Transplanting a Barn Swallow Nest
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Richard & Diane Van vleck- Personal Pages
Barn swallow colony sites are frequently destroyed when old buildings are demolished or sold to new owners, who wish to close them up. Attracting swallows to buildings where they will be allowed to nest has been simply a matter of opening a door or window, perhaps, providing nesting ledges, and leaving the rest to luck. The chances of attracting barn swallows to a specific building are about as good as attracting bats to a bat box. When a building housing a colony of swallows is to be closed, it should be done after the nesting season. Even then, chances are only fair that the colony will establish itself at a safe site the following spring. Homeowners and farmers go to great length to birdproof their garages and other outbuildings to keep out house sparrows. As old barns fall down, fewer and fewer prime swallow sites remain each year, although bridges offer adequate shelter to many colonies. One potential way to establish a new colony in a building is to transport a nest with young from a doomed site. By moving the nest very slowly, the parents will follow and continue to care for the young. When the old site is lost, it would be hoped that the parents, and perhaps, the entire colony would then nest in the new building the following year. The opportunity to test this theory arose in the summer of 1992, when the H.H.S. mail room was closed off to better control humidity.
Our swallow colony is located in the lower part of our barn in a large room (1300 sq ft). A single pair of swallows moved from the colony room to the mail room in 1990. When they could not be discouraged from nest building, I put up a shelf where I wanted the nest and they instantly switched their focus to the shelf. Previously, they were building on various tools hanging on the wall. We now had a working relationship in which I was committed to not forgetting to always leave at least one door open and to stay out of their way as much as possible, and, they seemed to agree to nest on the shelf, and not above stacks of Home Ground or other supplies or tools. In addition, I agreed to not suddenly turn on the lights at night and scare them off the nest.
The swallows and I got along quite well that summer. They had finished their nest late in the season and only raised one brood. However, in 1991, they again refused to nest with the main colony even though I was careful to keep the mailroom doors closed. Whenever I opened the large door to get out my bike, the pair of swallows would instantly enter and check out their empty nest, even though the other swallows had long since begun nesting in the colony room. So, I gave in again and opened the doors for them. They raised two broods that summer, and, although helpers would come to help feed the young, no other nest was ever begun in the mail room. At the same time, new nests were continually being built in the colony room and plenty of space was available in the large room. We apparently had a pair of “loners”. It is likely that at least one of the pair was the same individual each year.
In 1992, the mail room was going to be enclosed to better control humidity, and, the pair of swallows would not be able to nest there. In early summer, it appeared that the swallows had lost interest in the room, so the doors were left open for several days. Five days after the doors were opened a swallow was seen leaving the mail room nest and a clutch of eggs were found in the nest. At this point, I considered trying to move the nest, a little at a time, to the main colony room, but, decided this would be too disruptive to the entire colony. Also, this pair had refused to join the colony on their own for three years, always waiting for the first opportunity to enter the mail room. It was unlikely that I could force them to join the group now. Instead, I decided to move the nest to a room in the upper barn. If they took to this location, it could be theirs for years to come, with no human interference.
Since it was mid-summer, the in-transit nestlings would have to be protected from the sun while the nest was slowly moved 72 feet along the barn and then 14 feet up a ladder to the entrance of their new room. A louvered video monitor case was used for this purpose. The case was mounted on a tripod two feet from the mailroom nest and left in position for two days to allow the adults to become familiar with it.
Preparation for the move began soon after daybreak to allow as much time as possible to complete the move. A shaped piece of hardware cloth was fitted to the nest to prevent it from falling apart and a long bladed knife was gently worked between the nest and the wall to free the nest, which was then placed in the metal case. Since the nest had been built on a swallow shelf, it could be returned to the original position, if the adults didn’t accept the change.
