| dc.description.abstract | The land-bird community of Tsavo East National Park was studied for
two years. There are two wet seasons each year: November-December and April-
May, but the latter were very poor in both study years. Six habitat types
were designated on the basis of canopy cover of woody vegetation. Riverine
"vegetation was also studied. Most of the open habitats extant are derived
from woodland by destruction of trees, a process largely caused by elephants.
Food supplies are seasonally variable. Insects and grass seeds are
most abundant in December and January. In the open habitats the few fruits
also peak then, but Commiphora spp., which is only in woodland and is the
most abundant fruit in Tsavo, peaks July to September.
The ecology of each species of land-bird is described and most are
found to be ecologically separate from each other.
The annual cycle of numbers of birds in each habitat is closely
correlated with the food supplies. In the open habitats birds are almost
all insectivorous, granivorous or both, and peak numbers (about five times
the dry season density) occur in December and January. In woodland, numbers
remain fairly constant through the year and frugivores are more prominent,
especially around August. The wet season peaks in all habitats are caused
by immigrations of different species, both from elsewhere in Africa most
of which come,in to breed, and species which breed in the Palaearctic. The
August peak in Wood],and consists mainly of ."6pecieswhich have resident
populations.
The"results are particularly related to the recent habitat changes in
the Park. They are compared with other bird. studies in African savannas and
other components of the Tsavo ecosystem. Finally, the means by which birds
are able to survive in the harsh and unpredictable conditions of Tsavo are
discussed. | en |
