Ground Squirrel BMP 

Breeding facts:

Adult male ground squirrel.

• Squirrels reproduce once a year.
• Average litters are 7 or 8 young with a range of 1 to 15. Five to six are most likely to survive.
  
  Adult female ground squirrel
• Breeding season ranges from December to June with Southern California starting their season earlier than that of Central or Northern areas.
• 
  Males emerge earlier than females after hibernation. At peak breeding season, the ratio of males to females aboveground equalize.
• Squirrel gestation is 25 to 30 days. Young are nursed below ground for about 6 weeks
  
  Juvenile ground squirrel
  before they emerge and begin to forage above ground. Young squirrel numbers are greatest from late April until June, when they may disperse to set upon new territory or move to old, unoccupied burrows.

How Breeding relates to control:

Optimal time for control is during the breeding season when both males and females have emerged from hibernation for peak breeding season. At this time, a majority of the squirrels are aboveground foraging for food and breeding.

The young have not yet been born and, because of over-winter mortatlity, the squirrel numbers are usually at their lowest point. Fumigation is probably the best control method during this season as these squirrels are foraging for greens and are not often interested in the seed-based bait.