Further studies on the breeding biology of redshank (Tringa totanus L.)
Redshank breeding biology is examined ind reviewed in relation
to other sandpiper studies.
" Primarily, general aspects are described. The mean clutch size
was 3.82 eggs. Fourth eggs laid were significantly smaller and more
likely to hatch last. N&st hatching success varied annually from
30-741, with tidal flooding the main cause of nest failure. In
successful nests, hatch success was less variable. Chick size at
hatch was positively correlated with egg size. Pre-fledging mortality
is discussed in relation to overall fledging success.
Jurviving adults generally remained mate faithful.
Experienced birds were found to nest earlier in the season and
to produce larger eggs. In all years, female age correlated positively
with egg volume. Inexperienced birds laid smaller eggs later in the
season. Older birds were more successful at hatching eggs.
Experienced breeders were more likely to return to their former
breeding grounds than were younger birds, particularly when they were
successful the previous year. Birds unsuccessful in the pr,: vious year
were more likely to divorce. Divorced females were less site
faithful than males and were more likely to disperse.
Natal philopatry is discussed in relation to pre and postfledgin;
mortality. Philopatry is non sex biased and is estimated at
being very high.
Chick growth and development is considered and an age determining
formula devised for ageing chicks from their weight and bill length.
Growth rates were constant between and within years.
Annual adult survival (0.75), life expectancy (3.48 years), and
study area population are calculated. An estimated 175 pairs breed in
the restricted area (168 pairs/km ) and approximately 500 pairs on the
A model of population dynamics estimates pre-fledging mortality
at between 66-74'; x.
Timing of breeding in other waders and a comparison with the
related Greenshank are reviewed in the Appendices.