Bats Dislike Solar Farms New Study Suggests, Which May Be Another Hurdle For Renewable Energy Sources

A new study from Britain suggests that bats dislike solar farms. The activity of six different species is reduced nearby.

According to the results are troubling to researchers because bats are enormously important as insect predators. Reduced bat activity and numbers may have great consequences for people and other wildlife. If bats dislike solar farms harmful insects may abound.

1. & 2. Red bat
1. & 2. Red bat by Library of Congress is licensed under CC-CC0 1.0 Bats come in many sizes from tiny to very large. Most are insectivores but bats exist that eat anything from fruit to blood.

The issue is also cautionary as the world explores sources of renewable alternative energy. Energy production often impacts wildlife and often negatively. The fact that renewable sources such as wind and solar can be a negative impact requires re-thinking how to go about advancing renewables.

According to

“Lead author Lizy Tinsley from the University of Bristol’s School of Biological Sciences explained, “Renewable energies can have negative impacts on biodiversity and mitigation s essential to provide win-win solutions for energy suppliers and for wildlife

To carry out their experiment, the team set up bat static monitoring equipment in a solar farm field, and a matched field without solar panels (control site).

Fields were matched in size, land use, and boundary feature (e.g. hedge, fence, stream), and a bat detector was placed in the middle and edge of both fields, totaling four recording locations, repeated across 19 separate sites. Field boundaries were selected as they are important navigation features for bats.

The data from the different echolocation calls at recording points were then analyzed to identify the bat species and number of bat passes. They found that the activity level of common pipistrelle, noctule, myotis species, serotine, soprano pipistrelle and long-eared species was substantially lower at solar farm sites, compared to the paired control sites.” (Links in original)

Bat activity lower at solar farm sites, study finds
Illustration showing effect of solar farming on bat activity. Credit: Lizy Tinsley

Tinsley said, “Due to the significant negative impact identified, solar farm developments should be screened in an Environmental Impact Assessment for ecological impacts so that appropriate mitigation be designed against the impacts, and monitoring undertaken. This has already been done with wind farms—where mortality of bats has been reduced by changing the wind speeds at which turbines become operational and by using acoustic deterrents, at minimal cost.” (Links in original)

close up photo of a solar panel
Photo by Los Muertos Crew on Proponents tout solar panels as a perfect renewable energy source. But they may have negative impacts on bat populations, a study from the United Kingdom suggests.

Bats have been in science new lately. Vampire bats appear to be moving into Texas. The compound they use to keep victim’s blood from clotting is called Draculin. It is under intense study. It is hoped it will yield drugs for blood diseases. Meanwhile, Tinsley and fellow researchers are continuing to study bats and solar farms.

Cow Killing Ticks Present New Threat To Livestock And Other Wildlife

We have occasionally discussed ticks before. The spider relatives are a serious source of illnesses in humans and in wild and domestic animals too. Cow killing ticks appear to be on the move in the United States. They have been moving east to west and bringing disease with them.

The Asian long horned tick is moving its way west in the Unted States. It is considered a major threat to cattle and even to other animals.

The cow killing tick in question is the Asian long horned tick. An invasive species first spotted in the United States about six years ago. It appears to have brought theileria with it.

That collection of diseases can be fatal to cattle as it produces severe anemia. Treatments do exist but they are expensive and prevention becomes key.

field australia farm brown
Cattle can be killed by anemia brought on by the bites of the Asian long horned tick. Photo by Pixabay on

Acccording to KOSU

“Part of the reason theileria is so devastating to cattle is because it’s new to the U.S., said Cassandra Olds, a microbiologist at Kansas State University who studies the relationships between pathogens and hosts.

U.S. cows are naïve to the disease, Olds explained, meaning the animals have never been exposed to the pathogen. Without prior experience, their immune systems have no knowledge of how to contend with the disease.

“Outbreaks are always going to be the most severe when something is introduced to an environment,” Olds said. And at this point, only a statistically negligible portion of the U.S. cattle population has been infected with theileria.”

