This is the time of year when veterinarians, shelter workers and animal control folks often get more calls from kind-hearted people who lack ethological knowledge. This leads to a three-step process that can create behavioral problems for animals:

  1. They rescue young animals not in need of rescuing.
  2. They assume they or some other person can provide all the maternal benefits the animals' real mothers could.
  3. They assume those benefits are limited to feeding the young animal until the youngster can eat solid food.

Those who call their veterinarians usually want the practitioners either to sell them some sort of mother's-milk-in-a-can or to accept responsibility for raising the young animals themselves. But even if species-specific milk replacers existed and could address any changes in a specific young animal's nutritional needs during this period, these only would replace one of nursing's multiple functions.

While the young of all mammalian species can suffer when human hubris reduces animal mothers to short-term milk-producers, kittens may suffer particularly from this kind of naive interference.

In the typical feline scenario, people "rescue" kittens that queens temporarily parked as they moved their litters to cleaner or more secure locations to prevent the kittens' discovery. Even if you tell the rescuers this is normal cat behavior and ask them to leave the area so the queen will return, many of them won't listen.

Instead, they'll insist the queen either abandoned the kittens or was killed. Some even will provide gruesome descriptions of how she surely met her end. If the rescuer perceives nursing strictly in nutritional terms, this increase the potential for the young animals to experience behavioral problems as they get older.

Why can this happen? Domestic and semidomesticated cats along with their small wild cat relatives all face the same problem.

On the one hand, their long established and reinforced genetic legacy prepares them for lives as small, solitary, nocturnal, highly territorial predators who also are prey to larger species. On the other, the incursion of humans with their concurrent habitat destruction can provide cats with reliable food supplies, such as mice or rats in barns or warehouses or garbage.

Over time, a period of self-selection separated the more solitary and semisolitary domestic cats in response to environmental changes.

Cats living in areas with sufficient territory, prey and seasonal access to mates had no need to change their solitary orientation. Those living in areas where reliable sources of prey-attracting human activities, structures and garbage decreased the costs of finding food, shelter and mates, getting along with other cats became a viable option.

But how to make the transition from a solitary predator who tolerated the presence of other cats only when nursing, being nursed or mating to a more social feline willing to share space, food and other resources with other cats year-round?

Of the two, those who continued the solitary path had evolution on their side. Millennia of feline experience prepared them to survive given enough space to claim territories capable of supporting themselves and any kittens (temporarily) and to move freely during the breeding season to find mates. This included nursing strategies that triggered gene activation or suppression via the epigenome that resulted in behaviors that supported success in this environment.

On the upside, preliminary studies suggest that epigenome-related genetic changes could persist through several generations. On the downside, that means it may take a population longer to adapt to dramatic changes in the environment.

Currently, their deeply entrenched solitary genetic legacy undermines the survival of all solitary, small, wild cat species as human encroachment and habitat destruction destroy their environments. This human interference also increases the probability that, if the more social of these wild cats mate with anyone, it more likely will be a domestic cat. This will dilute the small wild cat gene pool even more.

But within the evolving domestic cat behavioral realm, the solitary maternal strategy adapted to ensure the success of kittens born into habitats that favored a more semisolitary feline orientation. Heading the list of behavioral adaptations was delayed weaning, i.e. nursing that extends beyond the time when the young can eat and digest food themselves. This confers multiple advantages to the kittens and the feline group.

Delayed weaning keeps the kittens in the learning mode longer. As her kittens grow, the queen's responses to the environment teach them what among that deluge of motions, scents, sounds and other stimuli surrounding them poses a potential danger and what they can safely ignore.

To get an idea how valuable this is, pause for a few minutes and consciously note every sound, scent, motion, texture or other stimulus in your immediate environment. Knowing what one can safely ignore is as important as knowing what deserves one's attention — if for no other reason than the former often comprises the bulk of the stimulus load.

To ensure their success in their more social environments, the kittens also must learn how to adapt their solitary behavioral repertoire to meet sometimes conflicting social demands. For solitary feline predators living in the woods with multiple species targeting the same prey population and even the cats themselves an aggressive response to any feline violators of that space confers multiple benefits.

But in a barn with a limited but reliable rodent population, the costs of a similarly aggressive response toward other cats will exceed any benefits. In this situation, the more social ties between the cats that permit them to share the food supply may cause them to drive out more competitive and aggressive felines.

However, upgrading a deeply entrenched solitary behavioral repertoire to meet the demands of a more social one and then fine-tuning it does take time.

In general, the more physically and mentally complex the environment, the longer the queen will nurse her young. It's not that uncommon for queens in such environments to delay weaning until their kittens are 12-18 months of age. But that's not as bad as it might seem at first glance.

Delayed weaning also delays sexual maturity. Animals of all species living in social groups get riled up during the breeding season. And during that time the desire to locate a willing mate, eliminate any competition and copulate often multiple times takes precedence over everything else. This essentially puts an end to kittenhood and limits the strong parental ties that foster the most energy-efficient forms of learning.

So in addition to gaining more time to teach her young the workings of the more social feline group, nursing through at least one breeding seasons keeps the litter and the queen out of the breeding population. The queen also won't go into heat, which also serves as a means of population control.

The kittens' and queen's removal from the breeding population also prevents the aggression among litter mates that otherwise would intensify during the breeding season. Within the general feline population, it also decreases the likelihood that kittens will be injured by bigger, stronger and more experienced cats vying for mates.

Although it may seem counterintuitive, delayed entry into the breeding population in an environment with reliable resources also may enhance male and female reproductive success in the future.

All in all, a delayed weaning strategy confers multiple advantages on the individuals and the group living in environments with reliable food and shelter that outweigh its costs. But, as we'll see in next month's brief, it also can create problems for cats in certain pet cat environments.