3 undergraduate research groups from the Undergraduate Research Program of the Ecological Systems Laboratory presented their research at 2016 Undergraduate Research Summer Poster Session on August 3rd.
Simulated effects of human-caused disturbance on population trends of Florida manatee
Paola Camposeco*, Jasmin Diaz-Lopez*, Hsiao-Hsuan (Rose) Wang, William Grant
Department of Wildlife and Fisheries Sciences, Texas A&M University
*undergraduate students, contributed equally
Florida Manatee populations had been dramatically declining due to various factors including perinatal mortality, habitat destruction and degradation, and human-related threats. Causes of manatee deaths can be broken down into 5 categories: watercrafts, crushed/drown by flood gate or canal lock, other human-related such as vandalism and entanglement, perinatal, cold stress, other natural such as disease, natural accident, and natural catastrophe. Three out of five of these categories are associated with human. Objective: Develop a population model of Florida manatee and estimate the effects of 5 mortality scenarios on the manatee population which include; all manatee deaths, cold stress, human-related threats, oil spill, and natural deaths. Methods: We conducted a literature review to obtain the basic demographic data available. Moreover, we added new data from synoptic surveys collected by the Florida Fish and Wildlife Conservation Commission. A stage-structure population dynamics model for Florida manatee was developed using STELLA 7.0.1. Using the total number of deaths and population size we were able calculate average mortality, and standard deviation from the 5 different mortality scenarios. We simulated each scenario with the worst, average, and better effects from each of their average mortality rates. Finally, the model ran for 30 years with an initial population of 2000 and carrying capacity of 5000, which projected the Florida Manatee population with the effects of each mortality scenario. Results: When comparing all 5 scenarios, the leading factors affecting the manatee population are natural causes followed by the cold stress, the oil spill, and then human related deaths.
Inbreeding effects on demography and population trends of the endangered Florida panther
Chris Chen1*, Anna Cole2*, Kelsea Anthony2*, Hsiao-Hsuan (Rose) Wang2, Tomasz Koralewski3, William Grant2
1Department of Animal Science, 2Department of Wildlife and Fisheries Sciences, 3Department of Ecosystem Science and Management, Texas A&M University, College Station, TX 77843, *Undergraduate Students
There are over 30 species of wild cat that occupy over 90 countries of the world. However, habitat fragmentation leads to common occurrences of inbreeding and subsequent biodiversity loss. One subspecies of felid experiencing such inbreeding is the Florida panther (Puma concolor coryi). A subspecies of puma, the Florida panther historically resided in a large expanse of the southeast United States. Due to urbanization, the habitat has been reduced to two areas in southwest Florida: the Big Cypress Swamp and Everglades National Park and the two populations of Florida panthers are isolated. Physical and reproductive characteristics, such as cryptorchidism, have resulted from inbreeding. Hence, we developed a population model to analyze inbreeding effects. When mortality rates were changed to maximum values, the simulated Florida panther population was close to extinction after 25 years, while the population size reached over 1700 when the parameters were set to minimum values. When each stage mortality rate was altered individually while the others remained at baseline, the population size was ranged from 0 to 10 panthers after 25 years. The natality parameters, however, had much different results; when only natality was manipulated, the population ranged from 0 to 218. These results suggest that natality rates play an important role to sustain the population of Florida panther. Such a scenario can happen by increasing available genes in the gene pool, which happened with the 8 Texas cougars bred with the native Florida panthers.
EFFECTS OF WILDFIRE ON ABUNDANCES AND MORPHOLOGICAL CHARACTERISTICS OF GREEN TREE FROG IN BASTRAP, TEXAS
Thanchira Suriyamongkol1†, Kaitlyn Forks1†, Andrea Villamizar-Gomez2, Ivana Mali3, Hsiao-Hsuan (Rose) Wang1, William Grant1, Michael Forstner2
1Department of Wildlife and Fisheries Sciences, Texas A&M University; 2Department of Biology, Texas State University; 3Department of Biology, Eastern New Mexico University; †Undergraduate students
Wildfires are natural phenomena that can impact native fauna by altering their habitats. In 2011, a large wildfire occurred in 2011 near Bastrop, Texas. Unfortunately, much of its Lost Pines habitats was destroyed, as a result of wildfire, and will take years to recover. The objective of this study is to compare the relative abundances and morphological characteristics of green tree frogs (Hyla cinerea) in burned areas with those in unburned areas near Bastrop to assess the effect of these fires on green tree frog populations in the area. Method: We analyzed weekly data on tree frogs distribution in GLR collected by Texas State University over the five-month period from June to October using PVC pipes placed around each of four ponds. Species trapped were predominantly Hyla cinerea. Results: Frogs were more abundant in unburned areas. However, statistically, the difference between the number of green tree frogs found in burned area and unburned area was not significant (P=0.0744).