1832-3.] THE CUCKOO. 63 



Birds of many kinds are extremely abundant on the un- 

 dulating grassy plains around Maldonado. There are 

 several species of a family allied in structure and manners 

 to our Starling : one of these {Molothrus niger) is remark- 

 able from its habits. Several may often be seen standing 

 together on the back of a cow or horse ; and while perched 

 on a hedge, pluming themselves in the sun, they sometimes 

 attempt to smg, or rather to hiss ; the noise being very 

 peculiar, resembling that of bubbles of air passing rapidly 

 from a small orifice under water, so as to produce an acute 

 sound. According to Azara, this bird, like the cuckoo, 

 deposits its eggs in other birds' nests. I was several times 

 told by the country people, that there certainly is some bird 

 having this habit ; and my assistant in collecting, who is 

 a very accurate person, found a nest of the sparrow of this 

 country {Zonotrichia matutina), with one ^%^ in it larger 

 than the others, and of a different colour and shape. In 

 North America there is another species of Molothrus {M. 

 pecoris), which has a similar cuckoo-like habit, and which 

 is most closely allied in every respect to the species from the 

 Plata, even in such trifling peculiarities as standing on the 

 backs of cattle ; it differs only in bein^ a little smaller, and 

 in its plumage and eggs being of a slightly different shade 

 of colour. This close agreement in structure and habits, 

 in representative species coming from opposite quarters of 

 a great continent, always strikes one as interesting, though 

 of common occurrence. 



Mr. Swainson has well remarked,* that with the exception 

 of the Molothrus pecoris, to which must be added the M. 

 niger, the cuckoos are the only birds which can be called 

 truly parasitical; namely, such as "fasten themselves, as 

 it were, on another living animal, whose animal heat brings 

 their young into life, whose food they live upon, and whose 

 death would cause theirs during the period of infancy." It 

 is remarkable that some of the species, but not all, both of 

 the Cuckoo and Molothrus, should agree in this one strange 

 habit of their parasitical propagation, whilst opposed to 

 each other in almost every other habit : the molothrus, like 

 our starling, is eminently sociable, and lives on the open 

 plains without art or disguise : the cuckoo, as every onr 

 knows, Is a singularly shy bird ; it frequents the most 

 retired thickets, and feeds on fruit and caterpillars. In 

 structure also these two genera are widely removed from 



" " Magrazinc of Zoolog^y and Botany," vol. i., p. 917. 



