In mid-August 2019, it was my privilege and good fortune to participate in an interesting, engaging and VERY fun “Birding Plus” tour in Costa Rica thanks to a great roommate, Nan, knowledgeable guide and tour organizer, Steve and Sherry, and group of fellow travelers (Ann, Art, Bill, Gordon, Len, Tom and Ylva). My next blogs will mostly focus on the birds, amphibians, mammals and insects we were fortunate to see there. The photos are not all great as taking shots in the rain and dark cloud/rain forests was challenging for multiple reasons. But they will give you an idea of the fascinating and beautiful sightings we had. (Clicking on photos enlarges them; then back arrow.)
One of the most difficult birds to “capture” in a good photo was likely the one about which I was most excited, the three-wattled bellbird (Procnias tricarunculatus). This species, which also lives in Honduras, Nicaragua and Panama, only breeds in the mountains of Costa Rica. These bellbirds are known to be shy, secretive and elusive as they remain mostly in the dense, high canopies of the forests. They apparently prefer to perch on uncluttered branches that are 33-72 ft (10-22 m) high and 0.98-2 in (25-50 mm) in diameter.
The males usually sing from March through June, so we were lucky that some of them were calling out in mid-August. Here we see a couple digiscoped photos of a male bird. The females look very different with olive coloring and a streaky yellow breast (we did not see a female). They are quite different in size, with males in one study having a mean wing length of 6.5 in (165.5 mm) compared to 5.7 in (145.1 mm) for the females.
The common name for these birds comes from the sound they make. In some articles, it is described as a 3-part song. To me, it sounded like they first made a high-pitched brief screech, squeak or whistle sound and then a deeper call.
Others have described their calls/songs as a “boink,” “bonk” or “Hee-aahh” sound. In any event, they obviously work at producing the sound. As we watched, “our” bird would open his mouth very wide, so that you could see the white and black lines surrounding the bill.
He seemed to be breathing in plenty of air as he sat there silently for a while. You could see his neck getting ridges, which I assumed was due to the oxygen he was gathering and holding to be expelled in the call. (This turned out to be a correct assumption according to one study!)
Then, he moved his head up and down a bit and you knew the sound was coming. It is unmistakable once you have heard it as in this brief video that fellow traveler Ylva made.
It is said that the bellbird’s sound is one of the loudest avian calls, audible to humans who are more than 0.5 miles (0.80 km) away. The calls and songs are not instinctive – the birds learn the calls and there are different “dialects” among the birds from different areas! One bird studied in Costa Rica could perform the song/call repertoires of Talamanca and Monteverde – in other words, he was bilingual!
Research has also shown that immature male bellbirds not only take 6 years to achieve their full adult plumage but also to perfect their entire song repertoire! Kroodsma et al. also note that: “Males appear to be highly attentive to the nuances of songs produced by their competitors, as both immatures and adults visit each others’ display perches, listening there for up to several minutes at a time.”
The other really striking characteristic of this species is the three wattles on the male’s head which begin growing when he is 6-12 months of age. One dangles from each side of the bird’s mouth and one is affixed to the base of the upper bill.
The wattles have been described as “wormlike”. Nan and I thought they looked a bit like hair-braids and on the flight home I sat next to a woman who had three braids ending in a point with interwoven gold thread that immediately made me want to give her the nickname “Bellbird”. (I didn’t tell her that though.)
The wattles are about one-third of the bird’s size (9.5-12 in or 25-30 cm). They cannot be controlled by muscles or made rigid, but they can be extended in length up to 3.9 in (10 cm) when the bird is interacting with others or singing.
The birds are frugivorous (eat only fruit) and prefer wild avocados (Lauraceae). They play an important role in the tree’s seed dispersal.
Due to habitat loss and hunting, the numbers of the three-wattled bellbird have declined to about 20,000 individuals and the International Union for Conservation of Nature (IUCN) has declared its conservation status to be vulnerable. They obviously inspire artists in Costa Rica, however, as witnessed by a mural at a restaurant where we stopped for lunch.
After three blogs in quick succession, I’ll now take a break to process and sort some more photos from Costa Rica to share with you. In the meantime, bye bye from the bellbird!