Planning the Release of a Squirrel
It’s a wild animal, don’t I just ‘let it go’?
The short answer is, absolutely not! Most prey species such as squirrels and rabbits, even those provided with the advantages of instinct and natural parenting, do no live to see their first birthday.
How much harder it will be to survive for orphans raised by well meaning humans. Even adult predatory species like raccoons are more likely than not to perish when released without proper planning and consideration for their natural history (R.C. Rosatte, and MacInnes, C.D. 1989).
Never leave any unprepared orphaned baby wild animal alone in an unfamiliar environment thinking you are releasing it back to nature or ‘giving it a chance’. You’re not, it has no chance. It is much kinder to take it to a humane society or veterinarian for humane euthanasia if no other options exist. The end result will be the same, but the means will be vastly more compassionate.
In one study 97% of adult squirrels relocated were either killed or chased off from the release location within three months of release (Adams, L.W., Hadidian J., and Flyger, V, 2004). These were healthy adult wild squirrels. Image how much more difficult it will be for young and inexperienced orphans.
At Squirrel Refuge, in post release follow-up studies done at two weeks, one month, and three months, most of the squirrels were seen at or near the release site. Some hosts accounted for all orphans released at the site at three months. One reported observing babies in the nest box the following fall. While errors in identification are possible, evidence strongly supports that the probability of survival is increased when factors such as appropriate pre-release preparation, time of year, release site selection, appropriate housing, and follow up support are provided.
Factors to Improve Post-Release Survival
1. Understand the natural history of the species you are releasing.
Natural history is a study of the species’ whole world. The more you know about how the species normally survives in the wild, the better you will be at making good rehabilitation and release planning decisions (Casy, 2011) . Wikipedia is a great source for this.
2. Choose a good day when the weather forecast is expected to be mild
3. Choosing the right time appropriate for the species
Diurnal - awake during the day - release at dawn or in the early morning (tree and ground squirrels, rabbits, deer, ...)
Nocturnal - awake during the night - release at dusk or in the evening (flying squirrels, opossum, raccoon...)
4. Selecting an appropriate location.
with few predators or domestic pets (ie. Cats!),
near plenty of thickets or underbrush to hide in for ground dwelling animals or near groves of trees or forests for tree dwelling wildlife.
near a source of natural foods (field or other greenery for rabbits, nut & seed bearing trees for squirrels, etc.)
within its natural range (where others of its species can be found)
near a reliable source of water (for aquatic or semi-aquatic species release near a year round pond or river)
away from busy streets
away from human traffic and interaction
in a place where it is legal for you to do so
5. Provide appropriate housing.
For some species, like a weaned eastern cottontail or opossum, it is as simple as doing all of the things above and waving goodbye, but for squirrels and most other species going out into the wild for the first time or as relocated adults, they need a house located in a safe place to provide at least temporary staging area while they find their bearings, assess the level of threat or competition from the existing residents, find food and water, and locate or build permanent shelter sites.
6. Provide follow up support.
If it's hot then water is essential.
If its fall and no food has been stored up for the winter, supplemental food support may be needed until spring.
Our Release Process
The process described here is how we at Squirrel Refuge release tree squirrels, taking into account their natural history and some things we have learned about squirrels along the way. It just takes ten easy (or not so easy) steps:
Step 1 - Raise a nutritionally healthy squirrel
We can always tell a squirrel raised at Squirrel Refuge from their wild counterparts.
Why? Because they are typically bigger and have much fluffier tails*. While that probably
seems counterintuitive, by providing the ideal nutrition, environment, healthcare
and physical conditioning, squirrels reared in captivity don’t have to contend with
many of nature’s little uglies such as food competition, disease and parasites. If a squirrel
in your care is failing to thrive, consider improving its diet and environment. Never release
any animal you are not 100% sure is healthy and fit to survive in the wild.
*Squirrels entering rehabilitation very young without the benefit of antibodies and a good start on mother’s milk or those with a sensitivity to formula are often smaller and require more time to archive healthy weight gain as compared to squirrels entering rehabilitation after three to four weeks in the care of their mothers. Obviously mother’s milk is superior to even formulas made specifically for squirrels.
Step 2 - Raise a physically healthy squirrel
At about six weeks, baby squirrels need to have plenty of room to run, learn to jump to and from various sized solid and unstable branches and surfaces, and play rough and tumble with other squirrels. Squirrels must have at least a few hours a day out of their cage to ensure they are strong enough to endure the physical demands they will be immediately faced with upon release.