Deer Tick
Deer Tick by Hill Walker is licensed under CC-BY-SA 2.0 Ticks are small arachnids related to spiders. Despite their small size they carry many diseases including about 14 in the United States.

According to the Merck Veterinary Manual:

“Theilerioses are a group of tickborne diseases caused by protozoan parasites of the Theileria genus. A large number of Theileria spp are found in domestic and wild ungulates in tropical and subtropical regions of the world. The most important species affecting cattle are T parva and T annulata, which cause acute disease resulting in high levels of mortality. T lestoquardiT luwenshuni, and T uilenbergi are important causes of mortality in sheep, and T equi sometimes causes clinical disease in horses. A therapeutic drug, buparvaquone, is available to treat the diseases, but it is expensive, and control of the diseases usually involves either prevention of tick infestation or, in some areas, vaccination.”

Tick control is crucial. In the long-term some advances have been made against the deadly arachnids. Ticks were considered to be ineligible for genetic altering. But recent research at the University of Nevada shows the way toward altering their genes. The research suggests there will be a way to edit tick genes to control the ability to spread disease. It can’t come soon enough to blunt the impact of cow-killing ticks.

Python Hybrids May Begin To Complicate Issues Of Python Control In Florida And The Southeast

In the effort to control the invasive Burmese python (Python bivittatus) scientists have discovered a potentially troubling development. Python hybrids between the Burmese and Indian python (Python molurus).

Python hybrids are a concern because the two species inhabit different habitats. The Burmese pythons are at home in the Everglades wetlands. Indian pythons tend to prefer drier land. The fear is that “intermarriage” could create pythons more adaptable to different habitats and ease the spread of the destructive snakes.

brown and beige snake in the grass during daytime
Apparently pythons can nterbreed potentially leading to hybrid vigor and super pedators Photo by Pixabay on

So far the number of python hybrids is not overly large. But there is some evidence Burmese pythons are already expanding their range. Anything that increases their ability to increase their range is unwelcome. The genetically mixed snakes were discovered during testing of 400 of the animals captured. It is assumed that the inbreeding occurred in Asia and is showing up in snakes hatched here.

The invasive pythons may have killed up to 90 percent of mammals in some parts of the Everglades. They are able to eat almost any animal around, including adult deer.

According to news reports in IFLscience:

“In 2018, researchers from the US Geological Survey carried out a genetic analysis of about 400 Burmese pythons captured across a wide area of South Florida. The study was published in the journal Ecology and Evolution.

At least 13 snakes were found to be a genetic blend of Burmese pythons and Indian pythons, indicating they were the production of hybridization

“The snakes in South Florida are physically identifiable as Burmese pythons, but genetically, there seems to be a different, more complicated story,” Margaret Hunter, a USGS research geneticist and lead author, said in a statement.

Often when two similar species interbreed, their offspring are put at a disadvantage. They might be infertile or face other challenges that make them less suited to the environment. Sometimes, however, the right combination can create a hybrid that can outperform its non-hybrid counterparts. This is what’s known as heterosis, or hybrid vigor.

Pythons are on the move in florida and potentially outside the state

“[Interbreeding] can lead to hybrid vigor, that is, the best traits of two species are passed onto their offspring. Hybrid vigor can potentially lead to a better ability to adapt to environmental stressors and changes. In an invasive population like the Burmese pythons in South Florida, this could result in a broader or more rapid distribution,” explained Hunter.

Meanwhile, the battle against invasive pythons continues. Part of the reason why the python population has been so tricky to control is that the snakes are extremely well-camouflaged to the environment. While advances in genetic sampling won’t solve the issue alone, it is providing scientists with a new weapon to better understand the threat. 

adorable animal canine cute
Mixed breed dogs are often cited as examples of hybrid vigor because the admixture reduces risk of diseases common to specific breeds.Photo by Pixabay on

“Our ability to detect Burmese pythons in the Greater Everglades has been limited by their effective camouflage and secretive behavior,” added Kristen Hart, a USGS research ecologist and a co-author on the study. 

