previous feed of sunflower seeds, millet, thistle seed and cracked corn in bird feeders in her yard. Over three years, Dr. Birde observed that the new mixture increased the number of songbirds at her feeders, especially during the months of April and May.As she has done for several years, Dr.Birde recorded, at the same time each day,the number of birds at each of her four feeders. She noted that the third year using the mixture coincided with the largest increase. There was a twenty-five percent increase in the number of songbirds over times when this mixture was not used. Dr. Birde also noted that in the third year she used a specific ratio of the ingredients, carefully measuring which she had not done in previous years The third year also had a warmer than normal spring , and a construction project began in a neighborhood near Dr. Birde's. Dr. Birde is now going to produce this formula for sale and advertise to customers that they may see the same twenty -five percent increase in songbirds at their feeders. Dr. E. Birde, Journal of Scientific Bird Feeding Which might be a cause for the increase in songbirds at the feeders? the time of day that the birds were counted at the inedes C the addition of dried apples s and raisins to the formula the temperature changes each year the increased number of bird feeders

## Step 1<br />The problem presents a scenario where Dr. Birde has been feeding birds with a mixture of sunflower seeds, millet, thistle seed, and cracked corn in her bird feeders. She observed an increase in the number of songbirds at her feeders, especially during the months of April and May. She also noted that the third year using the mixture coincided with the largest increase. <br /><br />## Step 2<br />The problem asks us to identify the possible cause for the increase in songbirds at the feeders. The options provided are: the time of day that the birds were counted, the addition of dried apples and raisins to the formula, the temperature changes, and the increased number of bird feeders.<br /><br />## Step 3<br />We need to analyze each option in relation to the information provided in the problem. The time of day that the birds were counted is not mentioned as a factor affecting the number of birds. The addition of dried apples and raisins to the formula is not mentioned in the problem. The temperature changes each year is mentioned as a factor that could affect the number of birds. The increased number of bird feeders is not mentioned in the problem.<br /><br />## Step 4<br />Based on the information provided in the problem, the most likely cause for the increase in songbirds at the feeders is the temperature changes each year. This is because the problem mentions that the third year using the mixture coincided with the largest increase, and it also mentions that the third year had a warmer than normal spring. This suggests that the temperature changes each year could be a factor affecting the number of birds.