Developmental differences between grey and fox squirrels?

[furryscaly]

Hi, all. This is my first post here. I do small-scale wildlife rehab and animal rescue in my local area. Although I've done orphaned raccoons, rabbits, birds, etc, and have done injured adult squirrels, this is my first time rearing infant squirrels. Thankfully my experiences working with other critters carried over, and it hasn't been terribly different from any other baby in need of frequent feedings and care. Of course there will be specific differences in rearing squirrels vs other animals that I've had to look up, such as how old they are, how much to feed them and what brand, etc. When I got the call to pick them up they were about 3 weeks old, and I'm happy to say they are now about 9 weeks old and doing well. Ok, so after that long-winded intro, here's my current issue:

Where I'm at we have fox squirrels (Sciurus niger). They're a larger cousin to the grey squirrel, but are overall similar. They're heftier, with shorter ears and orange highlights instead of white. The problem is that pretty much all information on rearing orphaned squirrels on the internet pertains to greys, not foxes. I assumed any differences in development and care would be minor, and I made only slight alterations, such as feeding them just slightly more than what is recommended for greys. However, I used descriptions of grey squirrel babies to determine the rough age of my fox squirrels when I obtained them, but based on that starting point (3 weeks old), they would be 9 weeks old now, but do not seem as developed as greys of that age. For example, when I got them their eyes were closed, with only thin, peach-fuzz hair covering their bodies, and hardly any hair on their bellies. But now, 6 weeks later, they're finally starting to explore a little, but still sleep a lot. They occasionally hop a little, but don't run or jump much, and I haven't observed them sitting up on their haunches at all. They nibble and eat hard foods a little bit, but still are very eager to take formula. Their tails are bushier, but nowhere even close to an adult's, and they've only recently started carrying them over their backs somewhat regularly.

Have I misjudged their age? And if so, does anyone have any pointers as to how old they may be? Also, what about care requirements for whatever age they are at? Because they're either 9 weeks old, and then apparently 9 week old foxes are much further behind 9 week old greys, or they're not 9 weeks old at all and I can't accurately tell how old they are. At what point do you think they will be getting closer to weaning? From what I'm gathering it seems fox squirrels may have a slightly longer developmental period than greys, but I could be wrong. Adult fox squirrels weigh up to 2.2 lbs, depending on locality, but mine are currently 6 oz on an empty stomach. I'm not too worried that anything negative will happen, but it would still be nice to know more. I'll see if I can add some photos of them when I first got them on March 2nd vs what they look like today, April 6th.

[Annabelle's papa]

Hi furryscaly, and to The Squirrel Board , you certainly do some amazing work those Lil' Ones are Beautiful.

Thank You very much for the information and the wonderful photographs, I'm sure with your experience you could offer a lot of great advice to Folk's. It's OK to let Squirrels self wean, some will even continue drinking formula from a shallow dish as they get older and begin solid food. Six ounces would mean your Lil' Ones are approx 180 grams, and there is an age weight chart on the Board I just don't have it readily available at the moment, but I will look it up. Some other members with far greater experience will soon post here, with all of the answers to your questions including age, species, etc.

[squirrelsrule&bunniestoo]

I think you are right on with the age, I would have guessed 3 weeks as well and think they look about 9-10 weeks old now. There is a HUGE difference between greys and fox squirrels as far as the speed at which they grow up. Fox squirrels are more laid back about everything and grow up a lot slower than greys. I've found greys tend to open their eyes closer to 5 weeks old whereas fox squirrels more like 6 weeks old. Once greys open their eyes, they're very quick to be up and about and start nibbling right away. Fox squirrels take their good old time with getting up and about and eating on their own. They usually figure it out by 10 weeks old, but are much slower than greys. Also, I have had to force wean all my fox squirrels or they'd likely take formula until the day they die. I drop them to 3 feedings a day when their eyes open and then no more than 2 feedings a day when they are over 200 grams. I try to wean around 300-350 grams.

