[locustella]

M. Ruddock & D.P. Whitfield, A Review of Disturbance Distances in Selected Bird Species, A report from Natural Research (Projects) Ltd to Scottish Natural Heritage, 2007
http://www.snh.org.uk/pdfs/strategy/...les/birdsd.pdf
alert distance (AD) - the distance between the disturbance source and the animal at the point where the animal changes its behaviour in response to the approaching disturbance source (specifically, in birds, when the head is raised in an alert posture)
flight initiation distance (FID) - the point at which the animal flushes or otherwise moves away from the approaching disturbance source.

FID is called sometimes also as
flush distance
escape flight distance
escape distance (ED)

Here are few sample links found in the Internet:

Fernandez-Juricic, E, Jimenez MD, Lucas E, Alert distance as an alternative measure of bird tolerance to human disturbance- implications for park design, Environmental Conservation (2001), pp. 263-269
http://www.bio.purdue.edu/people/fac...1492081880.PDF

Daniel T. Blumstein, Flight-Initiation Distance in Birds Is Dependent on Intruder Starting Distance, The Journal of Wildlife Management, Vol. 67, No. 4 (Oct., 2003), pp. 852-857
http://www.jstor.org/discover/10.230...21101162109711
https://www.eeb.ucla.edu/Faculty/Blu...einJWM2003.pdf

Karsten Laursen, Johnny Kahlert & John Frikke. Laursen, K., Kahlert, J. & Frikke, J., Factors affecting escape distances of staging waterbirds., Wildlife Biology (2005) 11:1, 13-19
http://www.wildlifebiology.com/Downl...en/oldpath.pdf

Thomas Bregnballe, Kim Aaen & Anthony D. Fox, Escape distances from human pedestrians by staging waterbirds in a Danish wetland, Wildfowl (2009) Special Issue 2: 115–130
http://www.wwt.org.uk/userfiles/files/11_Bregnballe.pdf

The escape distance (ED) most of all depends on:
1) species
and i.e. on:
2) age - young birds are less timid, for example dunlin
3) location - mallards or Canada geese are less shy in a park then somewhere in the wild. Or tits and nuthatches near the feeder or in the park are less shy then in the wild. They sometimes can sit on the camera lens hood several centimeters from it's front lens, on human hand to eat seeds ...
4) season - breeding or winter (?)
Grey Heron Ardea cinerea EDs increase through the autumn (Bregnballe 2009)
5) origin - wintering birds from north seem to be less shy then native
6) given individual
7) color of clothes of an observer and observer's behaviour

From the literature above (mainly Laursen 2005):
8) hunting status - quarry species have longer EDs than non-quarry ... (Laursen 2005, Bregnballe 2009)
I noticed that ducks in hunting season sometimes appear to be horribly nervous.
9) body mass - ED increases with body mass (Laursen 2005, Bregnballe 2009)
10) flock size
11) flock composition - birds in mixed flocks of Mallard Anas platyrhynchos and Teal Anas crecca react at longer distances than those in single species flocks for either species. (Bregnballe 2009)
12) visibility of the stimulus to the birds (Bregnballe 2009)
13) wind force
14) vegetation height (Bregnballe 2009)
10,13 - sometimes positive, other times negative relation ...

Basically it is almost impossible to take pictures of birds without hide.

Some of people say, that escape distance in some cases (like cranes) equals shooting range of an arch ... Because all birds having shorter escape distance were shot and could not pass their genes to further generations unfortunately ...

This message was supposed to be part of the thread:
http://www.birdforum.net/showthread.php?t=238810
but I created separate thread.