Asian Deer in Maryland Whitetail Country

[eshoremd]

Asian Deer in Maryland Whitetail Country
How do the exotic sika deer now established on Assateague Island impact the habitat – and the whitetails with which they share it? That's what researchers are working to find out.
By Jeffrey Mulhollem

Penn State graduate student Sonja Christensen cradles a young Assateague Island sika stag prior to putting a radio collar on him.
Photo courtesy of PSU



Maryland's famous Assateague Island is best known for its feral horses. Recently, though, it has been the exotic sika deer and their effect on the island's fragile habitat that have worried National Park Service officials. So they asked a Penn State University researcher to evaluate the sika population and its impact.

"Although the sikas are small in stature, their effect on Assateague's sensitive ecosystem is large," says Duane Diefenbach, adjunct assistant professor of wildlife at PSU. "We are studying the park's white-tailed deer, which are native to the island."

"We plan to capture between 30 and 40 deer, both sikas and whitetails, and put radio collars on them," he adds. "We will monitor their movements by radio telemetry through December 2007. We have captured and radio-collared nine deer already."


Sika deer are small members of the elk family introduced into Maryland in 1916 by private citizens. They are 2 1/2 feet high at the shoulder, weigh 50-100 pounds and originate in Asia. Their coat is dark brown to black. Some sikas have faint white, parallel spots on their backs. They also have white rumps. Males are larger than females and have antlers similar in shape to those of elk, though much smaller. Males also have dark, shaggy manes on their necks.

In recent years, sika numbers on Assateague grew while the whitetail population had declined, but those trends might have leveled off. Feral horse numbers are controlled with the use of a contraceptive drug administered by dart guns.

"The park has liberalized hunting seasons for sikas to control their numbers, but not for whitetails," says Diefenbach. "The question is, how do we best manage the species to limit effects on the island's plant community with so many deer? Visitors and hunters love sika deer. But they are an exotic species that may be upsetting the ecosystem."


The Assateague Island whitetail at right wears a radio collar affixed by PSU researchers to help them study deer impact on the national park's habitat.
Photo courtesy of PSU


The first step in Diefenbach's research will be to describe the habitat use and movements of both sikas and whitetails. "One interest is seasonal changes in habitat use," he explains. "We will quantify how these deer use different habitats throughout the year. For instance, during times of the year when biting insects are a problem, deer move out of the salt marshes seeking breezy areas near the beach to get some relief. Also, we are interested in documenting movements during the breeding season and interactions between whitetails and sikas."

PSU graduate student Sonja Christensen, who is pursuing a master's degree in wildlife and fisheries science, will do most of the project's deer monitoring. "It is the damage deer are doing to endangered plants in the interdune meadows that most concerns park officials," she says. "They worry that rising sika deer numbers are resulting in overbrowsing in this very sensitive area."

Mark Sturm, an ecologist with the National Park Service, has been experimenting with exclosure fences to study the effect of deer and horse foraging on vegetation. "We have exclosures that keep out horses but let deer freely enter and exit, and we have exclosures that keep out all deer and horses," he says. "We have already documented several responses by the plant community within these different exclosures. Some plant species that are rarely otherwise seen on the island have even appeared within these sites where ungulates (horses and/or deer) have been excluded.

"We see this Penn State research helping the National Park Service to better understand habitat use by deer, and that should guide future decisions about how to best manage the deer populations."

www.northamericanwhitetail.com/deermanagement/NAWsika_0206/#cont

[freedomrules3]

I personally wonder how they got so thick in dorchester county and skipped worcester and wicomico counties pretty much. i've heard several stories about sika killing whitetail by gouging them , i'm not so sure how true it is though. i've only seen 1 down where i hunted near snowhill. assateague is plum full of them and the whitetail numbers have gone down bigtime so there may be some truth to the stories. i call them mitsubishi deer

[eshoremd]

they were released first in dorchester than later on Assateague Island.

Maryland's Sika Deer

Maryland's exotic sika deer (pronounced SEE-kuh) is native to southern Japan, and first appeared on Maryland's lower Eastern Shore when Clement Henry released them on James Island in 1916.

