The Florida panther (\(Puma\) \(concolor\) \(coryi\)) is a subspecies of puma, also known as a mountain lion or cougar. Historically, the Florida panther’s decline can be attributed to hunting. It was listed as endangered in 1967 and became protected under federal and state laws.Yet, Florida panther numbers had declined to roughly 30 cats by the early 1980s and severe inbreeding resulted in many health and physical problems. A genetic restoration project in 1995 was successful in improving the genetic health and vigor of the panther population.

According to the Florida Fish and Wildlife Conservation Commission, there are approximately 120-230 adult panthers in the population today, where they are found primarily in the Big Cypress/Everglades ecosystem in Collier, Lee, Hendry, Monroe and Miami-Dade counties. One of the biggest threat to the future of the Florida panther is habitat loss. However, many panthers die each year due to vehicle strikes on roadways.

Florida Fish and Wildlife Conservation Commission veterinarians perform a complete necropsy (animal autopsy) on all panthers found dead in the wild. In all panther necropsies, a thorough examination of the dead panther can provide important information as to the true cause of death, as well as other factors affecting the panther’s health.

The Florida Fish and Wildlife Service’s Panther Pulse program tracks Florida Panther deaths, births and depredations. Data from 2014 to present are available online at: https://myfwc.com/wildlifehabitats/wildlife/panther/pulse/.

The dataset used in this investigation was sourced from Panther Pulse and includes the date of dead panther discovery, unique panther ID, age (averaged when necessary) in years, sex, cause of death and the Florida county where the dead panther was found. More accurate location data is available from Panther Pulse.

Analysis

1. How many Florida Panthers have died from 2014 to 2023? What was the deadliest year(s)? What is the yearly mean number of panther deaths?

267 Florida panthers have died since January 1st 2014 - December 31st 2023. The number of panther mortalities ranged from 42 in 2015 and 2016 to 13 in 2023. The mean mortality per year was 29.67 (SD ± 9.17) panthers. Panther mortality has declined over time.

2. What was the most common cause of death for panthers between 2014 - 2023? What was the number of ‘natural’ panther deaths?

The most common cause of death for panthers from 2014 to 2023 was vehicle collision (89.5% of identified cause of deaths, 95% CI: .86 - .93). Of the identified cause of deaths, 18 were ‘natural’ due to intraspecific aggression, panthers killing panthers. Usually adult males kill juvenile males, who often enter the adults’ ranges in search of females. Males also have killed females, and younger males have killed older males. There were 24 unknown or unidentified cause of deaths from 2014 to 2023. “Other” deaths include euthanasia, gun shot, starvation, and train.

3. What county had the most panther deaths?

56% of all panther mortalities from 2014 to 2023 were in Collier County (95% CI: 0.50 - 0.62), followed by Hendry (24%, 95% CI: 0.18 - 0.30) and Lee (12%, 95% CI: 0.06 - 0.18) counties. This aligns with the location of known wild Florida panther populations.

4. What was mean and median age of panthers at death (in years)?

Panther age at death ranged from 4 weeks to 17 years. The mean age of panther at death was 3.08 (SD ± 2.97) years. Median age was 2.5 years. Female panthers reach sexual maturity at about one and a half to two and a half years old, and males at about three years old.

5. Was there a difference in sex?

56.4 % (95% CI: .50 - .63 ) of panther mortalities with known sex were male, and 43.6% (95% CI: .38 - .50) were female, there was not a significant difference in panther mortality between sexes from 2014 to 2023. There were 13 unknown sex individuals.

6. Was there difference between seasons / times of year in panther deaths?

There were more panther mortalities in the winter dry season (November - February) than in the summer wet season (May - August), however this was not statistically significant.