Okay, so I'll preface this by saying that although I've had horses for years and worked on breeding farms, my current horse is the first mare I've owned or worked with long-term.
My girl is five this year, and up until this point it has been pretty much impossible to tell by her behavour when she's in heat, but this fall she's been having much more obvious cycles, and since moving barns for me to start graduate school seems to be in heat nearly constantly. Is this related to her age/maturity? Is it a seasonal issue? Or is it more likely a result of the move and being around a large group of new horses?