Assessing Feeding Ecology and Regional Dietary Differences of Humpback Whales (Megaptera novaeangliae) in the New York Bight

Northern hemisphere humpback whales ( Megaptera novaeangliae ) typically consume the most abundant prey species in their feeding area. Therefore, dietary shifts can reflect environmental conditions driving prey populations. In the New York Bight (NYB), increased humpback whale presence has prompted investigations into their habitat use and foraging behaviour. We analysed humpback whale feeding ecology and diet from stable isotope values of skin samples collected in the NYB from May to November of 2017–2023. Stable isotope values of nitrogen (δ 15 N) and carbon (δ 13 C), reflecting recent prey consumption and habitat, were compared by location, month, year and sex. Standard ellipse areas and generalized additive models characterized the relationship between isotopic signatures and distance from shore. Humpback whales in the nearshore ( n = 68) and mid‐shelf regions ( n = 30) had wider isotopic niches, potentially indicating more variable diets than individuals in the offshore region ( n = 5, collected in 2023). Little overlap between these niches suggests regionally distinct diets within the NYB. Both δ 15 N and δ 13 C declined with distance from shore, which is potentially a reflection of diet preferences and regional ecological differences within the NYB. Variability in δ 15 N and δ 13 C values between the nearshore and mid‐shelf regions of the NYB reflects the ecological complexity of the area and is suggestive of potential dietary preferences of humpback whales within the NYB. Knowledge of humpback whale dietary and behavioural differences can help inform NYB ecosystem dynamics and assist with environmental monitoring and conservation.