L’Anatra marmorizzata Marmaronetta angustirostris nidifica in Sardegna
Nell’estate del 2013 è stata riscontrata la prima nidificazione di
Anatra marmorizzata in Sardegna. L’evento è particolarmente interessante in
quanto la specie, oltre ad essere considerata minacciata a livello globale da
BirdLife International, in Italia nidifica solo in Sicilia con singole coppie.
La notizia è stata ufficializzata sulla rivista British Birds (Podda & Grussu 2014 –
Marbled Ducks breeding in Sardinia and Sicily – British Birds 107: 485-488); la località di nidificazione, per
motivi evidenti, è stata mantenuta segreta. Di seguito alleghiamo il testo
della nota, pubblicata di recente. Un articolo più approfondito e con un
maggior numero di fotografie è in preparazione da parte degli stessi AA. per il
prossimo Aves Ichnusae.
______________________________
British Birds 107 • August
2014 • 485– 488
Marbled
Ducks breeding in Sardinia and Sicily
Massimiliano Podda & Marcello Grussu
The
Marbled Duck Marmaronetta angustirostris is
classified as ‘Vulnerable’ by the IUCN. Four separate
biogeographical populations have been identified; the
west Mediterranean
population breeds in Morocco, Algeria, Tunisia
and Spain and is believed to winter in North Africa and
sub-Saharan West Africa. Largely because of extensive
habitat loss, but also fluctuating patterns of rainfall and
water levels in wetland areas, the population declined throughout
much of the twentieth century, although the last 20 years
or so have seen some recovery. In Spain, for example, the population
declined from several thousand pairs at the end of the
nineteenth century to 30–40 pairs in 1994
(BirdLife International 2004), recovering to 96
pairs in 2007, with a handful of pairs now
breeding in the Balearics and 30–200 pairs in the Canary Islands
during 1994–2001 (Martí & del Moral 2003; GOB 2010).
However, this apparent increase in the west
Mediterranean population may reflect improved awareness and
observer coverage rather than a true increase (www.birdlife.org). The Marbled Duck has always been a rare and
irregular visitor to Italy. The species may have bred occasionally in the past,
although there is no confirmed evidence. For example, about 50 documented
records in the nineteenth century included a group of c. 70 in June–August
1892 on Lago di Massacciucoli near Lucca, Tuscany, which led Giglioli (1907) to
suspect that breeding had occurred. There were just 20 records of Marbled Duck
in Italy in the twentieth century but, since 2000, breeding has occurred in
Sicily, the first confirmed breeding records for Italy. This note documents a
further breeding record, from Sardinia in 2013.
Breeding
in Sardinia
On 5th
May 2013, MP discovered a pair of Marbled Ducks on a wetland in southwestern
Sardinia. The site was visited regularly after that and on 30th June a female
and 14 ducklings (judged to be about one week old) were seen (Plate 01).
Fourteen young were still present on 10th July, but the brood had declined to
ten on 4th August, while at least four and possibly six young were present on
19th August. The wetland concerned is rich with emergent vegetation, including Phragmites
australis, Thypa, Juncus, Carex,
similar to the breeding sites elsewhere in the species’ range (Green 1996).
Since the incubation period is approximately 25–27 days (BWP), the
first observation suggests that the clutch was completed around 28th May,
followed by hatching on or about 23rd June. In Spain, broods have been recorded
between mid April and mid September, with a mean hatch date of 20th June (Green
1996). There are about ten historical records of Marbled Duck in Sardinia, two
in the twentieth century (Grussu 2001; Brichetti & Fracasso 2003), an adult
bird near Portoscuso, Cagliari, on 27th May 2007 and then up to three birds
present in wetlands near Portoscuso from 26th August to 3rd October 2012 (MP
and MG pers. obs., Roberta Corsi pers. comm.). Clearly, the habitat conditions
in southwest Sardinia are currently suitable for breeding and, if these can be
maintained, it is hoped that further breeding will occur. The species is fairly
numerous in North Africa (several thousand were recently discovered in Algeria
and Tunisia; www.birdlife.org), and this is probably the
source of the recent records in Sardinia.
Breeding
in Sicily
In
2000, five adults, including one pair with eight chicks, were found in the
Trapani region of western Sicily (Sciabica 2002). Subsequently, 1–2 pairs have
occasionally nested at this site, while 1–3 pairs have bred irregularly in
southeastern Sicily (Corso 2005; Ruggieri & Sighele 2007; Ruggieri &
Nicoli 2009; Nicoli et al. 2011). There were six records
(of 1–15 birds) in Sicily in 2012 but breeding was not established in that
year. It appears that the status of Marbled Duck in Sicily is slowly changing
from that of a vagrant and occasional breeder; most records are in the period from
April to September, but it remains rare in winter (Corso 2005; Nicoli et al.
2013).
Plate
01 - Adult
Marbled Duck Marmaronetta angustirostris with 14
ducklings (approximately seven days old), Sardinia, June 2013. The first
breeding record of this species in Sardinia (Massimiliano Podda).
References
BirdLife
International. 2004. Birds in Europe: population estimates,
trends and conservation status. BirdLife Conservation Series No. 12, Cambridge.
Brichetti, P., & Fracasso, G. 2003. Ornitologia italiana. Vol. 1. Perdisa Editore, Bologna.
Corso, A. 2005. Avifauna di Sicilia. L’Epos, Palermo.
Giglioli, E. H. 1907. Secondo resoconto dei risultati dell’inchiesta
ornitologica in Italia. Avifauna italica. Tip. S. Giuseppe, Firenze.
GOB. 2010. Atlas dels Aucelles Nidificants de Mallorca i Cabrera, 2003–2007. Grup Balear d’Ornitologia I Defensa de la Naturalesa, Palma.
Green, A. J. 1996. International action plan
for the Marbled Teal (Marmaronetta angustirostris). In:
Heredia, B., Rose, L., & Painter, M. (eds.). Globally Threatened
Birds in Europe: action plans, pp. 99–117. Council of Europe &
BirdLife International, Strasbourg.
Grussu,
M. 2001. Checklist of the birds of Sardinia. Updated to December 2001. Aves
Ichnusae 4:
2–55.
Martí, R., & del Moral, J.C. (eds.). 2003. Atlas
de las Aves Reproductoras de España. Dirección General de Conservación de la Naturaleza & SEO, Madrid.
Nicoli, A., Di Masso, E., & La Grua, G. (eds.).
2011. Annuario 2010. Quaderni di Birdwatching
4.
––, –– & ––. 2013. Annuario 2012. Quaderni di Birdwatching 10.
Ruggieri, L., & Sighele, M. (eds.). 2007. Annuario 2007. EBN Italia, Verona.
–– & Nicoli, A. (eds.). 2009. Annuario 2008. EBN Italia, Verona.
Sciabica, E. 2002. Nidificazione dell’Anatra marmorizzata
(Marmaronetta
angustirostris) in Sicilia. Naturalista siciliano 26: 117–119.
Massimiliano Podda, maxpodda@lanaturadelsulcis.it
