Research On Carmine Bee-eaters

29 Apr 2021

Mark Boorman from Swakopmund and I ringed a total of 530 Carmine Bee-eaters of the breeding colony between Zambezi Mubala Camp (previously Island View Lodge) and Zambezi Mubala Lodge (former Kalizo Lodge) in September this year. It was the third ringing effort after 2015 and 2016, and there was a difference this time: Jim Kairu, a wildlife management lecturer at the campus of the University of Namibia (UNAM) in Katima Mulilo in the Zambezi Region, was also taking part. Kairu, who hails from Kenya, wants to do research on Carmine Bee-eaters. Furthermore, the head of wildlife management and ecotourism at UNAM’s Katima Mulilo campus, Dr Ekkehard Klingelhoeffer, and 22 students were present while most of the Carmine Bee-eaters were ringed, measured and examined.

For two days the students had the opportunity to get introduced to ringing, learn more about Carmine Bee-eaters and their role in nature as well as for tourism and how many questions about these colourful birds are still unanswered. The ringing effort of almost four days was supported by the Gondwana Group, which provided accommodation and meals for us two bird ringers.

Since we did not want to get in the way of the photographers, who are numerous now, and of course didn’t want to disturb the growing number of Carmine Bee-eaters, we set up our nets on the periphery of the breeding colony, at its south-westernmost corner, early in the morning and late in the afternoon when the birds were in the colony and most active. They gathered in their thousands to carry away blades of grass and dig their nesting tunnels into the ground. Later in the morning and early in the afternoon they left the area in search of food. Shortly after sunset they disappear into the nesting cavities as if ordered to do so and suddenly all is quiet. The next morning all the Carmine Bee-eaters seem to emerge from their nesting tunnels at the command of a single bird to stretch their wings high above the breeding site and greet each other at the top of their voices. Shortly afterwards they continue to build their nests, defend their breeding place and add to the constant background noise.

The Carmine Bee-eaters are repeatedly plagued by Yellow-billed Kites and occasionally by an African Marsh Harrier, which grab careless birds. They are not much bothered, however, by the people around the colony, who are taking photos or busy ringing, and sit down just a few meters from them.

This year, together with the students and lecturers, we checked whether the brood patch of the ringed bird was fully developed. A brood patch is a featherless patch of skin on the underside of breeding birds. It is extremely well-supplied with blood vessels at the surface which makes it possible for the birds to transfer heat to the clutch through direct contact. All of the birds examined at the start of this year's breeding season had a brood patch. Therefore it can be assumed that both males and females are involved in incubating, which has not been scientifically proven yet.

Feather samples of bee-eaters were taken at the request of Dr Klingelhoeffer and Jim Kairu. Once a laboratory is found which can analyse the samples for UNAM, important DNA tests will be conducted. It may also be possible to determine the gender of each bird.

Furthermore, we hope that at least one of the more than 1500 birds which have been ringed since 2015 will be found in its winter quarters, so that we will finally know where exactly these birds spend the southern winter. They migrate to Equatorial Africa and return to the Zambezi from August. The Carmine Bee-eaters can be observed at the breeding colony until the beginning of December. After the chicks have fledged, they and their parents spread out over large areas, also to the south as far as Khaudum National Park. From April they move north again.

Author: Dirk Heinrich