24 On the trail of vanishing birds 



pairment, no genetic deficiency that can be observed in the birds 

 themselves. Not that we really suspected that there was, but once 

 any creature is classified in the "rare" category, all sorts of sugges- 

 tions are made as to the reason for this condition. This was one 

 of them. Another had to do with food. Was sufficient food avail- 

 able for a species that must have highly specialized feeding habits, 

 considering the unique shape of its bill, etc.? As is often the case, 

 we found that their habitual environment contains more food of 

 the character preferred by spoonbills than our small population 

 could possibly require. No problem in this field at all. The reasons 

 behind the spoonbills' rarity are abundantly clear and quite logical 

 once you are in a position to comprehend them. But it was nec- 

 essary to do a lot of spadework first, and that takes both time and 

 hard work. 



In the course of my study of the roseate spoonbill there were 

 many problems that could not be solved by the usual or the or- 

 dinary or the conventional research methods. I was forced to 

 devise methods of my own. One puzzle of major importance was 

 the status of the several hundred spoonbills that spend the sum- 

 mer on the southwest Florida coast without breeding. For some 

 years we had observed these scattered flocks and hoped that they 

 might nest somewhere in that area, as they once had years ago. 

 Our wardens went to considerable lengths to report on their 

 movements and to provide them with special protection. From 

 what I had seen of them it seemed to me that the first point to 

 be cleared up was the question of the age groups represented in 

 these flocks. How many of them were actually of breeding age? 



It had already been established that the roseate spoonbill goes 

 through several molts and plumage changes before attaining the 

 full splendor of the adult garb. And it was estimated that this en- 

 tire process requires perhaps as much as thirty-six months. In 

 addition, according to our observations, these birds do not breed 

 except in the complete adult plumage, or not until they are at 

 least three years of age. How was I to go about determining ac- 

 curately the ages of some four or five hundred spoonbills that 

 live during the hot summer months along a wild, mangrove-lined 

 coast nearly 150 miles in extent? A number of methods suggested 



