Effects of Jivcufork fences on antelope move- 

 ments. — To determine tlie type of fence tliat will 

 permit movement and migration of pronghorn 

 antelope and yet hold sheep, 15 fence types, includ- 

 ing standard cattleguards and simulated cattle- 

 guard devices, were tested in Wyoming by the 

 Utah Unit. 



It was found tiiat antelope readily cross hori- 

 zontal barriers such as cattleguards and simulated 

 cattleguard devices. Sheep also cros.sed the sim- 

 ulated structures. The maximum fence height 

 that most antelope readily jumped was approxi- 

 nuifely 32 inches. Of the fence types tested, a 

 •'V2-inch net-wire fence or a 26-inch net with one 

 barbed wire 5 inches alx)ve, olfered the best pos- 

 sibility of permitting movements or migrations 

 of antelope and holding sheep satisfactorily. 



Adult antelope possess an inherent learning 

 ability to cross different fence types. However, 

 the opix>site is indicated for the fawn and yearling- 

 age classes. Fawns and yearlings appeared to be 

 increasingly reluctant to cross fences as they were 

 subjected to increased numliers of replicate tests. 

 AVith few exceptions, antelope api)eared to be un- 

 aware of their ability to jump vertical barriers and 

 I'arely jumped fences over 32 inches high miless 

 under active pursuit or other stress. 



Reindeer. — A study of the St. Matthew Island 

 reindeer herd by the Alaska T'nit is providing in- 

 t'ormation on population dynamics and range 

 ecology' of value in understanding range-associated 

 pi-ol)lems of reindeer and caribou herds on the 



mainland of Alaska. The St. Matthew Island 

 reindeer herd has apparently approached the quan- 

 titative and qualitative limitations of its range. 

 This is reflected by change in the iK)pulation struc- 

 ture, decreas<» in the rate of population growth, 

 decrease in ilii' rate of growth, deterioration and 

 change in the vegetative comiilex of the winter 

 range, and limitations in the quality of summer 

 forage consumed by reindeer. Population stabili- 

 zation and possible '"die off" are indicated in the 

 nejir future, if experiences with other reindeer 

 herds run parallel. 



Grizzly hear population study in Yellowstone 

 National Park. — A long-tenn ecological study of 

 the grizzly be^ir in Yellowstone National Park is 

 being made by the Montana Unit. In 1964, 66 

 grizzlies were capfui-ed and marked, 34 for the 

 first time; 36 were free-roaming animals taken 

 with drug-filled automatic projector syringes, 29 

 were trajiped in culvert traps, and 1 cub was taken 

 with a noose. Sernylan, a fast-acting, immobil- 

 izing drag, was used extensively during the past 

 season. 



Seven grizzlies were instrumented with radio 

 transmitters and their movements, as well as those 

 of their family units (25 animals in all), were fol- 

 lowed for several months. Considerable informa- 

 tion was collected on daily and seasonal move- 

 ments, daily activities, InHlding sites, food habits, 

 prehibernation behavior, and denning areas. All 

 but one were tracked lo within "jumping distance" 

 several to many times and were visually observed. 







F.lk in corral and iifl tr:i|is i left and rij;lil, rcsixxtivel.v I, operated hy the ('i)lr>rjido Came, Fish, and Parks department, 

 with limit<>d as.sistan((' h.v the Colorado tiiit. The animals will be ntn-k-banded. sexed and aged, examined for 

 condition and oxtcnial iiarasitcs, and then relea.sed unharmed. Identification of marked elk in the wild will 

 l»ermit asswiation of herd segments with .specific summer and transition ranges. < I'hotos by Colorado Game. 

 Fish, and I'arks Department) 



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