Recently for the first time I embarked on a bird watching tour. Part of the event listing contained the following:

Don’t forget to bring a pair of binoculars!

Now I can buy the first pair of binoculars I find in a supermarket. Though, I always enjoy over-analyzing purchasing decisions and this isn’t an exception.

What considerations do you need to make when buying binoculars?

Most pairs of binoculars report a NxM measurement.

• N here denotes the magnification factor
• M denotes the diameter of the lens in millimeters

This isn’t a case where you buy the highest value in each section and call it a day. There are trade-offs:

• Magnification Factor
  • Higher means you can see farther away.
  • Lower means you have a greater field of view.
• Diameter Length
  • Higher means that more light gets captured which makes the overall image brighter.
  • Lower means that the binocular weighs less which can be important for long hikes.

For a typical bird watching session, you normally don’t look at birds that are too far away. In this case, you want to prioritize a greater field of view which can make the viewing feel more stable. The commonly recommended magnification factor is 8.

Binocular weight is generally only a massive concern for people hiking long distances. If the bird watching session is a quick one, then you should prioritize having a brighter picture than a lighter binocular. The commonly recommended diameter length is 42mm.

Therefore, the commonly recommended specification for bird-watching binoculars is 8x42.

Once you’re undergoing the bird watching session, how do you know what bird you’re looking at? In the ideal case, you’re already an expert and can identify it once you see it. Second best case, you have a guide that can tell you what it is. For the majority of us, however, we will have neither. In this case, we can rely on technology.

Merlin is a mobile app that can help identify birds.

Developed by the Cornel lab of Orthnology, Merlin can provide a database of bird photos and sounds, as well as tools to help identify them.

If you remember before a session, you can download localized bird data. This way during the session you can look at photos and sounds of birds that are typically found nearby your location.

Not only do they provide a database, but the app also allows for identification by both visuals and sound. When you ask the app the identify a bird visually, it’ll ask for your location, size of bird, colors found on the bird, and its behavior.

Birds often have fairly distinct calls. Merlin can also help identify based on these sounds.

So how did my bird watching tour go? Our group spotted the following birds in New York:

• Turkey Vulture
• Cooper’s Hawk
• Red-Shouldered Hawk
• Red-tailed Hawk
• Red-eyed Vireo
• Blue Jay
• Tree Swallow
• Barn Swallow
• Gray Catbird
• Wood thrush
• Cedar Waxwing
• American Goldfinch
• Song sparrow
• Red-winged blackbird
• Common yellowthroat
• Yellow Warbler