The Third Catalan Breeding Bird Atlas was published

The book methodology and main results are written in Catalan and fully translated into English, while the species accounts have bilingual maps and graphs and an English summary of the text.

The Atlas Highlights:

• Catalonia gains 17 new bird species in 40 years, including eight exotic species
• It is estimated that between 8 and 12 million pairs of birds breed in Catalonia every year. In total, they belong to 233 different species. The most abundant species is still the House Sparrow, although apparent regression was shown. It is followed by the Serin, the European Robin, the Common Nightingale and the Chaffinch.
• The four-year fieldwork of more than 1200 ornithologists coordinated by the Catalan Ornithological Institute (ICO) made it possible to cover the entire Catalan territory and determine the distribution and abundance of all the breeding species.
• The comparison with the first and second bird Atlases shows that forest and scrubland birds are expanding, while those of farmland and grassland suffer a marked regression. Birds of inland wetlands are also declining after raising at the end of the last century, and marine and coastal species are in a delicate situation.
• In general, in Catalonia, birds have not moved north or up the mountains, fleeing climate change.

The atlas reveals that 233 bird species breed in Catalonia, 17 more species than forty years ago and 39% of those nest in European territory. Of them, 124 species enjoy special legal protection at the Catalan, Spanish or European level. According to the Atlas, there are an estimated 8 to 12 million pairs of birds in Catalonia every year.

The House Sparrow is still the most abundant species in the country, with just under 900,000 breeding pairs, although its population has declined in recent decades. It is followed by the European Serin, the European Robin, the Common Nightingale and the Common Chaffinch, all four species with more than 400,000 pairs.

Of the other species, more than half have less than 2,000 breeding pairs and are considered scarce. The rarest species nesting in Catalonia are the Dupont’s Lark, the Hen Harrier, the Baillon’s Crake, the Red-knobbed Coot, and the Black-necked Grebe, all with less than ten breeding pairs.

On the other hand, this third atlas includes nine exotic species that regularly breed in Catalonia. Humans have introduced most of them as cage birds, which is reflected in the distribution of these species on the map, with a maximum concentration in and around large cities and coastal towns. The first atlas included only one exotic breeding species in Catalan territory, the Common Pheasant.

The Catalan Ornithological Institute (ICO) has presented the Third Catalan Breeding Bird Atlas in the auditorium of the Cartographic and Geological Institute of Catalonia, a project promoted by the Ministry of Climate Action, Food and Rural Agenda of the Catalan Government, and by the Barcelona Zoo. To obtain the data, 1,275 ornithologists voluntarily contributed to the field between 2015 and 2018. In addition, the work involved researchers from the European Bird Census Council, CREAF and the Forest Science and Technology Centre of Catalonia (CTFC), among others. Furthermore, the Barcelona Provincial Council (Diputació de Barcelona) has contributed to collecting data on the natural areas of this province, and the Natural Science Museum of Barcelona has hosted the ICO work team. The Breeding Bird Atlas is a project integrated into Catalonia’s Natural Heritage and Biodiversity Observatory. It aims to be available to society for decision-making related to nature.

“The knowledge provided by this atlas is fundamental to defining biodiversity conservation policies,” said Sergi Herrando, director of the atlas and researcher at the ICO, CREAF and the European Bird Census Council (EBCC). Herrando recalls that these policies have shown that they can be effective, as in the case of the Lesser Kestrel, which after the reintroduction program, already has more than 80 breeding pairs. „Catalonia has a great responsibility in conserving many species, such as those found almost exclusively in the Iberian Peninsula, for instance, the Red-necked Nightjar, the Iberian Green Woodpecker or the Western Orphean Warbler. For these species, nearly 10% of its European distribution area is found in Catalonia,“ Herrando points out.

The evolution of 40 years of data, winners and losers

The atlas was published almost 40 years after the first and 20 years after the second atlas. Thanks to the long series of data accumulated, the atlas has been able to focus on the changes that species have undergone since the early 1980s and 2000s.

