House sparrows need houses: An avoidable conflict between biodiversity and energy efficiency as rural areas modernize

It might be surprising to many that species protection doesn’t always involve keeping humans away from wild animals. In fact, the complete opposite is sometimes true. In rural areas of Europe, farmland animals have coexisted with humans for thousands of years. This relationship is so vital that some bird species, such as sparrows or doves, depend on typical features of traditional homes like beams, chimneys, and tiled roofs for nesting and foraging. In recent years, the modernization of old villages has led to the renovation and construction of many buildings without these features. This modernization has brought development to rural areas but has also led to a sharp decline in these “building-nesting” bird populations. Since birds play a key role in the ecosystem, their decline could amplify the rapid farmland biodiversity loss that is already being observed across Europe.

In a study published in the Journal of Applied Ecology, a team of Swedish and Polish researchers compared modernization levels and bird populations in 104 villages in the Wielkopolska region of Poland. Wielkopolska is an ideal place to study European bird populations for two reasons: first, the variety of modernization levels among these villages is representative of the larger Eastern European region. Second, the development pattern reflects that of Western Europe several decades ago. In this study, the researchers counted and identified farmland birds in equivalent areas in each village during breeding season. Then, they looked at the relationship between the number of birds observed in different villages and the percentage of old, renovated, and new houses.

The study’s results show that the population of building-nesting bird species in villages with mostly new or renovated houses was almost half of those with many old ones. Modernization affects some species, like the house sparrow or barn swallow, the most – even their common names reflect their dependence on traditional human structures. The rapid disappearance of house sparrows worldwide has been noticed by many both in Europe and North America. Moreover, this disappearance has been linked to the changing architecture in places as far from Poland as Australia. As a result, news outlets have raised questions
of what the decline of a bird so long associated with humans could suggest about the health of human environments.

While the modernization of old villages harms bird populations and reduces biodiversity, it also improves rural quality of life and energy efficiency in buildings. Following the United Nations’ Sustainable Development Goals (SDGs), the European Union (EU) has prioritized rural development and reduced energy consumption. For that purpose, over $10 billion has been allocated to retrofitting old buildings in Poland alone. However, current EU policies often overlook biodiversity preservation, which also forms a key part of the SDGs. To avoid conflicting approaches to meeting interconnected SDGs, researchers suggest two strategies: first, villages should be incorporated into EU conservation policies, which currently cover only protected areas and agricultural land. Second, architectural plans should preserve bird-friendly elements, such as lateral beams, or include nest boxes in renovations and new constructions. If this critical bird habitat is maintained, energy, rural wellbeing, and biodiversity goals can be accomplished together.