Moose Population Survey Lake Clark Unit III South (GMU 9B) December 1998 Annual Report RMP Project Number: LACL N002.00 Investigator: Penny Knuckles, Resource Management Specialist Lake Clark National Park and Preserve Port Alsworth, Alaska Background: Since 1984, annual moose population trend counts have been conducted in various portions of Lake Clark National Park and Preserve. Three trend zones were surveyed in the Telaquana Lake, Chlikatdrotna River, Miller Creek and Kijik River drainages. These areas represented a relatively small (<30%) proportion of total moose habitat in the park and preserve. Surveys were not systematic and were conducted anytime between November and late March. Trend zones were searched using a PA-18 aircraft until pilot and observer felt they had “covered” the area. In most years, survey results were too variable to measure population trends. To address the need for more definitive information on moose distribution, numbers and herd composition, several changes were implemented in 1992. Four moose survey units were defined which contain approximately 86% of available moose habitat. Unit boundaries conform to State of Alaska Game Management Units (GMUs) 19B, 17B, 9A and 9B. Units exhibit similarities in moose habitat, and in sport and subsistence hunting patterns. Units I and II comprise the northern half of the park and preserve, and contain the former trend survey areas. They are: Unit I Telaquana Lake/Two Lakes (GMU 19B) Unit II Twin Lakes/Chilikadrotna River (GMU 17B) Units III and IV encompass the southern half of the park and preserve, most of which had never been surveyed by NPS personnel prior to 1992. They are: Unit III Lake Clark (GMU 9B) Unit IV Cook Inlet coast (GMU9A) Due to its size, Unit III is further divided into two subunits, located north and south of Lake Clark. Since 1992, moose density and population composition have been measured in Units I, II and III using the stratified quadrat survey procedure (Gasaway, W.C. et.al., 1986. Estimating moose population parameters from aerial surveys. Biological Papers of the University of Alaska, No. 22, Fairbanks, 108 pp.). Because of the limited and fragmented nature of moose habitat in the coastal unit, it has been treated exclusively as a trend count area. In this unit, standard aerial moose survey techniques are used to measure relative abundance and herd composition in the West Glacier Creek, Johnson River and Tuxedni River drainages. Attempts have been made to obtain density estimates for Units I, II and III on a 3-year rotational schedule. Due to inadequate snow cover, adverse weather conditions or unavailability of personnel/aircraft, this schedule has not been achieved. Unit III South was surveyed in 1992. Units II and III North were surveyed in 1994. Trend and composition count surveys were also conducted in Unit I and Unit IV in 1994. A survey of Unit I was aborted in 1997 due to poor weather conditions midway through the effort. Survey Methods and Conditions: 1998 survey methods followed Gasaway, 1986, and were consistent with prior surveys carried out in the park and preserve since 1992. Unit III South was surveyed on 13-17 December 1998. Twenty-eight hours of flight time were expended searching 258 mi2 (65%) of the unit. Six hours of flight time were required to stratify the entire unit (394 mi2) into survey units of low, medium and high moose densities. Due to the unavailability of a Cessna 185, two PA-18 aircraft were used for both the stratification flights and the surveys. Pilots (Leon Alsworth, Dennis Knuckles) and observers (Dan Young, Penny Knuckles) carried out standard searches (avg. 4.6 min./mi2) of all randomly selected survey units. Intense surveys (avg. 10 min./mi2) were also carried out in the medium and high strata survey units to obtain a sightability correction factor (1.06 pooled across strata). Snow conditions were good, with a 1-2 foot snowfall occurring 8 days before the survey began. Weather conditions were generally good, although high winds and blowing snow delayed the survey on two different days. We noted that moose moved from high, exposed ridges down into forested habitat midway through the survey when the weather suddenly changed (on December 15, temperatures dropped below -10° F. coupled with high winds). Some survey units near treeline, stratified as medium or high, contained few or no moose a few days later although fresh tracks led into lower, forested habitat. Moose were highly visible in shrubby habitat at or near treeline. The worst sightability was in spruce forest, where moose were more dispersed and difficult to see without intense search effort. For this reason, much of the forested habitat was stratified as low although, in some cases, moose densities overlapped those found in the medium or high strata. These factors increased data variability, requiring that 25 out of 42 survey units be searched to obtain a reliable population estimate. Results: We counted a total of 169 moose. Estimated population was calculated using the program “moosepop”. The population estimate for the entire subunit was 229.1 ± 37.4 (CI=90%). Overall density was 0.58 moose/mi2. Densities were 0.30, 0.55 and 1.07 for low, medium and high strata respectively. Sex and age composition was 67.6% cows, 24.8% bulls, 5.6% calves and 2.0% unknown. “Large” bulls (>50 inch antler spread) comprised 37% of the bulls in the population. Only 2 yearling bulls were observed. Calf:cow ratio was 8.3 :100. Bull:cow ratio was 36 :100. Bulls in this area had been observed dropping antlers since late October, and 3 bulls each had 1 antler during the survey. Therefore, the calf:cow and bull:cow ratios may be underestimated. In 1992, the National Park Service carried out a Gasaway survey in Unit III South. The population was estimated to number 262 ± 23 moose. Density averaged 0.85 moose/mi2 and the calf:cow ratio was 14 :100. Although these results imply a negative population trend, there are notable discrepancies in survey unit area calculations between the two surveys. Therefore, the 1992 data require corrections before comparing results. Acknowledgements: Park Service pilots Leon Alsworth and Dennis Knuckles did an outstanding job of flying and spotting moose despite cranky aircraft and uncertain weather conditions. Alaska Support Office Wildlife Biologist Kyran Kunkel provided advice and encouragement. And a special thanks to volunteer Dan Young, who arrived on short notice, and whose persistence and dedication allowed us to complete this survey. .