I realized just how different they are when I took in greys for the first time at my apartment (I'm in vet school so my rehab setup is at home, but when I'm away at school, I take small babies in my apartment). I got them in March and they were pinkies (about 1 week old). I figured that by the end of April they'd be about 8-9 weeks old, and just getting ready to wean and move to a bigger cage like the fox squirrels (at home we have 80% fox squirrels whereas at my apartment it's almost 100% greys) would be. Ha ha, those little guys were crazy by the time the semester was over and were weaned and ready to move directly to the outside cage. Then last year I had fox squirrels over spring break at home and they were all calm cool and collected the whole way home after the semester and were still on formula. This year it's greys again and they're just opening their eyes, but it'll work out perfect because I start clinics so I have to give them back to the wildlife center and they should be big and weaned by May 4th when I start clinics.


Sorry that was long winded, but yes, greys and fox squirrels grow up at very different speeds. An interesting thing that I've found is that when you have both together, they almost take on characteristics of the other. If you have 7 fox squirrels and 1 grey (like I did last year), that'll be the most laid back grey squirrel you've ever seen. Still a little fiestier and more ready to go than the fox squirrels at a younger age, but compared to another grey, very laid back. If you have 1 fox squirrel with 5 greys- that fox squirrel will be very crazy. They never catch on to the being aggressive about the food part, but they will be up and about at a much younger age, eating regular food sooner, and pick up some of the weird things that greys do like the random jumping in the air when they're babies. It's interesting to watch them and to me it shows just how important it is to have baby squirrels raised with other squirrels because they really do learn from eachother.

[island rehabber]

I'm so glad that squirrelsrule&bunniestoo was here to respond to your question, because she's one of the few rehabbers here who regularly will take in both species of squirrel. Most of us are either/or, depending on our geography. There are no foxers within 250 miles of me, I'm afraid...however I do get melanistic (black) greys, which is always fun.

Ooops -- forgot: Welcome to The Squirrel Board!

[furryscaly]

Thanks so much for the help! I have already dropped feedings to about 3 times a day, some days 2. And of course not a day or two after my post I noticed them sitting up on their haunches and holding food in their hands now. They do like to nibble food, but as far as how much of it they're actually eating, I can't tell. For every bit they may swallow they seem to leave two bits on the ground, whether it be apple or pellets. They will hop and crawl across the ground, and hop up to climb things, but still no big leaps or severe "squirrely" behavior. I sure hope they do well in the wild. I planned to release them in my yard so I can keep an eye on them.

[furryscaly]

Actually, I had one more question. Seeing as how they're larger than grey squirrels, what is the most formula you'd recommend feeding them in a single sitting? My syringe goes up to about 13-14cc and I usually give them a whole syringe each feeding now, but have just started offering even more if they want it. Should I be feeding them more than that every time? Or is it too much?

[stepnstone]

Actually, I had one more question. Seeing as how they're larger than grey squirrels, what is the most formula you'd recommend feeding them in a single sitting? My syringe goes up to about 13-14cc and I usually give them a whole syringe each feeding now, but have just started offering even more if they want it. Should I be feeding them more than that every time? Or is it too much?

Your feeding a squirrel with that??

[squirrelsrule&bunniestoo]

I usually cap my guys off at 20 ccs. No more than 10% body weight.

Use caution with the large syringe, but if they aren't aspirating, I'd carry it on. I've been using a 10 cc syringe for my greys for the past 3 days and smallest ones are 110 grams, so as long as you're in control, that should be OK, they're pretty big. Main thing is to have a hold of the plunger so they can't suck down too much formula at one time because they suck with all their might! If you're using a 10 cc syringe and pulling the plunger as far back as it'll go beyond the marker for 10 ccs, I figure that's about 12 ccs.

[Nancy in New York]

I usually cap my guys off at 20 ccs. No more than 10% body weight.

Use caution with the large syringe, but if they aren't aspirating, I'd carry it on. I've been using a 10 cc syringe for my greys for the past 3 days and smallest ones are 110 grams, so as long as you're in control, that should be OK, they're pretty big. Main thing is to have a hold of the plunger so they can't suck down too much formula at one time because they suck with all their might! If you're using a 10 cc syringe and pulling the plunger as far back as it'll go beyond the marker for 10 ccs, I figure that's about 12 ccs.

