On a Thursday morning in late February, a litter of bottle babies – orphaned kittens too young to eat on their own – arrived at Humane Society Silicon Valley. They were days old, eyes still sealed shut, small enough to fit in your palm. By the time our logistics team had them settled, the planning for their care was already underway: Which foster homes are available this week? Do we have bottle-baby-experienced fosters, or do we need to train someone up? How many spay/neuter appointments are open, once the kittens are old enough? 

This is the kind of calculus that runs every day at HSSV – and it’s about to go into overdrive.  

What is Kitten Season?

Kitten season is the time of year when cats give birth in the highest numbers. Historically, it ran roughly from April through October. That window has been stretching. Climate change is a factor – warmer temperatures mean longer breeding periods, and our team has seen the season start earlier and end later, year over year. Now, it’s not uncommon to see bottle babies arriving in February, and not stop showing up through the fall months. 

But there’s something that doesn’t get explained very often: what happens behind the scenes when kitten season hits, and how shelters and local communities work together to help more kittens thrive.  

How kitten season actually works

Kittens arrive at HSSV from two main directions: community members who find litters outdoors, and partner shelters who have more animals coming in than they have room for.  

The planning starts early. Our Rescue Team watches capacity across the region – ours and our partners’ – and starts mapping moves well before kitten season peaks. If our foster network has room, the team may transport kittens from local partner shelters where numbers are already climbing. Occasionally, we also work with regional partners like the ASPCA when our needs align.  

But managing capacity only works if fosters are ready – and if the system can keep up with them. That’s why the team runs kitten showers ahead of the season: events designed to recruit new fosters, get returning fosters up to speed, and make sure the network is prepared when the first litters arrive. We also train fosters directly, including on bottle-feeding, which is always the biggest need. As kittens start moving through the system, HSSV’s FAVS (Foster Animal Vaccination Station) keeps them on track. Run by volunteers, FAVS is a one-stop-shop where foster animals get boosters, supplies, and adoption prep without awaiting on staff availability.  

During kitten season, rescue organizations are often the ones pulling animals from overwhelmed shelters, and the broader network coordinates so that when one organization has capacity, it steps in. The whole system works because no one is trying to do it alone.  

It’s the direction the field is moving: toward a model where shelters can be proactive instead of reactive, and the community shares the work.  

The illusion of space

Our operations team has a name for it: the illusion of space.  

You walk through HSSV and see empty kennels. It looks like there’s room. But we might have 25 kittens returning from foster homes this weekend, already altered and ready for the adoption floor. That space is spoken for.  

Our team reassesses what we can take in on a daily basis. It’s not a static number. It’s a constantly shifting equation that factors in on-site capacity, foster home availability, medical caseload, staff bandwidth, and how many spay/neuter appointments we have open. Every piece has to line up.  

Think of it less like a building with rooms and more like a chess board. The empty square isn’t empty – it’s holding for a move you just can’t see yet. 

 

Every kitten is a different decision

Every kitten that comes through our doors represents a different calculation. A two-week-old and a six-week-old need completely different care – and that changes what we can offer and when.  

At 0-3 weeks, a kitten – born with eyes barely open, small enough to hold in one hand – can’t eat on its own, can’t regulate its own body temperature, and needs feeding every few hours around the clock. At this age, kittens do best with their mom. When that’s not possible, these bottle babies can’t come into a shelter environment. They need experienced foster homes – and during peak season, the need outpaces the supply. Without one available, a shelter environment can do more harm than good.  

By four to seven weeks, kittens are sturdier – eating on their own, starting to play, figuring out how legs work. But they still need foster placement until they’re old enough for surgery and adoption. Whether we can take them in depends on whether foster homes and veterinary appointments are available in the weeks ahead.  

Once a kitten reaches eight weeks, they’re approaching adoption age. But the path to the adoption floor isn’t immediate. If a kitten is found at this age or older, they’re subject to a stray hold – a window of several days where the shelter has to make the animal available for an owner to reclaim before it can be adopted out. And there are often animals in foster who are already adoption-ready and waiting for space to open up on-site. The team is tracking all of it – who’s coming back, when spots will open, and what room that creates for the next group.  

Every age is a different equation. And the team is running them all at once.  

Not every kitten needs a shelter

When people find kittens outdoors, the instinct is often to scoop them up and bring them to the nearest shelter. Leave them where they are. More often than not, the mother cat is nearby – out searching for food or taking a break from the nest. She hasn’t abandoned them. Removing kittens too early can separate them from their best chance at survival in those first critical weeks: their mother.  

That’s why we encourage a simple first step: pause and observe. 

If you come across a litter of kittens outside, leave the area and check back in 8 to 12 hours. In many cases, mom returns. If the kittens are still alone when you return, that’s a good time to reach out to HSSV or your local shelter for guidance. [Learn more.]

This approach also means that when cats or kittens do need help – sick, injured, or without a mother – there’s more room to give it to them. 

Where most of kitten season actually happens

Fostering is what makes kitten season possible. Without foster homes, HSSV’s capacity would be limited to what fits inside our building – and that’s a fraction of what’s needed. Foster families are what allow us to keep saying yes. 

This is what modern sheltering looks like – not every animal funneling through one building, but a partnership between a shelter with resources and a community willing to use them. We have the medical infrastructure, the supplies, the expertise. You have the one thing no shelter can build: a home.  

What surprises most fosters isn’t how hard it is – it’s how little it takes. You’re giving a litter of kittens a quiet room, a warm bed, and a few weeks of stability while they grow big enough to find a permanent family. The shelter handles the rest – vaccines, vet visits, supplies, and a team that’s ready to take the call when something doesn’t look right.  

Some fosters sign up ahead of the season, ready for litters that need a few weeks of care or training to take on bottle babies. Others didn’t plan on fostering at all – they found a litter of kittens, brought them to HSSV, and we asked them a question: Will you keep them for a couple of weeks? They walked out as a foster parent with food, supplies, and the full support of our team behind them.  

More people say yes than you’d think. And most of them will tell you the same thing: it was easier than they expected. A spare bathroom. A dog crate. Kittens the size of your fist climbing over each other to get to a dish of wet food, then passing out in a warm pile twenty minutes later. A few weeks of that, and you bring them when they’re ready for adoption. [Sign up to be a bottle baby foster today.]

Every foster home that opens up is another move on the board – another kitten on its winding way home.

The answer lives in the community

No single shelter can manage kitten season. What makes it possible is community: shelters, foster homes, community members, veterinary partners, TNR programs, rescue partners – all working together so that fewer animals end up in crisis in the first place, and the ones who do get the right help at the right time.  

There are more paths for a kitten than the front door of a shelter – like a TNR program serving its interests as a community cat; a Good Samaritan who finds bottle babies and becomes a foster parent; or simply a mother cat who returns with dinner.  

Somewhere right now, there’s a litter about to be born. When they arrive, we want to be ready – and ready means a foster home is already waiting. That’s the move you can make on this board. 

But even if fostering isn’t for you, you are part of the answer. It might be knowing what to do when you find a kitten in your yard. It might be telling a neighbor. It might be volunteering your time or donating to keep the system running. Kitten season works when the community shows up — and showing up looks different for everyone.