I’ve received a few photos over the last several weeks asking what is causing ear damage in corn (see photos below). In both cases, the damage is caused by birds feeding on the ears.
Typical symptoms include missing or damaged kernels on the cobs. In the first photo, shredded husks is the key symptom in identifying birds as the culprit. Secondary damage can result from ear rots as kernels eaten by the birds will often turn brown or black once the ear rots begin infecting the damaged tissue.
Birds, especially large flocks, can cause quite a bit of damage. The most damage occurs along field edges or by wooded areas such as bush, but damage can extend throughout an entire field. Also, it is also not unusual for birds to prefer one hybrid over another, although the reasons are unclear. Perhaps it can be attributed to birds being able to detect slight differences in kernel maturity or other kernel characteristics between hybrids. I have seen this with other animal damage, such as racoons, in hybrid performance trials. Amazingly, the animal can pick out a hybrid within each replicate of the trial without damaging other hybrids.
Submitted by: Pam de Rocquigny, Provincial Cereal Crops Specialist, Manitoba Agriculture