BIOL 329 Lecture Notes - Lecture 32: Princess Royal Island
6 May 2018
School
Department
Course
Professor
Lect 32
Activity patterns of the two morphs? Day vs night? Behavioural interactions – dominant submissive?
Foraging techniques? Salmon capture success? Trophic differences – stable isotope analyses?
No difference in time spent in daylight and nighttime by black and white bears.
No difference in behavioural dominance by B + W bears.
W bear better in daytime at capturing salmon.
Predict greater contribution of salmon to the diet of the white bear than the black bear. Hair sampling:
base of hair is representative of current diet (taken in fall), middle = summer, tip = spring.
Gribbell Island:
Spring: white bears stay close to shore; black bears are in alpine locations.
Summer: similar diet
Fall: white bears have a much greater N15 concentration (many more salmon eaten) than black bears.
Sae eperiet o Priess Roal islad does’t give the sae result. White ear starts at higher N i
the spring but both black and white are similar in summer and fall.
Frequency of the white allele in different populations. White bear is competitively superior to the black
bear where the white allele is common. It is at a disadvantage where the white bears are rare.
Ecological segregation in feeding niches. Greater relative salmon use by white bears when the morph is
common. Less salmon use when white bears are infrequent.
Evasiveness of salmon: white vs black coat. No difference at dark or at twilight. During the day, the
salmon returned to the area where the white costume was but many less would return to the area with
the black costume.
Niche: activity range of an organism along n-dimensions of environment (Hutchinson). Ecological and
evolutionary opportunities/constraints take the form of environmental conditions and available
resources. Variation in food resource use (niche) among: sub-populations, social groups, individuals.
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
No difference in time spent in daylight and nighttime by black and white bears. No difference in behavioural dominance by b + w bears. W bear better in daytime at capturing salmon. Predict greater contribution of salmon to the diet of the white bear than the black bear. Hair sampling: base of hair is representative of current diet (taken in fall), middle = summer, tip = spring. Spring: white bears stay close to shore; black bears are in alpine locations. Fall: white bears have a much greater n15 concentration (many more salmon eaten) than black bears. Sa(cid:373)e e(cid:454)peri(cid:373)e(cid:374)t o(cid:374) pri(cid:374)(cid:272)ess ro(cid:455)al isla(cid:374)d does(cid:374)"t give the sa(cid:373)e result. White (cid:271)ear starts at higher n i(cid:374) the spring but both black and white are similar in summer and fall. Frequency of the white allele in different populations. White bear is competitively superior to the black bear where the white allele is common.
