152 IOWA ACADEMY OF' SCIENCE Vol. XXV, lUlS 



mouse (Microtus sp.) was found in the nest. On May 24, there 

 were tin-ee young. The oldest one had grown considerably and 

 was beginning to show trtices of pin feathers. A second Microtus 

 was found on tiiis visit. On May 80 the oldest one had distinct 

 feathers on the wings and showed faint black bars on the breast. 

 On the last visit, on June 7, the oldest bird was found on a 

 branch beside the nest. The wing quills were about two inches 

 long. The other's were in about the same state of development 

 as this bird was on May 30. The difference in the size of these 

 birds would seem to indicate that the parents begin incubation 

 as soon as the llrst egg is laid. 



Outside of this nesting pair and the four found roosting there 

 are only two records. These were of single birds seen on August 

 27, 1913, and March 14, 1914. 



72. Asio flatnmeus. Short-cared Owl. A regular winter vis- 

 itor from October 7 to March 21. There is only one summer 

 record for the county though it breeds regularly a little farUier 

 north. On August 19, 1914, a single bird of this species was 

 seen near the Goose ponds. On August 21 one (presumaWy the 

 same bird) was collected at this place. 



73. Strix varia varui. Barred Owl. On November 15, 1913, 

 Mr. Howard Graham and the writer were attracted by the noise 

 made by a large flock of crows and found an owl of this species 

 surrounded by them. We followed the bird for some time but 

 finally l^^st it when it crossed the river. This is the writer's 

 only record for the county. 



74. Otus asio asio. Screech Owl. A common permanent resi- 

 dent and the most abundant owl of the county. On June 6, 1913, 

 a nest of this species was found containing two young just able 

 to fly. July 20, 1915, while walking along the street in Marshall- 

 town about 8 :00 p. m. the writer was viciously attacked )\v a 

 screech owl. Investigation disclosed two barely fledged young 

 in the tree under which he was passing. People who resided in 

 tlie neighborhood said that these owls had made a regular prac- 

 tice of flying at people in the evening or even clutching at their 

 hats as they did at mine. 



75. Buho virginianius virginianus. Great Horned Owl. On 

 the evening of June 25, 1915, a great horned owl alighted in the 

 top of a broken aspen tree in front of a camp at Mormons Hidge 



