Question

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метр Researchers in the Netherlands studied the effects of parental care in European Kestrels. The researchers transferred chicks among nests to produce reduced broods (three or four chicks), normal broods (five or six chicks), and enlarged broods (seven or eight chicks). They then measured the percentage of male (bar on left) and female (bar on right) parent birds in each treatment that survived through the following winter. Both males and females provide care for chicks. Which of the following is a conclusion that can be drawn from this graph? 100 Male -Female 80 60 Parents surviving the following winter (%) 40 20 0 Reduced Normal Enlarged brood size brood size brood size Both males and females had to increase daily hunting with the enlarged brood size. Female survival is more affected by larger brood size than male survival. There appears to be a positive relationship between brood enlargements and parental survival. Chicks in reduced brood treatment received more food, weight gain, and had reduced mortality, Male survival decreased by about 60% between reduced and enlarged brood treatments

Answer 1

Answer: 4 and 5

From this graph ,we can understand the following,

1) we cant conclude that hunting increased eith brood size with this graph. But in winter the increased hunting is not possible. So the decrease in survival rate of both male and female woth increased brood size may be due to starvation. The food obtained must be just enough for the chicks and both parents may not get much food for survival.

2) Actually male survival is more affected by larger brood size than female survival. Male survival rate decreased by 60% from reduced brood size to enlarged brood size.

3) There appears to be a negative relationship between brood enlargement and parental survival. Because the survival rate of male decreased by 60% and female by 50%.

4) Chicks in reduced brood treatment received more food, weight gain and had reduced mortality as the parents have more survival rate and they both care their chicks.

5) Male survival decreased by about 60% between reduced and enlarged brood treatment. As the brood size increased, male is more affected and survival rate is much reduced.