[OWA ACADEMY OP SCIENCE 
213 
ORDER, HERODIONES: HERONS, ETC. 
American Bittern: Stake Driver. An evil looking inhabitant of the great, 
lonely marshes, the American bittern is probably almost excluded from Polk 
county because of the tiling, out of all our bigger swamps. Its season in Iowa 
is from May to November, and if found any more in Polk county, it will be 
along our river bottom marshes. I have found it a number of times here, 
though not in the past three years. 
Least Bittern. The smallest of its family is still a rather common bird in 
some of our meadow marshes. It is very hard to find because of its great shy- 
ness and is always in seclusion near tall reeds or cat tails. Most of our bird 
students will not find this peculiar little fellow in spite of his comparative 
abundance. 
Great Blue Heron: Blue Crane. One of the most picturesque as well as the 
largest resident bird of Iowa, the great blue heron has in the past few years 
ceased to reside in Polk county for the same reason as the American bittern. 
Naturally a very shy, suspicious bird, accustomed to the great, lonely marshes 
and pond filled meadows, this bird has sought more agreeable locations for 
nesting. 
In the early spring and late fall it may yet be seen along our rivers or near 
our larger ponds where it may make a brief stop in its migratory journey. 
Green Heron: ''Poke.'' This heron is common in Polk county, and I have 
several times found one or two pairs in the marshes along the Highland Park 
car line just north of the river. Most of our marshes contain one or several 
pairs, and they are not hard to find. 
Their nests are placed in trees not far from the ground, and are large, bulky 
structures of sticks and bark. 
Little Blue Heron. Not different from the green heron, but much less com- 
mon here. 
Black-croivned Night Heron. Not so common as the green heron and yet not 
uncommon, this nocturnal member of the heron tribe will be most often seen 
in the evening about dusk, fiying slowly from its roost or nesting place in the 
quiet woods, to some marsh or pond where it will spend the night in quest of 
food. 
These birds often nest in colonies, though I have never found it so in Iowa. 
ORDER ANSERES; LAMELLITROSTRAL SWIMMERS. 
Mallard. Once a frequent resident of Polk county, but now confined to the 
larger lakes and mostly to more northern latitudes, this progenitor of our tame 
ducks is well known as a game-bird, and is to be seen every spring and fall at 
the time of the migrations. 
Blue-winged Teal. Less common in the migrations than the green-winged 
variety, but more common as a summer resident, this duck may often be found 
nesting near our isolated ponds where wild-grass meadows surround them. The 
migrations are in early March and November. 
Green-winged Teal. Not different in habits from the species just described 
Wood Duck: Summer Duck. This is the most beautifuL of our native ducks, 
and of late years has also become the most rare. In fact, I have once seen 
the wood duck in Polk county, and can find very few persons who have found 