“By using genetic tools and techniques and continuing to monitor their movement patterns, we have been able to gain a better understanding of their habitat preferences and resource use. The new information in this study will help scientists and wildlife managers better understand these invasive predators’ capacity to adapt to new environments.” (Links in original).

That the pythons seem to b expanding their range appears clear. How far they can go is still conjectural

400 Elephants Died Almost At Once; Cause Of Mass Death Is Finally Clear

It was a shocking event several years ago. 350 elephants in Africa died suddenly and mysteriously. More mass deaths followed until 400 elephants died. The elephants literally dropped dead.

The mystery impelled researchers to find out what killed the animals and what the ramifications are. According to the Guardian the cause may finally be clear.

gray elephant
Habitat loss and poaching are two of the biggest threats elephants face. Infectius disease has now been added to the list. Photo by Harvey Sapir on

Some things were ruled out quickly. The ivory was not missing so it was not a case of mass poaching. Intentional poisoning was also ruled out. The other causes took more time to investigate:

P. Multocida is a bacteria closely related to the one that recently killed 400 elephants. It is the cause of numerous diseases in humans and animals.

According to the Guardian:

“In 2020, 350 elephants mysteriously died in Botswana, with a further 35 dying in similar circumstances in Zimbabwe. Now scientists think they may have found the reason the elephants died.

In May and June 2020, the death of 350 elephants in Botswana’s Okavango delta baffled conservationists and sparked global speculation about what had caused it. Elephants of all ages and both sexes were affected, with many walking in circles before dying suddenly, collapsing on their faces. Two months later, 35 more elephants died in north-western Zimbabwe.

At the time, the deaths in Botswana were attributed to an unspecified cyanobacterial toxin, government officials said, and no further details were published.”

“But tests on the elephants that died in Zimbabwe have finally come back and shown the cause was a little-known bacterium called Pasteurella Bisgaard taxon 45, which resulted in septicemiaor blood poisoning.” (Links in original.”

black elephant near trees
Most people are aware that poachers kill elephants for their ivory. Death by group infection is now added to the list of threats elephants face. Photo by Venkat Ragavan on

Pasturella is a family of bacteria widespread among animals. Members of the family pose various levels of threat to animals and humans. The bacteria here is as yet unnamed but is a close relative of P. multocida. That bacterium can cause hemorrhagic septicemia in other animals. Septicemia is a reaction to the invasion of the body by bacteria. This form of bacteria cause hemorrhage as well.

The outbreak has caused elephant guardians to add infectious disease to the list of threats to the species. The fact that 400 elephants died almost at once shocked animal experts. Efforts to better understand and deal with disease threats are now under consideration.

In better news two Asian elephants were recently recruited to help protect cheetahs in India’s ambitious reintroduction plan.

Los Angeles Zoo Joins New Effort To Streamline Rescue Of Trafficked Animals And Find Them New Homes

The struggle against animal trafficking is becoming better organized thanks to a a new effort spearheaded by the Association of Zoos and Aquariums (AZA) and Involving both los Angeles Airport (LAX) and the Los Angeles Zoo. The airport is the site of much attempted smuggling.

hippo with open mouth eating grass in zoo
Pablo Escobar smuggled hippos into Colombia where they are causing damage to the nation’s river systems. Photo by Mehmet Turgut Kirkgoz on

According to the new system will replace an older patchwork model with a coordinator dedicated to matching rescued animals with an appropriate new home. The old system relied on a system of informal contacts, not a specific organization. Los Angeles Zoo has been the recipient of many smuggled animals and is helping start the new program.

According to the website:

“In 2022, Fish and Wildlife special agents and the service’s law enforcement partners investigated more than 10,000 wildlife trafficking cases and collected more than $11 million in criminal penalties.”

Los Angeles Airport (LAX) has thwarted dozens of attempts and many of the animals live ou their lives at the Los Angeles Zoo.