Today, sika deer (Cervus nippon yakushimae) inhabit all of the lower Eastern Shore counties, with the highest density located in the marshes and wetlands of southern Dorchester County. Sika deer were also released and established populations on Assateague Island during the 1920's.

Maryland biologists and deer managers first worried that the “miniature elk” would expand into the upland territory of native white-tailed deer. This resulted in higher bag limits being set so that hunters would be encouraged to harvest and control the sika deer population. However, over the years, managers have learned that the sika predominantly lives most of its life in the sub optimal regions of the white-tailed deer's habitat; apparently lessening competition between the species. Thus, the Wildlife and Heritage Service's (WHS) management techniques have changed somewhat towards the sika deer.

Sika deer are now managed to keep the population at its "cultural carrying capacity" (meaning the maximum number of deer that can co-exist, compatibly, with local landowners and native species). Current population levels appear to be low enough to ensure crop damage is minimized, while still providing plenty of hunting opportunities for sportsmen and women.

WHS biologists initiated a tagging study in 1988 to obtain important information on harvest rates, longevity, and movements of sika deer. The average distance traveled by sika males (stags), as measured by comparing tagging location to recovery location, was 2.7 miles. Sika females (hinds) were recovered an average of 1.3 miles from the tagging location. Surprisingly, some of these tagged deer are still alive today (10+ years later)!

A radio-telemetry study was also conducted on Dorchester County sika deer, and revealed that most sika hinds had a home range of about 150 acres and moved about a half-mile between bedding and feeding areas. Sika stags had much larger home ranges, often greater than 500 acres, and depending on the time of the year, moved much longer distances in a given day. Habitat use by sika deer and white-tailed deer differed markedly during the study. Sika deer preferred marshes and thick, forested wetlands, whereas white-tailed deer preferred the more common agricultural and upland areas.

In addition to the habitat and movement studies, WHS, in cooperation with the University of Maryland Appalachian Environmental Laboratory, conducted a reproductive study to determine the breeding age of sika deer and the number of calves born per hind by age class. It was found that 24% of the six-month old calves were pregnant, and 76% of the adults were pregnant -- all of which contained a single fetus, except for one adult, which was carrying twins.

The popularity of sika deer hunting in Maryland has increased markedly over the last decade. The challenge of the hunt, their uniqueness as a trophy, and the excellent flavored venison they provide, has resulted in a steadily increasing harvest. Hunters interested in pursuing the elusive sika will find the field-dressed weights of yearling females to average 45lbs, with 53lbs the average dressed weight for yearling males. A big stag will dress around 100lbs.

Sika deer differ in looks from native white-tailed deer. They are shorter in stature -- adults stand about 2 ½ feet at the rump. Their coat tends to be reddish brown during summer months, and dark brown to black in color during winter. Even as adults they have white spots, mainly running parallel down their back. Stags generally have a dark, shaggy mane running down their neck, and their antlers are narrow and sweep backwards rather than forwards like the white-tail's antlers. A 6-point stag is a trophy, with 8-pointers being extremely rare. Finally, unlike white-tailed deer that raise their tail like a flag when alarmed, sika deer have a round white rump patch that flares outward when they are excited or alarmed.

Because sika deer are primarily nocturnal and inhabit marshy terrain, hunting can be very challenging and sometimes difficult. Therefore, the sika rut that occurs in mid-October is considered to produce the best chance to harvest an adult stag. During this time, males become very vocal by "bugling." These bugles usually consist of a series of three whistles, heard primarily during early morning and late afternoon. Stags during the rut define their breeding territories by making wallows -- scraped out depressions in the earth that are urinated in and wallowed in, causing the stags to smell strongly of urine. The rut generally results in increased movements by stags during the day, which can increase the odds of seeing one during legal hunting hours.

Both male and female sika deer use vocalizations to communicate. The "bark" they emit when alarmed is most distinct. Hinds often communicate with their calves using soft bleats and whistles. By mastering some sika vocalizations, hunters can increase their chances of bagging a stag during the rut. A hunter can also increase his or her luck by hunting on edges and gaps within patches of phragmites located between marsh and woodland terrains. Sika deer often use phragmites as movement corridors between feeding and bedding areas.

