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Fishery Bulletin 112(4) 
Figure 2 
Temperatures recorded by life history transmitters (LHX tags) during different cooling ex- 
periments in the laboratory. Temperatures were recorded in 30-min increments by LHX tags 
equilibrated at approximately 36-38°C and subsequently transferred to different media, such 
as air, water, and stomach tissue. Temperatures of the transfer media are indicated by gray 
symbols. (A) LHX tag transfer from water bath to air at 3.5°C. (B) LHX tag transfer from 
water bath into gastric tissue at 7.5°C. (C) LHX tag transfer from water bath into water at 
3.5°C. (D) LHX tag abdominally implanted into a 70-kg California sea lion (Zalophus cali- 
fornianus) immediately post mortem at the Alaska Sea Life Center in Seward, Alaska, and 
the carcass then cooling in ambient air at 4-12°C (gray squares). (E) LHX tag abdominally 
implanted into a 184-kg California sea lion at The Marine Mammal Center in Sausalito, 
California, immediately post mortem, and the carcass cooling in ambient water at 12-13°C 
(gray circles). Shaded areas for D, E represent ranges of 95% confidence intervals from 
the outputs of the algor mortis model (for details, see the Materials and methods section). 
Measurements shown for A, B, and C were data collected during laboratory experiments con- 
ducted at Oregon State University in Newport, Oregon, in 2005. The sea lion carcasses were 
made available by regional stranding networks in Alaska (2008) and California (2007). The 
sea lions were euthanized before insertion of LHX tags for reasons unrelated to this project. 
Figure 2, D and E. Tags that remain embedded in parts 
of dismembered bodies also should record temperatures 
that indicate gradual cooling but at rates considerably 
faster than the cooling rates for intact bodies (Horning 
and Mellish, 2009). Alternatively, the temperatures of 
tags that are fully liberated from dismembered bodies 
should quickly adjust to temperatures of the surround- 
ing medium, as illustrated in Figure 2, A-C. 
The above listed considerations indicate 4 possible 
causae mortis scenarios (see Horning and Mellish, 
2009). 
Type I: Very rapid drops in postmortem temperature 
(as shown in Figure 2, A and C) that are associated 
with immediate sensing of ambient light or air must 
be the result of direct tag extrusion. Such a sequence 
of events, when combined with the immediate onset of 
transmissions, indicates traumatic death by dismem- 
berment leading to immediate tag extrusion, most 
likely due to predation. A type-I scenario also could be 
caused by scavenging if this process releases the tags 
from the body and if it occurred within 60 min of death 
(depending on the mass of the sea lion; otherwise, the 
onset of gradual cooling would be detectable). In this 
case, scavenging would have been preceded immediate- 
ly by death due to other causes, and any deaths caused 
by disease or starvation additionally should be associ- 
ated with antemortem temperatures outside of the nor- 
mal range of 36.0-38.2°C. 
Type II: A gradual temperature drop with substan- 
tially delayed sensing of light or air and delayed onset 
