Animal Chronicles Spring 2007

Point Reyes Tule Elk - A Recovery Success Story

by John Thompson

Tule elk bugle to attract mates. It is a beautiful, haunting, eerie chorus rising from a single note to a shrill scream, like shrieks from another world. Listen closely, though, and you will also sense the lonesome, yearning, almost plaintive quality.
“It’s advertising,” says Natalie Gates, wildlife biologist at Point Reyes National Seashore. Each male wants to project an image of the biggest, most potent bull in the herd to attract the most females into his harem.

The harem can be two animals or 50, Gates says, and that means only a few males get to mate. “Those that don’t breed sit by themselves looking very depressed and sorry for themselves, and some hang around the outside of a harem trying to sneak in.” That strategy can work, though, as a bull usually can’t keep his harem for more than a couple of weeks. He doesn’t take time to eat, so he loses conditioning and his ability to protect his harem.

That rutting season action in the Point Reyes National Seashore herd is preceded by bulls shedding their beautiful antlers, a majestic rack made of bone, in late winter and early spring. “As a new set begins growing back, they’re super wimpy. I think they’re worried about damaging the velvet [a delicate web of blood vessels that feeds the growing bone] so they tend to avoid using their antlers at all,” Gates says. When the rut actually begins around late August, though, the antlers have hardened and are used to challenge other males in the competition for females. That continues until around Thanksgiving time when the rut gently winds down.

Fat Deer
Five hundred years ago, Sir Francis Drake called the Tule elk large, fat deer. At that time, there were probably around one half million, ranging from the Sacramento Valley, down the foothills of the Sierra Nevada in the Central Valley, and over to the coast. Then people descended on them, seized their habitat and killed them, sometimes for their meat and hides, sometimes to use their upper teeth for watch-fob charms, and often just for fun. Around 1900, an estimated 30 individuals remained.

The Tule elk we see today are all descendents of those few survivors and are thus very inbred. It is hard to tell if that has produced abnormalities, Gates says, but she does continuously monitor the herd. “They have recovered amazingly well in terms of numbers. They are a success story in spite of inbreeding.”

That success, though, has led to speculation in the press that the herd is too large for the park. “People always ask about ‘carrying capacity’ of the land, but it is a moving line, never a single number,” Gates says. “But to get a range, we’ve [radio] collared some animals and are taking a fast shot of the herd, looking at how rapidly it is growing and how long animals survive at different ages, and that may help us predict at what point the animals may exceed the carrying capacity.”

And when they do? Gates feels that simply leaving them alone, allowing food to become scarcer, would reduce their birth rates. There is also a threat of Johne’s Disease being transmitted from cattle on private ranches in the park, but, thus far, that has not proved to be a major influence. Predators, such as mountain lions and coyotes (grizzly bears would once have been among them), while not a large factor on Point Reyes, would also contribute. “Natural regulation is something we want to preserve,” Gates says. But the park service has also successfully tested a dart gun-delivered contraceptive that could be a fallback remedy.

Today, there are roughly 450 Tule elk in the fenced preserve on Tomales Point, and another 50 in the Limantour Beach-Drakes Estero area wilderness. When the latter group was introduced in1998, they were outfitted with radio collars so that rangers could track their dispersal, and to have warning if they wandered off the park and onto private land. Natural features, such as thick stands of trees, seem to be holding them in.

You can learn more about our beautiful Tule elk by exploring the Point Reyes National Seashore Web site. For an excellent article on the Point Reyes herd, go to: http://tinyurl.com/28s64o.

John Thompson is a local journalist focusing on environmental and animal issues. He is also an MHS board member.

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