Brood Parasitism Is Linked to Egg Pattern Diversity

Brood Parasitism Is Linked to Egg Pattern Diversity within and among Species of Australian Passerines Iliana Medina, Jolyon Troscianko, Martin Stevens, and Naomi E. Langmore. 2015. The American Naturalist. Image Source (1) Melanie Maldonado BIO-2000 December 2, 2016 Image Source (6) Image Source (1)

Study’s Objectives • Test if host species eggs, on average, evolve more differences in egg phenotype than non-host species • Major questions asked: • Can brood parasitism be associated with egg diversity among species? • Previous studies suggest variation in egg patterns and colors are a response to brood parasitism • Does nest shape affect brood parasitism? • Do different visual systems increase rejection of foreign eggs? 2 December 2, 2016 BIO-2000

Image Source (8) 3 December 2, 2016 BIO-2000

Background Information • Brood Parasitism • Clutches • Reflectance Spectrometry • Digital Pattern Analyses • Phylogenetic information • Nest Shape (Open Cup and Dome) Image Source (3) 4 December 2, 2016 BIO-2000 Image Source (7)

Background Information: Australian Passerines • Known as song birds • Order: Passeriformes • More than half of all bird species • > 5, 000 identified species • Smaller than other birds in different Orders • Typically lay colored eggs • The cuckoo is the most common threat • Brood parasite Image Source (9) 5 December 2, 2016 BIO-2000

Methods • Took 517 pictures and spectral data for 517 eggs • 200 clutches • 40 Australian passerine species (22 host species and 18 non-host species) • Measured 3 eggs per clutch (depending on typical clutch size) • Measured 5 clutches for species • Pairwise Comparisons • Pattern differences inbetween species • Color differences inbetween eggs and the visual systems birds use 6 December 2, 2016 BIO-2000

Major Findings • Host species are more likely to have a distinct egg pattern differences than non-host species (new hypothesis is accepted) • Egg pattern does evolve differently in hosts and non-hosts • Brood parasites = selective pressure • Nest shape does not matter • Hosts that are exploited by the same brood parasite have less diverse egg patterns than those hosts who are exploited by different parasites • Host species are more variable in patterns vs. the non-host species • Increases within-species variation • Within-clutch variations was higher in hosts than non-hosts • Goes against all previous studies • Possible explanation 7 December 2, 2016 BIO-2000

Major Findings • Black Dots= host species • Light Gray Dots=non-host species • Size of Gray Circles= level of within-species variation Image Source (8) 8 December 2, 2016 BIO-2000

Image Source (8) 9 December 2, 2016 BIO-2000

Additional References 1. Fernbank Science Center. . . Where Science Becomes an Adventure. [accessed 2016 Dec 2]. http: //www. fernbank. edu/Birding/parasitism. htm 2. Australian passerines - superfamily Meliphagoidea. Pinterest. [accessed 2016 Dec 2]. https: //www. pinterest. com/oliverkwok 39/australian-passerines-superfamily-meliphagoidea/ 3. Baby Birds. Wild. Bird. Scoop. com. [accessed 2016 Dec 2]. http: //www. wildbirdscoop. com/baby-birds. html 4. Crypsis. Wikipedia. [accessed 2016 Dec 2]. https: //en. wikipedia. org/wiki/Crypsis 5. Egg clutch. Wikipedia. [accessed 2016 Dec 2]. https: //en. wikipedia. org/wiki/Egg_clutch 6. Hooded. Hawk » Science. [accessed 2016 Dec 2]. http: //www. hoodedhawk. com/blog/category/science/ 7. How to identify garden bird nests | Discover Wildlife. [accessed 2016 Dec 2]. http: //www. discoverwildlife. com/wildlife-gardens/how-identify-garden-bird-nests 8. Medina I, Troscianko J, Stevens M, Langmore NE. Brood Parasitism Is Linked to Egg Pattern Diversity within and among Species of Australian Passerines. The American Naturalist. 2015; 187(3): 351– 362. 9. Passerines. [accessed 2016 Dec 2]. https: //www. beautyofbirds. com/passerines. html 10. Wallace MB, Wax A, Roberts DN, Graf RN. Reflectance Spectroscopy. Gastrointestinal Endoscopy Clinics of North America. 2009; 19(2): 233– 242. 10 December 2, 2016 BIO-2000

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