1)4 



THE OOLOGIST 



The Black and White Warbler. 

 (Mniotilta varia. 



Throughout the northern counties 

 of New Jersey, especially in Passiac, 

 Bergen, Sussex and Warren Counties, 

 this striped black and white Warbler 

 is a common summer resident. They 

 arrive in this section from April 25t!i 

 to May 4th and remain, in more or 

 less abundance, according to the years 

 in which the observations are made, 

 until October 1st to 10th. 



One very unusual feature of this 

 species is the fact that during some 

 years they are very common through- 

 out their period of residence in cer- 

 tain localities, whereas during others 

 they are entirely wanting. As a fur- 

 ther explanation of this feature, my 

 field notes for the past eleven years 

 have indicated numerous examples of 

 this fact. During the years 1902, 



1905, 1906, and 1909, this species was 

 very common in northern Passaic 

 County in the vicinity of Greenwood 

 Lake. Again this present year they 

 are rather abundant. During 1903 

 and 1904 they were entirely wanting 

 and not a single specimen was en 

 countered, either during tlie migra- 

 tions or during the summer. In 1907. 

 1908, 1910, 1911 and 1912 they were 

 rather common but not near as abund- 

 ant as during the years 1902, 1905, 



1906, and 1909. In Sussex and Ber- 

 gen Counties during the years 1903, 

 1904, 1910 and 1911 they were abund- 

 ant at points within fifteen or twenty 

 miles of Greenwood Lake. I have 

 attempted to learn the reason for this 

 varied distribution from year to year, 

 but have arrived at nothing as a uni- 

 form abundance of food has apparent- 

 ly been present and there has been 

 practically little difference in the 

 weather conditions. 



Up to the present season, however, 

 there has been no nests of this species 

 located and although I have investi- 



gated nearly all the available sites 

 where they might nest, nothing has 

 ever presented itself. In 1907 and 

 1910 the young birds of this species 

 were seen near Ringwood, Passaic 

 County. 



This season was more prolific and 

 two nests were located on May 15th, 

 within fifty feet of one another on 

 the easterly slope of the Bearfort 

 Mountains, about five miles south of 

 the southern extremity of Greenwood 

 Lake. Both of these were located di- 

 rectly on the ground among the loose 

 stones near the base of two shagbark 

 hickories in a rather damp and weedy 

 ravine about half way up the side of 

 the hills. The nests were similar in 

 appearance and were composed of 

 strips of bark, plant fibers, grasses 

 and decayed leaves and were lined 

 with fine grasses. On May 24th these 

 nests were again visited and found to 

 contain four and five eggs, respect- 

 ively. These eggs were white, spotted 

 and wreathed with numerous spots of 

 reddish brown and lavender, and 

 measured .65x.49; .64x.49; .65x.53 and 

 .63X.50 and .66x.50; .65x.50; .67x.49; 

 .64X.49 and .65x.48. On May 27th the 

 nests were again visited and, in both 

 cases, the males were found on the 

 nest. 



On June 5th the nests both contain- 

 ed young about two days old. All the 

 adults, both male and females, were 

 bringing food to the young at fre- 

 quent intervals. This food consisted 

 wholly of small insects, scale and lar- 

 vae, which they gathered from the 

 adjacent trees. During all of the times 

 when in the vicinity there was one or 

 the other of the adults at the nest con- 

 tinually, never leaving the young un- 

 guarded. On the morning of the 8th, 

 the brood of four proved a tempting 

 morsel for a Black Snake (Coluber 

 constrictor) and he quickly devoured 

 them. The other brood grew very 



