Hawaiian endemic species are species that only exist in Hawaii and in the surrounding waters. You will not be able to see these species in the wild in any other place of the world, except perhaps in a zoo.
To answer this we first need to talk about what we mean with ‘endemic’ and ‘native’. Afterward, we dive into the scientific literature to check the facts on Hawaiian species and conclude with an evolutionary comparison between Hawaii and the famous Galapagos islands:
Table of contents
Table of Contents
- Native, endemic and alien species
- Diving into the numbers: how many species are there?
- Hawaii: a showcase for evolution!
The quick answer is that the claim is partially true. About 90% or all native species that live on land in Hawaii are indeed endemic. However, when talking about all species on Hawaii, this number drops to a still very respectable 40%.
Native (endemic and non-endemic) and alien species
When talking about the incredibly diverse nature in Hawaii it is good to know the difference between native (endemic and non-endemic) and non-native (alien) species.
“Native” means that a species occurs naturally within a region. Either because they evolved there or because they arrived without human assistance. For example, the Iʻiwi bird shown below is native (and endemic!) to the Hawaiian islands.
The Iʻiwi bird is endemic to Hawaii. Source: Iʻiwi|Puʻu oʻo Trail | 2013-12-17at12-43-209 by HarmonyonPlanetEarth, licensed under CC BY 2.0
Native species can be split into endemic and non-endemic species. Endemic in biology means that a species is unique to a defined geographical location. Practically this means that a non-endemic native Hawaiian species have been found in ecosystems outside of Hawaii. Endemic species only can be found in Hawaii.
Alien species finally are introduced from outside ecosystems and can be harmful to local species because they compete for the same resources. Alien species are also called non-native or invasive species. In Hawaii, there are about 5000 non-native species (source).
How many species are there in Hawaii?
The Bishop museum has been surveying the biodiversity in Hawaii since 1992 through the good work of the Hawaii Biological Survey.
Following their latest survey in 2014 (source), there is a total of 26608 species in the state of Hawaii! Between 10000 and 10500 of those species are endemic. There are also ~5000 non-native species, which leaves a grand total of ~11000 native species that are not endemic.
Well, as always, the devil is in the details, and those details seem to have been lost along the way. Species are often split into different groups based on taxonomy or living habitat. If you look only at the native species living on land (terrestrial species), you will recover the 90% number. Marine species spread more easily (living on an island doesn’t stop them!), which lowers the number of endemic species.
You can see a breakdown of all the species that make up the Hawaiian biodiversity below. Note the few % difference between the totals shown in the last row with the more recent 2014 results that we mentioned earlier.
| Totals | Endemic | Alien | Species at risk | Extinct | |
| Algae + other protists | 2013 | 82 | 18 | 0 | 0 |
| Fungi and lichens | 2088 | 240 | ? | 0 | 0 |
| Flowering plants | 2264 | 918 | 1101 | 654 | 97 |
| Other plants | 766 | 241 | 47 | 0 | 0 |
| Molluscs | 1339 | 962 | 96 | 127 | 500 |
| Insects | 8427 | 5462 | 2609 | 289 | 74 |
| Other arthropods | 1191 | 366 | 735 | 4 | 0 |
| Other invertebrates | 4003 | 822 | 253 | 7 | 0 |
| Fish | 1216 | 149 | 73 | 1 | 0 |
| Amphibians | 8 | 0 | 8 | 0 | 0 |
| Reptiles | 27 | 0 | 23 | 0 | 0 |
| Birds | 294 | 63 | 53 | 36 | 88 |
| Mammals | 44 | 2 | 19 | 2 | 2 |
| Totals | 23680 | 9307 | 5035 | 1120 | 761 |
Hawaii vs the Galapagos islands: who wins the game of evolution?
Whether the number of endemic species is 40%, 50% or 90% doesn’t matter that much. Hawaii still is a champion if it comes to the number of endemic species!
Take for example the Galapagos islands. These South American islands have been made famous by Darwin as a showcase of evolution, and rightfully so. However, when compare the Galapagos with Hawaii it becomes clear that there are far more endemic species on Hawaii:
Comparison of the endemic diversity of the Galapagos islands (left) with Hawaii (right). Adapted from Table 2 in Allen Allison 2003, Org. Divers. Evol. 3, 103–110 (2003), doi:10.1078/1439-6092-00065
Of course, this makes sense when you consider that [a] the Hawaiian islands have more different climate zones (8/13, see our article on Big Island climate zones), and [b] that the Galapagos are less isolated than Hawaii. Hawaii is located 2390 miles from the nearest continent, and the Galapagos islands “only” 600 miles.
Resources used in this article
The writing of this article would not have been possible without the following resources:
- The Hawaii Biological Survey.
- The 2003 publication “Biological surveys – new perspectives in the Pacific” by Allen Anderson (source).