Discover the Dolphins of Monterey Bay: A Complete 6-part Guide to Dolphin watching with Ocean Safaris Common Dolphins part 1 of 6
The Monterey Bay National Marine Sanctuary along California’s central coast is one of the best places in the world to observe a variety of dolphin species. The nutrient-rich waters, influenced by the upwelling of cold currents from the deep ocean, support a thriving ecosystem that draws dolphins, whales and other marine life throughout the year.
This field guide will help you understand the different species of dolphins that frequent Monterey Bay, including their behaviors, identifying features, habitats, and seasons of peak activity. Whether you’re a researcher, a wildlife enthusiast, or someone just embarking on our whale-watching tour, this guide will enhance your experience and appreciation of these intelligent and graceful marine mammals. This is part 1 of a 6 part blog will feature one of the 6 dolphins, and porpoise that we may see during our Ocean Safaris on Monterey Bay tour. Common Dolphins, Northern Right Whale Dolphins, Risso’s Dolphin, Pacific White-sided dolphin, Bottle nose dolphin, Dall Porpoise and Harbor porpoise
- Common Dolphin (Delphinus delphis)
Identifying Features:
The common dolphin can be further categorized into two subspecies: the long-beaked common dolphin (Delphinus delphis capensis) and the short-beaked common dolphin (Delphinus delphis delphis). Both are frequently observed during Monterey Bay whale watching tours, but there are key differences between the two.
Long-Beaked Common Dolphin:
The long-beaked common dolphin has a slender, elongated beak that sets it apart from its short-beaked counterpart. Its body features a more subtle hourglass pattern on its sides, with shades of dark gray, lighter gray, and sometimes a tan or gold hue on the flanks. The dorsal fin is sharply pointed, and they grow to an average length of 6 to 8 feet (1.8 to 2.4 meters). Long-beaked common dolphins are generally more coastal, often found in shallower waters closer to shore. Their larger, extended beak helps them forage for fish and squid in these environments.
Short-Beaked Common Dolphin:
The short-beaked common dolphin has a noticeably shorter, more robust beak, and its color pattern is often more pronounced, with a bold contrast between the darker back and the light, cream-colored hourglass on its sides. They are slightly more compact than their long-beaked relatives, averaging around 5 to 7 feet (1.5 to 2.1 meters) in length. Short-beaked common dolphins tend to inhabit offshore waters, often traveling in larger, more active pods compared to the long-beaked variety. They are known for their impressive agility and high-energy displays, frequently breaching and porpoising in the open ocean.
Shared Features:
Both long-beaked and short-beaked common dolphins exhibit striking coloration, including a mix of dark gray, white, and yellow-tan hues along their bodies. Their streamlined shape and sharp dorsal fin, along with their acrobatic behaviors, make them easily identifiable during Monterey Bay Ocean Safaris. Both subspecies have similar behaviors in terms of bow-riding and interacting with boats, making them a joy to observe during any Monterey Bay dolphin-watching tour.
Behavior:
Common dolphins are highly social and can often be seen in large pods, sometimes numbering from dozens to into the hundreds or even thousands. They are incredibly acrobatic, frequently breaching, bow-riding, and porpoising, often engaging with boats. Their speed and playful nature make them a favorite among dolphin watchers.
Best Time for Sightings:
Both subspecies of the common dolphin can be seen year-round in Monterey Bay, though the short-beaked variety is more frequently spotted in offshore waters, while the long-beaked dolphins are often seen closer to shore. When booking a tour with Ocean Safaris, you’ll have an excellent chance of encountering one or both subspecies in the bay.
Habitat and Distribution:
Common dolphins are among the most widespread dolphin species in the world, inhabiting a wide range of marine environments. They are found in temperate and tropical waters across the globe, including the Atlantic, Pacific, and Indian Oceans. In Monterey Bay, both the long-beaked and short-beaked common dolphins are frequently spotted, although their preferred habitats differ slightly.
Long-Beaked Common Dolphin Habitat:
The long-beaked common dolphin (Delphinus delphis capensis) tends to prefer coastal waters, often staying in shallower areas close to shorelines and continental shelves. In Monterey Bay, they can be seen in waters ranging from shallow inshore regions to the outer continental shelf, where they forage for food. Long-beaked common dolphins are more common in regions with significant upwelling, like Monterey Bay, where nutrient-rich waters rise from the ocean depths, supporting abundant prey species.
Short-Beaked Common Dolphin Habitat:
The short-beaked common dolphin (Delphinus delphis delphis) favors deeper, offshore waters and is more frequently found further from the coastline, often in pelagic environments. In Monterey Bay, they can be spotted in the deeper, offshore regions, particularly around areas like the Monterey Submarine Canyon, where cold, nutrient-dense waters promote rich marine life. Short-beaked common dolphins are highly migratory and are known to move seasonally, following the movement of prey and changes in ocean temperature. They prefer open waters, where they form large, active pods.
Global Distribution:
Globally, common dolphins are widely distributed, occurring in both tropical and temperate oceans. Both subspecies thrive in areas where the ocean is influenced by upwelling currents, like Monterey Bay, which brings cold, nutrient-rich water to the surface, supporting the dense schools of fish that these dolphins depend on for survival.
Diet:
Common dolphins are opportunistic feeders, and their diet primarily consists of small schooling fish and squid. They are known to adjust their feeding behavior based on prey availability, which makes Monterey Bay an ideal habitat, given the abundance of food in these waters.
Primary Prey:
- Fish: The primary diet of common dolphins includes small schooling fish like sardines, anchovies, mackerel, and herring. Both long-beaked and short-beaked common dolphins hunt these fish in the nutrient-rich waters of Monterey Bay, where schools of prey can be found in large numbers, particularly during the summer months.
- Squid: Squid are another important food source for common dolphins, especially during the winter when schools of fish may be less abundant. Monterey Bay is known for its thriving squid population, particularly during the California market squid spawning season, which attracts large numbers of dolphins.
Hunting Behavior:
Common dolphins are skilled hunters and often use cooperative strategies to catch their prey. They typically hunt in large pods, working together to herd fish into tight balls, making them easier to catch. This behavior is often referred to as “bait balling.” They use their speed and agility to corral the fish, while their high intelligence allows them to communicate and coordinate during the hunt. This social hunting behavior is frequently observed during Monterey Bay dolphin watching tours with Ocean Safaris.
Common dolphins also engage in high-speed chases, leaping out of the water as they pursue their prey. Their diet is largely influenced by the abundance and movement of their preferred prey, so they often migrate or shift their hunting grounds based on food availability. Monterey Bay’s upwelling system, which draws cold, nutrient-rich waters to the surface, ensures a steady supply of food, making it one of the best habitats for common dolphins to thrive.
Feeding Times:
Common dolphins are primarily crepuscular feeders, meaning they are most active during dawn and dusk when their prey is closer to the surface. If you join an Ocean Safaris dolphin watching tour during these times, you’ll have an excellent chance of seeing these dolphins actively hunting and feeding in the waters of Monterey Bay.
In summary, common dolphins, whether long-beaked or short-beaked, thrive in the nutrient-rich waters of Monterey Bay, where the upwelling currents bring their favorite prey to the surface. They are highly social, intelligent hunters that use cooperative strategies to catch schools of fish and squid. Their adaptability in diet and habitat makes them one of the most common and exciting species to observe on an Ocean Safari dolphin tour in Monterey Bay.