Photo: Sander van Duuren. Andean cock-of-the-rock (Rupicola peruvianus): ‘One of my favourite species, photographed at Weltvogelpark Walsrode,’ Sander says


Dutch bird man Sander van Duuren explains how a delight in seeing ‘new’ species in aviculture has led him to a wider and deeper pleasure in our planet’s avifauna


TWITCHING, for readers who have no clue what the word means, is the passion of birders who travel around the country to see rare wild birds. Now, picture that, but for captive birds. In part I guess I can be called a “captive bird twitcher”, although I never really like to use that term.

Ever since childhood I’ve had an interest in the natural world, but I really started to get into birds about 10 years ago. A trip to Wuppertal Zoo in Germany sparked it when I saw a male Andean cock-of-the-rock (Rupicola peruvianus) for the first time. I had seen pictures of this species, but to see it in real life was almost magic: bright orange, bill almost concealed, with a crest of feathers. From that point on, my interest started to grow and I bought a small digital camera. For the first few years I mainly went to zoos and bird parks.

A few years later, by coincidence, I found an advert on a Dutch variant of eBay, in which the seller – a bird dealer – offered birds that I knew were almost impossible to see in the zoo world. With sweaty palms, I replied to the dealer and asked whether it was possible to come over and take some pictures. A few days later I was invited to visit and thus a new interest was born. I started travelling quite a lot and, after a few years, managed to see several rare species.

In 2014, I decided to go to the bird market in Zwolle for the first time. This is one of the biggest bird markets in Europe and is held twice a year. I had no idea what to expect or whether I’d see anything interesting. After a few rows of cages I knew I’d made the right choice: species that I had never seen or were unknown to me were present, including one of my favourites, the lesser green broadbill (Calyptomena viridis); the largest tit species, the sultan tit (Melanochlora sultanea); and a stunning member of the bush-shrike family, the white-crested helmetshrike (Prionops plumatus). In the following years, I usually tried to travel to Zwolle and saw many species that captive bird twitchers would find very interesting: red-crowned ant-tanager (Habia rubica), forest robin (Stiphrornis erythrothorax) and spot-breasted parrotbill (Paradoxornis guttaticollis), to name a few.

By now my main interest had become primarily softbills and in 2014 I became a member of the Dutch Softbill Society. Soon after that, I met a breeder of tanagers who I visited to see a pair of speckled tanagers (Tangara guttata).

Sadly, he’d sold the birds the day before I visited him, but after talking to him for about two hours an idea arose to see if it was possible to create a project in which private breeders and zoos participate in the breeding of various species, as well as gathering information on their husbandry.

This is where social media comes in useful. I had been on Facebook, but hadn’t really used it much. After searching a bit, I came across a big group of softbill breeders, the SBK group (now SBBK) and joined. I quickly became an active member and soon started to join conversations and make friends. It became the perfect place to expand my knowledge, from solely captive bird twitcher, to forming an interest in the identification of birds and the relationship between species.

So, on many questions regarding the identification of species, I tried to respond and with that came much more knowledge. I spent hours reading family identification guides and articles on birds on the internet. Now, I even get asked to help identify unknown birds, which can sometimes be challenging. Recently, I was asked by a dealer friend to identify a pair of birds that had been sold to him. He’d been told they were a species of shrike-babbler (Pteruthius), but after examination they proved to be a pair of spotted crocias (Crocias albonotatus). Shrike-babblers have a black cap and white eye-stripe, plus a mostly dark upperwing and primaries, whereas spotted crocias have a dark-blue head, reddish and white-spotted upperparts, and much white in the primaries.

In some cases, the relationship between species is obvious, but nonetheless interesting.
At the most recent Zwolle bird market, I saw the black-browed bushtit (Aegithalos bonvaloti), a close relative of our long-tailed tit, which is now considered a full species, rather than a subspecies of rufous-fronted bushtit (A. iouschistos). Interestingly, it is almost intermediate between the rufous-fronted, which is more rufous, and the sooty (A. fuliginosus), which is far whiter.

So, am I still a captive bird twitcher? Yes, I am, but I guess I have evolved to have a greater interest in birds; and the chance to help fellow aviculturists to a next level is what it makes it all worthwhile. ■