I know some of my fellow bloggers have been interested in some San Juan Island butterflies. It's been a few weeks coming, but believe me, I've been trying! It seems whenever I go out specifically looking for butterflies I can't find them, or when I do they're flying high overhead and never set down. Today, while I was enjoying a sunny afternoon reading on the rocks out at Lime Kiln, I had an unexpected visitor who stayed put long enough for me to snap a few photos. My best guess is it's a Western White (Pontia occidentalis):
Hi Monika
ReplyDeleteNice White - more to its wing pattern than our regular species. Well done - any more species to try for? How much is genetics a factor in the shape of the fins/saddle patch patterns in the differences between transients and your local pods? Is there any breeding between them? Do the transients always eat mammals and visa versa or are they adaptable in their diets if the need arises. Our orcas appear to be fairly catholic in taste eating whatever is locally available at the time from washing seals off the rocks to catching salmon. There is now a small pod in the northern part of the Irish Sea...oohh come closer little fellas...
Cheers
D
Dave - Definitely two or three other "regular" species I'll be trying to get photos of, so stay tuned!
ReplyDeleteIt is thought that genetics play some role in saddle patch patterns, just due to the similarity of some saddles between mothers and offspring. Not really much is known about it other than ancedotal notions of similarity, though. Everyone wants to know if our big male J1 Ruffles is the father of L73 Flash, since both have extremely wavy dorsal fins.
As for transients and residents, they are strict to their dietary choices. There is no documentation of residents ever consuming marine mammals (although they will occassionally kill and play with harbor porpoise, but not eat it). Whichever type of pod you're born into pretty much sets your diet for the rest of your life, and their whole socialization pattern and vocalizations with it.
We always say residents and transients don't interbreed at all, but a recent paper that came out said there may be a miniscule but non-zero amount of interbreeding. They've been genetically distinct populations for about 10,000 years (since the last ice age). If there is any interbreeding, it would be of great benefit to the small Southern Resident population, which down the road faces some issues of inbreeding depression and could certainly benefit from a "shot" of outside genetic diversity now and again.