Who new that one different shade could tell us so much about a birds evolutionary history....

References:

Ducatez, S., Giraudeau, M., Thebaud, C., & Jacquin, L. (2017). Colour polymorphism is associated with lower extinction risk in birds. Global Change Biology, 23(8), 3030-3039.

Ruzicka, F., Zwoinska, M. K., Goedert, D., Kokko, H., Li Richter, X. Y., Moodie, I. R., ... & Connallon, T. (2026). A century of theories of balancing selection. Biological Reviews, 101(2), 804-825.

Urban, L., Santure, A. W., Uddstrom, L., Digby, A., Vercoe, D., Eason, D., ... & Morales, H. E. (2024). The genetic basis of the kākāpō structural color polymorphism suggests balancing selection by an extinct apex predator. PLoS biology, 22(9), e3002755.

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Hear all about this one of a kind bird! I can't wait for you to see "hoatzin" store!

A big thank you to @theweenuthatch (instagram) for his insight and resources for this topic! Check him out for bird guiding services!

Follow me on instagram: @matt.rossella

Support the show: patreon.com/blurbs439

References:

Abourachid, A., Herrel, A., Decamps, T., Pages, F., Fabre, A. C., Van Hoorebeke, L., ... & Garcia Amado, M. A. (2019). Hoatzin nestling locomotion: acquisition of quadrupedal limb coordination in birds. Science advances, 5(5), eaat0787.

Buitrón-Jurado, G. (2014). An aberrant record of Hoatzin Opisthocomus hoazin (Statius Muller, 1976)(Aves: Opisthocomidae) in Venezuela. Check List, 10(1), 153-155.

Cracraft, J. (2022). The Hoatzin. Current Biology, 32(20), R1068-R1069.

Mayr, G. (2014). A hoatzin fossil from the middle Miocene of Kenya documents the past occurrence of modern-type Opisthocomiformes in Africa. The Auk: Ornithological Advances, 131(1), 55-60.

Mayr, G., Alvarenga, H., & Mourer-Chauviré, C. (2011). Out of Africa: Fossils shed light on the origin of the hoatzin, an iconic Neotropic bird. Naturwissenschaften, 98(11), 961.

Mayr, G., & De Pietri, V. L. (2014). Earliest and first Northern Hemispheric hoatzin fossils substantiate Old World origin of a “Neotropic endemic”. Naturwissenschaften, 101(2), 143-148.

Pagès, F. (2019). Compared and functional morphology of the hoatzin (Opisthocomus hoazin) (Doctoral dissertation, Museum national d'histoire naturelle-MNHN PARIS).

Other resources:

The Cornell Lab of Ornithology: Handbook of Bird Biology, 3rd edition.

The Science of Birds podcast episodes:

• Bird Bones: The Avian Skeleton
• The Avian Digestive System
• How Birds Fly

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The largest eagle ever known - hear all about this extinct apex predator!

Reach out to me on instagram: matt.rossella

Support the show (a.k.a become an endemic blurb!): patreon.com/blurbs439

References:

Brathwaite, D. H. (1992). Notes on the weight, flying ability, habitat, and prey of Haast’s Eagle (Harpagornis moorei). Notornis, 39(4), 239-247.

Bunce, M., Szulkin, M., Lerner, H. R. L., Barnes, I., Shapiro, B., Cooper, A., & Holdaway, R. N. (2005). Ancient DNA provides new insights into the evolutionary history of New Zealand's extinct giant eagle. PLoS biology, 3(1), e9.

Holdaway, R. N. (2021). Two new radiocarbon ages for Haast’s eagle (Hieraaetus moorei)(Aves: Accipitridae) and comments on the eagle’s past distribution and possible survival into the 19th century. Notornis, 68(4), 278.

Holdaway, R. N. (2025). The genus name for the extinct New Zealand Eagle (Accipitridae) and a suggested replacement for an inappropriate vernacular name. Bulletin of the British Ornithologists’ Club, 145(4), 406-410.

Knapp, M., Thomas, J. E., Haile, J., Prost, S., Ho, S. Y., Dussex, N., ... & Scofield, R. P. (2019). Mitogenomic evidence of close relationships between New Zealand’s extinct giant raptors and small-sized Australian sister-taxa. Molecular Phylogenetics and Evolution, 134, 122-128.

Scofield, R. P., & Ashwell, K. W. (2009). Rapid somatic expansion causes the brain to lag behind: the case of the brain and behavior of New Zealand's Haast's Eagle (Harpagornis moorei). Journal of Vertebrate Paleontology, 29(3), 637-649.

Van Heteren, A. H., Wroe, S., Tsang, L. R., Mitchell, D. R., Ross, P., Ledogar, J. A., ... & Sansalone, G. (2021). New Zealand's extinct giant raptor (Hieraaetus moorei) killed like an eagle, ate like a condor. Proceedings of the Royal Society B: Biological Sciences, 288(1964).

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