Weak third-quarter fundraising is triggering increased speculation about potential House retirements, which are expected to begin trickling out soon.

At the outset of retirement announcement season, the most recent reports filed with the Federal Election Commission signal the lack of intent to run or, in at least one case, the severe inability of some Members to raise money.

Rep. David Rivera (Fla.), a freshman Republican under state investigation and believed to be under federal scrutiny as well, raised just $27,000 last quarter. He’s one of a dozen or so Members from both parties atop retirement watch lists, populated mostly by the oldest Members and those with political and future career considerations.

Also submitting lackluster reports were Rep. Dennis Cardoza (D-Calif.), who raised $23,000, and Rep. Roscoe Bartlett (R-Md.), who raised just $1,000 from July to September. They were already seen as possible retirements, and the paltry fundraising will only invite further speculation.

Jon Vogel, managing partner at MVAR media firm and a former executive director of the Democratic Congressional Campaign Committee, said it’s a bit early to expect retirement announcements, but “This is around the time when you’re going to start to see them, historically.”

Redistricting is the decennial wrinkle likely to delay decisions even further, Vogel said. About half of states have approved final maps, meaning many Members have yet to even know who their constituents will be with one year to go until the elections.

But retirements this year are already ahead of the pace of the 2010 cycle. Five incumbents — not counting those running for another office — have already announced their retirements this year. No Members of Congress not running for higher office last cycle had announced their retirements by this time in 2009.

So far, those retirements have all been Democrats: Reps. Dan Boren (Okla.), Jerry Costello (Ill.), Dale Kildee (Mich.), Mike Ross (Ark.) and Lynn Woolsey (Calif.).

The National Republican Congressional Committee is watching several more, including a handful at the top of their target list: Reps. Jim Matheson (Utah), Brad Miller (N.C.), Heath Shuler (N.C.) and Cardoza.

While the shape of Matheson’s district hasn’t been finalized, he’s expected to join Miller and Shuler as Democrats severely hampered by redistricting. Matheson has openly contemplated running for governor or against Sen. Orrin Hatch (R) should his district be redrawn unfavorably. Utah state legislators reconvened Monday and hope to have a final map this week.

Among the four, Cardoza, who reported $62,000 in cash on hand, is the most likely to retire. His good friend and fellow Blue Dog Rep. Jim Costa is running in his district rather than a neighboring open district.

Shuler, another Blue Dog, was drawn into a more challenging district. He raised $87,000, including just $10,000 from individuals, and had $233,000 on hand.

Miller, who was drawn into the same district as Rep. David Price (D-N.C.), raised $93,000 and had $188,000 on hand. Price raised $122,000 and had $128,000 in the bank.

Two New York Democrats did little to quell retirement speculation with their third-quarter fundraising. Rep. Maurice Hinchey, who is 72 and had colon cancer surgery in July, raised just $44,000 and had $107,000 in cash on hand. Rep. Edolphus Towns, 77, raised $69,000 and had just $11,000 in the bank.

Democratic Assemblyman Hakeem Jeffries, running against Towns in a primary, raised $174,000 and had $159,000 in cash on hand. The state is losing two seats in reapportionment, so at least that many New York incumbents won’t be back in Congress in 2013.

Rep. Donald Payne (D-N.J.), born five days before Towns in 1934, raised just $19,000, but the 12-term incumbent has $1.2 million in cash on hand.

Rep. Pete Stark (D-Calif.) raised just $19,000 in the quarter, but he had $544,000 in the bank, and all indications are that he is running. Stark’s Democratic opponent, Dublin City Councilor Eric Swalwell, raised $75,000 and had $70,000 in cash on hand. Two other potential Democratic opponents have said they are sitting out the 2012 cycle and are raising money for 2014, when they expect Stark to retire.

Three Republicans in Southern California remain on retirement watch thanks in part to redistricting. Reps. Jerry Lewis, 76, and David Dreier, 59, were drawn into tougher districts. Lewis has said he is not inclined to move his family to a new city just to run in a more favorable district, and Dreier has given no indication of his plans.

Both turned in low fundraising quarters, as did Rep. Elton Gallegly (R-Calif.), 67. Lewis raised $46,000 last quarter but still had $756,000 in cash on hand; Dreier raised $44,000 but had $774,000 in cash on hand; and Gallegly raised $83,000 but had nearly 10 times as much in the bank.

Gallegly was drawn into a district with Armed Services Chairman Buck McKeon (R), who is not expected to retire while holding the gavel to a key committee. Gallegly has appeared on watch lists since attempting to retire in 2006 — he reversed his decision a week later. McKeon raised $250,000 and has $843,000 in the bank.

Other redistricting-fueled retirement speculation had centered on Bartlett and Rep. Judy Biggert (R-Ill.). Bartlett is still awaiting a final map, but Democrats are looking to cut the number of Republican-leaning districts in the state down to just one. His lack of fundraising could be an indication he does not plan to run in a less favorable district.

Biggert likely erased any remaining doubt she is running by raising $285,000 in the quarter. Although her home was drawn into a safe Democratic district, she has already begun circulating nominating petitions in a different, more GOP-friendly district. However, it still leans Democratic, and Biggert has yet to make it official she is running.

This time last cycle, Kansas Democrat Dennis Moore’s announcement on the Monday before Thanksgiving 2009 was the first shoe to drop for Democrats that year. Democrats John Tanner (Tenn.), Brian Baird (Wash.) and Bart Gordon (Tenn.) followed over the next few weeks.

A little more than half of the retirements last cycle were announced in January and February 2010, with Wisconsin Democrat David Obey the last to announce in early May.

With 50 Democrats defeated in November 2010 and 89 freshman Republicans in Congress now, there will likely be fewer retirements than normal. But retirements will come, and there is an expectation based on simple math that more Democrats than Republicans will retire this cycle.

More than one-third of the GOP conference is serving a first term, and the rest of the party’s Members are less likely to go now that their party holds power for the first time since 2006.

Still, Vogel said even if Democrats have more retirements, those vacancies likely won’t be in competitive districts.

“I wouldn’t expect an avalanche of Democrats in marginal districts announcing their retirements over the next several months,” Vogel said. “Frankly, after losing [a net] 63 seats last cycle, there are not that many Democrats left in marginal seats.”