Crithagra burtoni (Serinus burtoni)
Geographical distribution and habitat
Beside the nominate Crithagra burtoni burtoni, three subspecies are described. The Thick-Billed-Seedeater is a Crithagra species which not only is the beak size different, but also the bodysize and colour compared with most of the other Crithagra species. The chance to confuse with other Crithagra species is small because of that. Crithagra burtoni burtoni has been seen in Cameroon and East of Nigeria. C.b.tanganjicea lives in the East of Zaïre, Uganda and parts of Angola. C.b.kilimensis has been found in the South-West of Kenya and the North of Tanzania. C.b.albifrons natural habitat is Central Kenya. The Thick-Billed Seedeater lives in the West and the East of Africa, especially in the highlands and mountains up to 3000 metres (3.300 yards). Actually above the timber line. Because of the enormous range and the natural separations in that area, there are lots of differences between the subspecies.
Size: 16-18 cm (6.3-7.1 inch)
The size difference, depending the subspecies, is from 6.3 to 7.1 inch. C.b.tanganjicea is the biggest of the Thick-Billed Seedeaters.
Description and subspecies
There are not many reports about the Thick-Billed Seedeater or the Burtoni. It has been written that the sexes are equal of colour and design with a possible more bright colour on the male. C.b.kilimensis shows no white colour at the front of the head. C.b tanganjicea has a nearly black head, back and chest and a light coloured eye ring and some light spots below the eyes and in the beakedges(angles). C.(b).melanochroa, sometimes is assigned to the Grosbeak Canary’s, sometimes seen as separate species.
Grosbeak Canary’s are fed with a somewhat coarser seed mixture as is normal, for instance, for Goldfinches. They will eat Eggfood, berries, fruit and insects. These birds seem to have no special requirements of temperature, as seen in the natural habitat. Nothing is published about being aggressive against other birds. Little value is given to the singing of the Grosbeak Seedeater.