THE OSPREY. 



129 



LIFE HISTORY OF THE PROTHONOTARY WARBLER. 



W. E. LOUCKS. 

 Arranged for publication by the Author from a report made to the Illinois State Labratory of Natural History. 



Part Three. 



AS previously stated, a few days elapse between As a rule, the eggs are blunt at the smaller end ; 

 the completion of the nest and the deposition and while some are quite elongated and others ap- 

 of the eggs. As far as my observations go, an proach a spherical shape, probably the greater num- 

 egg is laid daily until the clutch is complete. There ber are ovate One egg that I found in a set of four 

 has been considerable controversy regarding the num- was ovate pyriform, the other three being normal, 

 ber of eggs laid. Four, five, and six are the usual Incubation is carried on entirely by the female, 

 numbers, sets of seven being occasionally found, and and extends over a period of ten days or two weeks, 

 sets of eight and nine in extremely rare instances. During incubation the male spends the most of his 

 Many regard the set of seven a rare find, but I do not time exploring every nook and crevice in the vicinity, 

 consider it so, having found it frequently around often meeting another husband on a similar foraging 

 Peoria. Mr. W. S. Cobleigh informs me that he found expedition. He keeps his mate well supplied with 

 a set of ten eggs in the Mackinaw Creek bottoms This food, but should there be any spare time, he indulges 

 is the largest clutch that has been reported to me. in singing. After the young are hatched, both birds 

 The first sets of the season are probably the largest, are kept continually busy filling the hungry little 

 consisting of five, six, or seven eggs ; the second lay- mouths with insect delicacies. After the nesting sea- 

 ing is of four, and frequently five eggs ; and if a son, the birds are usually found in small flocks, con- 

 third, it is very small. During the month of July, I sisting of the parents and the young, and so they re- 

 have found nests with one, two, and three incubated main until their departure. 



eggs, undoubtedly the third clutch of the year, and Frequently these birds are found breeding in 



probably belonging to birds repeatedly robbed of colonies, and many nests are found in a surprisingly 



their previous nests. If unmolested, the warbler ^^^^^ ^^^^ ^^ ^^^^ localities there are more pairs 

 generally raises two broods in a season, but if de- 

 prived of their first and second sets, a third is de- 

 posited. 



I have never found the markings to consist of more 

 than two colors, lilac and chestnut, each varying in 

 tints and shades in the different eggs. The lilac 

 markings are often styled "shell markings" from 

 their appearance of being within the shell, and are 

 frequently so dim that they are barely perceptible. 

 In the majority of specimens having blotches, the 



of birds than there are holes or cavities to nest in. 

 This scarcity of nesting sites is undoubtedly the cause 

 of the large sets of eggs and double nests that have 

 been found. The set of ten eggs, previously men- 

 tioned, taken by Mr. W. S. Cobleigh, certainly must 

 have been a double set. I can think of no Warbler 

 that lays a corresponding number of eggs. Mr. B. 

 F. Bolt, of Peoria, 111 , found a double nest a num- 

 ber of years ago, the lower half containing seven 

 chestnut overlaps the lilac, producing a purple effect eggs, and the upper five I am therefore quite posi 



The typical shell is china white, very glossy, and 

 quite thick and strong. Occasionally a calcareous 

 shell is found, but these are always of yellowish cast, 

 and very slightly, if at all, marked with pale lilac. 

 A fresh egg is of a beautiful pinkish color, which is 

 lost upon blowing the specimen. Albinism frequently 



tive that two females will lay their eggs in the same 

 cavity, and that one pair of birds will deprive an- 

 other of their nesting site, and build another nest 

 over that of the original owner, in localities wherein 

 nesting sites are few. I have never noticed but one 

 published account of such a procedure on the part of 



occurs. I have found numbers of white specimens, this bird. Mr. O. C. Poling, who found double 



and Mr. R. M. Barnes, of Lacon, 111., reports taking nests and sets of the Prothonotary Warbler near 



a whole set of white eggs. ('Ornithologist and Oolo- Quincy, 111., says ('Ornithologist and Oologist,' Vol. 



gist,' Vol. XIV, p. 38.) XV, p. 72,); 



The endless variation in the coloration of the eggs " ^ is also characteristic of this Warbler to remam 



is only equaled by the vast variation in their sizes close about the nest at all times to avoid being de- 



and shapes. The extreme measurements of an ex- prived of its home by some neighbormg pair, for 



ceedingly large series of these eggs are 62 and 79 in there are more birds than nesting places in the locali- 



length, by .50 and .62 in width In the 'Ornitholo- ties searched. 



gist and Oologist ■ (Vol. XIV, p. 38), R. M. Barnes, "On several occasions a hole would contain a nest 



Esq. , writes : "I have in my collection one ' runt ' and fresh eggs, with still another nest built on top of 



egg of this species that is not larger than a pea. It it also containing eggs, thus showing that some pair 



measures .48X. 40. The other four eggs in this set had driven off the first occupants, 



average .73X.55 The 'little fellow' is in every way "Still anothernest wasfound. in which two females 



as perfectly marked and formed as any of its larger had laid, containing nine eggs which were of two 



brothers" different types and piled up on top of each other. 