Can you just post a little disclaimer here?
You have probably done 6,497,821 squirrels and bunnies.
You are a licensed rehabber, and a vet student.
YOU could probably feed with a turkey baster and be fine, where
most of us stick with the 1 and tops 3 cc syringes and still worry.
Remember this is her first time rearing infant squirrels.

All said with love you know!

[TubeDriver]

Can you just post a little disclaimer here?
You have probably done 6,497,821 squirrels and bunnies.
You are a licensed rehabber, and a vet student.
YOU could probably feed with a turkey baster and be fine, where
most of us stick with the 1 and tops 3 cc syringes and still worry.
Remember this is her first time rearing infant squirrels.

All said with love you know!

[squirrelsrule&bunniestoo]

Oh, I thought they were a wildlife rehabber with a lot of experience, just not squirrel experience. If it's your first time with babies, then yes, they're more 3 cc size. One thing is I never use the 5 cc syringes. They suck the plunger down so easy and aspirate themselves before you even know they've started drinking.

[furryscaly]

lol, sorry for the late reply. Thanks again for the help. I wouldn't say I'm an expert, but yes, I've done rabbits, raccoons, and more birds than I can remember. Just never baby squirrels. The male was tricky back when he was 4-5 weeks old, but I learned quickly not to let him aspirate. He still eats like that scene from Beauty and the Beast when the Beast is trying to use a spoon for Belle, but at least he doesn't shoot any out his nose or inhale it. The female is the best eater I've possibly ever had of any species. I don't even have to clean her up afterward. She knows what she's doing.

They're about 10 weeks old now and are eating rodent block, monkey chow, kale, tree buds, almonds, peanuts in the shell, pistachios in the shell (they're the only nuts I could find in the shell at this time of year), small amounts of fruit, etc. I offered them small eggs, as I have painted quail and a dove that lay constantly, and I know that fox squirrels are quite fond of eggs and baby birds around here, but mine don't seem to recognize that they're food. They also don't seem to care for corn, although it's hard corn and it's on the cob, so I might try some loose stuff. And nobody had striped sunflower seeds, but I have black oil sunflowers. I haven't been offering them too much of the seed though as I want them to be eating their pellets still. I would like to wean them off of those though, since they won't be finding any in the wild. But around here I think the squirrels must eat a lot of buds and maybe some aspen or box-elder seeds when those are in season, which they are not. There aren't really any nut trees in town, not even acorns. I think they rely a lot on bird feeders, too, as I've rarely seen a wild squirrel here eating anything that wasn't provided by humans. Honestly I don't really know what they eat in this town at this time of year other than bird seed and tree buds and maybe pinecones. Any insight? I give them spruce cones, too, but they're not really eating those either. I'm pretty sure the native squirrels eat the seeds though. And the squirrels here eat a lot of crab apples.

They're in a large parrot cage now, have no source of heat any more, and have it adorned with cottonwood branches and a litter of dead leaves and grass. They have a nest box attached to the side of the cage with dead grass and leaves as nest material and they quite like that box. They're indoors, but I have them in their own room next to a window that I leave open, so they can get accustomed to the smells, sounds, and temperatures of the outdoors, as well as the sun's natural day/night cycle (I work 3pm-midnight. NOT good day/night cycle, lol). I still keep a dish of food in there for them, but I scatter and hide most of it in the litter on their floor now so they have to search for it. I feed them probably close to 20cc of formula once a day now, sometimes twice.

Might as well be my male with formula:
https://www.youtube.com/watch?v=q7AD4Mb5o_I

[Annabelle's papa]

Good Evening furryscaly, Here is a link to the healthy diet chart, http://thesquirrelboard.com/forums/s...rrelsSquirrels require a high calcium to phosphorus selection of food, because they are susceptible to metobolic bone disease or MBD. I have also included a link to Henry's Healthy Pets, http://www.henryspets.com/ where you can get the best blocks formulated just for Squirrels. Too many nuts and seeds, especially peanuts and corn are very bad for them and are treats only, and given less than two a day. It would probably be a good idea to see if the Lil' Ones would nibble on some Tums, in the event they are becoming calcium depleted, they prefer the berry flavors and a store brand is fine as long as they are comparable to Tums. Other antacids such as Rolaids contain other minerals they don't need, just using calcium carbonate only is the key.

