New-York tribune., 1909-04-25
THE MYSTERIOUS CUCKOO.

The MYSTERIOUS habits of the cuckoo have at
.-acted the attention of naturalists from the
..-Iiest times. More than two thousand years
90 Aristotle refuted the statement that cuckoos
~@@-,ed into hawks in winter Yet such is the
tarseryatism Of superstition that this belief IS
<-iU occasionally found among 1ngilsh game
1n.Ders in the twentieth century Perhaps TINS
~ rot surprising when consider how few
-.n7okeepers ever read the work Of Aristotle.
5S,-sne the last century, however. our knowl-
see Of ornithology has been greatly increased
= .,e-S country Of Europe field naturalists have
Zen Al work making collections and recording
onse-,-et tons An enormous literature has grown
-, treating Of the cuckOo's habits; but there
a. s-jl much that is uncertain and great deal
.s.t is at present unknown. There are, how
& ne Two things touching the cuckoos habits
= nich are familiar to every one. The bird Is a
mmer migrant TO the British Isles and the
rrs are deposited in the nests Of other birds
-he origin Of this parasitic custom is shrouded
a. mystery. Even in its migra tory habits the
.rczoo is peculiar. Unlike most birds. the Old
.uckoos are the first to depart on their Jourle!
o-.brard The parent birds leave in July;
+te Young birds remain until September Here
ne are at once confronted with a problem Is
:. -bis abnormal impulse To migrate early when
bse led cuckoos 10 put their eggs in other birds
nests? Or they able to leave early because
thev are relieved Of domestic duties?
Y must be confessed that there is very little
.1i5ence to explain how the parasitic habit OF
,be cuckoo arose. There is no doubt. however.
ma the habit is a beneficial one, for the com
non cuckoo is a fiourishing species 1t is a
zee therefore where natural selection may
have operated: that is to say. when some
cuckoos had taken to dropping their eggs III
s,her birds nests they and their progeny would
t1-fve in the struggle for life The parasitic
cuckoos would tend TO survive. and those Whlch
went en- building nests would tend 10 become
.xterriinated. II is worth noting that the cow
birds Of the New World, who are in no way
,slated to the cuckoo. are also parasites \
number Of birds have the habit of occasionally
favinC in each others nests. Cases OF pleas
,r+s and vartridges doing have been often
-scorded less frequently. cases Of gulls and
ss5e- ducks redstarts and pied fly catchers. and
species OF tit.niCe- But with these II
CONS 10 be an accidental matter Possibly the
sncestors Of our cuckoo may have begun IN
come such fashion. and the habit OF casually
isrinc in 4 strangers nest may have proved a
useful inheritance Stories Of Cuckoos building
nests and sitting on their own eggs are with
out foundation. and there IS no trustworthy evil
dsnce TO support the common belief that IheE
return 70 The foster parents nest 70 see how
their little one is faring The female cuckoo
takes no interest IN her offspring after the egg
Is laid and disposed Of a great many eNpiana-
lions have been advanced to explain WhY the
cucto0 does not sit upon Nher eggs. Some are
ingenious but none are satisfactory. Herssant.
a French naturalist Of the eighteenth century,
declared that the Cuckoo's stomach lay behind
the sterrum. and formed protuberance
which made incubation impossible. To TINS
White Of SeIborne. replied by showing that the
v5scera Of the nightjar are similar TO those or
the cuckoo and yet il is not prevented from
nesting Schlegel. in the nineteenth century,
thought that the Cuckoos food produced an en-
iarged stomach. that il got little nutrition from
diet Of hairy caterpiarS, and that constant
hunger interfered with domestic duties But IL
seems that the stomaChs OF the two common
North American cuckoos are precisely similar,
enG they are not parasites. The maternal feel
inFs of the cuckoo are undoubtedly weak. But
whether she leaves her eggs TO foster parents
hecsuse her maternal feelings weak. or
whether her maternal instincts have been weak
ened because she does not see her progeny. is a
problem that may be left for further cOnsidera-
tion.-Harold Russell. in The National Review