It is among the reeds and cattails, but no matter how hard you look in the peninsular wetlands, finding the Little Bittern Heron, or even hearing its “moo”, is an increasingly exceptional event. The species of the year 2024 for the Spanish Ornithological Society (SEO/Birdlife), chosen by popular vote, is below minimum levels and the overexploitation of aquifers and river environments is putting its survival at risk.
Only 18 breeding pairs in as many territories were registered in the NGO’s last census, in 2021, although their greatest decline has been detected since 1980. Doñana continues to be the place with the most population, although there are also some bitterns in La Rioja, Navarra, Aragon and Castilla-La Mancha. In Catalonia, his favorite place is Aiguamolls de l’Empordà (in Girona).
Given the increasing difficulties in locating specimens, and the limited information known about the behavior of the species, SEO/Birdlife has decided to resort to artificial intelligence (AI) for its detection and monitoring. “Given the complexity of identifying different individuals, we are going to record in breeding areas and through AI, with the sonograms obtained, we will be able to differentiate one from another and thus have a reliable census of this very peculiar heron,” says Blas Molina, biologist and expert. in bird monitoring in the organization.
During a visit to the Taray lagoon, one of the ‘eyes’ in the upper Guadiana basin, in Toledo, the heron cannot be seen or heard. It is known that the ‘mooing’ from which it owes its name, similar to that of a blow into an empty bottle, is easier to hear when night falls and at dawn. And during the visit the sun shines. This spring, the La Mancha wetland is overflowing because it has rained and also because they have retained water. Birds such as morels, grebes, marsh eagles, the colorful bee-eaters and the special rollers flutter in search of food, either on its surface or in its surroundings. Some have their beaks bursting with worms, bringing food to the young. This day, the small and emblematic “moustachioed” bird, of which there is a significant population in the area, cannot be seen either.
Two male Eurasian Bitterns have been seen in the Taray these days, with their short, thick neck, long legs and harpoon-like beak, which makes them highly effective in getting fish, amphibians or crabs. It was much more abundant in the first decade of the 20th century, both there and in the rest of Spain. It is now on the Red List of Birds as a migratory species in a critical situation due to the serious threat posed by industrial agriculture, although it remains common in Central Europe, from where it travels to China and even the Pacific coast.
“There were years when there were up to eight males,” recalls Luis Frechillo, head of the company that organizes the observation routes on this private property for people who love to see birds. He has set up 20 observatories (‘hides’, in ornithological jargon). Frechillo does not remember if that number of sightings coincided with that ‘peak’ of 28 pairs that were detected in Doñana in 2018. “The threats are visible,” explains the SEO/Birdlife biologist while showing the surroundings of the La Mancha lagoons, where you can see hundreds of olive trees and vines hooked to irrigation.
“And it is not only the overexploitation of water. You can hardly see a poppy. The fields are full of chemicals. They are humid areas that were always frowned upon and many areas of reed beds, which bitterns need, were eliminated. This Wet Mancha should have been a national park because it is what provides water to the Tablas de Daimiel, but as there were many private farms it was made further down, and now we have a large agricultural exploitation,” he points out.
Added to this is that the bittern is a species that is especially sensitive to excess nutrients in the water, which is something that agriculture generates (eutrophication). It is a factor that changes the vegetation and, with it, the populations of fish that the heron feeds on.
In the case of the Taray lagoon in La Mancha, it was the human hand that placed a gate that filled it with water that flowed through the Riánsares River that comes from the mountain range of Cuenca and now ends in that place. It is an exceptional case in which water, by a royal decree of the 18th century, is private. Hence the gate that cuts its union with the river of which it is a tributary, the Gigüela, source of the Guadiana. For many decades, that volume of water brought thousands of red ducks, which were hunted in that place, but as less water arrived due to agricultural overexploitation and climate change, the fauna changed and now there are not so many ducks, but there are other birds that require less quantity.
In total, up to 220 different ones have been censused, which makes the lagoon a magnet for nature photographers. “The owners now want to open the Riánsares channel to the Cigüela, and from there to Daimiel. Here we have had floods this year, when the Tablas, about a hundred kilometers below, are dry, but they did not reach an economic agreement with the Guadiana Hydrographic Confederation,” Frechillo acknowledges.
This spring it is known that there is a pair of imperial eagles that are breeding, among many other birds of prey. Above the heads of the visitors, a kestrel hovers as if it wanted to peek into what is happening below. There is some disappointment when seeing how difficult it is to see the Bird of the Year, a campaign with which SEO/BirdLife each season wants to draw attention to some species of Spanish birdlife, highlighting their poor state of conservation or using them as a symbol of urgency. to protect the habitats that host them, which are usually ecosystems of exquisite biodiversity.
“Solutions to make the Little Bittern common again? Well, it’s not easy. The first thing would be to protect their territories from the tremendous impact of industrial agriculture, which is increasing, and restore those that are damaged. The droughts that are increasingly longer and more intense, due to climate change, do not help either, but we must work to maintain their presence,” concludes Blas Molina.
It must be remembered that more than 50% of birds in Spain have conservation problems and 22 are at risk of extinction, according to the latest SEO/BirdLife Red List of Birds, published in 2021. The little bittern is in critical condition. conservation, but even those that were most numerous, such as quail or partridges, have been declared almost threatened.
