^"soS^^l WiDMANN, Gabbarci hland Bird Roosta. 22 



€ven irregular, and after the middle of August they cease alto- 

 gether. To the casual observer the species may now become one 

 of uncertain occurrence, but so much more certain and numerous 

 are they to be found in the evening at their common roost. JJut 

 where is the roost ? 



The experience of former years has taught us to look for it in 

 the large willow tracts along the banks of the Mississippi ; but it 

 cannot remain long in the same place. The willows must be of 

 a certain age and from ten to twenty feet high. At that period 

 they form a heavy thicket, standing as close together as one sap- 

 ling to every square foot. Of course not all of these can thrive 

 for many years ; many become sickly and succumb, leaving only 

 the strongest to grow to trees. Therefore, if for no other reason, 

 the Martins could not use the same tract for more than a few 

 years. 



Twelve years ago the roost was on Arsenal Island, ten miles 

 below the present location ; in the meantime it was above the 

 •city, near the mouth of the Missouri ; the last two seasons it has 

 been on Gabberet Island, opposite the northern end of St. Louis. 

 The island is nothing but a long and narrow sandbank of 

 extremely variable dimensions according to the stage of the river 

 The highest part, less than a quarter of a mile in width, and 

 twenty to twenty-five feet above the low water mark, is covered 

 by the willow thicket. During the flood of last spring the whole 

 island was under water, but with the falling of the water during 

 the summer an immense sandbank arose all along its western 

 side, as well as at its foot, and continued growing until with a 

 stage of three feet above low water in September it reached, in 

 places, a width of a quarter of a mile. 



On the east the island is separated from the Illinois shore by a 

 narrow and shallow arm of the river, forming large mud flats in 

 July and August, and drying up more and more, as the low stage 

 of water continued through September and October. The highest 

 part of the island, an area of about twenty acres, is where the 

 willows stand thickest, and the number of Martins that resorted 

 there nightly was beyond computation, especially during the latter 

 half of August, when they were most numerous. After the first 

 of September it became soon evident that they were on the 



