In the evening several of the common swallow, (Hirundo rustica, Linn.) and also, from a specimen which I caught and examined, the martin (Hirundo urbica, Linn.) were flying about the ship, occasionally seeking refuge in the cuddy: they appeared strong on the wing, in excellent plumage, and plump condition. They no doubt formed part of a flock migrating to the British shores, where the latter are said to arrive about the 16th of April; but the computation of the time of their arrival cannot be mentioned with any degree of certainty. Now their passage has probably been retarded by the long prevalence of easterly winds; and the cold, rainy weather, may have caused the little emigrants to seek refuge on board the ship. From calculation at noon, we were in north latitude 50° 14′; north and west longitude 12° 40′.
The swallow is found an inhabitant of the tropical regions of the globe, visits the northern climates during the warm months of the year, and is regarded as the harbinger of summer; emigrating, however, with its young, to a more congenial climate on the approach of winter. It is then that they are met with at sea, perching, in an exhausted condition, on the rigging and decks of ships. Being interrupted by adverse winds, they waver in their course, spent with famine and fatigue, until the ship affords them a temporary resting-place; from which, refreshed by a few hours’ rest, they renew their flight. They are said to arrive in Africa about the commencement of October, having performed their fatiguing journey in the space of seven days.
During a passage from England to New South Wales, on the 27th of September, 1828, several of these birds alighted in an exhausted condition on the rigging and deck of the ship, and were readily captured. We were at that time in latitude 13° 40′ north, and longitude 23° 20′ west. They were the Hirundo rustica of Linnæus.
These birds emigrate from one tropical country to another; and during a passage from Manilla to Singapore, through the China sea, on the 20th of October, 1830, for several days a number of these birds were flying about the ship; and I am inclined to suppose, derived at that period sustenance from the flies which infested the ship, as soon afterwards but few of those insects remained. In the evening they would roost on the rigging; and some even took refuge for the night in the chief officer’s cabin, which opened upon the deck, and were again set at liberty in the morning. They became after a few days exhausted; several were found dead, and others became so tame from fatigue and hunger, as to be easily caught, and would afterwards remain perched on the hand, without making any effort to regain their liberty. These were also of the species Hirundo rustica of Linnæus, which is widely distributed over the globe. We first observed them in latitude 15° 29′ north, and longitude 117° 40′ east; and we lost them, most having perished, in latitude 9° 30′ north, longitude 110° 45′ east, having been about the ship for thirteen days.
The question that arises is, whether in the latter instances they were emigrating, or had been blown off the land by the westerly gales we had experienced since leaving Manilla Bay. It may be mentioned, that as we had at the same time numerous other land birds about the ship, the latter supposition is not improbable.
After having been detained for several days by easterly winds, on the 29th of April we had fair breezes,—the swallows then departed, perhaps as glad as ourselves at having some chance of terminating a long voyage. We made the Scilly Islands on the 30th, and arrived at Gravesend on the 5th of May, 1834.