TITLE:    The effects of human activity and environmental 
	  variability on long-term changes in Adelie Penguin
	  populations at Palmer Station, Antarctica
AUTHORS:  Donna L. Patterson, Andrea Easter-Pilcher, and William 
	  R. Fraser
DATE:     27 August - 1 September 2001
PLACE:    Vrije Universiteit, Amsterdam, The Netherlands 
	  SCAR VIII, International Biology Symposium
	  
THEME:    Antarctic Biology in a Global Context
URL:     
         Polar Oceans Research Group, Sheridan, Montana 59749, USA
         *University of Montana-Western, Dillon, Montana 59725, USA
	 POSTER (accepted in proceedings, out next yr)

ABSTRACT
Human activity associated with tourism and research 
along the western Antarctic Peninsula has increased 
significantly over the past 25 years, and predictions are that 
this trend will continue.  The potential effect these activities 
may have on wildlife populations has thus become an 
important wildlife conservation issue because wildlife and 
human activity tend to converge on the same ice-free areas.  
To examine if human activities due to tourism and research 
were negatively impacting Adélie penguins (Pygoscelis 
adeliae), I undertook a study that compared long-term 
population trends and other demographic parameters at 
visited and non-visited (control) sites on Torgersen Island, a 
popular destination near Palmer Station, Anvers Island.  
A necessary prerequisite for detecting human impacts 
on wildlife populations is an understanding of the underlying 
factors associated with natural demographic variability. 
Recent evidence suggests that variability in Adélie penguin 
demography may be due in part to interactions between the 
topography of the breeding habitat and patterns of snow 
deposition.  To test this idea, a hillshade model of Torgersen 
Island was developed and linear regression and discriminant 
function analyses (DFA) were used to examine breeding 
population/landscape interactions.  The results of these 
analyses were then applied to human impact questions.
Results suggest that variability in population trends on 
Torgersen Island are forced primarily by colony aspect and 
colony area.  Colonies with south-facing aspects are 
decreasing faster than colonies with north-facing aspects.  
Smaller colonies are also decreasing faster than larger 
colonies.  Both trends are likely due to interactions between 
the effects of enhanced snow deposition and decreasing egg 
and/or chick survival due to predation and flooding.  
To look for possible human influences, subsequent 
analyses were standardised by pairing Adélie penguin 
colonies according to area and aspect on the visited and 
control sides of Torgersen Island. Tourism appears to be 
having no detectable impact on Adélie penguin breeding 
population size or breeding success on Torgersen Island; 
comparisons between population trends in visited and 
control sides of the island were either not significant or 
inconsistent with site-specific tourist visitation patterns.  
Some types of research, however, especially when 
associated with small colonies, may be detrimental to the 
long-term survival of these colonies.