Science fiction book about a world where bioengineered animals are used for common functions

Question

A novel/book from the 90's. Society used genetically modified animals to perform basic tasks. For example, birds were genetically modified to be large enough to carry passengers like our passenger jets. I believe the police used modified falcons or some other bird-of-prey (important to the story) as their transports. Turtles (I think) were modified and used as buses, though smaller things were also used for personal vehicles. I don't remember how they were used other than for transportation.

The story was a mystery where the main character was a police detective, investigating a recent string of events where some of the animals were suddenly reverting back to their base natures and killing people and hurting other bioengineered animals. The investigation inevitably started with the primary bioengineering lab where these animals were created, but beyond that, I don't recall.

It was an intelligent book of about 400 pages. I had a paperback copy, on which I think the cover showed a police bird-of-prey transport flying over the city.

Answer 1

This is Sparrowhawk (1990) by Thomas A. Easton.

At the start of the story we find a family riding along the highway in their gene engineered "Tortoise" when a passenger Sparrow lands on the highway and starts eating the other vehicles.

The blurb reads:

The chickadee at the bird feeder is the size of a Piper Cub... the house next door is an oversized pumpkin... and genetic engineers are turning jellyfish into blimps, tapeworms into drug factories, and beetles into Beetles.

When someone turns a Sparrow airliner into an implement of murder, gengineer Emily Gilman and police detective Bernie Fischer must track the villain down.

A description of the Gilmans' Tortoise:

The Tortoise didn't look like a tortoise. Its chief ancestor had been a lean, low terrapin. The gengineers had given it size and speed, and a cavity beneath the shell. The General Bodies shops had fitted a windshield, side windows, and doors, installed plush seats, added headlights and taillights, and wired the controls into the Tortoise's nervous system. At periodic checkups, they added new fittings and enlarged or refitted the old to keep pace with the creature’s growth.

Roachsters, half cockroach and half lobster; Hoppers, derived from grasshoppers; and other Buggies could keep pace with a family’s needs just as well. But Nick preferred the more classic lines of the Tortoise. Its shape reminded him of the gas burners his parents had driven when he had been a child, when the Machine Age had still been vigorous.

Detective Fischer rides the titular Hawk:

The pilot's name was Bernie, Bernie Fischer, and he was letting his Hawk soar at will while he bathed morosely in the whirling views. His hands rested lightly on the control yoke as he stared out over the sheet-metal cabinets, round-cornered, gray-enameled, of the vehicle’s console. Behind one of the panels, he knew, was the computer that translated his bendings of the yoke, his treadings of the pedals, and his twistings of knobs into landings, liftoffs, and smoothly sweeping turns to left and right.