The theft of cheetah cubs for pets is driving the cats closer to extinction in the wild.Photo by Pixabay on

Animal trafficking is a big business. Some experts put it in a triad with drugs and gun running. In fact, the three sometimes go together. Drug lord Pablo Escobar, for example, trafficked in weapons and also in animals. He brought hippos from Africa to Colombia, They thrived and are causing ecological damage to the countries rivers. The number has grown to about 400 and some may have to be killed to reduce the increase and limit the damage. They are also dangerous and kill as many as 500 people in a year

The illegal pet trade is also rampant. Many animals are captured for exotic pets. That trade is said to be driving cheetahs closer to extinction in the wild. India has aunched Proect Cheetah to try and reintroduce the cats to that nation.

condor airplane on grey concrete airport
Airports are a frequent site of smuggling attempts for many animals around the world. Photo by Pixabay on

French Wolves Kill An Estimated 15,000 Head Of Livestock Each Year, But France Seems Determined To Coexist With The Predator

Wolves are one of the hot button topics in conservation with proponents pushing expansion and reintroduction. Bitter opponents seek eradication. French wolves provide some answers about the cost of coexistence. But French wolves kill an increasing number of domestic animals.

Wolves were common in France. They were intensely hunted in the 19th Century. Canis lupus was eradicated from the country by the start of World War Two. Wolves returned to France from Italy about the turn of the 21st Century.

Wolf waiter png sticker, animal
Wolves are frequently found in cartoons or other forms of art, often for a laugh. But there is nothing funny about wolf predation to ranchers and sheepherders in France or the United States.

Today, there are an estimated 538 wolves in France. Having entered from the Italian region they have been steadily moving into other parts of the country. It is estimated their numbers are growing between 10 and 20 percent per year.

That growth rate is not without cost as the French authorities estimate the wolves kill 15,000 head of livestock annually. The French wolves kill sheep, cattle, goats and horses. That equates to 9 head per wolf annually. The number appears to be rising.

Livestock protection dogs (LPD) and
Livestock protection dogs (LPD) and by U.S. Department of Agriculture is licensed under CC-CC0 1.0 Guard dogs can deter wolves but sometimes wind up injured or on the menu

” More worryingly, the number of livestock victims has been increasing linearly and almost constantly over the last 12 years, with 1,000 more animals killed each year. Predation strongly impacts livestock systems that practice grazing, whether in the mountains, hilly regions or even in the plains. In the French alpine region, an area where wolves have been present for a quarter century, more than 90% of successful attacks take place on farms that have adopted the recommended means of protection, a condition verified by OFB staff who have assessed the damage. The indirect impacts of predation should not be forgotten either: following attacks, the animals are stressed and, in addition to abortions and loss of body condition, they sometimes refuse to graze for 2 to 3 years on the places where they have experienced a wolf attack.”

France, like other nations with wolf populations, is exploring co-existence measures. Better fencing, guard dogs, enclosing animals at night, increased human monitoring an compensation for loss by predation are among the methods being used. But the rate of loss continues. Even in regions where the recommended protections are enacted French wolves kill livestock.

Walkers' tour through France. Being
Modern French wolves arrived from Italy and most remain in the region. But they are expanding their range in the country.

Compensation for loss appears to be an equitable solution. But proving a wolf killed an animal can be problematic. Sometimes animals simply disappear when wolves are around. If proof is lacking payment may not be made. Ranchers also complain that the compensation method is slow and cumbersome.

The French experience is in line with fears by anti-wolf organizations in the United States where wolf re-introduction efforts are meeting stiff resistance from ranchers and other stakeholders. It is beyond doubt that wolves destroy livestock. In one incident 143 panicked sheep stampeded and died of suffocation or injury. Two wolves chased the sheep.

Ranchers point to the growing gulf between people who produce food and wool and the people who consume. They say city dwellers have no idea of the cost of producing meat, wool, milk and cheese. Urbanites have a romanticized idea of what wolves are and what predation means, they say. Defenders counter that the damages are exaggerated and that the wolf is a vital part of the ecosystem. Middle ground is hard to find.

