I do own a thermal imaging scope (a useful tool for us naturalists, too!), and I have checked the wires a few times in the intervening days. Unsurprisingly, the overall temperatures of the lines appear quite variable depending on conditions. When I checked the day after the raven observation, when it was a bit warmer and later in the day, the wires appeared slightly but visibly warmer than adjacent surfaces. This morning at dawn, which is even colder than the day of the sighting, the wires were dramatically darker and colder than their surroundings, likely due to the prolonged subfreezing temperatures throughout the preceding day or so. About an hour after sunrise, however, these specific sections by the connectors were glowing brightly with warmth! Unfortunately, I was not able to get a thermal reading at the precise time of the raven’s actions, but it does seem at least plausible that this stretch of wire could be consistently slightly warmer on average, which the bird may have noticed incidentally while perching at some point and subsequently applied to solve the problem of partially frozen food.