kittens cause older cat to go awol

Question
QUESTION: I have recently started fostering cats in my home.  One has been with us for 12 years, one (Misty) was adopted about 3 months ago, and Castro came on board last month (though he was a roommate's cat, and seemed to adjust very quickly to living with me again).
The last two additions are indoor-outdoor cats, and they have been slowly allowed to roam the backyard.  However, after I started caring for a pair of orphaned kittens, Castro has taken off.  I keep the kittens segregated from the other cats -- though the older cats seem to give the kitten room a wide berth.  Castro's space really wasn't directly affected, but he just left and hasn't been back in the last day.  Could this be an instinctive reaction?  The kittens are only 3 weeks old -- and though he did the wide-eyed thing, he certainly didn't seem threatened or overtly act out.  
I'm working on finding him, but if this is typical behaviour -- maybe I shouldn't be letting Misty roam anymore...and certainly not take on more kittens in future.

ANSWER: Mary,

I'm not sure that the kittens have much to do with Castro going AWOL. It's not unusual for intact male cats (I'm not sure if Castro's intact based on the history you've provided) to cause serious harm to unweaned kittens, if Castro has been a part of a colony of cats then he may have learned to give very young kittens their space since queens will become quite defensively aggressive when it comes to protecting their babies. Ultimately Castro may have left home on a feline vacation of sorts even if the kittens weren't brought into your home.

There are a lot of good reasons as far as I'm concerned to keep domestic cats indoors and well entertained within the safety of a pet parent's home and the fact that some cats seem to have a natural tendancy to wander even after being spayed/neutered is one of those reasons. There is a chance that Castro was picked up by someone with good intentions and he's currently in an animal control shelter or one of several local rescue organizations/animal shelters ~ I'd strongly recommend that you call around to local shelters and rescue groups to find out whether a kitty matching Castro's description was brought in recently because many of these groups have the ability to hold strays for a very limited amount of time. It's also good to ask around your neighborhood, talk to people and find out if they've seen Castro (if your little man is friendly someone may have taken him in believing that he was a stray). It's not a bad idea to check with local veterinary hospitals to see whether an injured or deceased kitty matching Castro's description was brought into their facility by a good samaritan. Most shelters have DOA records where they list descriptions of animals brought in by private citizens, I'd strongly suggest that you ask to see them when you speak with staff at your local shelter. If Castro hasn't come home by the end of tomorrow I'd suggest that you go ahead and make up Missing Kitty posters complete with at least one current photo of Castro that shows his markings accurately. It's also a good idea to include mention of a reward for Castro's safe return (you don't have to specify how much money you're offering, just the mention of a reward is enough for some people to return your kitty). You can put these posters up around your neighborhood, at local vet clinics, in local pet supply stores and hand in copies to local rescue groups and animal shelters. Your posters should include at least one phone number where you can be reached 24/7 so that anyone who finds Castro can call you ASAP so that you can bring your little wanderer home.

Unfortunately we don't live in a perfect world and there are some nasty humans out there who believe that it is their right to abuse off leash pets and in some cases (I had a lady write me not that long ago about the following situation) people feel justified in fatally injuring or even outright killing cats simply because the cats cross through their property. There are people who take a more indirect approach when it comes to hurting wandering cats such as leaving cat food mixed with rodenticide or antifreeze out where cats are sure to spot it and eat/drink tainted food, there are also those that believe it's their right to speed their cars up to hit cats crossing streets. Ultimately I think that it's important to be fully aware of potential dangers before allowing your kitties to roam unsupervised.

If you do want your kitties to have some time outside you could train them to be comfortable on a harness/leash set so that they could have short walks around the neighborhood with you and you'd know that they were absolutely safe. You may also want to consider building a kitty "kennel" type enclosure equipped with scratch posts, clean water and a litter box. Your enclosure should also have carpeted shelves where the cats can comfortably observe birds and small prey animals. Putting a few bird feeders in your yard near the kitty condo can also help entertain your feline friends.

I truly hope that you find Castro safe and sound. At this point in time I doubt that he's run off because of the kittens. In my opinion at this point he's more likely to be hanging out in someone else's living room having been mistaken as a stray or abandoned kitty. If you do decide to continue allowing the fur kids outside unsupervised be sure that they have break-away collars with legible tags listing the number for the vet and the rabies tag should also be present to ensure that anyone handling him knows he's been vaccinated against this fatal virus. Many cats make it their life's work to get out of collars and harnesses, if your kitties might react this way then I'd strongly suggest having the cats microchipped so that in the event they are picked up by a shelter or animal control they can be easily identified and safely returned home to you. It's also important to keep current photos of each of your resident cats handy at all times so that in the event one kitty goes missing you have proof of ownership (which most shelters require before they'll release a pet to their human caregiver).

At the moment although I wish I could do so much more for you and Castro, right now beyond the advice I've given all that I can offer are my thoughts and prayers. I truly hope that your little man comes home soon safe and sound. I would appreciate it if you would let me know when you find your little guy if at all possible. If you have any further cat related questions or concerns, please feel free to contact me again ~ I will do my absolute best to help you in any way that I'm able to.

---------- FOLLOW-UP ----------

QUESTION: Fantastic answer.
Castro is an altered male - I don't know much about the earliest portion of his life (cat colony/not) because he was adopted by my roommate and I back in 2006 from a couple who had in turn rescued him from another household.  I suspect he was never feral.  
He had taken off from the roommate's household in the dead of -30 degree winter in early 2009, and eventually showed up at Animal Control nearly 3 weeks later.  I believe he left because the other cat in that house was harassing him.  My sister and I are pretty sure we saw him last night, but he disappeared at the end of our laneway.  
I have posted an ad on kijiji and will be giving Animal Care Control a call in the morning when they reopen, and stop in if they have any near his description.
He is pretty self-reliant, up to date on shots, and medicated against fleas.  He gets depressed/reallly aggravating when he's not allowed to prowl - so I just let him out a little at a time..at first he was only allowed out on the second-story porch, but he climbed over the wall and down the railing (making me quite nervous - 20+ foot drop), so I'd let him out in the backyard for an hour at a time... but until the kittens came, he'd been sticking closeby.  I suspect he is in someone's home because he is such a social little guy, and this is a cat-friendly area (probably has just found someone to mooch off of) but I will keep you up to date.  Thank you again for your response :)

Answer
Mary,

I'm so glad that you've found my initial response helpful. If you'd like any further information on building the perfect outdoor kitty enclosure (as a means of saving your sanity while allowing Castro his outdoor time in a safe area) I'd be more than happy to help you. If you have any further cat related questions or concerns, please don't hesitate to contact me again and I will do my absolute best to help you in any way possible.