At first glance, this may seem like an odd question to ponder. A penny is a small coin made of metal that weighs just a few grams. A hummingbird is a tiny, delicate bird weighing only a few ounces. However, looks can be deceiving, and even objects that seem very different can have surprisingly similar weights.
The Weight of a Penny
In the United States, a penny has been minted from different metals over the years. Here is a quick overview of penny weights and compositions through history:
| Years | Metal Composition | Weight |
|---|---|---|
| 1793-1837 | 100% copper | 13 grams |
| 1837-1857 | 95% copper, 5% tin and zinc | 10.9 grams |
| 1857-1864 | 88% copper, 12% nickel | 10 grams |
| 1864-1942 | 95% copper, 5% tin and zinc | 3.11 grams |
| 1943 | Zinc-coated steel | 2.7 grams |
| 1944-1962 | 95% copper, 5% tin and zinc | 3.11 grams |
| 1962-1982 | 95% copper, 5% zinc | 3.11 grams |
| 1982-present | 97.5% zinc, 2.5% copper | 2.5 grams |
As the table shows, over time the penny’s composition has shifted from pure copper to mostly zinc with only a small copper plating. This change has resulted in a steady decrease in the penny’s weight over the last two centuries. Today, a modern U.S. penny weighs about 2.5 grams.
The Weight of a Hummingbird
Hummingbirds are the smallest birds found in nature, with most species weighing only a few grams. Here are the average weights for common North American hummingbird species:
| Species | Average Weight |
|---|---|
| Ruby-throated Hummingbird | 3-6 grams |
| Rufous Hummingbird | 3-4 grams |
| Allen’s Hummingbird | 2-5 grams |
| Anna’s Hummingbird | 4-6 grams |
| Black-chinned Hummingbird | 3-4 grams |
| Broad-tailed Hummingbird | 3-5 grams |
As you can see, most hummingbird species weigh in at 3-6 grams on average. The smallest is the Calliope Hummingbird at just 2-3 grams. The largest North American species is the Blue-throated Hummingbird which can reach 8 grams.
It’s important to note that a hummingbird’s weight can fluctuate dramatically throughout the day. Their super high metabolism requires them to consume more than their weight in nectar each day, so they are constantly burning calories. A hummingbird that weighs 4 grams in the morning when its belly is empty may weigh 6 grams by late afternoon after a day of active feeding.
Comparing the Weights
When we compare the weight of a modern U.S. penny at 2.5 grams versus the average weight of a hummingbird species at 3-6 grams, it appears that the hummingbird weighs slightly more than the penny.
However, with the hummingbird’s weight subject to fluctuations throughout the day, we cannot definitively say it is heavier than the penny. There are certainly points in time when a hummingbird could weigh less than 2.5 grams if its belly is empty after a long migratory flight, for example.
Why the Perception of Weight is Misleading
Although the numbers show that a hummingbird is likely to weigh marginally more than a penny, the difference is small enough that most people would perceive the penny as feeling much heavier if they were able to hold one in each hand.
There are a few reasons for this misleading perception of weight:
Size Difference
A penny has a diameter of about 19mm and thickness of 1.35mm. A hummingbird’s body is typically 3 to 4 inches long with a wingspan around 4 inches. The penny is far more compact in size, so it feels more dense and heavy to hold.
Metal vs. Feathers
The materials that make up each object also influence how heavy they feel. The penny is solid zinc and copper, two very dense metals. The hummingbird is composed mostly of feather bones which are lightweight and airy. The density of the metals gives the impression of greater mass.
Temperature
Temperature also affects perceived weight. The penny will feel cool and heavy in your hand. The hummingbird’s warm, soft body gives a sensation of lightness.
Movement
When holding the objects, the penny will stay stationary in your palm while the hummingbird’s movements and vibrations make it feel less substantial.
Our sensory impressions of size, texture, temperature, and motion override the true mass of these objects. So while the numbers indicate the weights are similar, our brains perceive the metal penny as heavier than the delicate hummingbird.
Conclusion
At first glance, a metal penny seems far heavier than a tiny, fragile hummingbird. But a direct comparison of weights reveals that an average adult hummingbird tips the scales at 3-6 grams, while a modern U.S. penny weighs in at 2.5 grams. The difference is small, but in most cases, the hummingbird will edge out the penny if placed on a scale.
However, the perception of weight has more to do with factors like size, density, temperature, and motion than actual mass. So the penny will likely feel much heavier in the hand due to its compact size and solid metal composition. While not exact opposites, the lightweight hummingbird and heavy penny provide an interesting demonstration of how reality does not always match our perceptions.
