My research focuses on the evolution of bird sperm cells, specifically the origin and the function of sperm morphology. I work with passerine birds who are generally promiscuous, and are subject to intense sexual selection (sperm competition). This is an excellent study system for understanding sperm evolution. Passerine bird sperm cells are generally shaped like screws or corkscrews, and I am trying to find out why they have this strange shape. I use electron microscopy to take high-resolution images of these cells. I compare species with high and low intensity of sperm competition (i.e. how many sexual partners the birds have), and look for correlations between this behaviour and sperm shape. I also look for correlations between sperm shape and their function, i.e. velocity or longevity, and try to understand sperm motion in a biomechanical framework.
I have a number of outreach projects with local schools and the museum exhibitions, and I was a participant in the science communication competition "Forsker Grand Prix" (http://www.fgposlo.no/deltagere-2017-2/hanna-n-stostad/).
- Støstad, Hanna Nyborg; Johnsen, Arild; Lifjeld, Jan Terje & Rowe, Melissah (2018). Sperm head morphology is associated with sperm swimming speed: a comparative study of songbirds using electron microscopy. Evolution. ISSN 0014-3820. 72(9), s 1918- 1932 . doi: 10.1111/evo.13555 Show summary
- Støstad, Hanna Nyborg; Aldwinckle, Phil; Allan, Andrew & Arnold, Kathryn E (2017). Foraging on human-derived foods by urban bird species. Bird Study. ISSN 0006-3657. 64(2), s 178- 186 . doi: 10.1080/00063657.2017.1311836
- Støstad, Hanna Nyborg; Rekdal, Silje Larsen; Kleven, Oddmund; Laskemoen, Terje; Marthinsen, Gunnhild; Johnsen, Arild & Lifjeld, Jan Terje (2016). Weak geographical structure in sperm morphology across the range of two willow warbler Phylloscopus trochilus subspecies in Scandinavia. Journal of Avian Biology. ISSN 0908-8857. 47(5), s 731- 741 . doi: 10.1111/jav.00981 Full text in Research Archive. Show summary
- Støstad, Hanna Nyborg; Birkeland, Siri; Delsett, Lene Liebe & Rosing-Schow, Nanna (2017). Fire råd til deg som vil knuse glasstaket. Aftenposten (morgenutg. : trykt utg.). ISSN 0804-3116. . doi: https://www.aftenposten.no/meninger/kronikk/i/woyGG/Fire-rad-til-deg-som-vil-knuse-glasstaket