With gulls and lichen on its roof and algae and lake trout down below in the water, the Chapel Bridge contributes hugely to urban biodiversity.
Bats live on the underside of the bridge deck – largely unnoticed by passers-by – and the Water Tower houses the largest colony of Alpine swifts in the whole of the canton. There are plenty of insects here for all. And if you look over the parapet, you’re likely to spot the odd lake trout or a tufted duck diving.
A life in the air
The elaborate aerial displays that Alpine swifts perform on fine summer evenings are legendary. With their typical trilling call, they circle the Water Tower in the early hours of the evening, soaring to ever greater heights and swooping back down again. This is the colony’s roosting ritual. Perfectly adapted to life in the air, Alpine swifts remain faithful to their nest site and to their mate for life. Breeding pairs have nested in the roof space of the Water Tower for decades. Most of the nesting sites are in the upper, wooden part of the tower, directly behind the outer wall.
The birds return from their winter quarters in tropical Africa in April and herald the start of spring in Lucerne. As hunters of flying insects, they can only find enough food here in summer. Whether feeding or sleeping, the animals are able to maintain all their bodily functions during their endurance flight. The Alpine swift is on the “Red List” as a potentially endangered species.
Not dependent on us feeding them
Animal watching is fun and provides an opportunity to gain an insight into their behaviour. However, waterbirds are not dependent on us feeding them. On the contrary: feeding – however well-intentioned – encourages the transmission of diseases. Rats and pigeons also eat food left for the birds and then, as a consequence, multiply uncontrollably.
A harmful disservice
When they feed pigeons, animal lovers are doing the objects of their affection a harmful disservice. Feeding them allows them to reproduce more prolifically and they end up living closer together. Diseases and parasites can spread more easily, which has a negative impact on the health of the animals. The city’s “Stadttauben Luzern” project calls on the public to refrain from feeding feral pigeons. The aim is to have fewer but healthier pigeons living in the city of Lucerne.
The bridge spider or grey cross spider is nocturnal and stays in its hiding place during the day. What are visible, however, are their large, spiral, wheel-shaped webs. It is a common and widespread spider species that tends to live on bridges near water.
They are very sociable. The bridge spider likes to build its web next to light sources, such as the lights on the Chapel Bridge, which help to attract nocturnal insects. Read about who is responsible for clearing away the webs and why it has to be done.
- From spring to late autumn
- During daylight hours and in any weather conditions
- The Chapel Bridge is a good vantage point for spotting common barbels searching for food at the bottom of the Reuss
- In winter, when the water temperature is cold, the fish are barely active
Hunters of the night
During the day they are at rest in their hiding place under the Chapel Bridge. In the evening they fly over the surface of the Reuss hunting. Despite the noise of feet pounding overhead, Daubenton’s bats raise their young here summer in, summer out. Bats use the same roosts over and over again, where they sleep upside down. Despite its small size, the Daubenton’s bat, also known as the “water bat”, has a good appetite – it can eat up to 500 mosquitoes an hour.
It finds its prey using ultrasonic echolocation. In other words, it continuously emits signals that are inaudible to humans. The signals hit potential prey and return as echoes. The Daubenton’s bat, like all bat species, is protected by law and considered endangered.gefährdet. Find out here who is responsible for their protection and why this is important.
Daubenton’s bat watching
- From May to early September
- The best time is when it is warm with no wind or rain
- As dusk falls, the Daubenton’s bats fly out from their roost under the bridge
- The Rathausquai and the square in front of St Peter’s Chapel both offer good vantage points from which to watch them. Keep an eye out for them on the parapet of the Chapel Bridge and the surface of the water
- On the Chapel Bridge, if you listen very carefully you can hear the bats’ social calls before they leave the roost