Interview: Lieke Mevis on the Importance of Luxembourg's Annual Bird Count, Recent Trends

Chronicle.lu recently got the opportunity to speak with Lieke Mevis, Coordinator of the Garden Bird Count, an annual event organised by Luxembourg environmental non-profit organisation natur&ëmwelt.

Every year during the last weekend in January, members of the public are invited to devote one hour to counting the birds they see in their garden. Whilst this year’s bird count took place last weekend, participants have until 11 February 2022 to submit their results. The full results are expected to be presented later this month.

With this in mind, Chronicle.lu reached out to Ms Mevis to learn more about this important nature event in particular and recent bird trends in Luxembourg in general.

Discussing the success of the annual bird count, Lieke Mevis confirmed that an increasing number of people have been getting involved each year since it started in Luxembourg in 2006. She described it as one of natur&ëmwelt’s “most successful campaigns” and the “biggest in terms of numbers”.

She recalled that this year’s responses are still arriving in the post; a large proportion of participants are older people, not all of whom have access to the online form. At present, the non-profit expects participation numbers to be close to those registered last year (despite the “grim weather” last weekend) – around 830 people took part in the 2021 Garden Bird Count.

What happens to the results?

Lieke Mevis explained that the natur&ëmwelt team look at the collected results at the national level. Whilst they can identify some trends, it is difficult to determine the reliability of the data. She stressed that this was primarily an awareness-raising campaign aimed at encouraging as many people as possible to get involved.

Moreover, whilst last year’s results showed that the number of garden birds remained “relatively stable” in Luxembourg, ornithologists have noticed a general decline in bird populations in the Grand Duchy and across Europe. For instance, house sparrows remain in the top rankings in Luxembourg’s annual bird count but have been in decline for the past 25 years. Ms Mevis added that those species which have “adapted to human settlements are doing relatively better than those in grassland habitats”.

Where can the public see different bird species?

Regarding the main nature reserves and habitats where people can view different bird species in Luxembourg, Lieke Mevis cited “Haff Réimech” in Remerschen and Echternach Lake for water birds, as well as Luxembourg-Clausen for kingfishers and herons, for example. The white stork can sometimes be seen on the platforms in the “Dumontshaff” nature reserve along the Alzette valley in Schifflange, as well. Beyond the nature reserves, Luxembourg’s many forests are home to “a nice woodpecker population”. Birds of prey such as the common buzzard can be seen in open fields.

Why and from / to where do birds migrate (via Luxembourg)?

On the subject of migration, Lieke Mevis explained that most of the migratory birds we see (and hear) flying in formation over Luxembourg are travelling from the north (for breeding) in spring to the south (for food) in winter, primarily between Mecklenburg-West Pomerania in north-eastern Germany (spring) and Champagne in north-eastern France (winter) – Luxembourg is “in the middle of their migration route”. Ms Mevis noted that Luxembourg residents are more likely to see these birds as they migrate north in spring, due to the fact that the Grand Duchy is geographically closer to Champagne where the birds start their journey and are thus “more concentrated” before they “spread out later”. They also arrive over Luxembourg around midday (rather than at night) which makes them easier to spot as they make their way north.

When asked about increasingly frequent sightings of migratory birds flying over Luxembourg outside these main migratory periods, Ms Mevis explained that climate change played a significant role. She noted that “migration costs a lot of energy. Being able to survive without it is an evolutionary advantage”. As such, some (not all) birds will try to migrate sooner if temperatures rise earlier than usual; if it is too cold when they arrive in the north, they will return south again. Agricultural changes also have an impact: with farmers growing more crops, for instance corn in Champagne over the last decade, there is a greater availability of food and some birds may “try to stay in the south”. However, this can cause conflict with farmers in the region.

Concerning which garden bird species migrate over Luxembourg, Ms Mevis cited swallows, cuckoos and redstarts, all of which tend to migrate to the Mediterranean. These are mainly insectivores who have to migrate for food due to a lack of insects in winter. Others are trans-Saharan migratory birds.

Rare bird sightings

When asked about the strangest or rarest bird sightings in Luxembourg in recent years, Lieke Mevis shared how one of the ornithologists at natur&ëmwelt spotted an Arctic skua during last year’s storms and flooding. This parasitic species traditionally migrates from the Arctic to the west coast of Africa. They are rarely seen in Europe and this marked the very first observation in Luxembourg. “It was likely blown over in the storms”, explained Ms Mevis.

Threats to garden birds

Regarding the impact of domestic cats on the garden bird population, Lieke Mevis recalled that there was “very little scientific evidence” of this, although if the bird population is already doing badly (for instance due to habitat loss or food unavailability), then it becomes “more vulnerable to natural and cat predators”. Simple actions cat owners can take to make their pet less dangerous for garden birds include keeping their cat indoors or fitting them with a collar with a bell on it.

On the subject of a “mystery” lung disease affecting blue tits over the past couple of years, Ms Mevis noted that there had been some cases in Luxembourg. A reporting system was set up, although it is still too early to see the impact of this disease on the overall population.

COVID-19 impact

Lieke Mevis confirmed that there had been a significant increase in the number of people “turning to nature reserves” during lockdown in Luxembourg. However, a lot of people failed to follow the rules, for example leaving litter behind. As such, Ms Mevis urged members of the public to “please respect the rules in nature reserves”.

Returning to the bird count itself, she expressed the hope that this awareness-raising event continues to reach as many people as possible. “It is a very accessible way to get in contact with nature. Once we actually look, we see more wildlife around us”.

She recommended the Ornitho.lu online resource (open data) for those interested in learning more about the different bird species in Luxembourg. At the end of 2020, natur&ëmwelt launched the first English-language edition of its “Birds of Luxembourg” guidebook, which also contains a wealth of information concerning the Grand Duchy’s bird life.