1998-4 - Dutch Birding

Striped Crake at Livorno, Jtd1y, in lanuary 199 7
Marittimo del porto di Livorno) and by Valter
Rinaldi . Daniele Marzi checked the files of [he
seabird rehabilitation c :entre (CRUMA, Livorno) .
Richard Bradbury and Michael Wilson ÍEdward
Grey Institute, Oxford, England) made a numher
of valuahle suggestions for changes to a draft of
this no[e .
References
Arrit;oni Des;li C7ddi, E 1929 . Ornitologia ltalia na .
dm ilan .
Cramp, S& Simmuns, ií E L feditcrrs} 198{} . The hirds ot
the Western Palearctic 2 . Oxforcl .
Ripley, S D 1977 . Rails ot the world . Boston .
Snow, D W & Perrins, C M (eclilorsi 1998 . The hirds of
the Western Palearclic . Concise edition . OxÍord .
del Hoyo, 1, Elliott, A& Sargatal, 1 Icxlilors) 1996 .
Handbook of the hirds of the world 3 . Barcelona .
Hudson, R 1974 . Allen's Galhnule in Britain and th e
Palearctic . Br Birds 67 : 405-41 3 .
Tiylor, B& van Perlo, B 1998 . Rails : a guide to the
rails, crakes, gallinules and cools of the world .
Mountfield .
Urhan, E K, Fry, C H & Keith, S(editorsl 1986 . The
hirds of Afric:a 2 . London .
Adriano De Faverr, Istituto Nazionale per Ja Fauna Selvatica, via Ca Fornacetta 9,
40064 Ozzano En 7ilia BU, Jtaly
Nicola Baccetti, Jstituto Nazionale per !a Fauna Selvatic a , via Ca Fornacetta 9,
40064 Ozzano Emilia BO, Italv
En 7iliano Arcamone, COT, Museo di Storia Naturale, via KonTa 234 ,
57100 Livorrlo L1, Jtaly
Trends in systematic s
Molecular study indicates sympatric
breeding of Atlantic and Continental
Great Cormorants in Britain
In Europe . Great Cormorant Phalacrocurax carho
is represented by two subspecies : Atlantic Great
Cormorant P c carbo ihereafter carbo) which
inh.i hits the coasts of Britain, France, Iceland and
Norway, and Continental G reat C.ormorant P c
sinensis ( hereafter sinensis), which breeds mainly
in inland tree colonies in continental Europe . In
the early 1960s, the north-western European
population of sinensis was restricted to 800 pairs
in two colonies in the Netherlands . In subsecluent
decades . the population of sinensis in
north-western Europe spectacularly increased to
more than 60 000 pairs in 1993 (van Eerden &
Gregersen 1995) . The increase coincided with a
range expansion to other European countries .
Until [he 1980s, inland nestin g of cormorants in
Britain was sporadic but since 1981 the numher
of inland breeding pairs has increased to more
than 1100 in 1995 and breeding attempts have
heen recorded at 35 sites (Goostrey et al 1998) .
Although inland breeding is commonly assoc:iatcd
with sinensis, the ori gin and identity of these
inland breeders has remained unce rtain ,
Sellers ( 1993 ) attempted to determine the status
of inland breeding cormorants at Abberton
Reservoir, Essex, England, on the basis of three
plumage characters, the shape of the gular pouch
and ringing recoveries . Differences in morphology
have been described and discussed on several
occasions (eg, Stokoe 1958, Cramp &
Simmons 1977, Alstr~m 1985) but assessing
plumage and structural differenc :es in the field is
not always easy and may be subject to age and
seasonal variation . Gloss to body plumaF;e is
greenish in sinensis and hluish or bluish-purple
in carbo but the difference may be very difficult
to determine in the field and its validity has been
questioned (Marion 19951 . Both carbo and sinensis
develop white head-feathers and white thigh
patches at Ihe start of the breeding season . These
feathers are at their hrit;htest and most extensive
in the early phase of the breeding season and
decrease in intensity as breeding proKresse.s
(Sellers 1993 ). The exient of white feathers on
the head is much greater in sinensis than in
carbo but some carbo, mostl,v old males, may
acquire heads as white as typical sinensis (Stokoe
1958, Cramp & Simmons 1977, Alstrrim 1985) .
Therefore, the presence or absence of white feathers
is an inadequate basis for assigning lone
birds to either carbo or sinensis. Aistrflm ( 1985 )
emphasized a difference in the shape of the t;ular
pouch; in sinensis the gular pouch exiends further
back beyond the gape than it does in carbo
(Alstr~m 1 985, Lewington et al 1991 } . Marion
(1995) questioned the validitv of this criterio n
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