So 



HARJDWICKE'S SCIENCE-GOSSIP. 



readily explained as something very different, if all 

 the facts of the case could be ascertained. But when 

 we come to study very closely the habits of a familiar 

 bird, that to all but ornithologists is a veritable 

 swallow, our common swift or "chimney-swallow," 

 then I am fairly staggered, and find myself saying 

 beneath my breath, " After all ! " 



In conclusion, then, it behoves me to consider this 

 common chimney swallow very carefully and can- 

 didly, and determine how far certain occurrences 

 that I have witnessed, are indicative of hibernation. 



In a large unused chimney of an old house built in 

 1708, standing near my home, thousands of chimney 

 swallows annually congregate, arriving in April — or 

 appearing then — and departing, well ! I am not 

 certain when. 



Now this chimney has an internal surface of about 

 425 square feet, and allowing one square foot to each 

 nest, will accommodate so many pairs of swallows. 

 But I find that not more than one-third of the avail- 

 able space is utilised. At this rate, there would be 

 one hundred and forty pairs of swallows occupying the 

 chimney at one time. Now this may seem like a 

 fish story, but it is an inconsiderable fraction of the 

 truth. I have carefully timed by my watch an un- 

 broken line of entering and out-going swallows, and 

 seen them in these processions steadily enter and re- 

 appear for five and a half minutes, without a break, 

 each bird followed by another so closely, that inter- 

 vening spaces were scarcely discernible. The down- 

 Avard and upward series were of course different birds 

 to a certain extent, and it is a fair estimate to say that 

 fully one thousand swallows were making a nesting 

 and roosting place of this one chimney at the one time. 



Not the least curious feature of these large colonies 

 is the evident fact that but a small proportion of these 

 birds are nesting at this time ; and we are lost in 

 amazement, when considering that the fragile eggs 

 and tender fledglings should escape destruction, sur- 

 rounded as they are by such a crowd of jostling, 

 climbing, crawling, tireless swallows. Nor is it at 

 all easy to reach any definite conclusion concerning 

 the object of these non-nesting birds, in thus continu- 

 ously through the day entering their roosting-place — 

 the chimney. 



Now these particulars are mentioned in this con- 

 nection, to show that many hundreds of these birds 

 often roost in the one place, and must be very closely 

 packed together when all are at home. For a portion 

 of every twenty-four hours they are well able to with- 

 stand the depressing influences of a crowded condition, 

 with certainly a minimum of fresh air to breathe. 

 The same conditions would prove fatal to most other 

 birds, if indeed not to all others. 



This feature of the summer-life of these birds please 

 bear in mind. 



Any time after the middle of September there is 

 likely to be a change. A severe north-east storm 

 coming, they are gone ! A week may pass, and not a 



swallow is to be seen. You may listen at the chimney 

 holes, and not a swallow is to be heard. The sky is 

 as birdless as in bleak December. But again the 

 weather becomes warm ; our magnificent October 

 days are come. The mellowest sunshine of all the 

 year gilds the broad meadows and adds a glory to 

 the scarlet maples ; and, again, scores of chimney 

 swallows as before are flitting all day long in the 

 cloudless skies. Whence come these birds? They 

 are not so many, indeed, as were here before the 

 biting north-east winds bade all our summer birds 

 depart ; but far too many to consider them as mere 

 stragglers. Indeed they are too strong of wing to be 

 thus looked upon. We felt, or might have felt 

 certain, that the swallows had gone ; but with the 

 returning cheery days, these birds are again with us. 

 Either they were closely stowed away during the 

 storm, or they are more northern birds which, 

 leaving their summer haunts beyond the track of the 

 storm that visited us, had only reached us as they 

 were moving southward after the storm had passed. 

 This, I think, very likely is the truth of the matter ; 

 but many circumstances strongly point to the former 

 supposition — that of temporary shelter during the 

 storm. Here is an instance. On the 4th of October 

 of the past year, the weather with us was warm, 

 the thermometer ranging from 65 to 85 Fahr. 

 Throughout the morning there was a brisk shower, 

 or series of them ; but by 2 p.m. it had cleared, with 

 a gentle wind from the north. It gradually grew 

 colder, and by sunrise on the 5 th, the temperature 

 had fallen to 40 Fahr., and the wind had increased 

 in violence. All this day thousands of chimney 

 swallows, and a few of other species, were seen flying 

 southward ; keeping as near to the ground as possi- 

 ble — just avoiding the tree tops, and in open spaces, 

 often just clearing the ground. They were in dense 

 flocks, and appeared to be driven helplessly before 

 the cutting blasts of the north wind then prevailing. 

 The weather moderated the next day, and on the 7th 

 of the month, there were very many swallows flying 

 about just^as usual ; they did not finally disappear 

 before the 20th of October. 



Such flocks of swallows, as I have mentioned, are 

 certainly indicative of a voluntary or forced migra- 

 tion, to a certain extent. What becomes of such 

 storm-driven colonies (and they are an annual occur- 

 rence) I cannot say ; but they are certainly indicative 

 of the habit of migration obtaining among these 

 birds, to a certain extent. On the other hand, what 

 of the many swallows that remained for fully two 

 weeks after the storm I have mentioned ? As bearing 

 upon this point, the following is worthy of note. In 

 December, 1879, I had occasion to have a wood-stove 

 removed from a fireplace, and one for burning coal 

 put in its place. The removed stove had not had a fire 

 in it for nearly a year. On detaching the pipe, there 

 were found seven swallows in one of the elbows, 

 occupying the space between the angle and the 



