The amount of crop milk and seed found in the squab’s crop is shown for the first 3 weeks post-hatch.   The amount of crop milk initially increases and then declines.  The amount of seed in the crop progressively increases after day 5 even though squab do not succeed in picking up seed until around days 16-18.   This gives squab a lot of experience with seed in their beaks prior to the initiation of independent feeding.