Adult male Williamson's Sapsucker bringing ants to nestlings in nest cavity, Nevada County California USA

---

Adult Williamson's Sapsucker bringing ants to nest cavity to feed nestlings. Among North American woodpeckers the sexual dimorphism is the most extreme in this species, so much so that for about 20 years in the 1800s the male and female were thought to be separate species. In 1852 John Cassin described females as the Black-breasted Woodpecker (Picus thyroideus) while in 1855 John Newberry described the male as Picus williamsonii. Spencer Baird later reclassified both "species" in the genus Sphyrapicus, along with the other sapsuckers. It wasn't until 1873 that Henry Henshaw observed that the two "species" were actually female and male of the same species.

---

Size: 6000px × 4800px
Location: Donner Camp, Nevada County California USA
Photo credit: © Douglas Herr / Alamy / Afripics
License: Royalty Free
Model Released: No

Keywords: america, animals, birds, california, cavity, county, dimorphism, feeding, male, nest, nestlings, nevada, perched, picidae, piciformes, sapsuckers, sierra, sphthy, sphyrapicus, states, thyroideus, united, usa, wildlife, wisa, woodpeckers