Medium Ground Finch Skull


One of the most common and conspicuous of the Galápagos finches. The Medium Ground Finch bill is at least as long as the bill is deep, with the upper edge slightly rounded. Lower edge of the bill is mostly straight.


Medium Ground Finch Skull Replica is museum quality polyurethane cast. Medium Ground Finch Skull is made in the USA. 2-part skull (separate cranium and jaw). Our precise skull can be used as a birdwatching teaching tool, museum bird skull exhibit, home décor bird skull, or office décor skull.

Geospiza fortis is a species of bird in the Thraupidae family. It is endemic to the Galapagos Islands. Its natural habitats are subtropical or tropical dry forests and subtropical or tropical dry shrub land.

One of Darwin’s finches, the species was the first which scientists have observed evolving in real-time. The female’s plumage is brown and streaky, while male’s is solid black, with white tips to the under tail coverts.

The bird measures 4.9 inches in length. The bill of this species is quite variable in size, though the length of the upper mandible is always greater than the depth of the bill at its base.

In 1977, a severe drought reduced the supply of seeds in the Galápagos. The finch, which normally preferred small and soft seeds, was forced to turn to harder, larger seeds.

This strong selective pressure favoring larger beaks, coupled with the high heritability of traits relating to beak size in finches, caused the medium ground finch population to experience evolution by natural selection, leading to an increase in average beak size in the subsequent generation.

Evidence of evolution through character displacement has been found in a population of medium ground finches on the Galápagos island of Daphne Major.

During a drought in 2004, overlap in the diets of the medium ground finch population and a recently settled population of large ground finches (Geospiza magnirostris) led to competition for a limited supply of seeds on which the medium ground finch population normally fed.

Because the large ground finches were able to out-compete the medium ground finches for these seeds due to both a larger beak and body size, the medium ground finch population experienced a strong selective pressure against large beaks to avoid competition, ultimately leading to dramatic evolutionary change favoring smaller beaks in the subsequent generation.

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Additional information

Weight 2 lbs
Medium Ground Finch Facts:

Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Family: Thraupidae
Genus: Geospiza
Species: G. fortis
Binomial name: Geospiza fortis
Conservation status: Least concern – A least concern species is a species that has been categorized by the International Union for Conservation of Nature as evaluated as not being a focus of species conservation.