The chart illustrates the quantity of birds in Wollai Park from 1990 to 2010.
Overall, there were fluctuated in the data of all types of birds,most of the number of bidrs species generally declined slightly at a certain level.However, in the end crows and parrots plateaued at the same amount,the figure of kookaburras and whip birds dwindled significantly.
As for the kookaburras ,crows,and parrots with it began generally high data.There was a slight growth in the number of parrots from 0.75 thousand to 0,9 thousand in 1995, and subsequently a gradual decline at 0,8 thousand in 2000 and decreased maginally to 0.75 thousand in 2010.Similarity figure between crows and kookaburras , it began at the highest point with 0.9 thousand in 1990.The following years, crows witnessed a dramatic downhill, ending at approximately 0.6 thousand in 2010.The kookaburras plummeted significantly by two-thirds to only around 0.3 thousand in the final year.
On the other hand, the whip birds fluctuated erratically between 0.5 thousand and 0.45 thousand from 1990 and 2005 ,and then plumged to 0.25 thousand in 2010.In addition,the figure of swallows started at the lowest point with 0.25 thousand in 1990,and then dropped sharply to just above 0.1 thousand 15 years later.In the final year, there was a remarkable growth in swallows from 0.1 thousand to 0.2 thousand .The data of swallows have bounce back but not significantly