What do water rats eat in the summer? - briefly
During the warm months, water rats mainly feed on aquatic insects, small crustaceans such as shrimp and crayfish, and plant material including algae and tender aquatic vegetation.
What do water rats eat in the summer? - in detail
Water rats shift their diet in warm months toward prey that are most abundant in aquatic and riparian habitats. Primary protein sources include:
- Aquatic insects such as mayfly and caddisfly larvae, which reach peak emergence in summer.
- Crustaceans, especially freshwater shrimp and small crayfish, taken from shallow streams and ponds.
- Juvenile fish, primarily small cyprinids and gobies, captured during daylight foraging trips.
- Amphibian larvae and newly metamorphosed frogs, exploited when breeding ponds are full.
Plant matter also forms a significant portion of the intake. Consumable vegetation consists of:
- Tender shoots of emergent macrophytes, notably water celery and reed stems.
- Algal mats on submerged surfaces, providing both nutrients and a foraging substrate.
- Seeds of riparian grasses and sedges that fall into the water during the reproductive season.
Foraging behavior adapts to the increased temperature and daylight. Water rats become more diurnal, swimming longer distances and diving to depths of up to 30 cm to extract hidden prey. Bite rates rise to approximately 150 g of wet weight per night, reflecting the higher metabolic demand of the season.
Digestive efficiency improves with the soft-bodied nature of summer insects, allowing rapid assimilation of protein. Concurrently, the intake of plant material supplies carbohydrates and fiber, supporting gut health during periods of high activity.
Overall, the summer diet of water rats is characterized by a balanced mix of animal protein from abundant invertebrates and fish, supplemented by readily available aquatic vegetation and seeds, ensuring adequate energy and nutrient supply for growth and reproduction.