An annotated checklist of the amphibians and reptiles of North Padre Island, Texas, USA, with comparisons to adjacent barrier island and mainland herpetofauna

Padre Island is the world’s longest barrier island and includes the longest stretch of undeveloped barrier island in the world. Largely due to harsh environmental conditions and difficult access, only cursory and incomplete checklists and subjective estimates of abundance have been produced. The results of an inventory of amphibians and reptiles of North Padre Island conducted 2002–2020, including the results of extensive field surveys conducted 2002–2003, are reported herein. Natural history museum and iNaturalist records are summarized and compared among North and South Padre and Mustang islands and the mainland portion of the seven counties in which the islands occur. The conservation status of rare species and extirpation of others is noted. The morphology and taxonomic status of some unique occurrences are discussed. Eleven species of amphibians and 39 species of reptiles presently occur or have occurred naturally or as introduced or accidental species on North Padre Island. Twelve species of amphibians and 50 species of reptiles occur or have occurred on North Padre, South Padre, and Mustang islands. Thirty-one species of amphibians and 93 species of reptiles have been reported from the seven counties in which the islands occur.

Rediscovering Kemp’s Ridley Sea Turtle (Lepidochelys kempii): Molecular Analysis and Threats

Sea turtles are reptiles that have inhabited the earth for 100 million years. These are divided into 2 families (Cheloniidae and Dermochelyidae) and 7 species of sea turtles in the world: the leatherback turtle (Dermochelys coriacea); hawksbill turtle (Eretmochelys imbricata); Kemp’s ridley (Lepidochelys kempii); olive ridley (L. olivacea); Loggerhead turtle (Caretta caretta); flatback sea turtle (Natator depressus) and green turtle (Chelonia mydas). In particular, Kemp’s ridley is included in the red list of IUCN categorized as “critically endangered”. The most important site around the Word is in Rancho Nuevo, Tamaulipas, Mexico. Where 80–95% of the world’s nesting is concentrated. Other nesting areas are Tepeguajes and Barra del Tordo, in Tamaulipas, and with less intensity in Veracruz (Lechuguillas and El Raudal beaches) and South Padre Island, Texas, USA. They deposit an average of about 90 eggs and hatching takes 40 to 60 days. Therefore, they are vulnerable to different anthropogenic activities and sources of pollution, such as heavy metals, which can cause toxic effects that are harmful to the turtles, damage their physiology and health. To understand the real situation about health and genetic parameters it is necessary to analyze biochemical and molecular factors in this species.

Biogeomorphic development of foredune trough blowouts quantified from medium-resolution satellite imagery

<p>Foredune trough blowouts are wind-eroded trough-shaped hollows in the most seaward coastal dune with their adjoining depositional lobes. They evolve on time scales ranging from strong wind events, seasons to multiple decades due to biogeomorphic interactions. Trough blowouts play an essential role in the sand budget of many coastal dune systems by connecting the beach with the backdune. There, the deposited sand can lead to vegetation rejuvenation and an overall larger floral diversity. In Northwestern Europe, nature and coastal managers have started to experiment with constructing trough blowouts in the hope that a positive sand budget beyond the foredune in concert with enlarged biodiversity improves coastal resilience in times of climate change. The spatio-temporal evolution of trough blowouts and the factors driving this evolution are not well understood, despite their common natural occurrence and construction for nature-based management.</p><p>The aim of this contribution is to quantify the spatio-temporal development of selected trough-blowout systems around the globe utilizing cloud-free medium-resolution Landsat and Sentinel-2 spectral imagery available in the Google Earth Engine platform. Linear spectral unmixing was applied on a single image basis to extract blowout surface area over time at one man-made blowout system (Zuid-Kennemerland, Netherlands) and two natural systems (Haurvig, Denmark; Padre Island, Texas, USA), assigning pixels with a fractional vegetation cover less than 50% to the blowout. At Zuid-Kennemerland and Haurvig, the blowout surface area fluctuated predominantly on seasonal time scales, with the smallest and largest values in late summer/early autumn and late winter/early spring, respectively. This seasonal variability reflects plant phenology in combination with increased sand accumulation in winter because of the more energetic wind conditions. In summer, vegetation regrew mainly at the edges of the depositional lobes and on the foredune between individual blowouts. The blowout surface area at the subtropical Padre Island varied predominantly on a multi-annual time scale. Most notably, multi-annual area decay was observed when a blowout progressed inland and lost its open connection to the beach, likely resulting in less physical disturbance and hence a dominance of ecological processes. In future work, we will combine our results with auxiliary information (e.g., multitemporal digital elevation models, time series of external forcing conditions, plant species and traits) to develop and test an eco-geomorphological model for blowout evolution. Such a model is adamant to understand what factors contribute to the success or failure of dune restoration projects involving blowouts as nature-based solutions to increase coastal resilience.</p>

INVITED ARTICLE FROM THE 2021 TEXAS ACADEMY OF SCIENCE TEXAS DISTINGUISHED SCIENTIST

Donna Shaver is the Chief of the Division of Sea Turtle Science and Recovery at Padre Island National Seashore and the Texas Coordinator of the U.S. Sea Turtle Stranding and Salvage Network. She received the Lifetime Achievement Award from the International Sea Turtle Society in 2018, the 2013 U.S. Fish and Wildlife Service Endangered Species Recovery Champion Award for Agency Partner in 2014, the Corpus Christi Caller Times 2011 Newsmaker of the Year in 2012, and she was the ABC World News Tonight’s Person of the Week on July 29, 2005. She has studied Texas sea turtles since 1980 and is well known for her leadership role in the recovery of the critically endangered Kemp’s ridley sea turtle. Her studies describing sea turtle migratory and foraging habitat use, as well as nesting and stranding trends, have led to increased protections for sea turtles in Texas and beyond. With over 400 scientific publications and presentations, Shaver is distinguished as one of the top sea turtle biologists in the USA and was named the 2021 Texas Distinguished Scientist at the annual meeting of the Texas Academy of Science. Shaver oversees a variety of sea turtle research and conservation projects conducted in Texas, collaborates with other researchers in the USA and Mexico, and provides training and leadership to hundreds of biologists and volunteers working with sea turtles in Texas.

Evaluation of Gonadal Tissue to Validate Size at Reproductive Maturity in Kemp’s Ridley Sea Turtles Found Stranded in Texas, USA

The Kemp’s ridley, Lepidochelys kempii, is the most endangered sea turtle in the world. Anthropogenic mortality of Kemp’s ridleys has been well documented in the Gulf of Mexico (GOM), USA. We evaluated the reproductive maturity of 75 Kemp’s ridley sea turtles found dead on GOM beaches on Mustang Island and North Padre Island, Texas, USA, 1994–1999. Straight carapace length (SCL) ranged from 40.8 to 68.7 cm. Preserved gonads and associated tissues were examined and measured. Gonadal measurements were then compared with SCL. Adults and juveniles shared a larger range of carapace measurements than expected, supporting the idea that juveniles spend several years in a pubertal state. Our results suggest caution when using SCL, tail length, or curved front claws alone as indicators of sexual maturity. In fact, SCL can be used to discern adults from juveniles with more predictive power when coupled with testis length or oviduct length measurements, thus allowing endangered species managers to more clearly identify demographic shifts in the number of mature animals, which can precede population changes. This study shows that information gained from the examination of stranded sea turtles allows wildlife managers to make more informed decisions regarding conservation priorities.