Volume 5 • Issue 3 • March 2011
Working Without the Lights On?
Management and Cave Protection for the Ozark Big-eared Bat and Gray Bat in Oklahoma
Up in the mountains of northeast Oklahoma (yep, we have mountains!) are some of the most important geographical features known to wildlife. Caves are one of the most sensitive ecosystems that exist. Therefore any wildlife that requires them must be habitat reliant. Or else they probably wouldn't be there!
Oklahoma is home to 22 species of bats. Of these, there are three species listed as federally endangered- Ozark big-eared, Indiana and gray bats.
|The Ozark big-eared bat is a federally threatened species. They are extremely intolerant of human disturbance. Photo by US Fish and Wildlife Service.
Again, human disturbance to populations of cave-dwelling wildlife species of greatest conservation need is difficult to control. Any human disturbance can cause nursing female bats to abandon habitat and/or simply abandon their young.
Recently a study was done to identify caves that were considered critical habitat for colonies of Ozark big-eared bats and gray bats in northeastern Oklahoma. This habitat is one of the least common and most difficult to manage for wildlife. This study was
performed by posting a warning sign at cave entrances, placing human restrictive structures at or within caves such as fencing around the cave entrance or a gate/grill structure within the cave’s passage. Caves also were monitored to determine the effectiveness of restrictive management plans, particularly gated caves, to determine the impact of these structures or other protection measures implemented at the site. As problems were identified with the cave protection plans, they were corrected.
With so many difficult issues that can be encountered with northeast Oklahoma caves, there is still work to be done. Thankfully the job has been started and is simply one step closer to finding the happy ending.
E-22-14, Principal Investigator: Dr. Keith W. Martin. Keith is an associate professor of biology, as well as the dean of the school of mathematics, science and health sciences at Rogers State University. Written by Lesley B. Carson. Lesley is the wildlife diversity information specialist with the Oklahoma Department of Wildlife Conservation.
This project is funded by the State Wildlife Grants Program. The State Wildlife Grants Program provides federal money to every state and territory for cost-effective conservation aimed at preventing wildlife from becoming endangered. This program is administered by the Oklahoma Department of Wildlife Conservation and continues the long history of cooperation between the federal government and the states for managing and conserving wildlife species. For more information, visit www.teaming.com.
The Big Birds are Back
Purple Martins Come to Town
For many wildlife enthusiasts and backyard birders, spring is announced by the arrival of one of the most popular migrants, the purple martin (Progne subis).
The largest of North American swallows, this colonial songbird is easily recognized by its blue-black plumage, shallow notched tail, and long pointed wings. When compared to other swallows, the uniformly dark belly and nearly iridescent black back are unique to the male purple martin. Females are more drab than males with a gray collar and gray-brown belly. Both sexes have small bills, large mouths and primarily feed on small flying insects. These birds consume both insects and water while in flight.
|The purple martin is known as the largest North American swallow. Photo by the University of Wisconsin.
Migrating to take advantage of seasonal insect movement, purple martins winter in South America, and summers are spent north of the equator. Primarily traveling to the eastern half of the United States, the purple martin is also found along the west coast, and even ranges into central Canada. In Oklahoma these birds can be found statewide, though less commonly in the Panhandle. Older adults arrive first in early spring with large flocks of juveniles and other adults migrating several weeks later. Once thought to be scouting for new nesting sites, the earliest migrants are in fact setting up breeding territories at the previous year’s nest site and exploiting early insect activity.
Historically, the purple martin nested in natural cavities like snags and abandoned woodpecker nests in riparian zones. Ideal areas are close to both permanent water bodies and meadows or other open spaces used for feeding. Increases in deforestation, along with growth of agriculture and urban sprawl in sensitive areas have challenged many species, including several purple martin populations.
One way to offset habitat loss is the use of nest boxes. Modestly beginning as groups of gourds hung by Native Americans, these artificial nesting sites have transformed into elaborate multi-chambered houses. While western purple martins still use natural cavities, the eastern birds almost exclusively nest in these man-made houses colonially, with the females being responsible for most of the nest building and all of the incubation. Four to six white eggs are laid, and the helpless chicks are hatched after 15-18 days. Both parents bring insects to the hatchlings, and chicks fledge 28-29 days later.
