14 
was (assuming an April hatching) a 3-year, 5-month- 
old female from Ferguson Creek. 
TABLE 7. — Relative survival of year classes of Etheos- 
toma squamiceps expressed as proportions of the —1 year 
class (1x1) and the 14 year class (ix2)s 
ee 
Year Number of Survival 
Sample Class Specimens 1x! 1x? 
Big Creek 
Males —1 146 1.000 Age 
tha 83 0.568 1.000 
2+ 26 0.178 0.313 
3+ 3 0.021 0.036 
Females ==] 189 1.000 rae 
jes 25 0.661 1.000 
2+ 29 0.153 0.232 
aja 0 0.000 0.000 
Total 
sample —1 335 1.000 ie 
ite 208 0.620 1.000 
2+ 55 0.164 0.264 
Sale 3 0.008 0.014 
Ferguson Creek 
Males —1 11005) 1.000 ae 
iL 18 0.156 1.000 
2+ 12 0.104 0.666 
Bal 2 0.017 0.111 
Females —1 195 1.000 apes 
Hise 70 0.359 1.000 
2+ IL 0.087 0.242 
3+ 1 0.005 0.014 
Total 
sample —1 310 1.000 one 
jie 88 0.284 1.000 
2+ 29 0.093 0.329 
ae 3 0.010 0.034 
1,000 a 
100 
NUMBER OF INDIVIDUALS 
] 
2 
——--—0 = BIG CREEK Ix 
wees A= BIG CREEK Ix 
———e - FERGUSON CREEK Ix! 
= FERGUSON CREEK |x 
YEAR CLASS 
ai) ike ae hy 
ee ee 
TOTAL 
=|) te 26 3+ 
MALES 
=] 1 24) 3+ 
FEMALES 
Fig. 10.—Survival curves for Etheostoma squamiceps. 
Points on the curves were obtained by multiplying the data 
in the survival columns of Table 6 by 1000. The vertical axis 
is a logarithmic scale. 
Migration 
After hatching in the upstream slab pools, young 
E. squamiceps dispersed throughout the Big Creek 
system, mostly moving downstream. As they ap. 
proached 1 year of age, the darters returned to up 
stream concentrations of slab rocks, where they 
generally remained the rest of their lives (Table 1) 
For the majority of the Big Creek population the 
dispersal as young from the spawning grounds anc 
the upstream return to slab pools by 1 year of age 
were the only major migratory movements. 
An indication of the magnitude of the upstrean 
spring migration of l-year-old E. squamiceps was thi 
large number of individuals collected at a bridg 
dam on a headwater tributary of Big Creek on 3 
March 1973. Darters moving upstream were unabl 
to get around the bridge and were concentrated it 
large numbers. One seine haul covering approxi 
mately 4 square meters yielded over 50 E. squami 
ceps; all were l-year-old (11 months) fish. 
For the majority of the Ferguson Creek popula 
tion, migratory movements consisted of an annua 
exodus each spring from the slab riffles into the slal 
pools, where most of the spawning activity occurrec 
and then a return to the riffles. 
Territoriality 
Aquarium and field observations indicated the 
E. squamiceps breeding males are strongly territoria 
females and nonbreeding males are only weakly te 
ritorial. 
When actively defending a territory, males wer 
boldly patterned with vertical banding and a darkene 
head and fins; breeding and nest-guarding males ha 
especially bold patterning. The threat posture of 
male was a lateral display of his pattern and ere 
median fins. Persistent intruders were chased fro 
the territory. 
Occasionally when two or more breeding mal 
were introduced into an aquarium, they briefly ba 
tled to determine the ownership of a nest ston 
Such combat consisted of repeated threat display 
nipping, and tail wagging against one another. 
The selective advantage for an aquarium-held ma 
in establishing and holding a nest territory W 
evident: all females after the first to spawn la 
eggs only in an already existing nest, and. therefor 
the first male to spawn was the only male to spaw 
In a large aquarium in which the males esta 
lished territories centered about slab stones and se 
eral females were forced to share the remain 
limited area, one female became highly belligere 
toward the other females and seemed to be guardi 
a nonstationary territory. She was easily recognize 
having a darkened head and vertical bands simil 
to those of a territorial male. 
DIET 
Stomach contents of 173 E. squamiceps from E 
Creek and of 67 from Ferguson Creek were ‘ 
