DENVER -- Humane societies in Boulder and Longmont have noticed an increase in the number of pit bull registrations and drop offs.

The increase was noticed after Denver, Commerce City, Northglenn and Aurora initiated ordinances that dealt specifically with the breed.

The city of Longmont now has 205 pit bulls registered for the year, compared with 160 for 2004, according to officials.

The head of the Longmont Humane Society said that the increase could be due to several reasons including heightened awareness about pit bulls, and making owners more conscious about licensing them.

"Rather than an increase in population numbers, it could be an increase in responsibility," De Fowler, the society's director of operations told the Longmont Daily Times-Call.

The Humane Society of Boulder Valley also reported a dramatic increase in the number of pit bulls dropped off at the agency.

The society took in 410 pit bulls in 2005, compared with 257 in 2004.

A Longmont Animal Control officer told the newspaper that she has noticed an increase in the number of pit bull calls while she's on duty.

"It’s a cycle," Diane Milford told the Times-Call. "The more pit bull incidents that come to the forefront, the more calls we get. Pit bulls are the dog of choice right now."