Colorado is attempting wolf reintroduction, despite vocal resistance. Italy has an expanding wolf population. But fears about wolf predation have led to poisonings in the United States and Italy.

Sicilian Fire Ants Found, Newcomers May Colonize Island With Some Bad Results

Fire ants (Family Solenopsis) are troublesome ants in much of the United States. They have medically significant bites and stings and are a destructive invasive species. Recently, the discovery of Sicilian fire ants has the authorities of Italy worried.

According to the Guardian the ants so far appear to be confined to about 12 acres (5 hectares) around the city of Syracuse . According to the paper:

“The red fire ant, Solenopsis invicta, has a powerful sting, damages crops and can infest electrical equipment including cars and computers.

The ant, considered one of the most destructive invasive species, can rapidly form “super colonies” with multiple queens. The colonies prey on invertebrates, larger vertebrates and plants, destroying native plants and out-competing native ants, insects and herbivores for food.

The red fire ant is the fifth most costly invasive species in the world, spreading via human trade from its native South America into Mexico, the Caribbean, Australia and the US, where it causes an estimated damage of $6bn (£4.8bn) each year.

Fire ant worker, Solenopsis invicta
Red fire ants. solenopsis invicta, can both bite and sting. Their venom can kill some people.

Researchers have identified 88 red fire ant nests across 5 hectares (12 acres) near the city of Syracuse, in Sicily, Italy. According to genetic analyses in a study published in Current Biology, the invasive colonies could have come from China or the US.” Links in original.

Researchers hope quick action can help control the ants and keep them from spreading to other nations.

In the United States fire ants have spread to many states and are beyond elimination. Texas has a significant problem with the ants, which infest 14 states from Florida to California. Puerto Rico is also infested.

Fire ants
Fire ants by Sergeant Matt Hecht is licensed under CC-CC0 1.0 Black fire ants are unwelcome visitors too.

Sicilian fire ants are potentially a serious problem for Europe. According to the United States Department of Agriculture (USDA) solenopsis ants do$6 billion in damage in the United States:

“Two species of Imported Fire Ants (IFA) were introduced into the United States from South America at the port of Mobile, Alabama. The black imported fire ant, Solenopsis richteri Forel, arrived around 1918 and the red imported fire ant, Solenopsis invicta Buren, in the late 1930’s. Both species probably came to the port in soil used as ballast in cargo ships. Today, IFA infest more than 367,000,000 acres in Alabama, Arkansas, California, Florida, Georgia, Louisiana, Mississippi, New Mexico, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, Virginia and Puerto Rico. IFA have an impact on agriculture and natural resources by damaging crops, agricultural equipment, and impacting wildlife. As an urban pest, IFA are a nuisance pest and can cause allergic reactions including rare instances of anaphylactic shock in humans.”

brown animal on green grass
Armadillos are known to eat fire ants, but are not enough to control them.Photo by Victor Miyata on

The ants destroy crops, can ruin agricultural electrical equipment, and kill or outcompete native ants. They also attack native wildlife and native plants.

Fire ant densities in the United States are many times greater than in South America. That is believed to be because viruses and other diseases that kill the ants have not been imported with them. Their main enemy appears to be a fly that lays eggs on the heads of live fire ants. The hatchings then consume the ant. Spiders and other American predators will also eat the ants. So far no “Magic Bullet” has been found.

The USDA has begun a phorid fly breeding program to reduce the ant numbers but it is not expected to totally end the outbreak:

“In an effort to manage IFA within the generally infested areas of the U.S, APHIS, along with cooperators in Agricultural Research Service, universities, and states, implement an Imported Fire Ant Phorid Fly (Pseudacteon spp.) rearing and release program. The first 2 species of this biocontrol agent, P. tricuspis and P. curvatus, were released from 2002-2009 and have become established in more than 65% of the IFA quarantined area. In 2010-2014 there were multiple releases of two additional species, P. obtusus and P. cultellatus, both of which have become established in limited areas. Phorid flies will not be a stand-alone biological control agent for IFA but will be an important tool in IFA management programs.”

