This year has not been kind to two of Florida's most treasured animals. Florida panthers and manatees have been killed in record numbers in 2016, with a couple of weeks still to go. These grim milestones are a reminder that wildlife managers must follow sensible measures to protect these vulnerable species and Floridians must be cautious not to add to the death toll even as the numbers of panthers and manatees are on the rise.On Dec. 2, a manatee was found dead in Fort Lauderdale's Stranahan River, the 98th fatality this year, breaking the record set in 2009. The 10-foot-long female died from boat propeller wounds, which is not the typical cause of death for manatees in Florida. Most die from boat strikes that shatter their bones and drive shards into their heart and lungs. Regardless, both types of injuries reinforce the critical need for boaters to abide by low-wake zones. Speeding through shallow manatee habitats poses mortal danger to these gentle animals, which have been on the U.S. endangered species list since the list's inception in 1967.That endangered status, however, is in doubt even as boat-related fatalities climb. The U.S. Fish and Wildlife Service announced in 2014 that it was considering changing the manatee's status from "endangered" to "threatened," a lower level of protection. The downgrade, based on computer modeling that tries to predict population levels, is not justified. Manatees weren't put on the endangered list because of their numbers. They were given the special protection because of threats to their habitat from pollution and development, as well as boat collisions — all threats that remain today. One bright spot for the sea cow: More than 6,000 manatees were counted in the latest aerial count of the state's waters. That's a healthy figure that has bounced back after a precipitous die-off in 2013.Panthers' numbers have rebounded as well, but their survival hopes remain precarious. The state estimates the panther population at between 100 and 180 adults, a big jump from the mid 1990s, when there were no more than 30 roaming Florida. But rapid development in southwest Florida is encroaching on panther habitat and resulting in deadly interactions. This year, a record 32 cats have been struck and killed by cars. The latest, a 4-month-old kitten, was found this month near the Fort Myers airport. The best hope for saving the Florida panther, which is also on the endangered species list, is protection of the Florida Wildlife Corridor, 16 million acres of public and private lands that provide wildlife habitat stretching from the Everglades to Georgia and Alabama. The corridor includes private ranches that are vulnerable to being sold for development as the state's agriculture industry struggles to remain competitive and land values rise. But their preservation is critical to the panther's survival. How critical? For the first time since 1973, a Florida panther was spotted on a former ranch north of the Caloosahatchee River in November. For decades the river was thought to be the northern boundary of the panther's breeding ground.The female was photographed on Babcock Ranch, a former private cattle and timber ranch between Punta Gorda and Lake Okeechobee. The ranch was sold to the state in 2006 and is now preserved as part of the wildlife corridor. For private ranches still in operation, conservation easements enable ranchers to keep working their land while protecting it from eventual development. In those deals, a state or county government buys the development rights, essentially taking the land off the market forever. The federal government also has a program that compensates ranchers for livestock that are killed by panthers — a significant problem in southwest Florida. Both the easements and the livestock program are reasonable policies that can help save Florida's state animal.Florida has made important progress in protecting manatees and panthers. But the work of defending vulnerable species is never done. Even as their numbers increase, record deaths this year of both animals due to interactions with humans are a clear sign that this is no time to pull back protections.