[Animals] The blow of the drought in the wildlife: this is how it affects frogs, butterflies, harriers, deer and other animals

[-CosmiNNe]

Many species see their po[CENSORED]tions reduced due to the scarcity of water and food, especially insects, fish and amphibians
Wetland birds suffer especially from the deterioration of their habitats and, when migrating, transfer the pressure to other ecosystems

Birds are quintessential climate migrants. Some fish, like the sardinia, have adapted to live in rivers that dwindle in the summer. But while the prolonged drought already extends to 35% of the peninsula, the lack of rain hits wildlife silently.

"It has an effect, above all, on species that depend directly on water, such as insects, fish and other aquatic species, but also on amphibians, which need water to develop the larval phase. If there is no water in the ponds and humid areas, this year they will not breed directly", explains Rafael Seiz, coordinator of WWF Spain's Water Program, to RTVE.es, who also mentions the impact on terrestrial species. In years like this, the deer and roe deer see how scarce the water to drink and the pastures to eat.

Still, some animals are better adapted than others. "On the Cantabrian coast, where the Atlantic climate is more characteristic, the species resist periods of lack of resources worse, with which there may be specific episodes in which some specimens fail to survive", he exemplifies. The state of the ecosystems before the emergency arrived can, in any case, make a difference.

Six out of ten threatened birds suffer more from droughts
Birds especially suffer from dry years and this manifests itself on different levels: "There is a more immediate one, which is the need for water to drink or, even, for things that are perhaps less intuitive, such as the lack of mud so that the swallows and planes can make their nests". The expert speaking is Mario Giménez, SEO Birdlife delegate in Valencia, who links to the WWF comments. "Less insects and less seed production is, ultimately, less food and that means that the birds are in worse physical condition. They lay fewer eggs, raise fewer chicks and this affects the size of the po[CENSORED]tions," he lists.

But Giménez highlights the problems that arise for birds due to the change in their habitats. Drought is a common cycle within the Mediterranean climate, but the latter are mounted on a process of climate change that is already influencing the patterns of some migratory species: flocks that increasingly stop further north because they find it too hot in the south and little food or because the rivers no longer freeze all year as before, others that have directly stopped migrating. "Storks are a classic example of a species that no longer crosses the strait, many times they stay in Spain," says the expert.

Regarding only droughts, the impact is more evident for two groups of birds, those linked to agricultural ecosystems and wetlands. With the bad rainfed harvest this year, the former have been left very exposed: "Since they don't have a place to nest, because the cereals haven't come out due to the drought, they have to go to worse places, where they will surely have more predation, they will have We have to put the nests on the ground and we go back to the beginning: there will be fewer chicks," says Giménez, from Seo BirdLife, about species such as the Montagu's harrier. Waterfowl can usually migrate to other wetlands, but the few nearby options are already beginning to suffer from some overbooking.

To size up the problem, the technician provides information: of the 90 species classified as "threats" in his Red Book, 25% live in wetlands and 34% are linked to agrosystems. In short, six out of ten vulnerable or endangered birds especially suffer from the conditions in which a good part of the country is now.

The situation is already perceived in the mountains, according to some hunters. "We have signs of animals that are not going to reproduce," says the head of research at the Artemisan Foundation, Carlos Sánchez, and gives as an example the flocks of partridges that now fly with few pellets —their young— for this time of year.

The lack of rain has dragged on for months and the organization has installed shelters with water to which all kinds of animals come to relieve their thirst. In a study in 2020, 75 different species were identified using the drinkers: 54 species of birds, 14 mammals, six reptiles and one amphibian, according to Sánchez. Almost half of the visits corresponded to non-hunting species.

Without flowers or leaves, butterflies die
Meanwhile, hundreds of butterflies die silently. "In these almost 30 years of monitoring, we have verified that there are many species of butterflies that have a negative trend. The causes are multifactorial, it must be taken into account that it is a complex reality that is not explained by a single reason, but a part Most of this general decline is related to droughts, which have increased in frequency and intensity in recent years," says Constantí Stefanescu, associate researcher at the Center for Ecological Research and Forestry Applications (CREAF).

