NATURAL CONTROL. 43 
stomachs of which the Biological Survey of this department has found 
ticks (McAtee, 1911a) are the killdeer (Oxyechus vociferus), wpland 
plover (Bartramia longicauda), meadowlark (Sturnella magna), dwarf 
hermit thrush (Hylocichla guttata nana), and house wren (Troglodytes 
zdon). Mr. J. D. Mitchell states that it is the habit of jackdaws to 
search for and destroy many cattle ticks on the range by inverting 
the dried dung, which furnishes a favorable protective covering for 
this tick. Pycraft has called attention (1910, p. 124) to a depraved 
habit that such birds may develop, citing the tick bird which occurs 
in Africa as an example: 
Take, for example, the case of the oxpecker or rhinoceros bird (Buphaga africanus), 
a native of South Africa and generally regarded as a species of starling. This bird is 
commonly found in intimate association with basking herds of cattle and big game, 
running about all over the bodies of these creatures in its search for the ticks and 
other parasites which harbor there. Lately, however, this bird has fallen into dis- 
grace, since it has extended its attentions to the horses and cattle of the colonists with 
anything but happy results. It would seem that in removing ticks from the more 
tender hides of these animals the birds caused wounds, and at the same time gained 
a taste for blood, with the result that, where horses and cattle are at all numerous, they 
become severely persecuted by these birds, who now seek not so much to prey upon 
the ticks as the hosts thereof, which suffer considerably in consequence. Thus we see 
how easily long-rooted habits may become changed, and how an originally useful 
instinct may become depraved. The tough hide of the rhinoceros was proof against 
the beaks of these birds, and consequently nothing but good resulted from their 
presence, but, as we have shown, a very different state of things began when the 
hides of the imported domesticated animals became subjected to a similar inspection. 
On account of the damage they do the restrictions imposed by Government for their 
protection have now been removed, but the oxpecker will doubtless long contrive to 
hold his own in this vast country. The work of the rhinoceros bird in England is 
performed by the common starling and so far no harm to cattle has been done by 
reason of injuries inflicted on the hides. Similarly, in East Africa, egrets swarm over 
the bodies of elephants when they approach the neighborhood of water, apparently, 
as it has been suggested, for the sake of capturing the various kinds of insects put up 
by the elephants as they move about. 
PARASITES. 
Two chalcidoid parasites have been found to attack engorged 
nymphs. ‘The first of the two, described by Dr. L. O. Howard in 1907 
as Izxodiphagus texanus, was reared by Hooker from specimens of 
engorged nymphs of Hemaphysalis leporis-palustris collected by Mr. 
J.D. Mitchell from rabbits in Jackson County, Tex. The extent of 
the parasitism and importance have not been determined. Nymphs 
subsequently collected in that locality were not parasitized. 
The second parasite (Hunterellus hookeri) was described by Dr. 
Howard’in 1908 from specimens reared by Hooker from engorged 
nymphs of Rhipicephalus sanguineus, collected by Wood from dogs 
at Corpus Christi, Tex. This species has been found to play an 
important part in destroying the brown dog tick in southern Texas. 
As specimens of this latter species have since been reared by Mr. C. W. 
