Tue CRANE-FuiEs or New York — Part II 721 
ENEMIES 
Crane-flies have many enemies and but few means of combating them. 
Every stage of the crane-fly’s existence is fraught with danger. The 
larvae of the majority of species are soft-bedied, herbivorous creatures, 
which form a choice morsel of food for carnivorous forms of many classes 
and orders. The period when the adult fly has just emerged from the 
pupal hull is undoubtedly the one in which the greatest danger is found, 
for then the insects are teneral and incapable of rapid motion. The 
adult flies are sometimes drowned in the sea or other large bodies of water 
and their dead fragments cast up in windrows on the shore. A very 
unusual instance of this kind is recorded for Tipula oleracea by Patterson 
(1908). At their best, the adult flies are poor, awkward fliers and are 
easily captured by a wide range of species, as indicated in the following 
pages. 
Predatory natural enemies 
Vertebrates 
Mammalia.— Undoubtedly many of the smaller mammals prey on the 
larvae of various species of Tipula. In another paper (Alexander, 1919 d: 
776-777) the writer has discussed the value of the larvae of an undeter- 
mined species of Tipula in the Pribilof Islands as an article of food for the 
arctic fox. These larvae occur in enormous numbers beneath the lichens 
of the tundra and the foxes can easily get them at a time when other food 
is scarce or unobtainable. Mice, shrews, and moles find an important 
element of their food from this source. White (1914) states that in North 
Wales the European mole, Talpa europaea, eats, on an average, twenty 
crane-fly larvae a day, these constituting one of the main foods of this 
‘mammal. — 
Aves.— Birds are well-known enemies of crane-flies, both in their imma- 
ture stages and as adult flies. Hyslop (1910:129-130) lists ninety-one 
species of birds which are known to feed on crane-flies. Baer (1913) 
describes ravens and starlings as feeding on the larvae of a species of 
Tipula. While working with the United States Biological Survey, the 
writer was given the opportunity to examine files for records. His thanks 
for assistance in this work are due to Messrs. Kalmbach, McAtee, and 
Wetmore. The records of the Survey are based on an examination of 
the contents of the stomachs of many thousands of individuals, and 
furnish very valuable and fairly complete data on the North American 
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