Apparently the federal government didn’t account for all the hipsters moving into Bay Ridge.

Mayor Michael Bloomberg today challenged the Census count for parts of Brooklyn and Queens, including Bay Ridge, Bensonhurts, Astoria and Jackson Heights — “which are among the most vibrant areas in New York City,” the mayor’s office said.

Bloomberg sent a letter to Census Director Robert Groves to challenge the findings.

“It is our expectation that the City’s population could increase by tens of thousands of New Yorkers if the errors from those two Census offices alone were corrected,” he writes.

Bloomberg notes in a news release that the count will not mean the city loses a seat in the House of Representatives. However, it does appear possible New York would lose one upstate district as well as a seat in one of the outerboroughs if the Census numbers hold.

Sen. Kirsten Gillibrand, meanwhile, seconded Bloomberg’s call for a challenge and wrote a letter of her own to Groves.

“While I am aware that extensive measures were taken by the Department to ensure that Census 2010 was the most inclusive in our history, I along with the Mayor, maintain that there is a significant undercount of New York City population growth,” she said.

Asked for his reaction, Gov. Andrew Cuomo earlier today said he was yet to see Bloomberg’s challenge to the Census data.

291-11 (Census Challenge)