The piercing buzz that radiated from the rankled timber rattlesnake's tail quickly persuaded Jon DeBerti, Pennsylvania Game Commission biologist, to stop searching for elk calves. The snake was close. So were the other two rattlers that immediately joined the first in announcing their presence to the biologist.

"Even if you never let your guard down, you'll still probably get within a few steps of a rattler at some point during our calving season searches," DeBerti said. "Rattlers and elk seem to share some similar habitat interests, and given the amount of territory we cover, we can't help but to have some chance encounters. As a general rule, rattlers try to slip away undetected. But if you surprise them, or get too close, they will let you know."

The solution to any close call with a rattlesnake is to keep your cool, locate the snake - or snakes - and depart in a direction that allows you to stay as far away from the snake as possible. In this instance, DeBerti slowly backtracked from his uncomfortable post and resumed searching for the elk calf.

Rattlers had been popping up almost daily on the agency's elk calf searches, which were conducted from the last week in May through the third week of June as part of a three-year elk calf study that intends to provide biologists with more details on and insight into elk calf movements and dispersal, habitat usage and survival. The study's findings are expected to improve the management and understanding of Pennsylvania's elk herd, which is America's oldest free-ranging wapiti population east of the Mississippi River.

The research effort starts annually by placing telemetry collars on newborn to five-day old elk calves, which are born mostly from late-May through mid-June. Calves older than five days usually are capable of distancing themselves from pursuers. Since the window of opportunity for collaring calves is limited, the agency's search team works long hours and covers a tremendous amount of territory to place electronic telemetry collars and ear tags on up to 20 calves. Ticks and deer flies are a frequent aggravation for searchers, as are rugged terrain and hot, humid conditions. Oh, and did we mention the rattlesnakes?

In 2005, the elk search team captured and collared 22 calves; their average weight at the time of capture was 42 pounds. Two of the 22 would eventually die, one from unknown causes, the other was legally taken by a licensed elk hunter. The harvested elk weighed 160 pounds (estimated live weight) according to the scale at the check station.

Calves grow fast, about two pounds a day, so the collars used in the study are expandable. They also incorporate a break-away design that eliminates their host's obligation to carry the collar beyond about two years. The transmitters emit a signal for about 18 months, so long as the calf breathes. If a calf doesn't move for four hours, the transmitter will produce a mortality signal.

A cow that reluctantly moves when field personnel approach often has a calf nearby.

Sometimes, the hunt for calves becomes more of a chase, especially if the calf is more than a few days old. Of course, runners are never really appreciated by searchers, because calves can be fleet-footed and relatively uncatchable after their first week. Searchers prefer those calves that rely on the "hider defense," an inherent reaction that compels the calf to lay motionless in a fetal position - head tight to the ground - to avoid detection.

"Many calves instinctively lay motionless on our approach, often even after we touch them," DeBerti pointed out. "This is their only defense against predators at this stage in their life, unless the cow intervenes on the elk calf's behalf. It can be bad news for a calf if a black bear, bobcat or coyote finds it, because the 'hider defense' leaves the young elk face-to-face with a predator if the tactic fails.

"Elk cows, however, are very protective of their calves, and generally stay within 100 yards of them during the first few days of their lives. The cow elk represents a serious obstacle to any predator - or a bull elk for that matter - that approaches her calf. This year, we had a cow elk force an officer back to her vehicle several times as she tried to check an area for a calf."

Elk cows understandably become more anxious when their calf is captured. The calf's yells or "bleats" during its processing - in which it receives a telemetry collar, ear tag and health check - usually draw the cow into closer range. But if there's more than one person involved in the undertaking, the cow usually keeps her distance. Most cows initially leave and cautiously circle back in cover.

Elk survey team members track and observe pregnant cows to determine where to search for calves. Daily drive-bys are used to monitor developments. When it appears a cow elk has birthed a calf, the team moves in.

An elk cow with a newborn calf on the ground tends to linger in an area nervously when a truck or searchers approach, rather than move on. Elk normally move some distance from day to day, and when they don't, the team makes note and moves in to search the area for a calf. Less than one percent of cow elk birth twins.

"Elk calves are not physically capable of moving any great distance for their first few days, but it wouldn't exactly be advantageous for them to do so even if they could," explained Tony Ross, Northcentral Region wildlife management supervisor. "So they lay flat and motionless. They get up to nurse and stretch. Otherwise, they lay low, but not in locations selected by the cow. Rather, wherever their limited movements take them."

Researchers believe elk cows are more protective of calves than white-tailed deer are of fawns. In fact, it's likely that the availability of whitetail fawns offsets the loss of elk calves to predators. A recent fawn survival study in Pennsylvania concluded predators took about 22 percent of collared fawns on two study areas; mortality was greatest in the Quehanna Wild Area, which also is where some of the elk calf telemetry work is occurring.

"In many western states, black bears have taken a toll on elk calves," DeBerti said. "They actually learned to hunt them out there. Since our elk range has spilled into other parts of the state from natural expansion and trap-and-transfer, we believe it's beneficial to the elk program to keep tabs on calf mortality. Over the past 10 years, the area elk inhabit in Pennsylvania has grown from several hundred square miles to more than 1,000.

"We'd like to determine if elk are more susceptible to predators or other mortality factors in the new areas they inhabit. We know plenty about elk in southwestern Elk and western Cameron counties, where elk have existed for more than 80 years since they were reintroduced. But, we are trying to learn more about the new populations in northern Clearfield, western Clinton, and southern Cameron counties. Elk are such an invaluable resource to Pennsylvania that we simply can't assume changes in elk survival didn't or won't occur in these new areas, especially when bear densities on portions of the new elk range are some of the highest in the state."

The Game Commission last performed elk calf survival field studies in the mid 1990s. During the four-year study, which started in 1993, 30 calves were monitored; 71 percent of the collared calves survived their first year. The ongoing fieldwork is attempting to collar up to 90 calves over three years. Pennsylvania's elk population has doubled in size over the past decade and now numbers 600 to 700, excluding whatever calf recruitment occurred this year.

"We plan to follow these study elk throughout their lives to get better information on the survival of calves and yearling elk to improve our elk population modeling, which is used to determine herd growth," Ross said. "We are convinced we're missing a significant number of yearlings in field counts, or we don't have a good handle on yearling survival. Brain-worm appears to be most prevalent in yearlings, and it is possible there's more brain-worm mortality than we've been able to ascertain. Time and telemetry will tell."

The wild elk inhabiting Pennsylvania today are descendents of 24 released in Cameron County in 1915, and 10 released in Elk County between 1924 and 1926. A total of 177 elk - mostly from Yellowstone National Park - were released in seven counties from 1913 to 1926, and served as a breeding base for what was hoped would develop into a population that could sustain hunting.

But things didn't work out. Although hunting seasons were provided from 1923 to 1931, and some bull elk were taken by hunters, the animals quickly disappeared from almost everywhere but Elk and Cameron counties, which was, coincidentally, where the state's last elk holed up before the species became extirpated in Pennsylvania around the time of the Civil War.

Elk were found throughout Pennsylvania prior to its colonization. Their numbers declined as civilization advanced, mostly as a result of deforestation and unregulated and commercial hunting. Elk were scarce in most areas by the beginning of the 1800s. They were protected in the Commonwealth from 1932 until the state held its first modern elk hunt in 2001.

For more information on Pennsylvania elk, visit the Game Commission's elk webpage.

7/14/2006