Luckily, after 8 minutes of flying to the nest’s previous position and circling, one of the adults landed on the nest and instantly fed one of the young. Soon both adults were tending to the young as if nothing had happened. After 15 minutes, the box was lowered 2 feet so that the tripod legs rested on the floor. As before, the adults went to the previous position, flying in tight circles, and totally ignoring the nest below. This time they discovered the nest in 5 minutes. Next the box was moved three feet at a time toward the door, which was 20 feet from the original nest site. After each move, the swallows would circle the exact point of the previous location for several minutes before locating the nest.
Once outside, the nest had to be moved 42 feet along the side of the barn, around a corner, and 30 feet further to the new entrance which was 14 feet above the ground. The incremental moves went smoothly until the entrance to the main colony was reached. But, despite some confusion, we reached the corner of the barn not far behind schedule. At one point the adults were frequently perching on a lever of a walking cultivator and, also, having more trouble than usual finding the nest. On the hunch that this perch was providing a reference point for them to find the nest, I began pulling the cultivator along with each nest move, and this appeared to help them find the nest. I had to give this up when we approached the corner of the barn because of several obstacles in the path.
When the nest was moved partially around the end of the barn, the adults were not able to find it. As before, it was in plain site, but after 15 minutes with no success, I moved the nest back to it’s previous position 3 feet away. This did not work either. The adults were now returning to the mail room and flying somewhat randomly around the path we had taken. Out of desperation, I returned the nest to the entrance to the mail room, where it was discovered in 3 minutes. Then, we once again began the 32′ journey to the corner of the barn. This time, I negotiated the corner with very short moves (less than 1 foot). Once around the corner, there were no obstacles and no nearby reference points and the move progressed rapidly. The move up the ladder also went without a hitch. In fact, the swallows seemed to cope with vertical movement better than horizontal. The final step was to very gradually move the nest into the barn, where the adults had, perhaps, never before entered. This, also, went smoothly and the adults seemed to adapt quite nicely to their new room. All four young fledged and the adults had begun construction of a mud nest directly above the tripod-mounted nest. However, the swallow nesting season was winding down and it was much too late to begin a new brood, but, the beginning of a new nest was a hopeful sign that they would return to nest in this room the following year.
In 1993, no swallows were observed entering the new room. Although swallows would occasionally enter the mail room when a door was left open, it appeared that they were chasing insects and not looking for a nest site. There is still hope that one of the swallows that fledged from the new room will return to nest there in the future. While this successful move demonstrates that active swallow nests can be moved from sites in an emergency, such as planned demolition or construction, it offers no evidence that a new colony can be established by such a move.
Addendum: Since the above article was written, no swallows have shown an interest in nesting in the 2nd floor room where the nest was introduced in 1992. The old mail room has served many purposes since then - it is now becoming a woodworking shop. Swallows have been discouraged from nesting there, but they show interest every year, whenever they find the large rear door open.
• barn swallow young in nest before moving. This is a brood of the previous year. Note the small platform nailed to the beam. Providing such shelves serves two important purposes. It allows the human to select where the swallow builds its nest and it provides a safe base to prevent the nest from falling.
• The day before the move, with the moving box in place
• The nest is placed in the moving box. This created a surprisingly difficult problem for the swallows, who hovered 18″ away at the original nestsite, ignoring their nest and young even though they could see and hear the young. After 8 minutes, the new location of the nest was discovered and the young were fed as frequently as usual, the adults going directly to the moving box each time.
• The move begins
• Feeding the young, now 6 feet along on their journey
• At the 12 foot mark - note both adults on the cow skull horn
• Finally outside, the nest is protected from direct sunlight by the louvred box.
• The adults seemed to have adjusted to the enclosed box, but still had difficulty acccepting each small move of the nest.
• The ladder to the second floor opening. A small platform which hooked over the rungs of the ladder allowed incremental moves up the ladder.
• Ready to enter the new room. The box was fitted to the tripod again and moved several feet into the room, where the nesting was allowed to continue undisturbed. Several helpers eventually began to enter the new room and feed the young, just as they had in the previous location. However, when the young fledged, the new room was ignored.
Add comment April 26th, 2006