Biological Invasions

, Volume 19, Issue 6, pp 1723–1731 | Cite as

Establishment of Anolis sagrei on Bermuda represents a novel ecological threat to Critically Endangered Bermuda skinks (Plestiodon longirostris)

  • James T. Stroud
  • Sean T. Giery
  • Mark E. Outerbridge
Invasion Note


Bermuda is an isolated, oceanic island with only one endemic terrestrial vertebrate, the Critically Endangered Bermuda skink (Plestiodon longirostris; Squamata, Scincidae). Major declines in P. longirostris populations have been caused primarily by habitat loss and mortality via invasive species (e.g., predation from birds and cats) and human waste products (e.g., trapped in discarded bottles). However, biotic interactions and interspecific competition with invasive lizards have also been identified as potentially detrimental to P. longisrostris populations. Here, we provide the first occurrence records of a highly invasive lizard, the Cuban brown anole (Anolis sagrei), on Bermuda. We assess the brown anole’s diet, habitat use, morphology, and island-wide distribution for comparison to the native skink, P. longirostris. Results of this study indicate that A. sagrei in Bermuda are highly terrestrial (>60% of all lizards observed on the ground vs. in trees) and forage primarily on terrestrial invertebrates. These data indicate substantial ecological overlap with the exclusively-terrestrial P. longirostris. This is in contrast to the other established non-native lizards on Bermuda, which are principally arboreal and have successfully coexisted with P. longirostris for >60 years. At present, the geographic distributions of A. sagrei and P. longirostris do not overlap. However, all extant skink populations are within several kilometers of brown anole populations (with the nearest being <0.5 km). The extensive overlap in ecological niche between the Bermuda skink and the invasive brown anole will likely present a serious conservation threat if contact is made. This study is exceptional in providing clear in situ ecological data which predict a conservation threat of an established invasive species to a Critically Endangered island endemic prior to coexistence. Continued monitoring of this situation as P. longirostris and A. sagrei inevitably come into contact will allow these a priori hypotheses of conservation risk via ecological overlap to be tested.


Anolis Invasive species Oceanic island Endemic Endangered Competition Niche 



This is contribution #246, Bermuda Biodiversity Project (BBP), Bermuda Aquarium, Natural History Museum and Zoo, Department of Environment and Natural Resources. We thank the Bermuda Zoological Society (Eric Clee Fund) for financial research support, as well as to Thad and Evan Outerbridge for providing accommodation. We thank Kenneth Feeley, Evan Rehm, Rachel Hillyer, Catherine Bravo-Avila, Jason Kolbe, Joe Macedonia, and one anonymous reviewer for providing important and insightful comments on previous versions of this manuscript. JS was supported by the FIU Judith Evans Parker Travel Fund and an FIU Dissertation Evidence Acquisition Fellowship. STG was supported by NSF DEB #1406399.


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Copyright information

© Springer International Publishing Switzerland 2017

Authors and Affiliations

  • James T. Stroud
    • 1
    • 2
  • Sean T. Giery
    • 3
  • Mark E. Outerbridge
    • 4
  1. 1.Department of Biological SciencesFlorida International UniversityMiamiUSA
  2. 2.Fairchild Tropical Botanical GardensCoral GablesUSA
  3. 3.Department of Applied EcologyNorth Carolina State UniversityRaleighUSA
  4. 4.Department of Environment and Natural ResourcesHamilton ParishBermuda

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