Although sika deer do not appear to rely on agricultural crops as heavily as white-tailed deer, they still respond favorably to agricultural food resources. Thus, many of the management techniques used for white-tailed deer (i.e., food plots, warm season grasses, etc.) also work well for sika deer. Sika deer also rely on mast during fall and winter, thus acorn-producing oaks are an important component of the forest overstory in sika habitat. Other common foods of sika deer include poison ivy, catbrier, and marshgrass. Choosing hunting areas that provide some of these food sources may aid your hunting success.

For current data on the sika deer harvest in Maryland, please see the Game Program Annual Report.

Where to Hunt
Two state Wildlife Management Area's (WMA's) in Dorchester County offer sika hunting opportunities. For information about the 1,000-acre Taylor's Island WMA or the 20,000+-acre Fishing Bay WMA, call the district office at LeCompte WMA: 410-376-3236.

Blackwater National Wildlife refuge allows permit hunts. For more information call 410-228-2677.

Along the ocean in Worcester County, Assateague Island National Seashore allows a full season of sika hunting with separate bag limits from the state. For more information, call 410-641-3030.

Bag limits and other regulations are listed for sika deer in the Guide to Hunting and Trapping in Maryland.

In addition to holding a Maryland hunting license, the following items are a must for hunting sika deer: insect repellant, hip boots, a boat or canoe (strongly recommended on public hunting lands) and, most important of all, time, patience, and a little luck.

Also, see Sika: Maryland's Exotic Little Elk, an article by Brian Eyler, Deer Biologist for the Wildlife and Heritage Service, that appeared in a recent issue of The Natural Resource magazine.

[ncboman]

excellent posts Todd.

[txm]

The Sika seems to out compete the Whitetails some what, due to a little less protein requirement and a bit more diverse diet.
I my area the exotic that can wreck the Whitetails are the Axis.
They live on grass as well as browse and forbs.
They breed at any time of the year assuring some fawn survival in almost any conditions.
The numbers need to be closely controlled.
Thankfully that is not as hard to do due to them not being nearly as nocturnal as Sika.

[eshoremd]

txm said:

The Sika seems to out compete the Whitetails some what, due to a little less protein requirement and a bit more diverse diet.
I my area the exotic that can wreck the Whitetails are the Axis.
They live on grass as well as browse and forbs.
They breed at any time of the year assuring some fawn survival in almost any conditions.
The numbers need to be closely controlled.
Thankfully that is not as hard to do due to them not being nearly as nocturnal as Sika.

sika do not breed at any time of the year. maybe your thinking of sitka.

[eshoremd]

ncboman said:

excellent posts Todd.

thanks, thats not a copy and paste job either. i knew all that by heart.

[ncboman]

eshoremd said:

txm said:

The Sika seems to out compete the Whitetails some what, due to a little less protein requirement and a bit more diverse diet.
I my area the exotic that can wreck the Whitetails are the Axis.
They live on grass as well as browse and forbs.
They breed at any time of the year assuring some fawn survival in almost any conditions.
The numbers need to be closely controlled.
Thankfully that is not as hard to do due to them not being nearly as nocturnal as Sika.

sika do not breed at any time of the year. maybe your thinking of sitka.

Reread his post. He was referring to Axis deer.

I've read several places that Sika deer kill whitetail bucks. That puts the Sika in direct competition with me, therefore I will attempt to kill every Sika I see.

[txm]

Sorry about that.
Axis are a prob. when numbers get high.
Sika do kill Whitatails ,but I have never seen it to a great extent.
They also blind other Sika bucks due to the location of the brow tines.

[freedomrules3]

I believe the sika deer on assateague kill whitetails frequently during their rutting period. i know that when i moved down here in 1983 that there were a bunch of whitetail on assateague. their numbers went down as the sika numbers skyrocketed. they had to put a moretorium on whitetail for over 10 years due to low numbers. i'm not sure if the sika caused the problem or not. i do know that the island is a little more of closed quarters type situation than say open areas. i do know now that the whitetail are coming back some but they still wont let you take does and only bucks with 3 points or more to one side.
i've heard that since the sika are smaller in height that if they charge a whitetail thier antlers can do some damage. if they hit a major artery then the whitetail is toast. i agree with killing any sika in a whitetails habitat is a good idea.

[eshoremd]

ncboman said:

eshoremd said:

sika do not breed at any time of the year. maybe your thinking of sitka.

