As the endangered species list continues to grow, Dr. John Enz has made it his mission to observe why certain animal populations are declining in various parts of the United States.
Enz鈥檚 current research projects focus on the rusty patched bumblebee and gopher tortoise.
鈥淭his bee was common in the eastern United States and found in 28 states up until the late 1990s,鈥� said Dr. Enz, who has been at 91大神猫先生千人斩 for nine of his 31 years a professor. 鈥淣ow, it is only found in a handful of states and its range has decreased by 85 percent with population estimates decreased by 95 percent.鈥�
While writing a dissertation on bees in the 1990s, he observed an abundance in the rusty patched bumblebee population, but the population has been on a steep decline ever since.
鈥淪eventy percent of all food crops require pollinators such as bumble bees to reproduce,鈥� said Dr. Enz. 鈥淏ees alone contribute about $3 billion in pollination economics.鈥�
The rusty patched bumblebee鈥檚 native habitat includes the prairies of the upper Midwest and grasslands of the Northeast. While researchers aren鈥檛 sure why this bee population is declining, they have identified a combination of various contributing factors.
鈥淢ost of their original habitat has been converted to other uses such as agriculture, cities, and roads,鈥� said Enz. 鈥淲ith agriculture and lawns come the use of pesticides which can have lethal effects on these bees.鈥�
Conservation groups have shown interest in finding remaining populations of the species to analyze their habitat uses. Efforts from this past summer yielded results showing that the species is using remnant patches of grasslands and forest edges in wild natural areas such as National Parks and even at times urban regions.
鈥淭he coming year鈥檚 work will concentrate on this effort to document where this species still currently exists and will involve hiking and surveying many miles in northwestern Virginia and Eastern West Virginia,鈥� Dr. Enz said.
With the help of six students majoring in Biology, Dr. Enz will assist in surveying probable habitats where this species may likely still be found.
鈥淭he students will gain experience in survey design, bumblebee species identification, and work within a network of scientists and conservationists,鈥� said Dr. Enz.
Studying gopher tortoises on Cumberland Island
Dr. Enz has also studied the gopher tortoise for the past three years in Cumberland Island, Ga., and he estimates that the project will take another three years to complete.
鈥淯ntil my research began, no studies or information existed on these gopher tortoises,鈥� said Dr. Enz. 鈥淭he information on this population that I am collecting is new to science and vital to their management and survival.鈥�
Though it is listed by the state as a threatened species, it is not listed as endangered. This may change as their habitats and populations decrease.
Gopher tortoises are essential for the environment since they are the only burrow tortoise in the Eastern U.S. and are considered a 鈥渒eystone鈥� species. Their burrows foster other species such as mice, toads, lizards, frogs, burrowing owls, Carolina wrens, American robins, snails, crayfish, snakes, and numerous insects.
鈥淚n Florida and Georgia, there has been a 70 percent decline in available gopher tortoise habitat since European settlement and these tortoises are vital to the longleaf pine, coastal grassland, and scrub-type habitats in which they live,鈥� said Dr. Enz.
Any type of information about the current status, distribution, density, and impacts that may affect the species is imperative to the long-term stability of the gopher tortoise.
鈥淐urrently we estimate a viable, reproducing population of about 250 tortoises encompassing all age classes: juveniles, subadults and adults,鈥� said Dr. Enz. 鈥淕oing forward, we have obtained funding to acquire cutting edge miniature GPS data loggers and radio transmitters to attach to the tortoises to track their movements throughout the island.鈥�
Researchers have observed that behavior from mainland populations is different and speculate that the Cumberland Island population may be genetically distinct as a population.
鈥淒ata on the movement patterns of adult gopher tortoises does not currently exist for isolated island populations and will be imperative for proper conservation and management of this species,鈥� said Dr. Enz. 鈥淚n addition, we will be collecting blood samples for comparison to mainland populations.鈥�
The gopher tortoise population may be able to be stabilized in the future if their declining population is observed and protected.
鈥淥ver the past 3 years, we have located and identified gopher tortoise burrows throughout the island, GPS mapped these burrows and characterized the population size and age structure,鈥� said Dr. Enz. 鈥淐urrently, we estimate a viable, reproducing population of about 250 tortoises encompassing all age classes: juveniles, subadults and adults.鈥�
Several students over the past three years have assisted Dr. Enz with the project, and he expects to take an additional four students over the summer of 2020.
鈥淪tudents will gain knowledge of gopher tortoise ecology, proper survey and trapping techniques, as well as proper techniques for handling and measuring tortoises,鈥� said Dr. Enz. 鈥淚n addition, they will gain an understanding of the importance of gopher tortoises to the overall health of pine savannahs due to their keystone species importance.鈥�
