News from Cave di Gaggio LIPU Reserve, near Venice
The conservation area located in the Marcon municipality keeps offering special emotions thanks to many achievements. The Oasis, run by LIPU astonishes again this year for some results, epochal in this particular case.
Black-crowned Night Heron
The first result is a new record of breeding couples inside the heronry (that means the place where many species of colonial heron nest) with important results even from a national point of view. A census conducted during the phenological stage of reproduction has shown the presence and the nesting of six colonial species of Ardeidae along with the nesting of the Little Bittern (Ixobrychus minutus). Among the 9 species of Ardeidae regularly nesting in Italy (according to the check list of Italian birds updated to 2014 by P. Brichetti and G. Fracasso) 7 of them breed inside Cave di Gaggio Oasis. The variety of species is really high and 5 species are considered of marked conservation interest since they can be found in the “Birds” directive’s n.1 attachment: Purple Heron (Ardea purpurea), Little Egret (Egretta garzetta), Black-crowned Night-heron (Nycticorax nycticorax), Squacco Heron (Ardeola ralloides) and Common Little Bittern (Ixobrychus minutus) (which doesn’t breed in colonies). The other two species found in the heronry are the Grey Heron (Ardea cinerea) and the Cattle Egret (Bubulcus ibis). Besides these species’ breeding status, some specimens of Great White Egret (Ardea alba) were recorded, without ascertaining their status and assuming they are immature specimens and/or are spending the summer in the area (also considered of marked conservation interest since it can be found in the “Birds” directive’s n.1 attachment).
Little Bittern
Pygmy Cormorant (Microcarbo pygmeus) has also reproduced inside Gaggio’s heronry with the presence of more than 400 nests, a remarkable number for LIPU Oasis, which turns it into a nationallt significant site for this species, also of marked conservation interest since it can be found in the “Birds” directive’s n.1 attachment. The high number of recorded nests for this species suggests that a number between 10 and 20% of the Italian nesting population breed at Cave di Gaggio (Bird of Italy, 2018, G. Fracasso, P. Brichetti, population estimates 2013).
Squacco Heron
The second big result is the discovery of the wild Pyramidal Orchid (Anacamptis pyramidalis) inside LIPU Oasis. For the first time since over thirty years of LIPU’s management of the area this species was discovered. The discovery constitutes an exceptional occurrence since Oasis’ lands are the result of agricultural activities and not a woodland with a fertile soil matured for centuries, where its presence wouldn’t have been noticed. The constant presence of human activity has brought to a depletion of the soil that only after decades (more than 30 years) of stability regained its health, allowing the development and growth of different types of plants. The fact that it is now possible to notice new species of orchids (as in this case) determines the right degree of the complexity and wealth of fungi and insects for their germination and it’s a result further related to the area’s best practice in terms of management and conservation managed by LIPU over 35 years of presence.
Indeed, since homegrown orchids are not pioneer species, they need insects to be pollinated (and insects don’t get on well with insecticides in agriculture) and most of all they need some particular fungi on the ground to make the seed germinate. These conditions require many years to develop (the whole of several species populations) and can’t be altered by chemicals or heavy mechanical machining. The careful management of this area for more than 30 years paid off and Cave di Gaggio are now a great example of complex and articulated biodiversity with numerous benefits in ecosystem services out of Oasis’ borders.
Venice, 30/06/2019
Luca Mamprin
Alvise Lucchetta
Michele Pegorer
Davide Pettenò
Marta Cicco