Please post a few current photos when you get a chance.

[squirrelsrule&bunniestoo]

Squirrels eat all kinds of stuff in the wild, buds, berries, insects, mushrooms, nuts, etc. I stick with predominantly fruits and veggies for all of rehab and then provide some for them as they transition to life in the wild as well. A good healthy diet is important though. I don't stick 100% to the healthy food lists (avocado and apple are the easiest weaning foods so I usually start with them). They have monkey biscuits with them from right after their eyes open but they don't eat them until they're older. As they start to eat regular food I give them more greens and also sweet potato. After they are chewing their food well I add grapes, cantaloupe, strawberries, etc. My guys always get a big variety and just one nut per day. I don't usually give corn, it's one of the least healthy items for them. I usually do give a little bit of sunflower seeds when they are in the outside cage though because that will likely be a food for them in the wild that I want them to recognize.

[furryscaly]

Thanks again. I will decrease the amount of nuts and seeds I feed them. They do eat a lot of kale though, which I supply for the calcium. They used to chew on an antler I gave them, but they now prefer to chew on branches. They also have a cuttlebone, but I've never seen them utilize it. I specialize in reptiles and they are very similar in their calcium requirements, though the means by which it is supplied is different, and they require the addition of UVB lighting to metabolize it. The primary reason I've been offering nuts and seeds is that it makes up a significant portion of their diet here, as from squirrel and bird feeders. Seeing as how they are fully aware that it is food though, I suppose I don't really need to keep feeding it to them. I'll increase the amount of rodent block for now, but I don't want them to become too dependent on its familiarity since they won't be eating any of it at all once I release them. If they were going to be pets it would be much easier, and if that were the case I would be feeding them much differently.

For now I think I will feed them as though they are pets, with pellets, fruits, and veggies making up the bulk of their diet. As I get within perhaps 2 weeks of release I may wean them off such foods and limit their diet to foods they are going to encounter in the wild, such as crab apple, pinecones, corn, sunflowers, buds, and eggs (I'll keep feeding kale for the calcium). I just hope I can get them to recognize the eggs, corn, and pinecones as food, since they are so disinterested in them right now. Healthy or not, it makes up a high percentage of the wild squirrel's diet here, and I want to make sure they at least know that it's food before I release them. It's not so much an issue of replicating what squirrels eat in the wild, but which of those items they eat here. Many wild squirrels rely heavily on nut-bearing trees, for example, but not the ones here because those trees are absent. Aside from some people who have crab-apple trees, and even fewer who have apple trees, there isn't much in the way of fruit around here. I've never seen or heard of anyone having squirrels raid their garden, and see few vegetable gardens anyway, so the wild squirrels here don't really get veggies in their diet. With the absence of nut-bearing trees, and with seed-bearing trees not producing seeds until late summer, I'm thinking the diet of the local squirrels must be almost exclusively buds and bird food at this point in the year, perhaps bark as well. Despite the apparent lack of obvious squirrel food, there is an abundance of fox squirrels here, so they are eating something. You can't drive a block without seeing one or two. I will try and find other foods that they will be likely to encounter. If dandelions start blooming before their release, I will add those to the mix. Has anyone ever heard of them feeding on tree leaves or shrubbery? Fox squirrels prey heavily on bird nests and sometimes eat voles if they can catch them, or dead animals, so I may offer them a couple pinkie mice as a treat, since I don't have any baby birds. I will increase the amount of gut-loaded insects offered as well.

Not the best pictures. They were taken a couple days ago with my phone. I really hope this site resizes them automatically, because in the preview the pictures are HUGE. The male in the nest box is Gandalf, and the female on the perch is Suzie

[Annabelle's papa]

Good Afternoon furryscaly, you are absolutely right with the diet you're feeding Lil' Gandolph and Suzie, and the seeds will be a large part of what they eat once they are released, so it is important to keep them familiar with seeds.