Abundant Deer Roam The United States Despite Predators, Winter, Traffic And Hunting

The United States is increasingly urban and wild lands are shrinking. But wildlife still exists and some thrive. Abundant deer, for example, can be found everywhere in the country.

According to A-Z Animals the national population is estimated to be up to 36 million. That is nearly as many as the number of people in California, estimated at 39 million. The numbers have been rising steadily.

a whitetail deer on a snow covered field
Deer have become abundant in the United States ad present a number of management challenges.Photo by Deloris Augustine on

The deer family (Cervids) is quite large. The United States is home to 5 native species, and a number of subspecies. The natives include whitetail and mule deer. Moose, Caribou (known as reindeer in Europe) and elk are also members of the deer family.

The population is large but millions of deer die each year. According to Deer and Deer Hunting website the number of deer that die annually is staggering. The website recognizes four main wild deer predators, coyotes (canis latrans) wolves (Canis lupus) black bears (Ursus americanus ) and mountain lions (Puma concolor). The statistics it gives are for whitetail deer.

The website estimates that there are about 5 million coyotes in the United States. About 500,000 of them are killed by humans in coyote control efforts. The survivors eat an estimated (by the website) 3 million deer a year. Most of them are fawns. Fawns are also killed by black bears. Bears may number 600,000 nationally and about 50,000 are killed by people annually. Those survivors are said to kill about 1.5 million deer annually.

Black Bear Cub We spotted this
Black Bear Cub We spotted this by U.S. Fish and Wildlife Service is licensed under CC-CC0 1.0 Black bears may not be the first predator that comes to min in connection with deer but they are predatory omnivores and eat many fawns annually.

The website claims that wolves kill about 1 million whitetail deer annually. Most of that must be in Canada as wolves are fairly uncommon in the contiguous United States.

Human hunters kill an estimated 6 million deer annually and about two million die in traffic accidents. Despite the carnage deer numbers appear to be increasing. Human proximity has apparently benefited deer. Human development has opened forage land to deer that was denied in very heavily forested land. They eat garden greenery, crops, and other vegetation once denied them. Abundant deer can become a problem for state wildlife management as they impinge on human property and cause damage.

Wolves like this one andthe smaller coyote eat deer at all life stages. Coyotes eat mostly juvenile deer while wolves consume many adults.

Managing deer populations can be a difficult task. Pennsylvania authoritis recently wrestled with deer leaping to their death from an overpass. Although their agendas vary greatly state traffic wildlife authorities, federal land managers, conservationists, hunters and landowners all work together on deer management.

Yellowstone Bison Survive Harsh Winter But Numbers Are Way Down Due To Deaths In The Cold

Visitors to Yellowstone National Park are treated to the chance to see one of the nation’s best and best protected bison herds. But Yellowstone bison face challenges even diligent park staff can’t save them from. These include wolves and harsh winters. But enough Yellowstone bison survive the winters to spark some debate on managing the herd.

photo of bison on grass field
Yellowstone National Park is home to several thousand bison. The herd suffered a hard winter last year but there was a significant calf crop in spring/ Photo by Chait Goli on

According to the Billings Gazette last winter was especially severe. About 4,800 Bison (Bison bison) survived after the winter of 2022-2023. That number was recorded in August 2023. This was down from about 6,000 at the peak summer population recorded in August 2022. As a result authorities will permit the hunting or transfer of no more than 1,100 bison this year. This number is selected to keep the Yellowstone bison herd at healthy numbers.

Bison management is a cooperative effort involving numerous agencies. Government agencies from neighboring states and the federal government have a say. Native American peoples have a special relationship with the bison and they are deeply involved in bison management efforts. A number of tribes have their own herds which they manage on tribal lands. There is often disagreement. The National Park Service aims to keep the herd number at 3,500 or more to maintain genetic diversity. Montana feels the number could be 3,000, the paper said.

