148 
THE WILSON JOURNAL OF ORNITHOLOGY • Vo/. 124. No. 1. March 2012 
TABLE 1. 
Birds found dead 
in volcanic areas in 2007- 
-2010 at Kiska Island. Alaska. 
Species 
Number found 
Totals 
Age” 
2007 
2008 
2009 
2010 
Peregrine Falcon 
SY 
0 
1 
0 
0 
1 
Glaucous-winged Gull 
ASY 
3 
0 
0 
0 
3 
Least Auklet 
HY 
80 
104 
51 
67 
302 
Least Auklet 
SY 
3 
0 
2 
0 
5 
Least Auklet 
ASY 
11 
0 
0 
0 
11 
Crested Auklet 
HY 
3 
2 
2 
2 
9 
Crested Auklet 
ASY 
3 
0 
0 
0 
3 
Brown Hawk-Owl 
AHY 
0 
1 
0 
0 
1 
Pacific Wren 
HY 
12 
0 
0 
0 
12 
Pacific Wren 
AHY 
4 
0 
0 
0 
4 
Gray-crowned Rosy-Finch 
AHY 
3 
0 
0 
0 
3 
Snow Bunting 
AHY 
2 
0 
0 
0 
2 
“ HY: Halc h year, SY: Second year, AHY: After hatch-year, ASY: After second-year. 
this valley (~200 m) at least once every 6 days 
during daylight hours from May to August in 
2007-2010. All bird carcasses were identified, 
collected, weighed, and measured throughout the 
season, and examined for evidence of rat predation 
or other causes of death (Major and Jones 2005, 
Major ct al. 2007). 
Three gas samples from the depressions were 
collected at ~ 2-week intervals during June-July 
2009. and three additional samples were taken 
1 month apart from June to August 2010. Briefly, a 
3 to 5-m Tygon tube was lowered into the seep, the 
air was suctioned out with a large syringe, and a gas 
sample was taken into a pre-evacuated glass 
sample cylinder. Samples were sealed and trans¬ 
ported to the U.S. Geological Survey (USGS) in 
Menlo Park, California, for identification and 
quantification of the following gases: He. H 2 . Ar. 
0 2 , N* CH 4 , C0 2 , C 2 H 6 . H 2 S. CO, C,H S “ and 
C 4 H|(|. Gas samples were analysed for bulk 
composition by gas chromatography, and the C0 2 
fraction was dried and purified cryogenically, 
using methods described by Evans et al. (1988). 
A C0 2 split was analysed for the ratio of n C/ l2 C at 
the USGS Reston Stable Isotope Laboratory usii 
methods described by Revesz and Coplcn (200) 
The remaining C'0 2 was reduced to graphite on 
Fe catalyst at the USGS laboratory in Restc 
Virginia, USA to ascertain the volcanic ai 
biogenic fraction of bulk C, and analysed for ti 
ratio ol ‘ ‘C/'-c at the Lawrence Livermore Cent 
or Accelerator Mass Spectrometry. 
,.p' ; ‘" S .' ICal wcre performed in SPSS 16.0 
(SPSS Inc, .008). and results were considere 
significant at /» < 0.05. We used analysis c 
variance to test differences among years in 
deceased Least Auklet wing chord and mass, as 
well as differences in gas composition between our 
samples and normal atmospheric concentrations. 
We used Games-Howell (GH) tests for multiple 
comparisons (Games and Howell 1976) of auklet 
measurements as variances were not homogeneous 
(Levenc I960, Day and Quinn 1989). 
RESULTS 
Dead birds (mostly fledged juvenile Least 
Auklets) were found in the canyon during 2001- 
2006. Other species, including passerines, gulls, 
and raptors began appearing in the canyon in 2007. 
suggesting factors other than natural deaths 
associated with a large seabird colony might be 
involved (Table 1). Most auklets appeared on 1- 
2 days each year: 30 July 2007, 1 August 2008,2-3 
August 2009, and 30 July 2010. Other species 
included: Peregrine Falcon (Falco peregrinus). 
Glaucous-winged Gull (Lams glaucescens), 
Brown Hawk-Owl ( Nino.x scutulata) (Bond and 
Jones 2010), Crested Auklet, Pacific Wren I Trog¬ 
lodytes pacificus). Gray-crowned Rosy-Finch 
(Leucosticte tephrocotis), and Snow Bunting 
(Plectrophenax nivalis) (Table 1). 
The mass of individual dead Least Auklet 
fledglings ranged from 35 to 84 g and differed 
among years (F X297 = 79.42, P < 0.001). Past-hoc 
tests revealed the mass of dead fledglings differed 
each year with 2009 < 2010 < 2008 < 2007 (GH 
tests, all P < 0,003). Fifty-six birds in 2007 (69 %), 
96 in 2008 (91%), and all birds in 2009 (n = 52) 
and 2010 (n = 67) were below the asymptotic 
