After the last Cuckoo-sightings during the ant’s statary phase, it has become silent again in the reserve. The army ants didn’t do us a favor when they got nomadic again and they moved far away from the reserve. First they decided to go down on a steep slope again which made it difficult to follow them, but Wilo still managed to follow them at night time despite the difficult terrain. For a few days they got further and further down towards a little stream and we hoped that they would turn when they reach the water. But when they finally got to the stream they showed how little these natural boundaries bother them. They crossed the stream using twigs and fallen logs and continued their journey through thick Bamboo (Guadua) growth on the other side. By that time it got already impossible to take visitors with us anymore. The hike to get to the ant’s bivouac already took us over an hour, and even longer with visitors who were not used to hiking in forest without trails. We still hoped that the ants would get statary in a spot which we could access and continue our observations of the Cuckoo, but almost at the end of their nomadic phase the ants moved so far each night that it almost felt like they were running away from us.
In the last night Wilo followed the ants, I was waiting at our house with the Walky Talky for Wilo’s news on the ants and a spark of hope crossed my mind when he reported that he had found another column of army ants on his way, a lot closer to the reserve. We had not seen the Cuckoo anymore for a few mornings and so I already started thinking that it might have been together with those other ants. And maybe they would even come closer to the reserve as they were on their way towards us. Half an hour later Wilo reported again and the news were disillusioning. The army ants were crossing another river and continuing onward on the other side of the valley. When Wilo came back later that night, we both knew that this was the last night Wilo followed the ants. The tracking of the ants had already taken him 5 hours and the hike to other side of the valley was far too difficult and dangerous to take any visitor.
The next morning we got up by dawn again to get to the spot where Wilo had found the other army ants. I was doubting already that these ants were another Eciton burchelli colony. Wilo told me that the column he had followed was not as big as the ones we had usually and there hadn’t been any soldiers around. I also couldn’t imagine that we had overseen another ant swarm so close to the one we were following. When we got to the spot where Wilo had seen the ants the night before, we heard an Immaculate and an Esmeraldas Antbird. My hope rose again. But a few minutes later I had to notice that the army ants were not Eciton burchelli. First of all they had not formed the same big ball of ants which E. burchelli forms. They were walking around inside a tree trunk. And then we found a column leaving the nest site. The ants were column raiders, very similar in appearance to Eciton burchelli, but with a very distinct behavior. Wilo probably had found a colony of Eciton vagans which is a nocturnal species and the larvae they were carrying the night before were not their own but prey items from other ants.
On our way back I felt really sad. The last hope of being able to continue our work had vanished. Finally after five months of tracking the army ants and observing the Cuckoo, we had to accept that there is a limit to our possibilities. Not so easy! After all I got really attached to these birds and I was already missing them. But who knows maybe the ants come back someday in the future and with them a Cuckoo. Most of our neighbors know this species and apparently not only one bird has been around in the area. Who knows where the other Cuckoo individuals are. During the past five months we had at least seen three individuals, maybe even four and in the last weeks we had only observed one. So where are the others? Of course, we could search for another ant swarm on the neighboring properties and we could maybe find a Cuckoo nearby. But that’s a little bit like searching for a needle in a haystack. Anyways we have told our neighbors to tell us when they find an antswarm (or even a Cuckoo) and in the meantime we have to wait and hope for the ants to come back. As we have always had army ants in the reserve, I am sure they will return or another colony appears. So fingers crossed and patience….
All in all the time with the Cuckoo was very interesting and apart from getting to know so many interesting people associated with birds, bird tourism, ornithology and conservation, we have learnt a lot more about this bird’s behavior. But just as anytime when studying a specific subject, the more you learn the more questions arise. This morning I heard about the news that a nest of a Banded Ground-Cuckoo has been found in Bilsa. I really hope somebody will be able to study the nesting and feeding behavior of the Cuckoo during this important period of reproduction. It would be very interesting to know if the birds also follow ant swarms during breeding. And who knows maybe our Cuckoos are also breeding at the moment and producing more Wilitos….?!!