PostDoc Info: Falk Hüttmann (Ph.D., Diplom-Forstwirt univ.) PostDoc Fellow, Simon Fraser University

Falk Hüttmann
Centre for Wildlife Ecology, Biology Dept.
8888 University Drive, Simon Fraser University (SFU), Burnaby B.C., Canada V5A 1S6
Tel: 604 291 5618 Fax: 604 291 3496 Email: huettman@sfu.ca

Abstracts (as presented at the Pacific Seabird Group PSG meeting, held on Hawaii 2001)

NESTING HABITAT PREFERENCES IN MARBLED MURRELETS:

GIS AND TELEMETRY APPROACHES COMBINED.

Falk Huettmann*, and Fred Cooke, Centre for Wildlife Ecology, Biology Dept., 8888 University Drive, Simon Fraser University, Burnaby B.C. V5A 1S6 Canada, huettman@sfu.ca

We used nests from 85 Marbled Murrelets (Brachyramphus marmoratus) located by radio-telemetry during the field seasons 1998 (n=23), 1999 (n=34) and 2000 (n=28) in Desolation Sound, southern British Columbia, and 9 nest locations in 2000 from a second study area, Clayoqout Sound, on western Vancouver Island. All nest locations were characterized for the following landscape characteristics: slope, aspect, elevation, edge and patch size of 'old forest'. Findings were related to a larger landscape context of habitat availability using a 50 km circle around the centre of the suspected foraging activity, as determined by 'dipnetting'. Our approach allows us to investigate habitat preferences of nesting Marbled Murrelets by comparing habitat use to habitat availability. Using several provincial and international GIS data sets, we examine the relationship of nests to the landscape features described above. We then develop a multivariate nesting habitat model to predict the occurrence of this bird within the two study areas using a GLM (Generalized Linear Model), Classification and Regression Tree (Cart) and other advanced modelling algorithms. Results are compared with existing models and knowledge for this bird.

A LARGE-SCALE MODEL FOR THE AT_SEA DISTRIBUTION OF

MARBLED MURRELETS (BRACHYRAMPHUS MARMORATUS)

IN COASTAL BRITISH COLUMBIA, CANADA

Peggy Yen*, and Falk Huettmann, Centre for Wildlife Ecology, Biology Dept., 8888 University Drive, Simon Fraser University, Burnaby B.C. V5A 1S6 Canada, ppyen@sfu.ca

The role of the marine environment in the breeding season distribution and abundance of Marbled Murrelets (Brachyramphus marmoratus) is not fully understood. Consistent information on the marine and terrestrial distribution of Marbled Murrelets does not exist in British Columbia, Canada. We compiled and investigated (1) murrelet surveys (count and density), (2) environmental factors, and (3) prey distribution and overlaid these data in a Geographic Information System (GIS, Arcview). We identified the significant predictors by evaluating their shortest distances from survey locations to the predictors in a multivariate scenario and found strong correlation between Marbled Murrelet abundance and several environmental and prey predictors. Spatially explicit large-scale distribution models employ these significant predictors to estimate Marbled Murrelet abundance in coastal British Columbia. The algorithms used include Generalized Linear Models (GLM), Multivariate Adaptive Regression Splines (MARS, Salford Systems) and Classification and Regression Trees (Cart from S-PLUS and CART from Salford Systems). Model predictions are evaluated by several methods (e.g. Bootstrapping, model comparison, and distance to old-growth forest), allowing for discernible and transparent results.