Imma Perfetto
Cosmos science journalist
As life for an amusingly named bird species becomes harder, Spanish scientists have proposed new measures to restore its fortunes.
Suitable habitats for the little bustard (Tetrax tetrax) are shrinking due to a reduction in steppe-land and the disappearance of traditional agriculture and livestock farming, according to a new study in the journal Biological Conservation.
The researchers behind the study say increasing the area of fallow lands – unsown farmland – is key to stabilising the most threatened populations.
“This strategy has a positive impact on the little bustard, mainly because it increases the reproductive success,” says Santi Mañosa, an avian conservationist at the University of Barcelona, Spain.
“It provides the species with everything that has disappeared in the rain-fed agricultural environments because of the intensification of agricultural practices.
“In spring they find food, places for the males to stop and attract females, mate, nest and feed the baby birds. In summer and autumn, and a great part of the winter, when crops are reaped and cultivated, fallow lands are the only places with enough plants to provide the little bustard flocks shelter and food.”
Fallow lands are becoming less common in Spain, which has led to the little bustard being listed as ‘near threatened’ by the International Union for the Conservation of Nature and Natural Resources.
“Between 2009 and 2018, 21% of the fallow land surface has been lost in Catalonia, and steppe-land bird populations have reduced by 27% between 2002 and 2019, mainly due the loss of fallow lands,” says co-author Gerard Bota, from the Forest Science and Technology Center of Catalonia.
But while population models generated in this study suggest that increasing the area of fallow lands could halt the decline of the species, it would not be enough to recover population numbers.
Instead, implementing other conservation measures to reduce mortality from both natural and human causes, which have so far been neglected by little bustard conservation programs, will be essential.
“For instance, reducing the mortality of adult females. We know the little bustard is sensitive to death by collision with power lines because of its relatively reduced frontal vision when flying,” Bota says.
“It would be necessary to identify the main areas of post-breeding and winter aggregation and to act on the power lines installed to reduce the probability of death of the specimens. In the most important breeding and hibernation areas, some lines should be buried or eliminated, and in the rest of the areas, the lines should be properly marked with anti-collision elements.”
