Animal Groups and Number of Species
Here are 10 major animal groups with an approximate number of known species in each:
- Mammals – ~6,500 species
- Birds – ~11,000 species
- Reptiles – ~11,500 species
- Amphibians – ~8,000 species
- Fish – ~34,000 species
- Insects – ~1,000,000+ species
- Arachnids (spiders, scorpions, etc.) – ~100,000 species
- Mollusks (snails, clams, squids) – ~85,000 species
Red-Breasted Nuthatch: Identification, Call and Range
July 25, 2026
The Red-breasted Nuthatch (Sitta canadensis) is a small, energetic songbird recognized by its blue-gray back, rusty-orange underparts, black eye stripe, and white eyebrow. It is
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Female Downy Woodpecker: Identification and Male Comparison
July 25, 2026
The female Downy Woodpecker is a small black-and-white bird commonly seen in woodlands, parks, orchards, and suburban yards across North America. She closely resembles the
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What Do Downy Woodpeckers Eat? 15 Favorite Foods
July 23, 2026
Downy Woodpeckers eat insects, larvae, seeds, nuts, berries, tree sap, and other energy-rich foods. Their diet changes throughout the year depending on what is available.
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Downy Woodpecker Nesting: Nest, Eggs, Season and Habits
July 23, 2026
Downy Woodpecker nesting begins with the excavation of a small cavity in a dead tree, decaying branch, or other piece of soft wood. These tiny
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Hairy Woodpecker vs Downy Woodpecker: Key Differences
July 22, 2026
The Hairy Woodpecker and Downy Woodpecker are among the most easily confused birds in North America. Both have black-and-white plumage, white backs, spotted wings, and
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Downy Woodpecker: Identification, Diet, Call and Nesting
July 22, 2026
The Downy Woodpecker is a small, energetic bird commonly seen in forests, parks, orchards, and residential backyards across North America. Its bold black-and-white feathers, short
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Black-and-White Warbler: Call, Habitat, Diet and Facts
July 21, 2026
The Black-and-white Warbler is a small migratory songbird known for its bold striped plumage and unusual tree-climbing behavior. Rather than hopping through leaves like most
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Blackpoll Warbler: Migration, Call, Habitat and Facts
July 21, 2026
The Blackpoll Warbler is a small North American songbird famous for completing one of the most demanding migrations recorded among birds of its size. Breeding
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White-Throated Sparrow: Identification, Song, Diet & Facts
July 20, 2026
The White-throated Sparrow is a plump North American songbird recognized by its bright white throat, yellow eyebrow patches, striped crown, and musical whistling song. Although
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White-Crowned Sparrow: Identification, Song, Diet & Range
July 20, 2026
The White-crowned Sparrow is a handsome North American songbird recognized by its bold black-and-white head stripes, pale bill, gray breast, and long tail. Often seen
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