On several occasions this month when we have been in the Ludo/Quinta do Lago area we have seen a group of five Sacred Ibises which seem to have settled there. Possibly they are the same five birds that were reported earlier in the year further west at Paul de Lagos.
There have been regular reports of Sacred Ibises in the Algarve in recent years and records of the species elsewhere in Portugal as long ago as 1998 when a pair may have bred near Coimbra.
Sacred Ibis is a very common bird in sub-Saharan Africa but wild birds are not known to have ever reached Europe, so where then have the current five birds come from?
With Sacred Ibises held in zoos and waterfowl collections in most European countries (presumably including Portugal) and established breeding colonies in France, Italy and probably Spain which result from escapes from captivity, there are clearly many possibilities. At least one of the Ludo birds has a ring on its leg which might provide a clue if only we could read it but that really isn’t the issue.
Sacred Ibises are reasonably attractive birds and are still something of a novelty here. Some people might even welcome the possibility that the Algarve might soon have a new breeding bird. Indeed, there might already have been breeding here. There are several precedents for allowing colonisation by non-native species (Common Waxbill, Black-headed Weaver, etc, etc) so why should it matter if we have another one?
Well, in some other parts of the world these birds have become serious pests, particularly as predators in colonies of ground-nesting birds such as terns and waders. In France, Common, Sandwich, Black and Whiskered Terns, Black-winged Stilts and Northern Lapwings have all been seen to lose eggs to Sacred Ibises and, in South Africa, Cape Cormorants have been amongst the victims. This is surely something we would want to avoid happening here – ground-nesting birds in the Ria Formosa already have enough to contend with! Also, Sacred Ibises are competitors for nest sites with Little Egrets and Cattle Egrets.
So, with this in mind and remembering our very costly experience with Ruddy Ducks in the UK, perhaps now, while there are still only a handful of them, would be the time to ‘remove’ them rather than wait until there are hundreds or even thousands to be dealt with as there are now in France.
With good reason, The African-Eurasian Waterbird Agreement requires that the Contracting Parties (which include Portugal) shall:
prohibit the deliberate introduction of non-native waterbird species into the environment and take all appropriate measures to prevent the unintentional release of such species if this introduction or release would prejudice the conservation status of wild flora and fauna; when non-native waterbird species have already been introduced, the Parties shall take all appropriate measures to prevent these species from becoming a potential threat to indigenous species.
What do you think?
Lockdown Diary: Sunday 28.6.20
5 days ago