Their future living environment and what they will have access too in the wild, certainly has to be taken into consideration. Mid North Central areas of the country do have an entirely different selection of foodstuffs for Squirrels to forage, cactus for example has a 23:1 cal/phos ratio, although I'm not sure if cacti are indigenous to your area nor am I sure if it contains high oxalic levels.

Please contribute to some of the ongoing calcium/vitamin D threads currently active, and your input on the hydration discussions would definitely be an asset I'm Sure.

[FergieBoo]

I think you are right on with the age, I would have guessed 3 weeks as well and think they look about 9-10 weeks old now. There is a HUGE difference between greys and fox squirrels as far as the speed at which they grow up. Fox squirrels are more laid back about everything and grow up a lot slower than greys. I've found greys tend to open their eyes closer to 5 weeks old whereas fox squirrels more like 6 weeks old. Once greys open their eyes, they're very quick to be up and about and start nibbling right away. Fox squirrels take their good old time with getting up and about and eating on their own. They usually figure it out by 10 weeks old, but are much slower than greys. Also, I have had to force wean all my fox squirrels or they'd likely take formula until the day they die. I drop them to 3 feedings a day when their eyes open and then no more than 2 feedings a day when they are over 200 grams. I try to wean around 300-350 grams.

I realized just how different they are when I took in greys for the first time at my apartment (I'm in vet school so my rehab setup is at home, but when I'm away at school, I take small babies in my apartment). I got them in March and they were pinkies (about 1 week old). I figured that by the end of April they'd be about 8-9 weeks old, and just getting ready to wean and move to a bigger cage like the fox squirrels (at home we have 80% fox squirrels whereas at my apartment it's almost 100% greys) would be. Ha ha, those little guys were crazy by the time the semester was over and were weaned and ready to move directly to the outside cage. Then last year I had fox squirrels over spring break at home and they were all calm cool and collected the whole way home after the semester and were still on formula. This year it's greys again and they're just opening their eyes, but it'll work out perfect because I start clinics so I have to give them back to the wildlife center and they should be big and weaned by May 4th when I start clinics.


Sorry that was long winded, but yes, greys and fox squirrels grow up at very different speeds. An interesting thing that I've found is that when you have both together, they almost take on characteristics of the other. If you have 7 fox squirrels and 1 grey (like I did last year), that'll be the most laid back grey squirrel you've ever seen. Still a little fiestier and more ready to go than the fox squirrels at a younger age, but compared to another grey, very laid back. If you have 1 fox squirrel with 5 greys- that fox squirrel will be very crazy. They never catch on to the being aggressive about the food part, but they will be up and about at a much younger age, eating regular food sooner, and pick up some of the weird things that greys do like the random jumping in the air when they're babies. It's interesting to watch them and to me it shows just how important it is to have baby squirrels raised with other squirrels because they really do learn from eachother.

I’m not sure if this is the place to post this or if I should go to the main page... you seem to have some experience with fox squirrels. It is definitely hard to find information about babies. I have a fox squirrel ( sub species, Bachman’s or Hill country) I believe he is 7 weeks. I got him at what I’m calling 4 weeks. His eyes were closed still. He was 98 grams then, now (as of this morning before feeding) he is 270 grams. He gets around 21ml of FV with yogurt. Growing very well no problems with Bowels or aspirations. He seems like he is starving all the tim. I started him with rodent cubes after eyes opened and Henry protein cubes last week. He is getting water from the water bottle in his cage. He seems very slow developing though . Falls over a lot and acts drunk... is is starting to try to climb a bit. he broke his right hind leg when he fell from his nest. The splint came off about 2 weeks ago. But he was still very sleepy and not venturing out of his bed much. He has gotten more active in the last few days So I’ve been giving him a bit of supervised exercise time to rehab and gain strength back. Is all the falling and incoordination normal, is he just a giant toddler or could he have some neurological things going on? I have a video and will try to post it...


Fergus at what I guess to be about 4 weeks. The vet had just splinted his leg.


7 weeks, peeing on the blankets during play time😂


Practicing climbing skills 7 weeks