Ecological Archives A016-025-A2

John F. Lehmkuhl, Keith D. Kistler, James S. Begley, and John Boulanger. Year. Demography of northern flying squirrels informs ecosystem management of western interior forests. Ecological Applications VOL: pp-pp.

Appendix B. A priori hypotheses including the effects of cover type and vegetation attributes on northern flying squirrel demography in the third step of the Pradel demography model building process. Covariate abbreviations used in model selection tables are in parentheses.

Parameter

Covariate

Hypothesis

Survivala

cover type (trt)

Apparent survival should increase from open pine to young to mature cover types because of increasing food and shelter.

 

crown cover (ccov)

Survival increases with crown cover better snow interception = less snow depth, more constant microclimate, high tree density = security.

 

large snag density (snags)

Survival increases with more den sites.

 

mistletoe index (mtoe)

Survival increases with thicker and more den sites.

 

truffle biomass (trufbiom) truffle richness (trufrich)

Survival increases with greater biomass and variety of primary truffle food.

  lichen biomass (lichbiom) Overwinter survival increases with greater Bryoria forage lichen biomass.
  understory spp. cover (ucov) understory spp. richness (uspp) Survival increases greater cover and diversity of secondary vegetative food sources.

Recruitmentb

cover type

Birth rates should be lowest in open pine, intermediate in young, and highest in mature forest. Immigration should be high in open pine forests (sink habitat) vs. mature or young forest (source habitat).

 

crown cover

Birth rate increases with greater stand density, which is associated with greater security, shelter, and food abundance.

 

large snag density

Birth rate increases with increasing abundance of den sites.

 

mistletoe index

Birth rate increases with increasing abundance of den sites.

 

truffle biomass & richness

Birth rate increases with increasing abundance and variety of primary food.

 

understory spp cover or richness

Birth rate increases with increasing abundance and variety of secondary food.

a The probability of remaining on site and surviving until the next sampling period.

b Rates of addition from births and immigration.



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