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Did you know that of all the swallow species that occur in Portugal, the House Martin (Delichon urbicum) is the species that forms the largest breeding colonies?


This martin builds its nests, closed mud bowls with a narrow circular entrance, on the eaves of buildings or viaducts. The nests of this species can be found from small villages to large urban centres.


As well as being an urban species, this martin is also a gregarious species, so it can form large nesting colonies, often overlapping several nests.


The largest colony recorded in the andorin campaign is made up of more than 560 nests. If you too know of an isolated nest or colony, register it on our website!



Do you have a swallow's nest at home? Here's what you need to know!


Swallows share the urban space with us, often choosing the façades of our buildings as nesting sites.


These birds are exclusively insectivorous, so their diet includes invertebrates that are vectors of human diseases or agricultural and forestry pests, responsible for incalculable damage.

And despite their crucial role in eliminating these invertebrates, every year swallow nests are destroyed due to the dirt they can cause.


As well as the removal of nests being expressly forbidden by law, swallows are very loyal to their breeding sites and if nests are removed they are very likely to rebuild them in subsequent years.


In most cases, periodic cleaning of the façade or floor will be enough to ensure peaceful coexistence with these birds.


However, if you wish, you can install a shelf underneath the nest so that dirt can accumulate there. Pay attention to the distance between the shelf and the nest, so that it doesn't serve as a landing place for natural predators such as birds of prey, or unnatural predators such as cats. Find out more about these shelves on our website.


Did you know that there is a species of martin in Portugal that digs its nests instead of building them?


The Sand Martin (Riparia riparia) is the smallest martin that occurs in Portugal and the one that stands out most for its nesting habits. Unlike its counterparts, which build their nests in mud, the Sand Martin digs tunnels in the sandy slopes of river banks or sand pits. This martin can also use holes in retaining walls for nesting.


This is a gregarious species that forms colonies of several hundred individuals. The largest colony recorded in the andorin campaign has more than 150 nests. If you too know of one of these colonies, register it on our website!



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