Another major issue with nests is competition with other birds in the area. To address this problem, artificial dome nests were created for tropicbirds along areas, not used by the Bermuda petrel, and by applying wooden baffles over the entrances of petrel burrows. These baffles only allow petrels to enter, keeping the competition of tropicbirds out. Another factor may be that the cahow will have an increased risk of extinction because of restricted ranges, small population sizes, and lower genetic diversity. Additionally, the characteristic philopatry of petrel species may mean that birds continually return to the same high-mortality breeding sites year after year.