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Samuel R Fisher

Publications and source records attributed to Samuel R Fisher.

7 recordsLinked to original sources

On the origin and current distribution of the Oceania Snake-Eyed Skink (Cryptoblepharus poecilopleurus) in the Hawaiian archipelago

Because of its extreme isolation and lack of historical connection to a mainland, the Hawaiian Archipelago is thought to have no native nonvolant terrestrial reptiles. Several squamate species have been introduced to the archipelago, likely starting with early Polynesian contact, and increasing as human traffic in the Pacific has amplified. Of the earlier introductions, one species of skink, Cryptoblepharus poecilopleurus , belongs to a genus known for its ability to naturally disperse long distances, even across oceans. The earliest herpetofaunal surveys from Hawai‘i describe the skink as widespread and abundant across the archipelago. A recent phylogenetic analysis reveals substantial haplotype divergence between Hawaiian individuals and other known populations in the Pacific, raising the possibility that this species was an early and natural arrival to the archipelago before human contact. Recent surveys suggest that the species has undergone a dramatic reduction in range across the archipelago, possibly due to the invasion of highly competitive species. Given this information, we aim to further assess the origin of C. poecilopleurus in Hawai‘i, determine its current range, and suggest specific needs for future work. Here, we review the earliest European voyages in the Pacific that are known to have sampled C. poecilopleurus , review literature and museum specimens to develop an understanding of this species’ history in the islands, survey the island of O‘ahu to characterize its current range, and provide preliminary genetic analyses to show the relationship of the Hawai’i populations to the rest of the Pacific.

Hawaii

Hidden in plain sight: Detecting invasive species when they are morphologically similar to native species

Early detection and rapid response (EDRR) can help mitigate and control invasive species outbreaks early on but its success is dependent on accurate identification of invasive species. We evaluated a novel outbreak in San Diego County, California of the Sonoran Spotted Whiptail ( Aspidoscelis sonorae ) in order to confirm their spread as well as quantify how to better detect and potentially manage this invasive species in California. We found that A. sonorae went undetected for over two years due to its morphological similarity to native whiptails and that it has spread rapidly since they were first observed. There are two species of native California whiptails with which A. sonorae can be confused locally, the Orange-throated Whiptail ( Aspidoscelis hyperythrus ), and to a lesser extent the Tiger Whiptail ( Aspidoscelis tigris ). We review key diagnostic features to distinguish A. sonorae from native California whiptails. We also discuss how to efficiently use widely available community science tools to rapidly assess a novel invasive species outbreak and outline suggestions to help manage cryptic invasive species.

California

Tarentola annularis (white-spotted wall gecko)

USA: CALIFORNIA: Orange Co.: San Juan Capistrano (33.51°N,117.66°W; WGS 84). 25 August 2020. Samuel Fisher, Chelsea Martin, Robert Fisher. Verified by Gregory B. Pauly. Natural History Museum of Los Angeles County (LACM 191974). New county record. One juvenile (33 mm SVL) was collected, and another juvenile was seen 40 m away. Another juvenile was also observed during a second visit to the site on 19 September 2020. Wall geckos were first documented at this site since at least 2019 by Gary Nafis (G. Nafis, pers. comm. and as posted on www.californiaherps.com; 23 Aug 2020). Given that multiple individuals were observed at this site over 2 mo, this appears to be an established population. Invasive T. annularis were first detected in California in Redlands, San Bernardino County in the early 2000s (Wilcox et al. 2014. Herpetol. Rev. 45:464). This new Orange County population is ca. 80 km SW of the other known California population. While T. annularis has not spread much in the downtown urban center in Redlands over the last 20 years (S. Fisher, unpubl. data), it is possible it might expand its range more rapidly in a less urbanized habitat if there were more landscaping and natural features present. The only other published records for North America are from Florida where they are also invasive, and they have been known since the 1990s from several locations and continued to spread (Krysko et al. 2016. IRCF Rept. Amphib. 23:110-143). In the native range of T. annularis their habitat consists of desert, indicating that even though they are able to breed and persist in coastal Orange County they may not be in the optimal habitat (Ibrahim 2004. Zool. Middle East 31:23–38). A potential concern is that if T. annularis becomes more widespread in Southern California, they could present a risk to endemic nocturnal rock-dwelling species such as Xantusia henshawi and Phyllodactylus nocticolus because T. annularis has been shown to engage in saurophagy (Ibrahim 2004, op. cit.). It is much larger than these species (X antusia henshawi SVL = 70 mm; Phyllodactylus nocticolus SVL = 63 mm; Tarentola SVL = 108 mm) and well adapted to desert habitats where it could be a potential predator or competitor.