Step 3 - Raise to be mentally prepared
As with children leaving home for the first time, it takes more than physical preparedness
to handle the challenges of the adult world. A coddled baby isn’t going to be ready to see
your tail lights if you don’t take purposeful steps to prepare for the big day.
Step 4 - Form a good sized release group
At Squirrel Refuge, when an orphan arrives, it is placed with orphans of the same species and
developmental stage as part of a ‘release group.’ These squirrels will go through the rehabilitation
process together, grow and develop together, wild up together, and be released together.
Growing up with ‘siblings’ (Even those artificially introduced) builds life long relationships and the social skills that will be the backbone of hand rearing a squirrel that knows what he or she is and how to interact with its own species in the wild. The ideal group size is at least 3 to 5 squirrels Per box. The larger the release group, the less likely it will be that a resident squirrel will even attempt to display your squirrels at the release site. After all, no squirrel wants to mess with a ‘gang’ of large healthy squirrels.
We don’t ever recommend releasing a single squirrel, particularly one reared alone. A baby raised with humans before its eyes open and then subsequently not given the opportunity to interact with other squirrels will never behave properly in the wild much like a human would behave in an analogous situation. Squirrels such as these will live as outcasts. Always raise wildlife with others of its kind. A single squirrel raised alone past sixteen weeks is what we call at Squirrel Refuge, a pet squirrel. If the single squirrel entered care at an age where its eyes were opened (after five weeks), it can often be successfully released alone if returned where it was found among genetically related squirrels.
Step 5 - Build or buy a release box
Reference the links for building or buying a release box to help you to provide appropriate housing. The squirrel must be use to the box before being released. We recommend moving the release box into the enclosure a minimum of one week before release, preferably longer. Fill the box with any material that is warm but will dry out quickly if wet such as dried moss or artificial fabrics like fleece cut into strips so the squirrels can easily arrange to their liking. (We HIGHLY recommend Polyfil as it is very insulating and will wick any moisture that a squirrel will bring into the box on its fur.) Do not include any ‘stringy’ materials that may get wrapped around legs or toes.
Step 6 - Acclimate to outside temperatures
If you’re releasing in spring or summer, this is usually not a huge issue. If you are releasing in weather that is substantially different than their climate of rearing (or in winter), you must acclimate the squirrel to the outside temperatures before release. This means putting the squirrels outside in a large predator proof cage protected from direct sun, snow, cold wind, or rain during the day for a few weeks before leaving out overnight. The cage bars should be no larger than 1/2 inch apart. Whenever, you leave a squirrel outside you must provide it with ample room to move away from the sides of the cage and a box where it can retreat from the sight of predators.
The box must be positioned to prevent raccoons or cats reaching in and grasping an arm or tail.
Step 7 - Select the release location
The ideal location is at or near where the squirrels where recovered. While parks look ideal, its usually illegal to release there and generally there’s already an abundant population of squirrels present who will chase off your squirrels at the first opportunity.
Select an area with lots of trees where the branches overlap. Squirrels are safest when they are able to move from tree to tree without traveling at ground level. This is true for Eastern Gray, Douglas squirrels and chipmunks. Fox squirrels and any species of ground squirrel are more comfortable on the ground.
Select a tree that’s 10 or more inches in diameter. Bigger is better! Evergreens are ideal but deciduous trees work as well. If its near nut bearing oaks, walnuts or filberts all the better.
Step 8 - Get prepared!
On the morning of the release, have your nails, hammer, something ‘breathable’ to block the squirrels in the box (we place a piece of hardware mesh over the opening and secure with a bungee cord), ladder and and anything else you need ready to go. If the squirrels are wild and not easily contained, you will need to block them in early in the morning while its still dark to make sure everyone is in the box for their big adventure. The squirrels must not be contained in the small box for more than an hour and always make sure that air is available.
Step 9 - Up you go!
This is the riskiest part of the entire process (and my least favorite!). We recommend hiring a tree trimmer or someone use to climbing trees to place the nest box. If you do decide to do this yourself (at your own risk), we have a few suggestions pulled from our own Squirrel Refuge book of shame.
The nest box must be at least 20 feet up in the tree and you must get the squirrels up to the nest box. If they don't know where the nest box is, they may be disoriented and run off once released. Usually they will reconnect with each other and find the nest box, but to ensure that they do, we recommend releasing the squirrels in or near the nest box.
