With police sirens wailing and lights flashing, fleeing "suspects" and mock gunfire, the popular police dog show returns to Picnic Day at the University of California, Davis, Saturday.

It is one of the highlights of the day's lineup for the university's 91st annual open house, which is expected to attract more than 50,000 people. Picnic Day is believed to be the largest student-run event in the country, and the more than 150 offerings include exhibits and demonstrations, tours, entertainment, animal events, children's activities, athletic events, and a student organization faire.

Student Ami Vora, publicity director for Picnic Day, says this year's theme, "LIVE on One Shields Avenue," reflects the wide range of activities and the liveliness of the institution itself.

At dozens of activities across campus, Picnic Day-goers will be able to do a myriad of things from rooting for the rugby team to milking a goat and from cheering on their favorite in Jack Russell terrier races to signing up on California's newly launched organ and tissue donor registry.

The UC Davis Police Department's own Maverick, a German shepherd, and Officer Walter Broussard, will host canine units from seven law enforcement agencies as they demonstrate how the specially trained dogs are used to catch suspects and detect explosive devices. Maverick, now about 2 years old, has been with the police department for about nine months and is trained in apprehension and explosive detection.

"We'll create scenarios that depict some real-life law enforcement situations," said Sgt. John D. Johnson, who will serve as emcee for the show.

In one situation, a dog will give chase as suspects flee a stolen car stopped by police. In another, a dog will help capture a cyclist who exchanges gunfire with police.

The show is a Picnic Day crowd pleaser that has drawn thousands each year that it has been offered, said Johnson, who played the role of a suspect or "chew toy" for four years. "It was wonderful to see the excitement on kids' faces and listen to the roar of the crowd when the dogs chased me and took me down."

Johnson said budget constraints and other factors kept the department from staging the show for three years. "We missed performing for the community," he said. "The canine teams and other volunteers are really jazzed about coming back."

The 14th edition of the show will include two hour-long presentations at 11 a.m. and 1 p.m. on Russell Field, south of Russell Boulevard and west of Howard Way.

Picnic Day kicks off at 9:30 a.m. with opening ceremonies on North Quad Avenue across from Wickson Hall, and, at 10:10 a.m., the Cal Aggie Marching Band-uh! will lead a parade through campus and downtown Davis. Most events will conclude by 5 p.m. A full schedule of events and other information are available at http://picnicday.ucdavis.edu.

The popular Chemistry Magic Show will feature a variety of new demonstrations including flashlights under water and a growing gummy bear. Four shows -- 10:30 a.m., 11:30 a.m., 1 p.m. and 2 p.m. -- will be held in Chemistry 194.

Kids at the Multicultural Children's Faire will travel through different countries and cultures -- and even space -- as they enjoy games, crafts and entertainment. Activities will be as varied as making an Italian carnival mask, playing space bingo and listening to a Native American storyteller. Most events will take place between 10 a.m. and 4 p.m. in and around Hart Hall.

Seven entertainment stages will feature a variety of music and dance performances until 5 p.m. And the Cal Aggie Marching Band-uh! will defend Aggie pride against UC Berkeley, UC Irvine, UC San Diego, Stanford University and Humboldt State University at the Battle of the Bands. The competition will begin at 2 p.m. at Lake Spafford.

The second annual evening show, "Davis Dance Revolution," will showcase registered student organizations in choreographed dances as they compete for a $1,000 grand prize. The event begins at 7:30 p.m. in Freeborn Hall. Admission is $5, and tickets are available at the UC Davis Ticket Office, tickets.com, and Raley's and Bel Air outlets.

Alumni activities

Activities of special interest to alumni include:

• A wine tasting and dessert social hosted by the Cal Aggie Alumni Association the evening before Picnic Day will feature fine wines created by alumni. For tickets and more information, visit http://www.alumni.ucdavis.edu/rsvp.
• The Cal Aggie Alumni Association's 22nd annual Picnic Day Breakfast will feature a hearty breakfast and entertainment by the Cal Aggie Alumni Marching Band from 7:30 to 9:30 a.m. in Freeborn Hall. Tickets are $8 for association members, $12 for non-members, $5 for students ages 5 to 21, and free for children 4 and under.
• An Alumni Zone on the Quad will help alumni reconnect through an alumni locator service and other activities.

Parking is free. Unitrans, the bus service in Davis, will operate its special Picnic Day Service, and information on routes and schedules is available at http://unitrans.ucdavis.edu/. Shuttles will help Picnic Day-goers move around the perimeter of the main campus.