--- title: Narwhals: Tusk Size Indicates Fertility, Study Says description: Attracting the ladies one giant tooth at a time canonical: https://time.com/3419809/narwhal-tusks-fertility/ author: Nolan Feeney article:opinion: false article:content_tier: free article:published_time: 2014-09-23T01:28:08.000Z article:modified_time: 2026-02-21T10:20:53.330Z article:section: Science og:title: Narwhal Tusks Correlate With Testicle Size and Fertility og:description: Attracting the ladies one giant tooth at a time. og:url: https://time.com/3419809/narwhal-tusks-fertility/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt05c0d8d6c8070c6d/6986a4b2adae44f868545172/narwhal.jpg?branch=production&width=3840&quality=75&auto=webp&crop=16:9 og:image:width: 1200 og:image:height: 675 og:image:alt: Narwhals og:type: article twitter:card: summary_large_image twitter:title: Narwhal Tusks Correlate With Testicle Size and Fertility twitter:description: Attracting the ladies one giant tooth at a time. twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt05c0d8d6c8070c6d/6986a4b2adae44f868545172/narwhal.jpg?branch=production&width=3840&quality=75&auto=webp&crop=16:9 ---  # Study: Narwhal Tusk Size Correlates With Testicle Size and Fertility  by [Nolan Feeney](https://time.com/author/nolan-feeney/)  ## Nolan Feeney Sep 23, 2014 1:28 AM UTC  Lancaster Sound, Nunavut, Canada. Lancaster Sound, Nunavut, Canada.Paul Nicklen—National Geographic/Getty Images  by [Nolan Feeney](https://time.com/author/nolan-feeney/)  ## Nolan Feeney Sep 23, 2014 1:28 AM UTC A ballsy new study may have unlocked the secret behind narwhals’ unicorn-like tusks, or the single tooth found atop males’ heads. Researchers studied the testicle size of [144 narwhals](http://animals.io9.com/size-matters-narwhals-with-longer-tusks-have-bigger-te-1637869535?utm%5Fcampaign=socialflow%5Fio9%5Ftwitter&utm%5Fsource=io9%5Ftwitter&utm%5Fmedium=socialflow) collected during aboriginal Inuit hunts between the years 1990 and 2008, and found that the bigger the tusks, the better the testes, pretty much — tusk length and teste mass (which indicates fertility) were closely related. In a study published in _Marine Mammal Science_, these researchers suggest that a tusk’s length signals to female narwhals which males are the most fertile and would make the best mates, _Science_ [reports](http://news.sciencemag.org/plants-animals/2014/09/narwhals-tusk-may-be-its-status-symbol). That means narwhal tusks aren’t unlike peacock feathers or antlers in the sense that they’re animal body parts used to attract females with their impressive displays. Previous theories about the tusks’ usage have included that they might serve as a (literal) icebreaker or a sensor of water salinity and temperature. The latest study notes that while the tusks may serve other purposes, the fact that it’s such a gendered trait means it likely plays a small role in survival and providing a competitive evolutionary advantage. \[[_Science_](http://news.sciencemag.org/plants-animals/2014/09/narwhals-tusk-may-be-its-status-symbol)\] ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/3419809/narwhal-tusks-fertility/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/3419809/narwhal-tusks-fertility/"},"headline":"Study: Narwhal Tusk Size Correlates With Testicle Size and Fertility","datePublished":"2014-09-23T01:28:08.000Z","dateModified":"2026-02-21T10:20:53.330Z","description":"Is that a giant tooth on your head or are you just happy to see me?","url":"https://time.com/3419809/narwhal-tusks-fertility/","keywords":["animals","fertility"],"thumbnailUrl":"https://static.time.com/v3/assets/bltea6093859af6183b/blt05c0d8d6c8070c6d/6986a4b2adae44f868545172/narwhal.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","author":[{"@type":"Person","name":"Nolan Feeney","jobTitle":null,"url":"https://time.com/author/nolan-feeney/"}],"articleSection":"Science","image":[{"@type":"ImageObject","url":"https://static.time.com/v3/assets/bltea6093859af6183b/blt05c0d8d6c8070c6d/6986a4b2adae44f868545172/narwhal.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","width":1200,"height":675,"headline":"Narwhals","caption":"Narwhals","creditText":"Paul Nicklen—National Geographic/Getty Images","representativeOfPage":true}],"publisher":{"@type":"Organization","name":"Time","url":"https://time.com/","logo":{"@type":"ImageObject","url":"https://time.com/images/logo.png","width":528,"height":156},"foundingDate":"March 3, 1923","sameAs":["https://www.facebook.com/time","https://www.instagram.com/time/?hl=en","https://twitter.com/time","https://www.pinterest.com/timemagazine"]}},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/section/science/","name":"Science"}},{"@type":"ListItem","position":2,"item":{"@id":"/tag/animals/","name":"animals"}},{"@type":"ListItem","position":3,"item":{"@id":"https://time.com/3419809/narwhal-tusks-fertility/","name":"Study: Narwhal Tusk Size Correlates With Testicle Size and Fertility"}}]}] ```