It’s been a while since we’ve had a data update – in the meantime, I attended an ecology conference in Portland, Oregon, and saw several cool talks about phenology, milkweeds and monarchs. Seeing those talks always makes me more aware of how interesting and unique this dataset is – there really are very few datasets like it.
We haven’t seen plots of the data for a few weeks. Before you look below, try to imagine what you think those plots will look like. (Hint: they are the same kinds of plots we always have, but just with more data for the past few weeks.) Based on your intuition being out in the field, what patterns do you think the data will show?
It looks like the plants are continuing to grow pretty well:
The number of observed ALIVE milkweeds seems to be holding pretty steady around 213; it looks like the peak population size of emergent milkweeds might have been around week 13 or 14.
The peak of milkweed size seems to have been around week 17, at least so far. The pattern of monarch egg counts has been all over the place, but seems to have settled down to low numbers in the past 4 weeks at least; the pattern of larvae counts has been consistently low for several weeks. With relatively few caterpillars to count, the data on caterpillar size should be pretty variable, but actually seems to show a pattern of some kind. It looks like the caterpillars were largest around weeks 12 and 13, and have been bouncing around 10-20 mm in the last few weeks.
I wonder if we will start to see an increase in larval numbers and sizes towards the end of the season this year, as we have in past years. Or, since this winter was so much wetter than the past few years and it looks like the ditch is occasionally flowing with irrigation water, will the plants just keep growing strong until the end of the season, with no let up in their defenses?