With reference to the above passage, the following assumptions have been made :
1. Global warming is causing spring to come early and for longer durations.
2. Early spring and longer period of spring is not good for bird populations.

Which of the above assumptions is/are correct ?

Correct Option: Both 1 and 2

Let us evaluate the assumptions based on Passage 1: Assumption 1: 'Global warming is causing spring to come early and for longer durations.' The passage states that 'warmer winters with less snow resulted in a longer lag time between spring events and a more protracted vernal window... As the ice melts earlier, the birds don't return, causing a delay...' This directly supports the idea that climate conditions (warmer winters/global warming indicators) are causing shifts toward earlier and longer spring transitions (vernal window). Hence, Assumption 1 is valid. Assumption 2: 'Early spring and longer period of spring is not good for bird populations.' The passage notes that 'As the ice melts earlier, the birds don't return, causing a delay, or lengthening in springtime ecological events' and links this disruption to ecological, social, and economic consequences. This indicates a negative impact on bird populations and natural timing. Hence, Assumption 2 is valid. Therefore, both assumptions are correct. Option (c) is correct.