Installing a purple martin house is an easy way to become involved with the Department’s conservation efforts and even pick up a new hobby – bird watching. One of the first and most important steps of the planning stage is deciding where to put a house. Because purple martins prefer to nest away from obstructions, assembling the nest box 30 feet from a residence and surrounding trees is far enough away to give the birds a sense of security, but close enough to still watch the colony with ease. A typical one-unit house is a six inch square box. The entrance should be about two inches in diameter, with the hole being drilled at least one inch from the nest box floor. This allows the purple martin to enter without difficulty, but discourages larger birds from using the nest box before the martins arrive and lowers the possibility of brood parasitism once nesting begins. In order to deter predators, the house should be placed on a pole 15 to 25 feet tall with no climbing vines or wires attached. Additionally, placing predator guards around the entrance hole prevents snakes and even starlings from entering. Because purple martins start arriving in southern Oklahoma in mid February, it is best to have new houses installed and old houses cleaned out in January. To learn more about maintaining purple martin houses, log onto purplemartin.org.
Written by Jena Donnell. Jena is a wildlife biologist with the Oklahoma Department of Wildlife Conservation.
Note from Editor: By mistake one image of a Texas horned lizard, taken by Dr. Greg Sievert of Emporia State University, has been used twice without permission. Once in April 2009 and again in November 2010. We regret this error and we have corrected the photographer credit online.
To see more of Greg Sievert's photographs, please be sure to order A Field Guide to Oklahoma's Amphibians and Reptiles.
Birding Hotspots in Oklahoma
Boasting of 13 distinct ecological regions (the same number as Texas and California, by the way!), combined with its location in the middle of the country, it is not surprising that bird diversity is high in Oklahoma. For those interested in locating the birding hotspots, there are many venues available. If you are interested in reading online discussions about bird sightings in the state, the Sutton Avian Research Center sponsors the Oklahoma Bird List Service. You can subscribe by selecting the “Oklahoma Bird listserv” under the “Education” menu.
For information on birding routes in the state check out the Tulsa Audubon Society website and view the interactive maps on their “Guide to Birding in Oklahoma”. A source for birding routes in western Oklahoma specifically is the Great Plains Trail of Oklahoma, a project of the OK Wildlife and Prairie Heritage Alliance in partnership with the Oklahoma Department of Wildlife Conservation. Thirteen scenic driving loops highlight native wildlife, prairies, culture and terrain. Loops take the visitor through areas that provide the greatest likelihood to see wildlife (boasting 220 bird species), while offering routes that traverse the most scenic and remote roads in the state. For the birdwatcher, each loop has a recommended birding route detailing where to start at dawn and where to end at sunset with bathroom and eating breaks included. Each loop can be printed off the website or to receive the Trail road map click here.
Within the Oklahoma City area check out the Oklahoma City Audubon Society’s website with links to all the good birding spots in and around the metro area.
Attending birding festivals is another great way to learn about birding hot spots in the state. This spring there are four great festivals to attend. From the Cherokee Birding and Heritage Festival and the Woodward Lesser Prairie-Chicken Festival in the northwest to the Arbuckle-Simpson Nature Festival in the south central to the Red Slough Birding Convention in the far southeast. Grab your binoculars, wear clothes for any possible weather condition and experience the bird life in Oklahoma!
Written by Melynda Hickman. Melynda is a
wildlife diversity biologist with the
Oklahoma Department of Wildlife
Laurie Ross, Tulsa, OK
Wildlife Diversity Donations
Morris H. Ramsey, Lawton, OK
The Wildlife Diversity Program - a program of the Oklahoma Department of Wildlife Conservation - monitors, manages and promotes rare, declining, and endangered wildlife, as well as common wildlife not fished or hunted. Oklahomans help fund the Wildlife Diversity Program through an annual state income tax check-off, the purchase of wildlife conservation specialty license plates, product purchases, and individual donations.