Reread his post. He was referring to Axis deer.

I've read several places that Sika deer kill whitetail bucks. That puts the Sika in direct competition with me, therefore I will attempt to kill every Sika I see.

ohhhhhh! i thought he was refering to the sika as one of the "axis of evil"

i need a beer bad! sorry txm

[txm]

I thought that I would share what I have learned during over thirty years working with Whitetails and exotics.
I will write only about the Axis and Sika at this time and there impact on native deer.
My experience with exotics has only been in Texas
I have done Whitetail management in six states.
SIKA: I conducted elimination programs on these .Ranchers found that overall the Japanese Sika are not a desirable commercial animal due to being very nocturnal and are small with limited trophy value.
A given area can support just so many animal units and there or other animals of more value to occupy there space. The ranches that want Sika now work with the Manchurian and other larger sub- species.
Sika is in the Elk family and cannot breed with anything except others in that family.
They can and do cross with Red Deer and Elk if in the same area.
And are true herd animals while the other two are more family group animals.
In my area there is little interaction of Sika with other deer.
The rut for them is virtually over When the Whitetail rut starts, so there is not much aggression shown.
When observing food plots I find that when Sika appear most Axis and Whitetail leave the field if hogs come all deer leave.Just as Muledeer give way to Elk.
I have seen very few cases of fighting between Axis, Whitetail and Sika except in small pastures that were high fenced.
The Sika is just using available resources that the other deer need.

Axis: As a general rule there is little fighting with the other deer.
This is due in part because there are not many bucks in rut at any one time and they don’t cross with Whitetails or Sika so they show little interest in the does.
There are Axis does in estrous and bucks in hard antler at any time of the year.
There is a small peak during early fall. This spread in fawn production gives them an edge, especially in bad years.
You can see bucks in velvet, with dropped horns and hard antler at any time.
Due to this there are relatively few bucks ready to fight at any given time.
The main competition with Whitetails is because using the available resources.
Both Sika and Axis are one to one replacements for Whitetails and because they eat the same foods and in addition can utilize grass well then Whitetails they out compete them.
In every case the Whitetail population decreases in direct proportion to the rise in population of the exotics.
We have a growing commercial demand for Axis meat and if you get a chance to kill one ,I think that you will find it to be the bet venison that you have ever eaten.
Please excuse my first post.
Haste maks waste.

[txm]

This is a direct quote from our wildlife dept ,from a detailed study.

All these studies indicated most exotics were sheep or goats in a deer's clothing. That is, they either preferred forbs or preferred browse, but could do well on grass too. White-tailed deer prefer forbs when they are available. As forbs become unavailable, they shift their diet to browse. White-tailed deer cannot live on grass; in fact, they will die with a belly full of grass.

Texas Parks and Wildlife Department also conducted competition studies between white-tailed deer and exotics. Six 96-acre pastures, enclosed with "deer-proof" fence and not grazed by any other animals, were used to determine the effects of exotic ungulates (axis deer, sika deer, fallow deer, blackbuck antelope, and aoudad sheep) on white-tailed deer. Each pasture was stocked with 6 white-tailed deer, and 6 animals of one exotic species. For example, Pasture 1 contained 6 whitetails and 6 axis deer; Pasture 2 contained 6 whitetails and 6 sika; etc.



These studies indicated that exotic ungulates out-compete white-tailed deer, and white-tailed deer will die while exotics continue to thrive. Remember, white-tailed deer can live on only 2 classes of forage (forbs and browse), while exotics can do well on 3 classes (forbs, browse, and grass). As forbs and browse are removed from the area (from excessive grazing/browsing pressure), exotics can shift their diet to grass and white-tailed deer die from malnutrition.

[ARO]

txm, what part of texas are you from? have you heard of the adobe lodge?
i am going there in april for turkey's, just wondering if you have heard anything about there operation.

thanks
shane

[txm]

I live in North Texas, but have done most of my wildlife work in West and South Texas.
If this is the Adobe Lodge located in SanAngelo I am familiar with them, but don’t know them personally.
I have heard nothing but good things about them and they hunt several locations in West and South West Texas.
I will be in SanAngelo this Thursday to take a deer count about 65 miles from town.