Exactly three years after the killing of Cecil the lion sparked outrage among the American public, one more U.S. trophy hunter is making international headlines for killing an imperiled animal -- this time a giraffe. The news of this hunt comes just weeks after another American killed a lion, alleged to be Skye, a male dominant lion, also in South Africa.

The hunter who shot the giraffe in South Africa and posted photos of herself, grinning, next to the dead animal, evoked reactions raging from disbelief to anger in the media and on the internet.

“I didn’t even know people hunted giraffes,” said Gayle King, cohost of the CBS Morning Show.

While most of us are reacting from the gut to this crude display of animal cruelty, the hunt also exposes the callous disregard the American trophy-hunting universe, led by hunting groups like Safari Club International, has for the conservation status of animals whose numbers are rapidly declining and who are at serious risk for extinction.

While habitat destruction, poaching and ecological changes are all to blame for this decline, American trophy hunters have played an important role as well. Almost 4,000 giraffe trophies were imported into the United States between 2006 and 2015 – that is more than one giraffe killed by an American every day.

In an assessment published in 2016, the International Union for Conservation of Nature (IUCN) determined that wild giraffe populations have plummeted about 40 percent over the last 30 years in what some call a “silent extinction” – a term evoked by the fact that a giraffe cannot make a sound even when he is in danger. The giraffe species is assessed as “vulnerable” on the IUCN Red List of Threatened Species and two of the animal’s nine subspecies are assessed as “endangered.” There are now less than 100,000 giraffes in Africa -- far fewer than even elephants.

Last year the Humane Society of the United States, Humane Society International and our conservation partners petitioned the U.S. Fish and Wildlife Service (FWS) to list the giraffe as endangered under the U.S. Endangered Species Act (ESA). If the government moves forward with protections under the ESA, the import, export and interstate sale of giraffe parts would be prohibited in the United States. An ESA listing would also mandate the FWS to demonstrate that the import of giraffe hunting trophies would enhance the survival of the species -- a tall order given the precarious status the species is in.

The American hunter who killed the giraffe is pushing back against the criticism, arguing that the animal she hunted was more than 18 years old and that he had killed three other giraffes. But that argument makes no sense from a conservation perspective. Giraffes have a breeding life span of about 18 years, and bulls are able reproduce right up until their last years. In the wild, displays of dominance determine who will breed, and among giraffes, dominance is achieved through necking behavior which is a critical component of natural selection as it ensures that only the strongest, fittest males will reproduce. If the giraffe killed by this hunter indeed killed three other giraffes, then she just wiped out the strongest and fittest individual from that population, weakening the gene pool.

It is time that we call out trophy hunting as the harmful activity that it is. Hunters who travel across the world are not doing so for conservation but for bagging and bragging rights of animal trophies and for the disgusting thrill of killing exotic species.

Americans have made it clear this week that they do not approve of this unnecessary killing. There has never been a better time for our government to stand tall for giraffes, before these graceful animals disappear forever. You can do your part by asking the U.S. Fish and Wildlife Service to stop the trophy hunting of giraffes by listing them as “endangered” under the U.S. Endangered Species Act.

Protect giraffes under the Endangered Species Act