California

Hemidactylus turcicus (Mediterranean Gecko). Endoparasite.

Hemidactylus turcicus is a native of western India, Somalia, the Middle East, and the Mediterranean region and is one of the most successful invasive species in the world (Kraus. 2009. Alien Reptiles and Amphibians: A Scientific Compendium and Analysis. Springer Verlag, Berlin. 563 pp.). Since its introduction into the USA via the Port of Miami, Florida, around 1915, the range of this gecko has increased to include much of southern North America from Virginia and Florida west to California (Meshaka et al. 2006. Herpetol. Conserv. Biol. 1:145–150). A summation of the helminth parasites of both introduced and native H. turcicus was provided by McAllister and Bursey (2016. Acta Parasitol. 61:576–584). Here, we document a new host record for a tapeworm parasite of an introduced H. turcicus.

Herpetological Review

Establishment of brown anoles (Anolis sagrei) across a southern California county and potential interactions with a native lizard species

The brown anole, Anolis sagrei , is a native species to the Caribbean; however, A. sagrei has invaded multiple parts of the USA, including Florida, Louisiana, Hawai’i and more recently California. The biological impacts of A. sagrei invading California are currently unknown. Evidence from the invasion in Taiwan shows that they spread quickly and when immediate action is not taken eradication stops being a viable option. In Orange County, California, five urban sites, each less than 100 ha, were surveyed for an average of 49.2 min. Approximately 200 A. sagrei were seen and verified across all survey sites. The paucity of native lizards encountered during the surveys within these sites suggests little to no overlap between the dominant diurnal western fence lizard, Sceloporus occidentalis , and A. sagrei . This notable lack of overlap could indicate a potentially disturbing reality that A. sagrei are driving local extirpations of S. occidentalis .

California

Holocene Sea-Level Variability from Chesapeake Bay Tidal Marshes

We reconstructed the last 10,000 years of Holocene relative sea-level rise (RSLR) from sediment core records in near Chesapeake Bay, eastern U.S.A., including new marsh records from the Potomac and Rappahannock Rivers, Virginia. Results show mean RSLR rates of 2.6 mm yr-1 from 10 to 8 kilo-annum (ka) due to combined final ice-sheet melting during deglaciation and glacio-isostatic adjustment (GIA subsidence). Mean RSLR rates from ~6 ka to present were 1.4 mm yr-1 due mainly to GIA, consistent with other east coast marsh records and geophysical models. However, a progressively slower mean rate (< 1.0 mm yr-1) characterized the last 1000 years when a multi-century-long period of tidal marsh development occurred during the Medieval Climate Anomaly (MCA) and Little Ice Age (LIA) in the Chesapeake Bay region and other East Coast marshes. This decrease was most likely due to climatic and glaciological processes and, correcting for GIA, represents a fall in global mean sea level (GMSL) at near the end of Holocene Neoglacial cooling. These pre-historical climate- and GIA-driven Chesapeake Bay sea-level changes contrast sharply with those based on Chesapeake Bay tide-gauge rates (3.1-4.5 mm yr-1) (back to 1903). After subtracting the GIA subsidence component, these rates can be attributed to long-term (millennial) global factors of accelerated ocean thermal expansion (~ 1.0 mm yr-1) and mass loss from alpine glaciers and Greenland and Antarctic Ice Sheets (1.5-2.0 mm yr-1).

Delaware, Maryland, Virginia