Figure 1.
Madingley Wood in Cambridgeshire (UK) is a popular nesting site for great tits (Parus major).
(A) A male great tit. (B) A nest (day = 0) containing newly hatched chicks as well as several eggs that have not yet hatched. (C) A woodcrete nestbox in Madingley Wood. Photo credits: D. Kjaer (A) and M. C. Stoddard (B-C).
Figure 2.
Great tit eggs were photographed in the wild using a UV-sensitive camera, producing images in the (A) human-visible spectrum and (B) ultraviolet spectrum.
Images were converted to correspond to a blue tit’s (Cyanistes caeruleus) double cones (C). Egg patterns were measured using a digital image analysis technique (D) based on the fast Fourier transform, in which information about egg speckling is captured at different spatial frequencies. The original image is broken down into seven new images, each containing information at a different spatial scale. Low spatial frequencies (E) capture information about the relative contribution of large markings and high spatial frequencies (F) capture information about the relative contribution of small markings (see Stoddard and Stevens 2010 for details). Egg photograph by M. C. Stoddard.
Table 1.
General Linear Model showing the amount of prey delivered by males was not related to the speckling on the eggs his partner laid or the eggs that he saw during incubation (N = 29 nests).
Table 2.
DAY 3. Linear Mixed-effects Model showing no effect of egg speckling on chick mass on day 3.
Table 3.
DAY 7. Linear Mixed-effects Model showing no effect of egg speckling on chick mass on day 7.
Table 4.
DAY 15. Linear Mixed-effects Model showing no effect of egg speckling on chick mass on day 15.
Figure 3.
The amount of prey delivered by males was not related to egg speckling on the eggs (A) that his partner laid or (B) that he saw (his partner incubated).
N = 29 nests. Brood size is controlled for by using the residuals of prey delivered by males over brood size on the y-axis.
Figure 4.
Heavier females laid less speckled eggs (PC1).
N = 28 nests (see text for statistics).
Figure 5.
Female lay date had no effect on egg speckling (PC1).
N = 47 (see text for statistics). Lay date is the date a female laid her first egg, shown here as the number of days after 31 March 2009.
Table 5.
General Linear Model showing that heavier females laid less speckled eggs (N = 25 nests).