Bees starting to bring in pollen

I checked the beehives today and they were all still doing well.  I took some pictures to record their status.
This is the bottom entrance of the North hive where bees were coming and going quickly.

I opened it up to check the sugar stores and see that they are getting close to consuming it all.  This box was full of 16 pounds of sugar in November when I put it on.  This hive has eaten more than the other two.

I added some pollen patties to help them build up brood as the Spring progresses.  The pollen patties give them protein to help raise new bees.

The top entrance of the middle hive (on the right) was quite active as well.

They haven't consumed nearly as much as the first hive but have eaten through the sugar in one spot and much of the rest of the sugar block is largely gone underneath.  I pushed in a few thin places t open it up more.

I added a small pollen patty to this hive too.  I went smaller because there aren't quite as many bees here and this hive has shown some signs of having hive beetles, who are strongly attracted to these patties. So, I didn't want to put any more in than the bees could consume fairly quickly.

The bottom entrance of the south hive was pretty busy as well.

The top entrance of that hive was also very active.

This hive was between the other two in consumption of sugar.  The had eaten through most of the sugar block but still had quite a bit left.and showed a lot of bees on the top bar.

I put some pollen patties in this hive as well to help with the buildup.

I noticed though that some bees were bringing in natural pollen as well.  Here one of the bees returning to the hive through the open top has large yellow balls of pollen in her pollen sacs on her hind legs.  By the color, I would say that this is maple pollen.

I watched the bottom entrance of the north hive as well and saw several bees returning with the same kind of pollen.  here two bees returning have pollen on their legs.