Answer: Flood, drought and tsunami
Step-by-step explanation:
The short-term environmental changes are the temporary environmental changes, which can effect the abiotic factors and biotic factors of the environment for short time. The environment resumes to its original forms in a short duration after such changes. The living species adapt to their environment in short term change thus they continue to live and not die off. The drought, flood, pollution, blizzard, volcanic eruption and smog are the examples of short-term environmental changes.
The Ergrets are the birds which have long beaks so they can consume fishes in shallow water of wetlands and marshes. But the flood and tsunami are likely to elevate the water levels in the shallow wetlands and marshes. Thus, until the effect of effect of flood and tsunami remain they may find some difficulty in catching fish but the long beaks may help the birds to even catch fishes in deep waters. The drought is likely to dry up the shallow waters of marshes and wetland, but if an adequate amount of rainfall is received by these regions the water level resumes to be of its level for fish growth.