1. BirdWatch Ireland – Roseate Tern
One worrying development happened late in July when all the remaining colony of birds deserted the rock apart from two pairs of birds which were nesting on the left side of the rock. This desertion was unprecedented in the nine years of the project and there was a strong suspicion that the birds might have been disturbed by human presence.
2. BioOne - Black-naped and Roseate Terns
http://www.bioone.org/perlserv/? ... SOTSLO%5D2.0.CO%3B2
The recent increase in the frequency of visits to islets by people from Nouméa (ca.100,000 inhabitants), resulting from the increase in the number of leisure boats, may be the principal factor responsible for the current trends and threats. Human disturbance seems to be a major threat that may lead to desertion of seabirds on islets, or reduced breeding success.
3. Bird life of Pulau Layang Layang - Black-naped Tern
Unsuccessful breeding seemed to be due primarily to disturbance in the form of inquisitive visitors (tourists from the resort and Navy personnel), predation by cats and the twice daily flights which flew directly over the breeding colonies.
4. Tampa Bay Soundings, USA – Bridled, Caspian, Royal, Sandwich, Roseate, Least, Sooty, Brown Noddy
But by far the most important cause of outright nesting failure is disturbance by people. Forcing adults to fly exposes eggs containing delicate embryos to the hot sun and almost certain death. Year after year, repeated human intrusion at nesting colonies has caused steep declines in some populations.
5. Birds in Backyards - Little Tern
The Little Tern is extremely sensitive to human disturbance when breeding and is rapidly declining in numbers and range. Nesting sites are usually located where humans swim, walk, exercise dogs, picnic and drive off-road vehicles.The mere presence of people on the beach may cause these terns to desert their eggs and eventually leave the colony altogether.
6. Joint Nature Conservation Committee, UK – Common Tern
Declines in specific colonies in Britain and Ireland, with some complete losses, can mostly be
put down to habitat changes, e.g. coastal developments and increased disturbance, especially
recreational, although as with all terns birds can desert breeding colonies for behavioural
reasons, resettling again after a period of time.
7. John F. Kennedy Space Center Environmental Program Branch - Least Tern
http://environmental.ksc.nasa.go ... s/tern_skimmers.pdf
Other factors that are correlated with abandonment are human disturbance, presence of mammalian predators, and flooding. Of these, human disturbance is probably the factor most responsible for recent declines. Human-caused disturbances can exacerbate many of these problems, which increases the rate of turnover and decreases the reproductive success of colonies. The same areas that these birds value for nesting habitat are unfortunately the same areas humans value for recreational activities. Human intrusion along beaches, lakes, and streams reduces the available nesting area for these birds.
8. National Audubon Society, USA - Gull-billed Tern
Human disturbance from boating, recreation, and development is a primary conservation concern, as it causes the young to disperse from the nest too early, sometimes resulting in heavy losses due to exposure to weather and predators. Where human activities are concentrated on some Atlantic Coast barrier islands, this species has shifted to nesting on marshes and dredge spoil islands.