Course Info / question of the week

Question Guidelines

A correct answer submitted to Shilo Felton before the answer is posted earns 1 extra credit point. A new question will be posted every Monday morning. Submit a question that is chosen as the question of the week and earn 2 extra credit points. Submit a question that is posted and remains unanswered for 1 week and receive 5 extra credit points.

Note: If you submit an incorrect or incomplete answer, you will not be able to submit another answer for credit. You are welcome to continue to figure it out and talk to us, but no extra credit will be provided.

Week 5

To which avian family do the eggs in the picture belong?

Week 4

Alright, I have a tough one for you! Give the common and scientific names of the two species pictured below. Hint: they’re not going to be on your bird list.

Left: Alpine Thrush (Zoothera mollissima sensu stricto).

Right: Himalayan Forest Thrush (Zoothera salimalii, sp. nov.).

Alstrom et al. 2016

BBC News

Thank you, Ana, Lucas, and Khai for providing complete, correct responses. I love how engaged a lot of you were in trying to find the correct answer!

Week 3

There are 3 parts to this question: 1) What is the name of the avian species in this photo and 2) what is the “just so story” often used to describe the relationship between the species captured in this photo? 3) Scientific evidence provides a very different story—what is it?

Thank you to Khai, Frankie, Franco, Colleen, Jens, Mary, Lanette, and Kristen for your correct responses this week. The bird pictured is the Yellow-billed Oxpecker (Buphagus africanus). The typical "just-so-story" is that oxpeckers have a mutualistic relationship with their ungulate hosts (like the African buffalo pictured) by reducing the numbers of insect parasites and removing infected tissue for clean wound healing. In addition to food the oxpecker gets protection through the proximity to the larger mammals. Scientific evidence for the above claims is disputed. It could be that oxpeckers are ectoparasites that use the ungulates as a food source, often opening wounds or keeping old wounds open in order to maintain a supply of blood and tissue to eat. Even the removal of ticks (which is not significant; see Weeks P. 2000. Red-billed Oxpeckers: vampires or tickbirds? Behavioral Ecology 11(2): 154-160) is not very helpful to the host as oxpeckers prefer ticks that filled their stomachs with blood. However, other studies claim that the oxpeckers prefer hosts with higher counts of ticks and ignore the hide thickness (which would be important for foraging ungulate tissue), making them mutualistic symbionts after all (Nunn CL, Ezenwa VO, Arnold C, Koenig WD. 2011. MUTUALISM OR PARASITISM? USING A PHYLOGENETIC APPROACH TO CHARACTERIZE THE OXPECKER-UNGULATE RELATIONSHIP. Evolution 65(5): 1297–1304). Thank you to Jens for providing this well-written response!

Note: I was lenient this week and gave full credit this week even if you just gave me "oxpecker" as the species name for the bird in the picture, because the species pictured was different from that in the Weeks P. 2000 article. In the future I will not be so generous, so remember: FULL species name please.

Week 2

Provide the name missing in this image to the once diverse group of extinct birds. Also name the anatomical characteristic that distinguishes this group of birds from others. Thanks to Jens for providing the question!

Thank you to Khai and Megan for submitting correct answers! The group in question is Enantiornithes which has a shoulder bone (coracoid and scapula) articulation opposite that of other bird groups. Additionally, the fusion of the tarsometatarsus has been shown to be opposite that of living birds, fusing proximally to distally instead of the reverse. This highly diverse clade was perhaps more ecologically disparate than the lineage the would give rise to modern birds, but to the best of our knowledge, none survived the Cretaceous-Paleogene Mass Extinction that also killed off all non-avian dinosaurs as well as many other species (thank you, Khai, for this additional description).

Week 1

This large scavenger was once extirpated from its native habitat, due in large part to _________. While this and other human factors continue to effect the population, a collaborative reintroduction program now sees individuals of this species nesting in cliffs in parts of the southwestern United States and Mexico.

Please name the species, as well as the factor most closely associated with its population decline.

Thank you to April, Khai, Franco, Megan, Jens, Madi, Mary 0., and Lanette for submitting correct answers! The species is the California Condor (Gymnogyps californianus) and the factor I was looking for that partially lead to its extirpation (and still continues to be a threat to reintroduced populations) is lead poisoning, though there are many other factors that have contributed to the species' instability. The state of California has recently enacted legislation to limit the use of lead ammunition
in an effort to reduce the amount of lead ingested by wild condors.