To be successful, experienced coastal fishermen have developed many different techniques to help them find likely schools of fish more quickly. Along with weather patterns, moon phases, tidal heights and current flows, nature offers anglers a great clue to the presence of feeding fish – in the form of bird activity.

Sea birds have developed incredibly sensitive eyesight over millions of years, which allows them to see baitfish clearly below the water surface. Anglers can make good use of their superior eyesight and vantage point, but only if the location of feeding birds in flight can be detected.

Under good conditions, sea birds are hard to see at any significant range. People with good eyesight can typically see them out to about ¾ of a mile, and maybe a bit more if the birds are larger or in a flock. Beyond ¾ of mile, binoculars or other electronic aids are required for locating sea birds.

That’s where Raymarine radar comes in. Using the Bird Mode function, available in select radar scanners, captains can identify sea birds in-flight at greater distances – often several miles away -- and use that information to locate the hottest fishing activity.

After all, if the birds are feeding on the bait from above, it’s a natural extension to believe that game fish are doing the same from below. Birds move differently to other targets and therefore appear differently on your radar screen. Learning to recognize what birds look like on your radar will allow you to find prime fishing spots that are too far away for the human eye to see.

A new fishing technique

We spoke with Captain Terry Nugent, owner of Riptide Charters in Cape Cod, Massachusetts about his experiences finding birds with radar. Terry has perfected the “run and gun” fishing technique using his 12kW Magnum open-array radar scanner and his Axiom 2 XL chartplotter displays. “We’ve had great luck catching Bonito, False Albacore, and even Bluefin Tuna using the Raymarine radar to find the birds,” says Nugent. “Birds like gannets and terns are common in the coastal waters here, and easily identifiable on the radar.”

Terry switches the radar into bird mode, which automatically adapts the radar’s gain and sensitivity settings to make bird detection possible. “The flocks of birds are readily apparent on the radar. One of the key things I look for is the motion of the flock. When the cluster of bird targets is expanding, that tells me the birds are still on the hunt. When I see the flock contracting on the radar, I know they are on the fish and that’s the time to get moving in their direction.”

While the automatic bird mode settings are a great starting place, Terry has found some customized settings that work better for his needs. “On my Magnum radar I’ll normally run the Gain setting somewhere between 92 and 94 percent. You want to find that small line between when the radar is near its maximum sensitivity, but just below where it gets overwhelmed with noise” says Terry. “Birds are naturally poor targets, so the gain needs to be turned up to detect them. Unless it’s a rough day I’ll try to keep the sea clutter and rain clutter at Zero. The Magnum radars also have a setting called 'Power Boost’ which makes my 4-foot antenna behave like a larger radar antenna. I run the 'Power Boost' at 100%.”

Understanding Bird Behavior

So, what does Terry look for on the radar screen? Terry says it’s all about looking for single and clustered targets in the bluish green to blue part of the color palette. It’s also helpful to know what kinds of birds frequent the area you’re fishing and how they typically behave. “Gulls are loaners and fly as singles, well-spaced out until one of them gets on the fish. Then their buddies all swoop in on the action. Being larger, the gulls are easier to see as singles on the radar.” Other species of birds behave differently and it’s valuable to observe them whenever you have the chance. “Another common bird here, Terns, fly and hunt in tight packs. Their radar signature is a bit more obvious because of this. You’ll see a cluster of small returns that constantly changes shape from sweep to sweep.

Bird Detection Tips for Any Radar System

So, what kinds of radar systems are bird-capable? The answer is all of them. However, some birds have more favorable characteristics than others. With a bit of experimenting and observation, you can locate birds with just about any radar system. Here are a few tips if you’re considering what to buy:

• Open Array radars have an advantage over enclosed radome antennas because of their larger physical size. The length of the radar’s antenna section does 2 things. Like a lens, it focuses the outgoing microwave energy into a narrow beam. Longer antennas have better beam-shaping ability. The antenna is also the receiving surface for the very weak microwave pulses returning to the scanner. The larger surface area creates more antenna gain, making it more sensitive.
• High-powered antennas offer an advantage just because they put more energy on-target. Small, fuzzy and rounded birds have a natural “stealth” advantage that challenges any radar. By putting more power in-the-air, you have a better chance of receiving a signal back with small, weak targets. Plus, the higher-power output increases the maximum range to which birds can be detected.
• Some Raymarine scanners like Magnum, HD Color and Cyclone have adjustable rotation speeds. If you are looking for the changing shape of a bird flock, increasing the rotation speed of the scanner can help to make that more evident.

For a charter fishing captain, having many different tools at his disposal helps Terry greatly by giving him multiple strategies for finding fish and keeping his clients happy. “Sometimes you can sit on a very productive spot and then suddenly, it all stops. The fish are on the move. Being able to fire up the radar and spot the birds helps me to figure out where the school is headed. I can run out ahead of them and be ready with lines in the water when they arrive. That keeps the clients happy, smiling and coming back year after year.”