236 Lake Maxinkuckee, Physical and Biological Survey 



BIOLOGY 

 INTRODUCTION 



More attention was naturally given to the biology of the lake 

 than to the physical features. The scope of the investigations as 

 originally planned contemplated as careful study of the vertebrate 

 animals of the lake as time and facilities at command would per- 

 mit. It soon became evident however, that no very satisfactory 

 progress could be made with those groups without consideration 

 of the plants and the various groups of invertebrate animals of 

 the lake. It also became increasingly evident as the work pro- 

 gressed that no hard and fast line could be drawn between the 

 species directly related to the lake and those only indirectly so 

 related. This fact was strongly impressed upon us when we came 

 to study the habits of the mammals, reptiles, batrachians, and birds 

 of the lake and vicinity, and the distribution of the trees and 

 shrubs and other shore vegetation in their relation to the various 

 species of insects upon which fishes and other aquatic animals 

 feed. Many illustrations could be given of the ways in which 

 various species of purely land animals and plants are related eco- 

 logically to purely aquatic species inhabiting the lake. A few 

 examples may be mentioned. One might think that the common 

 house mouse and field mouse bear no relation to the life of the lake ; 

 but we have found both in the stomachs of large-mouth black bass. 

 We have found the raccoon feeding on the mussels of the lake. The 

 larvaB of certain species of dipterous insects of the genus 

 Ghironomus, are exceedingly abundant in the lake and constitute 

 a very important part of the food of the fishes, also of several 

 species of birds such as the various snipes, plovers, phalaropes, and 

 even of rusty blackbirds, red-winged blackbirds, and crow black- 

 birds. And in September and October, when these larvae com- 

 plete their metamorphoses and the air and the trees along the 

 shore about the lake become filled in the evening and on quiet days 

 with vast swarms of the large mosquito-like insects, making the 

 evening vocal with the constant humming of the millions on the 

 wing, they then are fed upon by various species of birds, among 

 which have been observed nighthawks, swallows, yellow-billed 

 cuckoos, yellow-rumped warblers, and even red-headed woodpeck- 

 ers and song sparrows. But the story does not end here. After 

 the nuptial flight has been made, these insects, myriads upon 

 myriads in number, and all about the lake, return to the surface 

 of the water upon which they lay their eggs, and there fall a prey 

 to various species of fishes from the tiny top minnow to the blue- 



