Two Arlington jail inmates, one of them sentenced hours earlier to 30 years in prison for the county's bizarre "parakeet murder," hanged themselves within a six-hour period late Thursday and early yesterday morning. One of the inmates died, and the other was listed in serious condition last night.

Gregory L. Warfield, 27, son of a Northern Virginia mortgage banker, died at Arlington Hospital six hours after guards found him about 7 p.m. hanging from a bed sheet in his cell.

Shortly after midnight, Skip Adams-Taylor, a 20 year-old Washington man who, his lawyer had said, could not survive a long prison sentence, was apparently saved by sheriff's deputies who discovered him dangling from bed sheets in a nearby cellblock.

The hangings are the lastest problem confronting Arlington's 33 year-old sheriff Jim Gondles, who was elected in 1979 and is in charge of the 162-inmate facility near the county courthouse.

Last month, after a firestorm of criticism, Gondles abandoned his policy of trip-searching all persons brought into his jail to ensure they were not carrying drugs or weapons in their "body cavities."

I thought 1981 was going to be a better year," said Gondles yesterday, obviously shaken by the hangings. He called them "tragic" and said that like "all suicides, they were postponable but not preventable."

The sheriff said he may use the incidents in his quest for state financial aid in obtaining additional deputies. If he is turned down and if the Arlington County Board backs him, he said, he may sue the state to get more personnel.

Gondles said his staff had been particularly concerned about Adams-Taylor, who was convicted and sentenced Thursday evening for the first-degree strangulation murder of a young Arlington woman he had met in a Washington disco. The woman's body was discovered the next day, lying near headless carcass of her pale yellow pet parakeet.

Less than an hour after his conviction, jailers circulated a memo warning that Adams-Taylor might attempt suicide. "He is very despondent, and I am requesting that all personnel please watch him as closely as possible," the memo read.

I told the shift supervisor to watch him like a hawk," Gondles said. He described Adams-Taylor, a homosexual, as a particularly troublesome inmate who had been placed in a cell by himself to protect him from other inmates whom, the sheriff said, Adams-Taylor would call "bitches," "whores" and "faggots."

Gondles said Adams-Taylor was last seen sitting in his cell at 12:05 a.m. yesterday. Twelve minutes later, he was discovered hanging from the bars of his cell. Deputies administered mouth-to-mouth resuscitation and he was taken to Arlington Hospital where he was admitted to the intensive care unit. He is under 24-hour guard, Gondles said.

Adams-Taylor, a dark-haired, delicate-featured man who displayed little emotion during his sentencing, left three suicide notes, the sheriff said. One was addressed to his mother in rural Georgia, one to a "D. Gregory" in Washington and the third, written on a sheet of white notebook paper, to five jail deputies.

"I gues what I really need is someone to lean on, to cry on and to hold," Adams-Taylor said in the letter to the jail staff, according to the sheriff. I'm sorry I broke my promise (not to hurt myself) . . . Being alone didn't help matters, but that's the sheriff fault."

On the back of the note, Gondles said, Adams-Taylor had written "I'm sorry I did not do much for the gay movement." The envelope addressed to his mother bore the handwritten phrase "No reply necessary."

Adams-Taylor's court-appointed attorney George Varoutsos, who had called the murder case "stranger then fiction," yesterday called the attempted suicide "terrible and sad."

He had some serious mental problems," said Varoutsos who abruptly abandoned a planned defense that Adams-Taylor was innocent by reason of insanity and offered no explanation for the July 26 murder of Joyce Robertson. Court-ordered psychiatric tests indicated that Adams-Taylor, a Georgia native also known as George Williams Adams, was competent to stand trial.

Adams-Taylor told police he had strangled Robertson with the sash of her maroon satin bathrobe in order to avoid having sex with her. He said he then ripped the head off her parakeet because its chirping made him nervous.

Like Adams-Taylor who had been arrested several times before on lesser charges, Warfield was no stranger to the criminal justice system. Earlier this week he had begun serving a three-year sentence on charges of forgery and bad checks. Jail officials and his attorney, Benjamin Kendrick, said Warfield had been in and out of area jails on similar charges for more than five years and had a serious drug habit.

"He did not act despondent, desperate or down," said Gondles. Warfield, who had a bachelor's degree in economics from Old Dominion University in Norfolk, was last seen by a deputy at 6:47 p.m. Thursday when he asked how soon he could be moved to a cell with other inmates.

Seven minutes later, Gondles said, guards heard an inmate in an adjacent cell frantically pounding a shoe on the bars of his cell. The prisoner had apparently heard Warfield gagging and summoned help, the sheriff said.

Warfield, who had been placed in the solitary cell because of overcrowding at the jail, was taken to Arlington Hospital where he died. An autopsy listed cause of death as asphyxiation.

Warfield, who lived with his parents in Falls Church, had been married for five years and had a 7-month old daughter.

Warfield's family declined to comment on his death yesterday, but his attorney Kendrick said he was upset and puzzled by the apparently inexplicable suicide.

"What can I say?" Kendrick said sadly. "He would have ended up serving only about eight months and he wasn't afraid of jail. I don't know why he did it but he had lots of problems."