Feb Birding: Finding feathers in a furnace!

February has proven a productive birding month and in just a few days we clocked up 130 species on the basic birding course at Karongwe Game Reserve with the year-long Ecotraining students (http://www.ecotraining.co.za/). This is remarkable simply because the weather was exceptionally hot with one particularly eager thermometer clocking a 48⁰C at one point. We resorted to very early starts and much birding from the vehicle so that in between bouts of viewing we could engage the ‘manual air-conditioning solution’ that an open Land Rover provides!

Being in a vehicle also enables you to cover more habitats which house different species. The most obvious feathered feature wherever we went was the Woodlands Kingfisher. These are conspicuous birds thanks to their bright colours and noisy, active habits. The “chip-crrrrrrrrr” is unmistakeable and unrelenting but when one considers that the Woodland’s is a migrant, it is understandable that they call so incessantly. Their breeding efforts need to be wracked-stacked-and-packed before its time to move on again.

Most species of kingfisher are strictly monogamous (one male and one female pair up). The males defend territories and establish a pair bond with the female through visual displays and courtship feeding. The Woodland’s Kingfisher has a particularly elaborate display in which it opens its wings and pivoting on a branch displays the white and then the blue side of the wing alternately all the time vocalizing loudly. A female taken by his exhibitions will be further convinced to pair up with a male depending on the nuptial gifts he brings her. Some bird species (including the kingfishers) engage in courtship feeding where the male proves his ability to care for a female and her brood by bringing her morsels of food. This also serves to build up the female’s reserves before she must produce and then incubate for an egg.

The bright blue of the Woodlands kingfisher’s feathers is the result of an effect called tyndal scattering. This is where the layers of structural keratin that make up the feathers are interspersed with air spaces and reflect particular wavelengths of light to appear blue. There is no colour pigment in the feathers.

Without any colour yet just as conspicuous for its vocal habits as the Woodlands, is the fork-tailed drongo. It’s a resident species but to impress females and ward of rivals it has developed a unique technique. In a process known as mimicry, the fork-tailed drongo copies phrases of songs and sounds belonging to other species of bird much like robin-chats. The complexity of the assembled tune is suspected to be an indication of fitness to females. Males that are able to remember and knit together long sequences of phrases are considered better partners. A strong mimicked vocal signal also will intimidate rivals and convince them of the singer’s superiority.

Birds sing to advertise their territories and to attract mates and subsequently build bonds with those mates (especially if they are monogamous and only have one). Birds sing most earnestly in the morning when the air is clear and still and sound travels furthest and loudest. This is known as the ‘dawn chorus’. They also utilize the dawn chorus to remind their neighbours that in spite of a night of darkness since last they called, they are still very much in attendance of their turf. Birds call in the late afternoon again to establish ownership of an area before they sleep.

Good rain has meant that Karongwe is green, lush and somewhat overgrown. Spotting birds along the shorelines at the waterholes was difficult but the characteristic 3-syllabled whistle of the white-faced ducks betrayed their presence in the area as they were flying over in the evenings to forage. These ducks are fairly unique among ducks for their tendency to both whistle instead of quacking and also to feed at night on grass, seeds, grain and even fruit (like geese). Ducks have flat bills which are used for sieving edible particles out of the water. Many ducks up-end or dabble, partially submerging their upper bodies in order to access food below the water. The food they usually consume includes various parts of aquatic plants, insects, detritus in mud, algae, crustaceans and other invertebrates. White-faced ducks dabble for food but may also dive fully under the water to obtain something they desire.

Despite the fiery weather conditions, the birding week was productive and satisfying and I look forward to the next one when I can listen to the fiery-necked nightjar under cooler night skies!