory to approach the lure at a
coastal site.
Time of response was ionger on the coast.
Presumably most birds arrived from the nearest colony, as the probability of attracting
these birds is smalier at a point away from
the colony. Moreover, birds would spend
more time iiying to the tape-lure. Perhaps,
breeding individuals that can be attracted
witbin the colony (possibly by territorial reason$ are less frequently attracted near the
coast (Fowler et al., 1982), as probably the
meanings of calls and the type of response
would be different according to sex and reproductive status of the birds (Bretagnolle,
1989; Bretagnolle & Lequette, 1990). Response-delay times to the European Storm-petrel
147
ATTRACTION OF THE EUROPEAN STORM-PETREL
lures were difíerent with respect to the other
lures in Benidorm, but not in Asturias. This
may be expiained because arrival times at the
Atlantic localities showed a large dispersion
and the sample was small (see Table 2).
Attraction to nonspecific lures seems to
occur also at other sites and with different
species of petrels: Leachs Storm-petrel is attiacted b y the European ~torm$etrel lure
{Fowler et al. 1982). even thoueh its resDonse
io the consp&c &ll appears l o be hetirosexual (Taoka et aL, 1989). Broadcast calls of
Leach's Storm-petrel attracts the Ashy
Storm-petrel O. homochroa (Ainley et al.,
1976). Probably a large proportion o í the
European storm-petrels caught by Love
(1979) using Leach's Storm-petrel tapes, were
lured when calls were playing. Also, Swinhoe's Storm-petrel O. (leucorhoa) monorhis
has been attracted by recorded calls of H.
pelagicus and 0. leucorhoa in Atlantic colonies (Bretagnolle et al., 1991). Even a Cory's
Shearwater was caught presumably lured by
broadcast calls of the European Storm-petrel
(Hams & Jackson, 1992).
Although the European Storm-petrel is
highly phylopatric (Cramp & Simmons, 1977;
Htmery et al., 1987), it is possible that a significant proportion of the population does not
breed on the natal island, but in general relatively close to it (e& Brooke, 1978b). It is also
no¡ uncommon to find storrn-petrels in burrows mrforminn ore-breedine activities on
localiti& iar from ihe original-breeding area
(Warham, 1990; Bretagnolle et al., 1991), and
it has been suggested (James, 1983; Storey &
Lien, 1985) that wandering individuals, with
their constant movements (Fowler et al.. 1982;
Furness & Baillie, 1981; Podolsky & Kress,
1989; Mfnguez et al.. 1992) could evaluate potential breeding areas. As Podolsky & Kress
(1992) have suggested for conspecific vocalizations in the Dark-rumped Petrel, the calls of
wnspecifics are perhaps a good indicator of
the quality of a breeding site (social facilitation hypothesis). However, it is also possible
that attraction to heterospecific lures of species nesting in a similar habitat would be also
advantageous at least for some oí the species
searching for appropriate breeding sites. Perhaps for this reason, attraction to the single
storm-petrel vocalization tested (O. leucorhoa
lure) was higher than to the shearwaters calls.
It is important taking into account that
most storm-petrels come ashore only after
dark and it is probable that their vision is not
strongiy adapted to their nocturnal habits, as
in other nocturnal procellariiforms (Brooke,
1989; Martin & Brooke, 1991) and as behavioural observations by night hint for H. pelaoicus (Mfnguez, unpublished data). Under
these condit~ons,crucial informatión about
ohvsical and ecoloacal asaects of the Doteniiaí breeding siie,&ch as'if it is a sife site
without mammalian predators, could not be
obtained.
Attracting heterospecifics may be costly for
the birds due to increasing wmpetition ior
nest-sites and food, and transmission of ectoparasites and diseases, but this relatively
small cost (as interspecific competition is
smaller than within species) is balanced
against the large benefít of a conspicuous
auditory display in the darkness, that has a
variety of functions (see Introduction). So,
the selective pressures to adopt mechanisms
for the avoidance of attracting other species
would be small. In fact, most of the burrowing and nocturnal species of petrels present
acoustic displays. Another possible mechanism to avoid being heard by heterospecifics
would be to emitt calls in inaudibles frequencies, but ultrasonic calls have not been detected in the European Storm-petrel and
Leach's ~torm-petrel,which are the oniy species that have been investieated (Ranft & Slater, 1987).
Apparently, breeding in mixed colonies
does no appear to offer benefits to nocturnal
petrels, since it is unlikely that active defense
against predation could occur in these species. Nevertheless, breeding colonies would
perhaps serve as 'infonation centres' (Ward
& Zahavi, 1973) also for closely related species.
-
ACKNOWLEDGEMENTS.~
am most grateful to
José Eugenio Ortega for his suggestions and to
Jos6 Pablo Veiga, Rafael Mdrquez and Juan Moreno lor revising (he original draft. 1 thank Jesds
Pinilla and Andy M. Paterson for correcting the
language. Also 1 am grateful to ALOSA editions
for permitting me to use iheir recordings for playback tests and plot the sonograms that were obtained by R. Mdrquez in the Bioawustic Laboratory
of the Museo Nacional de Ciencias Naturales
(CSIQ. Thanks are extended to V. BretagnoUe and
an anonymous referee for greatly improving tbe
first version of the manuscript.
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ATlRACTlON OF THE EUROPEAN STORM-PETREL
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