“This period coincides with a major advance of climate change and other large-scale social and economic changes that have greatly impacted Catalonia. Among these, I would mention the abandonment of traditional agricultural activities and the consequent occupation of abandoned areas by forests and scrub”, says Martí Franch, ICO researcher and one of the main authors of the work.

This coincidence over time has shown that species have not responded to these changes equally. For example, forest and urban species have generally fared quite well. The growth of new forests and the maturation of many existing ones have meant that some forest species, such as the Booted Eagle or the Lesser Spotted Woodpecker, which were very scarce 40 years ago, have experienced a spectacular expansion of their range. Other species more closely related to dry forests, such as the Western Bonelli’s Warbler, currently seem to be favoured by the growth of the forest and perhaps also by the drier conditions caused by climate change in the Mediterranean basin and have become much more common in the last 20 years.

“But not all forest birds are doing well. For example, there are specialists in cold and humid forests who, like the Western Capercaillie, are experiencing significant declines, probably associated with climate change and the management of these forests”, explains Sergi Herrando.

Also, some urban species like the Collared Dove have undergone a substantial expansion, while it was considered very scarce and non-breeding in the first atlas.

On the opposite side are loser species, such as the Barn Owl, the Iberian Grey Shrike and the European Turtle Dove, which have reduced their populations significantly in recent decades and have already disappeared from 20–60% of the areas where they were found 40 years ago. The three of them are species of farmland and grassland areas, the group of species that are suffering the most significant regression of their populations, especially in mountainous regions. The reason is the growth of new forests in abandoned crops and meadows. Moreover, the transformation of the agroforestry mosaic into intensive monoculture crops is to blame.

“The crops make life difficult for species that feed in open areas but nest in wooded or bushy areas, such as the European Turtle Dove. As a result, it has virtually disappeared from the Pyrenees and becomes scarcer in Catalonia,” according to Lluís Brotons, another of the authors and researchers at CREAF, the ICO and the Forest Science and Technology Centre of Catalonia (CTFC). „In addition, monocultures often use phytosanitary treatments against insects and small vertebrates, affecting their predators. This is what has happened to Barn Owls or Iberian Grey Shrikes,” concludes Brotons.

On the other hand, the Little Egret, the Common Moorhen and other species typical of rivers and wetlands experienced remarkable growth of their populations and distribution when the protection of many wetlands was declared at the end of the 20th century. However, this general increase process has come to a halt in the last two decades, and significant losses have recently been detected in the country’s major wetlands, where species have regressed due to multiple causes. In the case of the Little Egret, it seems that the shortening of the flooding periods of the rice fields to control the expansion of the apple snail might have something to do with it.

If we look at the birds living in the sea, the atlas shows they have maintained their populations but faced significant threats. Twenty years ago, Catalonia was home to most of the world’s breeding population of Audouin’s Gull in the Ebro delta. Still, the population has spread to other localities in recent years while the number of breeding birds has declined.

“Part of that reduction may be due to deaths from accidental catches in fishing,” Herrando said, “but the arrival of terrestrial predators such as foxes to the delta colony has surely influenced it.”

This cause is also present in the local declines of other marine species, especially when they are highly concentrated in breeding colonies.

Biodiversity shelters

Thanks to the Atlas, Catalonia knows which species nest in its territory and where they are distributed and whether they have moved due to climate change. Data shows that, in general, there are a more significant number of native species in the northern half of Catalonia, especially in the plains and valleys. La Cerdanya stands out as a hotspot of incredible biodiversity due to the diversity of habitats in this territory. In addition, contrary to what has been observed in Europe as a whole, in the last 20 years in Catalonia, in general, native species have not systematically moved either to the north or up the mountains fleeing climate change.

“We live in a complex and rapidly changing world, and birds, like us, are trying to adapt. From the multiple stories in this atlas, we will try to learn a little about how to do it,” Sergi Herrando concludes.

Check the Participants in the fieldwork for the Catalan Breeding Bird Atlas.

You can find the details about the sale of the book and the original watercolours made by Martí Franch and Toni Llobet on the Oryx store webpage.