In addition, because bison have made a spectacular comeback, other stakeholders are involved in the management of bison herds. Cattle ranchers need to be reassured that brucellosis, a serious cattle disease, will not be spread to cows from bison. Since recovery efforts in the 19th and 20th century involved various types of crossbreeding efforts are made to keep the bloodlines pure.

Medicine Crow was a prominent chief and warrior of the Crow Nation. He was active in the second half of the 19th Century. Today, the Crow people maintain a bison herd of their own and conduct select trophy hunts.

The Yellowstone bison survive various threats and some do wander out of the park, there are health concerns, and wandering buffalo do cause problems. So the herd is culled annually.

The culling can take place in three ways. Hunting by Native American tribes and other hunters, processing by the tribes, and transfers through the Bison Conservation Transfer Program. The program was initiated by the NPS and the Fort Peck Assiniboine and Sioux tribes on the Fort Peck Indian Reservation in Montana. Under the program healthy bison are transferred to various tribal herds. The program works with more than one dozen plains area tribes interested in bison conservation. Native American tribes are fully involved in the decisions taken. Fort Peck was founded in 1871 and is home to members of the Assiniboine tribe. Members of a number of Sioux bands live there too, including some descendants of Hunkpapa who fled to Canada with Siting Bull.

hot springs in wyoming yellowstone park
Yellowstone National Park is the oldest national park. President Ulysses S. Grant signed it into law March 1, 1872. Photo by James Lee on

One of the tribes sponsoring hunts is the Crow Nation. The Crow offer hunts for trophy quality bison for a set fee. The hunts are of a limited number of tribal buffalo on tribal land. The tribe is also seeking to join six other tribes in permitted hunts outside the park in winter,


4,500 Cougars Call California Home, New, More Accurate Study Concludes

Researchers have developed a more accurate estimate of the number of cougars (Puma concolor) who share California with more that 39 millions people. The new best estimate is that 4,500 cougars can be found roaming close to us.

photo of a cougar near a log
Cougars are the largest cat in California. Almost all of the state is potential home land for the cats. But increasing contact with people has not proven good for the cats. Photo by Nicky Pe on

According to CapRadio the research is brand new and likely won’ be published for about a year. It is the product of work done by Justin Dellinger. Dellinger is a wildlife biologist and specialist in wolves and cougars for the California Department of Fish and Wildlife (CDFW).

The new number replaces an old estimate of up to 6,000 resident cats. That number dated to the 1980’s and technology has advanced greatly since then. The 4,500 cougars can be found virtually everywhere in the state.

An artist’s rendering of the 101 Freeway crossing near Liberty Canyon. The overcrossing should help all wildlife avoid traffic on the freeway and prevent or seriously reduce inbreeding.

Dellinger told the radio station:

“Newer technology allows his team to both analyze mountain lion scat collected from their home range and follow their movements with tracking collars has helped.

“They didn’t have genetic capabilities [and] collars were pretty much in their infancy in that time,” Dellinger said of the limitations behind the decades-old estimate. “The technology is a lot different now.”   

But even with that technology at hand, he said mountain lions are fairly secretive and have large home ranges, making them a hard species to follow. “

aerial photography of concrete road
Freeways are dangerous places for both people and animals. Photo by mhtoori .com on

The old days saw “back of the napkin estimates” in which the estimated size of the potential mountain lion range in the state was divided by a rough estimate of the size of an adult mountain lion’s range.

Although 4500 cougars may seem a hefty number California’s biggest cats face a number of threats from humans. The biggest is traffic collisions which kill numerous cougars annually. CalTrans, the state’s traffic and highway agency, now works to create under and overpass options into roadwork. Projects such as Liberty Canyon are also being funded. That project will help with the traffic problems and also inbreeding. Los Angeles area cougars number about 20 in the Santa Monica Mountains. They are virtually trapped by freeways and inbreeding is a serious issue. Finally areas of high mortality have been identified and that will focus attention on remedies.