This morning Darío Gijón and I visited some of the wetlands south of Alicante and had the chance to release two diving ducks in a very compromised conservation status throughout their distribution ranges. The common pochard (Aythya ferina) is currently classified as vulnerable worldwide and endangered in Spain, and the ferruginous duck (Aythya nyroca) is near threatened worldwide, but critically endangered in Spain. Hunting pressure, habitat loss, and invasive species combine with climate change and diseases as threats to these ducks.
Avian botulism causes outbreaks as it spread very fast in areas where conditions are suitable and bird density is high. Because wetlands meet these requirements, waterfowl and other aquatic birds are especially sensitive to it. Wildlife rescue centers play an important role in helping birds (and wildlife) overcoming these diseases. Some weeks ago, two black-headed gulls (Chroicocephalus ridibundus), a female common pochard and a female ferruginous duck entered CRF Santa Faz, the wildlife shelter in Alicante, in pretty bad shape, unable to feed by themselves. Today, we released all four of them in Clot de Galvany, a littoral wetland home to an impressive bird diversity, despite being surrounded by touristic development, and thus far free of botulism.
The four birds rapidly joined the rest of waterfowl in the small lagoon we released them in. Young gadwalls (Mareca strepera) and red-crested pochards (Netta rufina), Eurasian coots (Fulica atra) and some couples of little grebes (Tachybaptus ruficollis) fed under the sun.
A squacco heron (Ardeola ralloides) takes off from the reedbed, where bright red legs reveal a hidden western swamphen (Porphyrio porphyrio). Another usually-hidden reedbed specialist crosses the scene, a male little bittern (Botaurus minutus).
Between the closer vegetation, some dragonflies seem colorful darts as they fly fast, back and forth in their business — we recognize scarlet dragonflies (Crocothemys erythraea) and keeled skimmers (Orthretum coerulescens). Among other fauna, an an invasive pond slider (Trachemys scripta) and a native Iberian pond turtle (Mauremys leprosa) share a sunning spot — a scene that is unfortunately common and detrimental for the latter.
Conservation efforts of CRF Santa Faz and other institutions are evident in this lagoon, as the pochards we released are not the only endangered waterbirds swimming in these waters. One of the very few pairs of red-knobbed coots (Fulica cristata) in Europe, where it is critically endangered, fight against Eurasian coots for their territory. Joining the party from the back side of the lagoon, a couple of globally endangered white-headed ducks (Oxyura leucocephala). At the very bottom of the lagoon, a couple of mallards (Anas platyrhynchos) share area with the extremely localized marbled duck (Marmaronetta angustirostris), whose Spanish populations are critically endangered. The role of this wetland is key for the conservation of these species.
We pay a quick visit afterwards to the biggest lagoon in Clot de Galvany, on our way finding a flying European turtle-dove (Streptopelia turtur) and some groups of linnets (Linaria cannabina) and spotted flycatchers (Muscicapa striata). In the water, a group of eared grebes (Podiceps nigricollis) pop out in the surface, and an adult great crested grebe (Podiceps cristatus) feeds its fledgling.
A purple heron (Ardea purpurea) and a gray heron (Ardea cinerea) fish closeby in the reedbed, but fly away as they notice us. Not far from there, a very vocal great reed warbler (Acrocephalus arundinaceus) is the only warbler we notice in the piping hot midday temperature. A black-crowned night-heron (Nycticorax nycticorax) pops its head out of the tamarisks, checking on us. Further away in the lagoon, big groups of black-headed gulls and slender-billed gulls (Chroicocephalus genei) gather between the waterfowl and cause some noise. On the distant dead trees over the water rest a pair of great cormorants (Phalacrocorax carbo), little egrets (Egretta garzetta), and a group of whiskered terns (Chlidonias hybrida).
On the way back home, we stopped at a vineyard area where some interesting birds have lately been reported, not far from there. We spot at least four of the locally breeding European rollers (Coracias garrulus), an impressive sight due to the relative scarcity of the species in the area and the electric, bright blue of its plumage. Nearby we find the two bush hunters, the woodchat shrike (Lanius senator) and the Iberian gray shrike (Lanius meridionalis), as well as a Eurasian thick-knee (Burhinus oedicnemus). However, the bird that most caught our attention in the area was a single black tern (Chlidonias niger) flying over us from the direction of the sea, probably on its way between nearby wetlands, as did some western cattle egret (Ardea ibis) and glossy ibis (Plegadis falcinellus).