Clear away any branches that may impair access to the tree and ensure the ladder is firmly set on level ground.
Avoid setting the ladder on or near a beehive.
Go up the ladder and firmly place a nail in the tree before going up with the box.
Ensure the nail is long enough to go into the trunk and not just the bark so that it can bear the weight of the box.
Make sure the nest box has some way to hook it on the nail before taking it up the tree (A). This will make it much easier to affix the box to the tree and reduce the likelihood of needing to balance on the ladder, while balancing a box of angry squirrels in one hand and leaning back to reach over the box to affix it to the tree with the other (This is much harder than it sounds).
Attach flexible metal bands to the box. The bands can be bent to the contour of the tree making attaching it to the tree much easier. (B)
Ensure you can easily remove the covering over the opening of the box once its secured to the tree. I replace the covering used during transport with a big wadded up towel that I can just pull out when the box is on the tree.
Avoid dropping the box full of squirrels. It makes you feel bad and it freaks out the squirrels.
You can put them in a carrier and take the carrier up the ladder to the box if you have any doubts.
Be prepared to have squirrels either jump from the carrier or refuse to leave the carrier, placing you in the position of balancing on a ladder suspended twenty or more feet above the ground trying to coax them out. This can prove impossible and require you dismantle the carrier while balancing on the ladder.
Don’t drop the carrier full of squirrels.
Don’t stick your bare hand in the carrier and try dragging the squirrels out if they are upset. Be prepared to take the carrier apart with the opening facing the tree and push them towards the box or trunk.
When opening the box or the carrier Its best to have the opening facing a branch - some overly ambitious squirrels use to jumping from the box onto a nearby side wall have been sadly disappointed to find it now replaced with air.
Make sure the house is right side up before securing it to the tree.
Lastly, avoid bringing anyone with you who will laugh, heckle or post videos on Facebook but do make sure you do not attempt this without someone there with access to a phone who can direct emergency services to your exact location.
Rehabilitating that squirrel on your own doesn't sound so good anymore, does it?
Step 10 - Follow up support
Squirrels born in the spring have it much easier since they have plenty of food and time to prepare for winter. These squirrels should still be provided with supplemental food and water (if no natural source is readily available) for at least a month post release.
Fall born squirrels don’t have it nearly as easy. In the wild, fall born squirrels ‘over winter ‘with their mothers who have presumably prepared for them by storing food. Since they have no mother and no food stores, they MUST be provided for until spring, otherwise they will very likely starve over the winter months or fall prey as they venture out in search of food in unfamiliar areas.
You Did the Right Thing!
You bottle fed it, mothered it and worried over every sniffle and now its gone. Is it cold? Will it find its nest box? Is something going to eat it? All of these are normal feelings. Even after releasing hundreds of animals, even experienced rehabilitators second guess every decision and still know that returning an animal to its rightful place in the natural world is the right thing to do. Rehabilitation provides no guarantees. We can't promise that any animal we release back into the wild will survive, but we can give it a second change to survive. Wild animals can never be happy confined to a small cage with no normal social interaction. Take a deep breath, poor yourself a nice glass of wine, put up your feet and pat yourself on the back. You did it!
Releasing Recovered Adult Squirrels
Always return adult squirrels to the area where they were recovered. This is where their home is, where they are familiar, and where all of their food stores are. Every squirrel needs a home to retreat to for shelter, protection, food storage, rest, and rearing young. If an adult squirrel is returning to the same location where it was recovered in a reasonably short time, it is unlikely that a house is needed - or even appropriate - as most will prefer the familiarity of their dray or den. This is particularly true for species that often have multiple nest sites, such as eastern grays. If it's been a month or so and the weather has turned cold, follow the same suggestions as for releasing orphans.
We always arrange with property owner to provide supplemental food and follow up to make sure the squirrels are doing well.
Adams, L.W., Hadidian J., and Flyger, V. Movement and mortality of translocated urban-suburban grey squirrels. Animal Welfare 2004, 13: 45-50
Casy, S., Understanding Squirrel Natural History in Squirrel Wildlife Rehabilitation Decisions. 2011. http://www.ewildagain.org/pubs/rehab_articles.htm
R.C. Rosatte, and MacInnes, C.D. Relocation of city raccoons. Proceedings of the Great Plains Wildlife Damage Conference 1989. 9: 87-92
Please note: Washington State residents are prohibited from caring for wildlife.
This information is for trained wildlife rehabilitators only.