Nelson's Sparrow Ammospiza nelsoni

  • Order: Passeriformes
  • Family: Passerellidae
  • Polytypic: 3 subspecies
  • Authors needed...
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The taxonomy of this sparrow has shifted over the years, and so has its name. The Nelson’s and Saltmarsh sparrows were at one time classified together as the Sharp-tailed Sparrow. They were divided based largely on sympatry in coastal North Atlantic marsh sites; and where then given the name Nelson’s Sharp-tailed, and Saltmarsh Sharp-tailed sparrows. This mouthful of names just was shortened recently to Nelson’s and Salmarsh sparrows, losing the “sharp-tailed” moniker altogether. These sparrows do have pointed tail feathers, so in a way the tails are sharp. More obvious on the Nelson’s is the warm pumpkin-orange face pattern with a dark post-ocular line and a grey face and dark crown. The breast and flanks are also tawny-orange and lightly streaked, while the warm colored back shows nice white lines (suspenders). Perhaps the most unusual aspect of this sparrow’s lifestyle is that it is non-territorial, and no pair bonds are formed. During the breeding season the males are singing away, full-force, but they are singing just to attract mates, not to defend a territory. When a female is attracted she will mate with a male, but forms no pair bond and she may turn around and mate with various males to fertilize the eggs – the system is truly promiscuous; a relative rarity in the bird world. Due to the fact that so many males are “battling” to fertilize the eggs of a female, they have developed very large testes and produce copious amounts of sperm to compete (maybe outnumber) with the sperm of other males within the female!

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© Charles Duncan

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  • Year-round
  • Migration
  • Breeding
  • Non-Breeding

Recommended Citation

Nelson's Sparrow (Ammospiza nelsoni), In Neotropical Birds Online (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. retrieved from Neotropical Birds Online: https://neotropical.birds.cornell.edu/Species-Account/nb/species/nstspa