Armendaris Ranch, NM
Z Bar Ranch, KS/OK
Laura Kloepper, St. Mary’s College
Ken Brunson, The Nature Conservancy
Kansas Department of Wildlife, Parks & Tourism
US Fish & Wildlife Service
Many bat populations in North America have undergone precipitous population declines since the emergence of white-nose syndrome (WNS) in 2006. The WNS epidemic is considered the worst wildlife disease outbreak in recent North American history and threatens to drive some bat species to extinction. Resident, hibernating bats on Turner western properties may soon be affected by WNS.
• Listed as USFWS threatened: Northern long-eared bat (Myotis septentrionalis)
• Listed as USFWS Species of Concern: Big brown bat (Eptesicus fuscus); Cave myotis (M. velifer); Allen’s big-eared bat (Idionycteris phyllotis)
• Listed as NMDGF Species of Greatest Conservation Need: Allen’s big-eared bat (I. phyllotis); Spotted bat (Euderma maculatum)
• Listed as KDWPT Species of Greatest Conservation Need: Townsend’s big-eared bat (Corynorhinus townsendii);
• Listed as ODWC Species of Greatest Conservation Need: Mexican free-tailed bat (Tadarida brasiliensis)
We aim to monitor resident and migratory bat populations at the Z Bar and Armendaris Ranches to determine species richness and population trends, document the arrival and impacts of WNS, improve bat habitat, and foster and facilitate innovative bat research and education on Turner properties.
TESF and its partners will perform biennial summer and winter population and species classification surveys of bat populations at the Armendaris and Z Bar Ranches to document any significant population fluctuations. TESF personnel will collaborate with bat biologists and remain current on bat ecology and, through these contacts and information, advise and assist ranch managers in improving bat habitat and alleviating threats.
Supporting Rationale for Objectives
WNS, an epizootic disease caused by the fungus Pseudogymnoascus destructans, is the only known disease of concern for bats on Turner properties. Most bat species are relatively long lived (10-15 years) and produce one offspring a year; consequently, bat population growth depends on high rates of adult survival. Bat populations affected by WNS often experience a 95% loss of the adult population. Documenting the arrival of WNS and its impacts on bat populations on Turner properties will play an important role in a larger nationwide effort to track, study, and ultimately minimize the impacts of the disease.
Mexican free-tailed bats make up the majority of bats on Turner properties. While they may not be susceptible to WNS because they migrate rather than hibernate, much remains unknown about the species and its seasonal use of caves on Turner properties. Collaborating with bat researchers at the two ranches will begin to fill in those basic ecological information gaps and offer insight into how best to manage bat populations on Turner lands.
Population surveys, WNS monitoring, and habitat management and improvement will be accomplished through collaboration with current state, federal, and NGO partners. Restricting access to caves used by bats will limit the potential for the human-caused spread of WNS.
The Jornada caves at the Armendaris Ranch are the second largest lava tubes in North America and provide habitat for eight bat species: Mexican free-tailed bat, Pallid bat (Antrozous pallidus), Allen’s big-eared bat, Yuma myotis (M. yumanensis), Townsend’s big-eared bat, spotted bat, California myotis (M. californicus), and fringed myotis (M. thysanodes). The migratory population of Mexican free-tailed bats at Jornada is the largest in New Mexico and the fifth largest in North America.
The Merrihew, Rattlesnake, and Skunk caves (gypsum cave) at the Z Bar are occupied by at least five bat species: Mexican free-tailed bat, Townsend’s big-eared bat, big brown bat, cave myotis, and tricolored bat (Perimyotis subflavus). Four of these hibernate, and all are either federally or state listed. Four caves in the Oklahoma-Kansas Red Hills region were tested for WNS in 2014 and 2016 and all tests returned negative for the disease.
Project Activities in 2018
In late March TESF and KDWPT biologists surveyed three Z Bar caves to identify and count hibernating bat species and to collect samples to determine if WNS was present. One bat in one cave (Rattlesnake Cave) was symptomatic and was subsequently collected and tested. Results confirmed the bat had WNS. The vast majority of bats that occupy the caves at the Z Bar are migratory (Mexican free-tails) and current research suggests the species is not affected by the disease. We will continue biannual hibernating bat surveys at the Z Bar to determine the impacts the disease is having on resident, hibernating bat populations.
Visual population surveys at Merrihew Cave indicate a late August bat population of 115,200 bats living in the cave which translates into >1,500 lbs. of insects eaten every night.
Dr. Laura Kloepper conducted field research at the bat caves on the Armendaris in June 2018, continuing her ongoing project investigating the echolocation adaptations of bats in groups. Kloepper’s team, which included researchers from Oxford University (UK) and the University of Notre Dame, also began a new project characterizing the predatory behavior of Swainson’s hawks on bats. Additional work included entering the cave to determine an overall health assessment of the colony. At the beginning of June, bat populations were 10% lower than expected at the Armendaris caves. Kloepper contacted Carlsbad biologists, who observed the same population reduction at their location. By the middle of June, populations had returned to expected levels, indicating a delay in the migration of the bat colony. By the end of June healthy newborn bats were evident in the cave. The population of bats appeared healthy with no observable signs of WNS.
Proposed Future Activities
It is likely bat populations on all Turner properties will eventually be exposed to P. destructans. Currently, there is no treatment for the disease and preventing exposure of bats on Turner properties to the fungus is not practical since transmission is primarily from bat to bat. What we can do for bats living on Turner properties is to limit the potential for humans to transmit WNS by enforcing decontamination protocols for those entering Turner caves, ensuring human activities around bat caves are not detrimental to bat populations, improving existing bat habitat, and improving the overall understanding of bat ecology and behavior through collaborative research and education efforts.