Am I a Boy or a Girl?


In my blog posts, I often use pronouns of he, she, or s/he when referring to a bird.  In reality, I often don’t know for sure.  The gender of a falcon is recorded at the time of banding, based on size alone.  Female raptors are bigger than males, so the larger eyasses are recorded as females and the smaller ones as male.  However, size at the age of 21 days is influenced by hatching date and food availability.  As the chicks get older, the size differences become more reliable.  Our own Kewpee is an example of gender ambiguity (not to be confused with reports in the popular media about celebrity sex transformations).  We should note that the confusion is on the part of humans only, not the birds!  Kewpee was recorded as being female at the time of banding.  However, at maturity, he is definitely smaller than Rebecca and without a doubt, male.  At the time of banding, the 2015 eyasses were determined to consist of two males and two females.  Between the time of banding and fledging, the size differences have further developed, but not necessarily as expected.  The juvenile bird with band Black 97 over Red P was identified as male at banding.  At that time, he was smaller than the other two chicks and bigger than “Tiny.”  He was the first bird to fledge and ended up on the ground and went to flight camp.  The third bird that fledge, Black A over Red 14, also landed on the ground shortly after takeoff.  This bird was identified as female at the time of banding.  However, the Wild Life Rehabilitator reported that bird 97/P is larger than A/14, which would suggest that 97/P is female and A/14 is male.    


According to, unisex names are increasing in popularity and use.  With names such as Kerry, Casey, Riley, Dakota, Emerson, Kelly, or Gail, it is often hard to guess someone’s gender by their name alone.  This may not be a bad practice to promote for Peregrine falcons!

Tags: Kalamazoo falcons, peregrine falcon video cam