MEROPS BULLOCKOIDES.
DIMENSIONS.
Incites. Lines.
Length from the tip of the bill to the
point of the .tail................... 7 6
of the tail................................. 4 0
of the bill from the angle of
the mouth............................ 1 7
Inches. Lines.
Length of the wings when closed....... 4 6
of the tarsus............................ 0 3^
of the middle to e .................... 0 3
of the hinder to e .................... 0 2
The female resembles the male, with the exception that the colours are not
quite so bright.
Between this species and Merops Bullockii many discrepancies might be
instanced, but the diagnostic character, which will prove the most readily
available, is the colour of the upper tail coverts. In the present species, this
colour is invariably similar to that of the lower ones, whereas in Merops
Bullockii it is very different.
It was not until the expedition attained the 25° o f south latitude that this bird was discovered,
though north of that it appeared not uncommon. When observed, it was generally
either perched upon the tops of trees, along the immediate banks of rivers, or in the act of
making short circuits through the air, apparently in chase of flying insects. As may be inferred
from the structure of its wings, it is not a bird which flies for any great length of time
without resting; it seeks its food during frequent low and short flights, and after each of these,
often returns to the perch from whence it proceeded. In respect of its habits, as well as its
wings, it closely resembles M erops E r y th r o p ter us, Lin. ; but, in regard to both these characters,
it differs from the other species of the genus yet observed in South Africa. Upon the modified
structure of the wings in this species and M . E r y th ro p te ru s may depend the circumstance of their
being permanent inhabitants of the districts where they are found, and where they encounter
a cold during the winter much more severe than ever occurs farther to the southward, and from
which the M erops A p ia s te r , Lin. M . S a v ig n ii, Levaill. and M . chrysolaimus, Jard., fly towards
the end o f summer. From observations I have had occasion to make, I think it probable that
the migrations, both of birds and quadrupeds, will be found often to depend more upon causes
which have hitherto been comparatively overlooked, than upon any absolute deficiency o f food
in the countries from whence they retire. Connected with this opinion, I may instance the circumstance
of a species o f swallow, which inhabits the mountains of the Cape Colony during
the summer months, repairing in the winter to the vicinity of houses left, by another species,
on the approach of the cold season. It there finds food sufficient for its support, till the other
species, gifted with more vigorous powers of flight, and a superior courage, returns and drives
it back again to situations which it had for a time abandoned.