How Birds Identify Tomatoes That Are Ripening


Have you ever wondered how birds spot tomatoes that are just starting to ripen? Birds can easily spot the change in color from green to yellow to slight pink to orange to red. How do birds know when tomatoes are starting to ripen?

Birds have photoreceptor cells that enable them to see up to five non-spectral colors: ultraviolet & red, ultraviolet & green, ultraviolet & yellow, purple and ultraviolet & purple. Birds can see ultraviolet yellow & red reflecting from orange, yellow, or slight pink colors of ripening tomatoes.

“Did you know that many birds can see in ultraviolet light? The capability of UV vision was first documented in pigeons in the early 1970’s. The National Wildlife Federation states, “With the exception of night-flying birds such as owls, the eyes of most birds probably are even more sensitive to ultraviolet light than they are to what we call visible light.”

Buffalo Bill Center of the West
https://centerofthewest.org/2018/12/27/ultraviolet-vision-avian-bird-world/

Tomatoes have a waxy coating on their skin that reflects UV light and UV colors like green, yellow, orange, slight pink and red. This reflection of UV light and colors is very important to birds as they search for food. Birds can see the UV reflection from a tomato skin as the tomato ripens. As the color of the tomato turns from green to yellow to orange to slight pink to red, these colors are reflected in UV light frequency as the tomato ripens helping birds to easily identify the ripening tomato much sooner than we do.

“Parent birds may rely on UV signals when they’re off finding food…. Many seeds also are [UV] reflective, and berries and fruits develop a highly [UV] reflective waxy coating as they ripen.”

The National Wildlife Federation: True Colors: How Birds See the World
https://www.nwf.org/Magazines/National-Wildlife/2012/AugSept/Animals/Bird-Vision

Birds can easily spot ripening tomatoes. Birds vision is tetrachromatic, a fourth cone type enabling them to see ultraviolet range with retinal oil droplets that help screen out extraneous wavelengths. Birds can see the ultraviolet colors of a ripening tomato and are attracted to the ultraviolet yellow, orange, slight pink and red light reflecting from the waxy skin of a ripening tomato.

The UV reflection of the tomatoes increases as the tomato ripens. The color green changes to yellow, then orange, then pink and finally red. Because the UV reflection increases, these colors become a lot brighter to a bird than the green leaves and green tomatoes.

Just imagine the glow of yellow, orange, pink and red colors of ripening tomatoes among the green leaves and green plants of your small garden. A hungry and thirsty bird would know exactly where to go. The UV brightness allows the colors a ripening tomato to really stand out in your garden making it easy for birds to peck your tomatoes long before harvest time.

Contact calls are another way birds find your tomatoes.

Birds communicate with each other with songs and calls.

Oftentimes birds will call other birds informing others where they find food. These are contact calls. “These sounds are usually short, quick, and quiet…”

Because of contact calls, more birds will know about your tomatoes and more of your harvest will be ruined before you even have a chance of harvesting your tomato crop. So frustrating.

5 Reasons Why Birds Peck Tomatoes

  1. Birds eat 2 times their weight every day. Birds eat 5-6 times every day. So birds are hungry and need to eat a lot of food. Tomatoes are juicy and sweet and a favorite of many domestic birds.
  2. Birds drink up to 5 percent of their weight every day. So birds are thirsty. Tomatoes are juicy and sweet. Birds will peck a tomato for a quick drink to satisfy their thirst.
  3. Tomatoes are abundant. Typically several tomato plants are grown together in rows or in a section in a small garden. At harvest time, each tomato plant can have up to 20 or more tomatoes at a time for the bird’s choosing. So there are lots of yummy tomatoes for hungry and thirst birds to choose from.
  4. Almost no predators to scare birds away. Birds have easy access to tomatoes with no predators. So a bird has little fear when searching for and eating a tomato. Oftentimes a bird will sit on a tomato cage pecking one tomato after another. Birds really love tomatoes.
  5. There are little to no barriers preventing birds from pecking sweet and juicy tomatoes. No barriers means easy access for the birds to eat your tomatoes.

How Do Birds Get To Tomatoes?

There are many small wild birds that weigh less than an ounce. Birds like Goldfinches, Chickadees, Carolina wren, Downy Woodpecker, Bluebirds, House Finches, House Sparrows, Buntings, Hummingbird, Tufted Titmouse and Nuthatches all weigh less than one ounce. Small birds could easily sit on a thick, strong tomato branch and peck away on many of your ripening tomatoes.

Small birds like Carolina Wrens, Sparrows, and others prefer the ground to forage for food. After landing on the ground, these small birds can then hop deeper into the tomato garden, feeling quite safe, and jump up to a branch or a thick side stem strong enough to safely hold small birds, allowing birds easy access to peck your juicy sweet ripening tomatoes.

Hummingbirds often peck tomatoes without anyone noticing them doing so. Hummingbirds peck nectar from flowers while flying and can easily peck your ripening tomatoes while hovering close to the tomato. Hummingbirds are small enough to fly in between tomato plants to gain access into the inner sanctum of the tomato section of your small garden.

All this can be happening without your knowledge.

Conclusion: When Do Birds Start Pecking Tomatoes?

By the time your tomato plants start bearing fruit, you will have already put in much time, effort and money. It can be incredibly frustrating when birds start pecking your tomatoes just before you begin to harvest.

As a general rule, birds start pecking tomatoes when the color begins to change. Birds’ eyes are sensitive to the ultraviolet colors of orange, yellow, red and slightly pink that are reflected from the skin of a ripening tomato. Birds may also eat green tomatoes when very hungry or thirsty.

So let’s find out how to keep hungry and thirsty birds out of your small garden. To keep these birds from harvesting your tomatoes before you do, check out the following articles.

Read more: How Birds Identify Tomatoes That Are Ripening

How To Stop Birds From Pecking My Tomatoes

Should I Put Netting Over Tomato Plants

Can You Eat A Tomato That A Bird Has Pecked?

What Animals Eat Tomatoes At Night?

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