I have read claims that bees can communicate not only that there is forage. but the direction. distance. color, quantity and even provide a sample of the food to the colony. As a result only a certain number of bees will respond to the recruitment.
I know for a fact that my bees do not forage from just one source even though they will return to the same source day ofter day. I don't believe that the colony is ever recruited in a majority to any forage. Even prevalent forage in my are such as sagebrush in the fall. Observations indicate that recruitment is less than 10% of the foraging force. and this is a huge pollen source in the fall. This is from a watch them land and see if they have pollen on their legs observation.
Overall it has never appeared to me that honey bees have a real strong recruitment to anything. I have sen bees foraging on blue flowers for example that will readily explore both white and red flowers at the same time. I have myself observed that if you place a piece of food on the trail of ants. they will actually walk around it and completely ignore it for a significant period of time in order to continue on their way to the recruited food source. I have not seen this to be anywhere near true in bees. Just my impression from observations. Btu it seems that a bees is always on teh look out for another source. even if they are currently working one that will provide ample resources for days or even weeks.
I do have one source of nectar that I can observe daily. this bush tends to produce nectar all spring and summer. The bees that forage on it's small white flowers do tend to be focused strongly on that flower , color , size or whatever. This introduces that possibly not only the size of a forage source. but even it's length of time it is available may influence just how "Recruited" to exclusion even bees may get. My first thought on this is. It could be true that a food source that lasts say 3 months. could in fact be the only source a particular bees forages on in it's entire life. it never even knows there are other flowers out there. This could be one explanation of a variability in how completely recruited a particular bee may get. it is a matter of learning and experience. why even know to find other food sources. when you have one that is more than you can gather in a life time? While the next bee may forage on a flower that only produces nectar in the morning and when that shuts of it is then forced to learn to look for more. This bee once it learns to look for forage. will never be able to get lazer focused on just one source. it will bee a bee that no matter how large a food source is. It will be observed to check out that other type of flower as well.
Location of forage relative to each other I have also observed makes a difference. if you have a patch of blue, a patch of red and a patch of white flowers. but they are all separated. bees will tend toward only one color. but if you have all three flowers mixed together. bees are more likely to forage on all three colors at once.
Nearly all the above is a result of my own observations of bees. both feral and my own.