Finding a Valentine Can Be Hard for Animals Too, Cameras Show

John Roach
for National Geographic News

Valentine's Day Special Report

This story is one of a series looking at National Geographic Crittercam research. Crittercam is a research instrument worn by wild animals and equipped with a video camera and other information-gathering equipment. (Get the basics on underwater and terrestrial Crittercams.)

For more on this story, tune in to the Crittercam TV series on the National Geographic Channel in the U.S. Watch video previews online.

For National Geographic researchers, it's all in the name of science, but a camera-equipped system they developed to deploy on wild animals has a certain voyeuristic quality to it.

The research tool, known as Crittercam, has been carried by all kinds of male marine mammals trying to woo their female counterparts. In a seeming testament to the plight of males throughout the animal kingdom, the Crittercam footage shows that getting a female to mate is a tough task.

"It appears in all the work we've done that it's a struggle for males to find mating opportunities," said Greg Marshall, Crittercam's creator and director of National Geographic's Remote Imaging Program.

Among the action captured on film includes a male monk seal chasing a female for three days to no avail; male harbor seals singing their hearts out and blowing bubbles to an audience of none; and male hawksbill sea turtles searching far and near for female companionship—only to find other males on similar wanderings.

When the researchers deployed a Crittercam on a female hawksbill sea turtle to find out why the males were having such a hard time, they discovered that she was taking cover in a cave, presumably hiding from the lonely males out on the prowl.

"One thing we see is that males are a whole lot more interested in mating than females," said Mike Heithaus, a marine biologist at Florida International University in Miami and host of the Crittercam television series currently airing on the National Geographic Channel.

Research Insight

Crittercam has never actually caught a male and female in the throes of … well, the physical act of mating. But the courtship behaviors and rituals documented are a boon to science.

For example, footage of leatherback sea turtles in Costa Rica showed males in search of a mate migrating to waters off of beaches where females lay their eggs.

"Biologists studying leatherbacks didn't think males were coming near beaches. They thought all the mating was offshore on the feeding grounds," Heithaus said.

Although none of the males observed were successful—the females actively avoided them—Heithaus said that some of the males must eventually get what they came for.

According to Heithaus, once a female has mated, she probably has enough sperm to last the entire breeding season. So when she comes off the beach after laying eggs, she's not interested in the males lurking in the shallow waters.

Marshall said the finding that males come near the beaches at all is a "whole mating dynamic we knew nothing about. This discovery changes the whole picture of mating-strategy theory for leatherbacks."

Another insight gleaned from Crittercam footage is the persistence with which monk seals pursue females, as in the case of one following a female for three days. Some males also show what humans call "very aggressive harassment" behavior towards pups, apparently attempting, unsuccessfully, to mate with them, Marshall said.

Male monk seals have also been shown to swim out to mid-depth waters and vocalize, a behavior that Marshall said is likely related to courtship. No male has been seen successfully wooing a female with his song.

Crittercam Voyeurism

On most deployments of the Crittercam, researchers are too busy studying species' habitat and food requirements to delve into the study of courtship and mating, but on occasion their missions take on a more voyeuristic intent.

Heithaus recently joined researchers in the Florida Keys to find out what nurse sharks do outside of their well-documented, shallow-water mating area. With Crittercam attached to the shark, they followed it to deeper water.

"It turns out shallow waters are where most mating occurs," Heithaus said. "They go to deep water to rest. We haven't seen any mating there, yet."

This project is just starting and Heithaus clings to hope that Crittercam will eventually open a new window into the mating of these sharks. For now, the researchers will have to be content with the shallow-water observations of the aggressive mating tussle—males biting female fins and females twisting and rolling violently to test the males' vigor.

On another occasion, the Crittercam crew spent six months in Antarctica to study leopard seal mating behavior. But owing to a string of mishaps—helicopter groundings, lost ships—they missed the mating season.

"It was a logistical catastrophe," Marshall said. "By the time we were able to do our work, that behavior had ended, so we looked at foraging and hunting behavior instead."

Marshall hasn't given up on capturing secret mating behaviors on film. He is organizing a trip to study humpback whales at their breeding grounds in the Pacific Ocean.

"No one has seen humpback mating in the wild. This could provide the first opportunity to do that," he said.