After last year's holiday hiring frenzy, retailers are showing more restraint in ramping up their staff for the crucial holiday shopping season.
Toys R Us became the latest retailer to announce its seasonal hiring plans on Monday, saying it plans to add 45,000 employees to staff its stores and distribution centers. This is roughly on par with its hiring plans last year.
After a surge in overall holiday hiring last year to a 12-year high, shaky consumer confidence and increased retail efficiency and online shopping may prevent similar gains again, according to an outlook from Challenger, Gray & Christmas released Monday.
"Whether it is related to increased online shopping or the shakiness in consumer confidence, the expectation that there will be fewer people in the stores could prompt some retailers to reduce the number of extra people they will need on the sales floor," said John A. Challenger, the executive outplacement firm's chief executive officer, in a release.
(Read more: Holiday sales forecast moderately higher)
Retailers' increased reliance on big data could also mean slower growth in holiday hires.
Target, which plans to hire about 20 percent fewer seasonal workers, is one such retailer looking to use spending data to adjust its plans.
"We're getting smarter in terms of anticipating how many resources we need when guests are really going to be shopping the hardest," said Jodee Kozlak, Target's executive vice president of human resources.
(Read more: Real men don't shop? Not so: Retail's new frontier)
As online sales growth continues to outpace that of brick and mortar, retailers are turning more of their attention to beefing up their distribution centers.
While Kohl's announced on Monday it plans to decrease the number of seasonal workers it hires per store, it will increase the number of positions at distribution centers and credit operations.
"Price-conscious consumers are doing more and more of their holiday shopping online, where they often find the best deals and can typically enjoy free delivery and no sales tax," Challenger said. "The ongoing shift to Internet shopping could see some seasonal hiring in this area, but the numbers will never match the employment gains seen in traditional brick-and-mortar establishments."
Stronger retail hiring earlier in the year could also dampen the need to add as many temporary workers. Between March and April, retail employment jumped by 42 percent compared with the year-ago period.
(Read more: 'Tis the season: Do's and don'ts of layaway)
Some retailers, such as Wal-Mart, may choose to dip into this pool of workers as they evaluate their holiday needs. The discount giant plans to hire 55,000 seasonal workers and and move more than 35,000 associates from temporary to part time and another 35,000 associates from part time to full time.
"Just as the holiday ads and decorations appear earlier and earlier each year, we may be seeing earlier holiday hiring," Challenger said. "With enough flexible, part-time workers, retailers can handle the wide fluctuations that occur in the last half of the year, starting with back-to-school sales, followed by Halloween, and culminating with Christmas."
—By CNBC's Katie Little. Follow her on Twitter @KatieLittle.