Friendliness
The Pet Tails website reports that neutered male tabby cats may be friendlier than female tabbies and quicker to trust their owners. A study cited by the Purina website partially supports this assertion. It finds that neutered male cats are less aggressive and more affectionate than spayed females. According to the Animal Planet website, male tabby cats are more outgoing than female cats.
Spraying
Spraying refers to a tabby cat's depositing urine on vertical surfaces such as doorways and household furniture. According to the Cat World website, spraying most often occurs in unneutered male tabby cats. The behavior typically begins when male tabby cats reach sexual maturity. The Cats of Australia website suggests that while spraying is usually a form of territorial marking, it can also be stress related. Spaying or neutering a kitten early in its life can prevent future spraying problems.
Aggression
Unneutered male tabby cats may be territorial and aggressive in the presence of other male cats. They may also stray far from home in search of females to mate with. According to the Animal Planet website, homeowners shouldn't bring unneutered males together unless they're prepared for inevitable territorial conflicts and urine spraying. The Animal Behavior Associates website reports that male tabby cats may become amorous with inappropriate objects, such as a person's leg.
Noise
Unspayed female tabby cats may yowl loudly when they come into heat and their reproductive hormones cause physiologic changes in their body. Female tabby cats may also anxiously pace or try to escape in order to find a mate. After finding a mate, female tabby cats may become pregnant and give birth to a litter of kittens. According to the Animal Behavior Associates website, mother cats may become aggressively protective over their kittens.