1. K-State home
  2. »Research and Extension
  3. »Johnson County
  4. »Natural Resources
  5. »Natural Resources Agent Articles
  6. »Stop Aggressive Cardinals

Johnson County

Research-based Information You Can Trust — Localized for your needs

Johnson County
11811 S. Sunset Drive
Suite 1500
Olathe, KS 66061

Office Hours:

Monday - Friday,
8:30 a.m. - 5 p.m.

(913) 715-7000
(913) 715-7005 fax

Map to our office

K-State Research and Extension is committed to making its services, activities and programs accessible to all participants. Reasonable accommodations for persons with disabilities may be requested by contacting Johnson County Extension at (913)715-7000. Notify staff of accommodation needs as early as possible.

Kansas State University Agricultural Experiment Station and Cooperative Extension Service

K-State Research and Extension is an equal opportunity provider and employer.

Stop Aggressive Cardinals

Cardinals are common sights around homes, frequent visitors of birdfeeders and often desired by homeowners who enjoy the bright red plumage the males display. However, complaints sometimes arise in early spring as nesting pairs begin getting fiesty.

Northern Cardinal sitting in tree

 Cardinals will defend their territory and nests from other birds and especially from other cardinals. Sometimes what they percieve as a threat is their own reflection, which is often when homeowners get worried and frustrated as a bird attacks their window. Both male and female cardinals will display territorial behavior.

Luckily you only need to try changing the reflection your window displays to discourage the behavior. 


  • Try closing the blinds, especially when the cardinals are active.
  • Hang beads or shiny objects in front of the window to break up the reflection. 
  • Temporarily cover the outside of the window with fabric or newspaper.
  • Apply semi-transparent decals to the window to break up up the reflection.

Hopefully as they get busy rearing young they will be less worried about the other bird reflected in the window and you can return to your regular viewing setup. 

Contact Us

Amy Keigher

Natural Resources Agent