EASTERN AND CANADIAN CHIPPING SPARROWS 1169 



trap. He flew directly to the nest where again the female was at the 

 empt}'' nest. She hnmediately drove him out. He soon returned, 

 giving the twitter the male usually uses when approaching the incubat- 

 ing female, and she showed no aggressiveness toward him. 



Territories are about an acre in extent. Walkinshaw found them to 

 be between 1 and IK acres at Battle Creek, Mich. In 1953 at the 

 Lake Itasca Forestry and Biological Station, 21 pairs nested on 52 

 acres, but much of this area was unoccupied and some territories were 

 about one-half acre. At the Ed\\'in S. George Reserve in southeast- 

 ern Michigan, Sutton (1960) concluded that one territory was 70 yards 

 by 45 yards, or approximately two-thirds acre. 



Courtship and mating. — Bradley (1940) reports that in the pair she 

 observed at Douglas Lake, Mich., courtship took place while the 

 female was nest building, "It consisted of outbursts of song by the 

 male from the top of a cabin, interspersed with quick flights to the 

 ground where the female was puUing up weed stalks for the nest. 

 Copulation took place on the ground soon after this display." Walkin- 

 shaw (1944b) observes that copulation "which usually took place on 

 the ground, but sometimes on a horizontal branch, \\ire, or roof, is 

 frequent during the days preceding egg laying and often occurs 

 several times in succession. The female assumes a crouching posture 

 with head and tail slightly raised and wings rapidly vibrating; the male 

 approaches and hovers over her for a few seconds. During copulation 

 the female (and perhaps the male) utters a rapid call, see-see-see- 

 see-see J* 



Nesting. — The female does all the gathering of nesting material. 

 AU observers agree that the female does all the nest building and 

 while the male often accompanies her on her trips to gather nesting 

 material, he usually does not return to the nest tree with her. Nest 

 building goes on throughout the day with greatest activity before 

 noon. Walkinshaw (1944b) states that "most of the nest building 

 was done in the early morning hours." In the single case I observed, 

 nest building was greater during mid-morning than dming the first 

 K hour of the day. The greatest frequency of trips was 11 in 30 

 minutes. Walkinshaw (1944b) found that nests in May were com- 

 pleted in 3 to 4 days, while the one July nest observed was completed 

 in 2 days. A single observation of what was probably a second nest- 

 ing in Minnesota in the 2nd week of June indicated that the nest was 

 built in 2 days. 



The nest is almost invariably constructed of dead grass, weed stalks, 

 and rootlets and lined vnWi fine grasses and hair. Horsehair seems 

 by all odds the favorite nest lining material and when available is 

 always the principle component of the hning. When horsehau- is not 

 available, the birds will use human hau- or that of cattle, deer, raccoon, 



6-16-737— 68— pt. 2 38 



