Chirps, warbles and trills
An interview with Dr Tobias Rahde
When autumn arrives, the skies, fields and meadows offer a stage for spectacular scenes of natural beauty. Bird enthusiasts gaze in awe at cranes flying high overhead in incredible V formations, or at the thousands of geese that gather on misty wetlands to rest before continuing their long journey south.
Each year, an estimated five billion birds travel between Europe and Africa. That is the largest migration in the world – for comparison, the famous Serengeti wildebeest migration involves about 1.2 million animals. For many birds, much of this long journey takes place at night and goes largely unnoticed by humans below. But you might occasionally wake up in the morning to the sound of unusual birdsong outside your window.
The fascinating world of birds
Many of the staff at Zoo Berlin are passionate amateur ornithologists. And some – like bird curator Dr Tobias Rahde – have even turned their hobby into a career. We met up with Dr Rahde to talk about his fascination for feathered friends and his commitment to protecting bird life around the globe.
Dr Rahde, thank you for taking the time to talk to us. You have worked with birds for a number of years already. When or how did your interest in birds develop?
I have actually always found birds fascinating. I think that stems from the fact that they are so completely different to humans and yet we keep finding parallels – particularly when it comes to behaviour. This general interest intensified during my period of community service, which I spent at a marshland reserve in Lower Saxony. There, I met some extremely knowledgeable birdwatchers –commonly known as “birders” – who became mentors to me and taught me the best way to observe birds in the wild. I was also able to hone my own skills during that time and learned to distinguish the songs of some common birds. It was a really wonderful and exciting time, and it left a big impression on me.
Your PhD thesis involved in-depth research into parrots. What was the specific aim of your research and how did you come up with the idea?
I was particularly intrigued by the behaviour and intelligence of birds. Parrots and corvids (the crow family) are seen as the primates of the bird kingdom because of their intelligence. In particular keas – the species that I worked with – are known for their innovative capability, curiosity, and technical intelligence. The aim of my research was to determine the keas' cognitive capacity for mental imagery. For example, I tested the birds’ concept of object permanence – i.e. whether they know that things continue to exist when they can no longer be seen. This can generally be determined using the shell game, and the results showed that these birds do indeed possess object permanence. This is a skill that humans only acquire at around twelve to 18 months. My research also demonstrated that keas have a mental image of themselves. This can be determined using a mirror test. In this case, the test showed that keas recognise their own reflection and are able to use a mirror as an aid to remove a marking on their own body. Such a high level of cognitive ability had previously only been witnessed in chimpanzees, dolphins, elephants and magpies.
You are now bird curator at Zoo Berlin, which means you spend every working day with numerous birds from more than 300 species. Is the study of birds still part of your personal life too?
Birds are still a big part of my personal life. Every October I travel to Linum with my children to watch the arrival of the cranes. This is always a very special natural spectacle that attracts birders from all over Europe. This year, we were able to observe more than 30,000 cranes. I would also recommend everyone to put out bird feeders, especially now during the colder months, and see what comes to perch on them. But please bear in mind you should only put out high-quality food and keep the feeders clean. With a bit of luck, you might attract the odd seasonal guest like a brambling or a goldcrest.
This autumn you became the international studbook coordinator for the Edwards’s pheasant. What is so special about this particular bird?
For several years, Zoo Berlin has been supporting efforts in Vietnam to look for any Edwards’s pheasants left in the wild using camera traps. While our cameras captured images of many rare species, not one Edwards’s pheasant made an appearance. We therefore sadly have to assume that this bird is now extinct in its natural habitat. One reason for this tragic situation is the lasting impact of the Vietnam War, which led to the defoliation of trees in the region. During the war, which lasted some 20 years, the embattled demilitarised zone lay in the province of Quảng Trị – right in the middle of the Edwards’s pheasants’ habitat. This region witnessed the heaviest fighting, including the aggressive use of chemical weapons such as the highly toxic defoliant Agent Orange. The herbicide was sprayed across fields and forests, with catastrophic consequences for the environment and the people living there. Those consequences are still felt to this day. The Edwards’s pheasants have also been hit hard by constant poaching and the steady decline of their forest habitat.
What exactly does your new role entail?
To ensure that this species does not die out completely, it is essential that we keep a studbook to accurately record and manage the remaining population – which currently stands at a few hundred, all in the care of zoos and some private keepers. That is the task I have assumed this year. I am currently mapping the genealogy of the individual birds so as to create pairings that are as genetically diverse as possible. The studbook is accompanied by an on-site project in Vietnam, which Zoo Berlin is also closely involved in. The aim of the project is to have a stable population of Edwards’s pheasants back in their natural habitat within ten years. To achieve this, we are helping to build a breeding and reintroduction station in central Vietnam.
That sounds like an exciting project. Is the Zoo only active in Vietnam, or are you working to protect endangered birds in other parts of the world?
We support species conservation projects all over the world, and have even helped initiate some of them. Examples of other species that Zoo Berlin is helping to protect are the Madagascar sacred ibises, the hornbills of India, and the hyacinth macaws of Bolivia. We are also passionate about nature closer to home, like the Lower Oder Valley National Park on the German-Polish border. With its regularly flooded meadows, the Lower Oder Valley is a paradise for water birds, which use it as a breeding ground, a resting place, and winter quarters. Around 200,000 geese, ducks and cranes pass through the valley during the autumn and spring. For several weeks each October, up to 15,000 cranes roost in the northern part of the valley. In addition, more than 145 bird species regularly breed here, including eagles, black storks, corncrakes, and the threatened aquatic warblers. We also support EAZA’s Silent Forest campaign, which is raising awareness of the disappearing numbers of songbirds in the forests of Southeast Asia.
Why are these birds disappearing?
The rapid disappearance of the songbirds is tied to a cultural tradition in the region. Aviaries have always been popular in Indonesia, and roughly one in five households has a bird as a pet. Fierce competition also exists among songbird keepers, as owning the most talented bird with the most beautiful song not only confers higher social status, it also has a financial incentive. The tradition of songbird competitions still enjoys widespread popularity, and has now grown into a genuine sporting event with a following comparable to that of football in Europe. That means there is real money to be made from the sale of songbirds. Songbirds hatched in the wild are believed to possess more beautiful songs than their relatives bred in captivity. What’s more, it is often easier to catch birds in the wild than it is to breed them, as many captured birds die shortly after being shut in a cage. Indonesian songbirds are also hunted for export, consumption, and medicinal use. Demand for the birds is therefore high, negatively affecting hundreds of species and millions of individual birds every year. This is another location where we are working to establish a breeding station, with a view to reintroducing young songbirds into the wild.
How can you get zoo visitors here in Berlin involved in topics such as these?
We are currently collecting old, but still functional, binoculars. These are going to be sent to schools across Indonesia in an attempt to increase local awareness of and appreciation for the birds living wild in the country – and perhaps even encourage birdwatching as a hobby. So if you come across an old and unused pair of binoculars sitting in grandma’s cupboard or while you’re clearing out the attic, the Zoo ServiceCenter will happily take them off your hands.