May 25, 2025 Breaking News, Latest News, and Videos

Local Mountain Lions Show First Reproductive Effects of Inbreeding

“It’s quite severe,” says the lead researcher in UCLA study 

By Sam Catanzaro

UCLA scientists tracking two local mountain lion populations, one in the Santa Monica Mountains and another in the Santa Anas, have reported signs of inbreeding among these groups. 

According to the study, these two populations are cut off from other cougar populations by busy freeways, and therefore face limited breeding opportunities. 

The study reported the animals averaged a 93 percent abnormal sperm rate. In addition, while some of the mountain lions displayed physical signs of inbreeding, like deformed tails or testicular defects. 

“Researchers have long had genetic evidence of inbreeding, but the malformed sperm is the first evidence that inbreeding is manifesting in the reproductive system,” reads a press release announcing the results. 

The study’s lead author is Audra Huffmeyer, a UCLA postdoctoral researcher who studies fertility in large cat species and is a National Geographic Explorer. 

“This is a serious problem for an animal that’s already endangered locally,” Huffmeyer said. “It’s quite severe.”

Over the past year, researchers identified nine adult males from the Santa Monica and Santa Ana ranges displaying signs of inbreeding. The scientists took sperm samples from five cougars that had died from unrelated incidents, including rat poisoning and car collisions. They found that each had very high levels of abnormal sperm, together averaging an “exceedingly high” 93 percent abnormal sperm rate. One of the five also had testes of dramatically different sizes.

The researchers also found other signs of inbreeding among living cougars:  four had kinks in their tails, including one that also had only one descended testicle. 

The study called for the need for wildlife crossings, which would allow the mountain lions and other animals find a broader pool of potential mates. The California Department of Transportation has scheduled groundbreaking for early 2022 on one such crossing, a wildlife bridge over Highway 101 in Agoura Hills in northwestern Los Angeles County, thanks to a mix of public and private funding.

“Mountain lions, also known as cougars, are a bellwether species, making them a leading indicator that inbreeding could soon cause problems for other wildlife species in the Santa Monica and Santa Ana mountains,” researchers said in announcing the study. “The study warned that there’s a real risk of extinction for the mountain lions in the Santa Monica and Santa Ana ranges. Although they haven’t seen evidence yet, once scientists start finding significant inbreeding depression — meaning decreased fertility and reduced kitten survival — extinction is predicted to occur within 50 years, with a median extinction time of 12 to 15 years.” 

Biologists and land managers hope this project will lead to more crossings. In fact, early plans are being formulated for a possible structure over Interstate 15 in in Riverside County. Crossings, the researchers say, help all local animal species amp up their genetic mix. 

For now, the researchers will continue monitoring how the newly discovered fertility issues affect the mountain lions’ breeding, keeping a close eye on potential decreases in the number of kitten litters and kitten survival rates.

“If we don’t do anything to add genetic diversity, the end is near,” Huffmeyer stressed. “That sounds dramatic, but that’s what we’ve seen.”

in News
<>Related Posts

Resilient Palisades Named Nonprofit of the Year by Sen. Ben Allen

May 23, 2025

May 23, 2025

Volunteer-led group honored for climate resilience work and wildfire recovery efforts Resilient Palisades, a grassroots environmental organization based in Pacific...

Governor Announces Early Reopening of Pacific Coast Highway After Wildfire Closures

May 22, 2025

May 22, 2025

Major Stretch of PCH Reopens May 23 After Months of Wildfire-Related Closures Governor Gavin Newsom announced Wednesday that State Route...

Film Review: Final Destination: Bloodlines

May 22, 2025

May 22, 2025

FILM REVIEWFINAL DESTINATION: BLOODLINESRated R110 MinutesReleased May 16th  This is the sixth entry in the Final Destination movie franchise that...

Bay Cities Deli Temporarily Closed After Health Violations

May 22, 2025

May 22, 2025

Eleven violation points were attributed to the presence of rodents and insects Bay Cities Italian Deli & Bakery, a popular...

Man Arrested in Stabbing Near Santa Monica Pier

May 22, 2025

May 22, 2025

Victim hospitalized with non-life-threatening injuries following altercation A man was arrested after allegedly stabbing another man during an altercation near...

Exclusive Interview with Cardinale du Vin’s New Chef-in-Residence Paul Chuanchaisit

May 22, 2025

May 22, 2025

The Westside Wine Bar Expands Its Culinary Horizons With a Bold New Menu By Dolores Quintana Cardinale du Vin is...

Palisades Bakery Aids Displaced Residents with Deliveries, Cookbook Donations After Fire

May 21, 2025

May 21, 2025

The bakery’s relief effort is aimed at ensuring that displaced residents continue to have access to familiar foods during recovery...

Memorial Day Weekend in L.A.: Rosé, Beach BBQs, and Brunches Ring in the Summer

May 21, 2025

May 21, 2025

The Westside Is Packed With Culinary Events, Pop-Ups, and Parties This Weekend Angelenos looking to kick off the summer season...

Summer at Annenberg Beach House to Include Sunset Picnics, Yoga Classes and the Annual Cardboard Yacht Regatta

May 21, 2025

May 21, 2025

The Beach House, located on the former Marion Davies estate, remains free and open to the public The Annenberg Community...

(Video) Interview with Chef Roy Choi for his new book The Choi of Cooking

May 21, 2025

May 21, 2025

We speak with the world-famous Socal Chef in Manhattan Beach at the Los Angeles Public Library.

FDA Probes Salmonella Outbreak Tied to Recalled Cucumbers Distributed in California

May 21, 2025

May 21, 2025

At Least 26 People Sickened and 9 Hospitalized in Multiple States  Federal health officials are investigating a multistate outbreak of...

10th Annual MAINopoly: A Taste of Main Street Comes to Santa Monica This Weekend

May 21, 2025

May 21, 2025

Annual board game-inspired food event set for Sunday, May 25 The 10th annual MAINopoly: A Taste of Main Street will...

Michelin Three Star Institution Brings 20th Anniversary Culinary Experience to Beverly Hills

May 21, 2025

May 21, 2025

Grant Achatz’s Alinea Heads to Beverly Hills for Summer Residency Renowned chef Grant Achatz and his team at Alinea, Chicago’s Michelin...

$2.2M Awarded to LA County for Wildfire Prevention Ahead of 2025 Fire Season

May 21, 2025

May 21, 2025

The grants mark the first disbursement of funds from Proposition 4, a bond measure that provides millions for wildfire resilience...

(Video) Classic Cars and Hot Rods Showcased During Santa Monica Pier’s Locals Night

May 20, 2025

May 20, 2025

It Was The Last Locals Night of the Season It Was The Last Locals Night of the Season. pic.twitter.com/mUo6hMJpPZ —...