Well done to Jordan and Kane from Aspendale Gardens Primary School, Victoria in Australia who sent in this excellent solution!
The table on the left is about the average per garden, while the one on the right is about the percent of gardens with the bird.
The Carrion Crow is amazingly ranked $18$th on each table.
About half of the gardens have Starlings.
The Starling is ranked $2$nd in the left table but ranked $10$th in the percentage table.
The Robin has an average of just under $1.5$ and is ranked $9$th.
The Robin is ranked pretty high in the right table.
We also had a solution from Erin from St Johns The Baptist School, who said:
Based on the table on the right the robin was more common than the starling across the gardens. There were $86.60$% of gardens with robins but only just over half with starlings.
However the other table shows that more starlings were seen in each garden than robins.
This means that starlings aren't as common as robins but there are more of them seen in gardens on average.
The pupils from classes $4$V and $4$J at Croydon High School suggested that starlings come in groups while robins tend to appear separately, because there are more starlings per average garden than robins.
Well done to everyone who investigated this problem!