Page 59 - Brighetti1979

in tutto il basso bacino dd Meditern:neo, sia verso sud che verso nord, dimostrando un
notevole senso di orientamento nel ritornare alle stesse colonie di nidifi~::1z~one.

Si ricordano a tal proposito alcuni esperimenti di "homing" effettuati con indivi-
dui nidifiea::~li nell'Isola di Skokho!m (Galles), che dimostrarono ( 2 individui su 12
liberati) di oaper ritornare al nido (purtroppo nel frattempo l'altro partner aveva
abbandonato l'uovo od il pullus) (LACK e LocKLEY 1938).

Com'è noto la specie è di abitudini altamente gregarie (soprattutto nel pe1·iodo
riproduttivo, allorché diviene anche stret:,mente noaurna) e si fa nnt:1re di solito in
gruppetti di 10-20 individui, che staziona:1o al largo o a non meno di 5-15 km. dai
litmali, verso i quali vengono sospinti in seguito a violente tempeste; il maltempo persi·
stente causa spesso serie difficoltà a questi piccoli uccelli, che in tali occasioni si riuni-
scono in stormi a volte molto consistenti.

SUMMARY - Storm Petrel - Hydrobates pelagicus

Partinlly sedentary and breeding in some rocky islets off the coasts of the Mediterranean
and Tyrrhenian Eeas. It breeds frcm sea level up to 50-60 lY'8tres.
The cituation shown by the map is very uncertain, excluding the Maltese Islands.
Breeding is known for the Egadi, Pelagie and more generi~ally for the Eolie islands
and is prob,ble for Pantelleria 2nd possible for UstiPI'. Tn t'le Maltese Islands (Filfla)

the grealest Mediterr~l'ean cokny exi.cts, with vbcmt ] o ono pai'C.S.

Vague news concerning breeding akng the coasts of Sicily ancl the continent has not
been confirmed.
In the Tyrrhenian Sea breeding is possible for the Pontine Islands and o:her n~arby ones
and the sam3 con be ,;nid a1nnt the nune::ons islands of the Tuscan Archipe1ago,
where sightings of spe~imens dm-ing tln breeding seuc,on are frequent and regnlar:
breeding was known in historical times. As regards Coreica 3 breeding sites are known
(the number of pairs is Hppraie8b1e with difficu\ty and varies between some tens and
some hund::eds). As r":'-p-·ds Sm-dinia seme clne.o indicate possible and pwb~ble 1y·~ccling
in islets of the northern, central-wec-tern, Ernthern and north-eastern coasts; old and
scarce inform3tion indi~~tPd b~·e~ding i~ the j_,lr.
On the basis of p:-esent rccords (excluding Ma!tese Ishnds) it is absolutely impossible
to estimate, even approxim"-tely, the totr.I existing popu!ation.
Amonl'\ limiting fo.,-,tm·c WP ca~ .. c:17.8'Tibcl- th2 pr~sence of rats ( Rattus sp.) and
feral dCJgs and cat>, tm,·ict distn,.banre (motorboat navigation), the picking of er,p;s and
chid:s and the coh.~bitnticn with l.ccru.s arr:entatus which preys upon juveniles and
adnlts surprised on lnnd during the day. The presence of Caionectris diomedea does
not appear to produce any negative effects.

MOVEMENTE. Relatively mÌ[Fant it makes movrment.s more or J,ss regular and
important according to the pbces and periods (August/Octcber and Febraury/April);
these movcments usually coincide with the departure from coloni8s and the following
reoccupation and concern in parti,ular the centrai and s'luth-western Mediterranean:
the movements towa1·ds the eastern areas during autumn (Blaclc Sea and Sea of Azov)
are scarce and irregular. The presence is regular in the Straits of Gibrnltar, although
the movements towa•ds th3 Atl:m'ic Ocean ( of the Mediterrancan populations) are
little known and not sufficiently ccnfirmed. In the Tyrrhenian and Adriatic seas the
populations disperse northwards and also southwards, regularly reaching Liguria and
Quarnero. The ringing program undertaken by The Ornithological Society in the
Maltese Islands has made it possible to establish (9800 ringed specimens since 1965-1978
with 20 recoveries) that specimens move in va"rious directions ( also during breeding
season) and are noted off the coasts of Tunisia, Sicily and in the lower Ionian Sea.

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