Using infrared-triggered cameras at 65 sites, UA researchers captured 36 photographs of mountain lions roaming the Tucson Mountains. The study confirmed that lions in at least two age groups – adults and almost-grown kittens – use the Tucson Mountains as either their home range or are in transit.
"We have established that there are mountain lions in the Tucson Mountains, and they have been there fairly consistently over time," said Lisa Haynes, a researcher with the Wild Cat Research Conservation Program at the UA's School of Natural Resources and the Environment.Not only did the study confirm the presence of mountain lions, it detected other wildlife including bobcats, deer, gray foxes and ringtails. While the team was able to identify specific bobcats in the snapshots based on their unique pattern of fur spots, the photographs did not allow for the identification of individual mountain lions.
Subadults are almost-grown kittens that are newly independent of their mother. They can be distinguished by very faint spots on their fur, which disappear as they approach adulthood.
"Unfortunately, you cannot tell individual mountain lions apart by the photographs. They almost all look alike, so in most cases, you have the same individuals walking in front of the camera multiple times," Haynes explained.
Urban sprawl threatens habitat
An important goal of the study was to assess whether the mountain lions call the Tucson Mountains their primary home range or whether they migrate along wildlife corridors.
To detect migrating lions, the group monitored potential wildlife corridors surrounding the Tucson Mountains, including the designated wildlife crossings of the Central Arizona Project canal. None of those camera sites photographed mountain lions, but bobcats and a variety of other wildlife.
"Although we were not able to document mountain lions moving in or out of the Tucson Mountains, the fact that two wild cat species still exist in the Tucson Mountains is testament to its ecological value in this remarkable and diverse bioregion," Haynes said.
But she added a word of caution, too: "The Tucson Mountain area is a template for what will happen to larger mountain ranges and habitat patches in the future as sprawl increases."
Why we need mountain lions
Using infrared cameras set off by a passing animal triggering a motion sensor, Haynes' group obtained more than 12,000 photos during the project, most of which were taken in the interior of the Tucson Mountains. The team of co-workers and volunteers took on the task of checking the cameras and processing the thousands of photos.
"Only 36 of those photos showed mountain lions," Haynes said. "That just tells you the number of photos we would need to document their movements in the corridors. We would have to set up cameras in a much higher density. A mountain lion could still have made it through a corridor without a camera picking it up, because the cameras only capture what goes on within about 15 feet."
Limited resources and permitting issues prevented the team from setting up cameras in the most promising corridor spots for very long. "We only had a six-month period in some of the best locations," Haynes said.
Urban sprawl, road construction and other infrastructure developments such as the Central Arizona Project Canal threaten to cut the mountain lions' habitat into smaller and smaller fragments. Trapped in a shrinking habitat and with migratory routes interrupted, the animals are at high risk from inbreeding and even local extinction.
"In an ideal situation, you have resident adults and interchange with juvenile animals coming through from outside areas," Haynes said.According to the study, the mountain lion population in this area is already facing greater geographic constriction than other lion populations deemed genetically isolated and ultimately unlikely to survive. If a top carnivore such as the mountain lion becomes locally extinct, it can have detrimental effects on the ecosystem. Overpopulation of deer is a likely result, in turn leading to over-browsing of native vegetation.
"Typically in the Southwest, a resident adult male has a home range anywhere from 30 to 120 square miles. If they have to ‘island-hop' between mountain ranges, it could be up to 400 square miles. The males do not get along with each other. They will mark their territory and communicate that way to stay out of each other's way. But if they do come across each other, they often will fight, sometimes to the death."
According to Haynes, the home ranges of female lions overlap a lot more, and females are much more tolerant of each other.
"A male home range may encompass, say, four to five female home ranges, and he may be the breeding male," she said. "The females can have kittens all year round, but there is usually a spike in the spring, when they have a lot of prey available to them, fawns for example."
Life as a cougar kitten
The female gives birth to one to four kittens, only one or two of which usually survive. For the first 11 to 18 months, the mother stays with her kittens.
"She teaches them how to hunt and how to survive," Haynes said. "But once they're subadults, they're on their own."
In areas where the population does not experience a lot of stress, a mountain lion can live up to 12 years. Despite facing intensive pressure from relentless persecution in first half of the 1900s and modern pressures such as habitat fragmentation and destruction, mountain lions are a remarkably resilient species that has managed to endure from Alaska all the way to the tip of South America.
"Mountain lions are a very successful species because enough kittens are being born and enough females get it figured out to raise them safely to young adulthood," Haynes said. "The males basically live for two things: access to females and checking out the other guys and making sure they're not coming in. Food is not a big deal in most habitats. For them, it's like going to the Circle K. They can get a deer or a javelina if they want. Hunting is just something that they do."
"Sometimes kittens and subadults may not survive, but those adults are pretty good at what they're doing."Although the cameras were distributed throughout the Tucson Mountains, mountain lions were only photographed in the backcountry, not near residential areas, and most of the lion photographs were triggered at night, exemplifying the mountain lions' natural tendency to avoid humans.
"There is a range of possible conclusions. It could be anything from, ‘these cats are just transients coming from the surrounding areas, or they live solely on the mountain essentially being trapped, or there still is a mix of residents and transients, which would be ideal.'"
"The Sonoran Desert Conservation Plan calls for the conservation of critical wildlife corridors throughout Pima County. The only way to fully identify the corridors that mountain lions use, would be to radio collar the cats. That is something that we as a community should decide after weighing the risks and benefits," she added.
As a side benefit, the study, which was funded primarily by Pima County's Starr Pass Wildlife Enhancement Fund and augmented by the National Park Service, collected thousands of photos of other wildlife in the Tucson Mountains, documenting, among other species, raccoon, spotted skunk, striped skunk, ringtail, badger, Virginia opossum, gray fox, gila monster, mule deer, bobcat, coyote, javelina, pack rat, jackrabbit and cottontail rabbit.
The UA's Wild Cat Research and Conservation Program combines research on Tucson's native bobcats and mountain lions with conservation of the world's 36 species of wild cats. More information can be found at the websites of the program (www.uawildcatresearch.org) and the Arizona Game and Fish Department (http://www.azgfd.gov/w_c/mtn_lion_tips.shtml).Media Contact:
Multi-year study finds 'hotspots' of ammonia over world's major agricultural areas
17.03.2017 | University of Maryland
Diabetes Drug May Improve Bone Fat-induced Defects of Fracture Healing
17.03.2017 | Deutsches Institut für Ernährungsforschung Potsdam-Rehbrücke
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
28.03.2017 | Life Sciences
28.03.2017 | Information Technology
28.03.2017 | Physics and Astronomy