The entomologist explains that it is normal for a very high number of caterpillars to die on the way to metamorphosis, but that the proportion may be higher when the quality and quantity of plants, their food, "drops sharply" due to the scarcity of water. . "The smaller caterpillars, early in their development when they hatch, are hypersensitive to desiccation," he says.

Later, the few chosen ones who have managed to transform into a butterfly don't have it easy either. The issue, according to Stefanescu, is somewhat less studied: "Drought means that there is a much lower availability of flowers. There are plants that don't even flower and, when they do, they last very little. Butterflies, and this can be extrapolated "To all pollinating insects, they need to visit the flowers to get nectar. If there are fewer flowers, they have trouble finding the resources they need to be active, hatch eggs, etc. So their adult mortality also increases."
Domino effect in ecosystems
In ecosystems where, by definition, everything is connected, the lack of insects ends up affecting everything else: if there are fewer pollinating insects, there are fewer pollinated plants, including fruit trees and orchards for our food. For their part, other predators directly lose part of their sustenance and this, the biologist settles, "is transmitted through the trophic pyramid until it affects the highest levels."

If we talk about birds, on the other hand, the domino effect has more to do with their migrations than the expert described before. Faced with the degradation of the Tablas de Daimiel or Doñana wetlands, ducks and flamingos take flight and take refuge in other waters, such as those of the Valencian Albufera.

"We have a load of birds that is not what we should normally have, and the Albufera is not overflowing with water, far from it," says Mario Giménez of Seo BirdLife from Valencia, about the —before rare— image of flamingos in the Mediterranean lagoon . These animals easily adapt to their new habitat, but the truth is that with their long pink legs they stir up the bottoms to eat and release sediments that complicate the planting of rice, one of the main economic engines of the area. So much so that farmers have already claimed aid for the damage and the department of the branch is studying compensation.

Habitats that, before the drought, were already in the ICU
Added to climate change, droughts have been aggravated by "mismanagement" of water and, therefore, "poor conservation" of ecosystems, according to WWF and Seo BirdLife. "If you have a patient who already has an ailment and another disease occurs, that aggravates it. The same thing happens with an ecosystem," says Rafael Seiz, making an analogy with the human body. In his opinion, the problems of pressure, contamination and modification of forests or wetlands have a lot to do with the extension of crops and monocultures, a criticism in which Giménez agrees. This denounces that the "legal obligation" to maintain the minimum ecological flows of rivers and wetlands is being breached and gives, again, the examples of Doñana, in Andalusia, and Daimiel, in Castilla-La Mancha, which maintain an agricultural model intensive around the parks. "We are distributing and consuming more water than we have," he says.

Finally, what the species that live in an ecosystem are like and where they come from also influences their chances of survival. Endemic species are far ahead of exotics, explains Seiz: "Paradoxically, when there is water, [exotics] are opportunistic species that easily occupy niches and displace endemics with their ability to reproduce and feed. But when there is a lack of water, They are the most vulnerable because they are not adapted. It is what makes, for example, that some fish can die when they run out of "literally without oxygen" even when they are submerged.

The "child's solution" of just waiting for the rain
Faced with a problem in which the causes are intertwined and add up, environmental organizations demand better planning and management of resources, as well as compliance with the law that already exists in this regard. "Now, looking at the sky to see if it rains is a childish solution," reproaches the WWF technician.

From the Artemisan Foundation, they also ask the administrations "to get involved" in the management of habitats so as not to have to reach extreme situations. Meanwhile, says Carlos Sánchez, hunters and managers can act with drinking fountains and water points to alleviate the drought that threatens biodiversity.

https://www.rtve.es/noticias/20230530/sequia-fauna-silvestre-animales/2447488.shtml