I see more reaction to Rem's absence from Jake than from Tika.
Rem used to lie in my office, either on his bed or behind my chair, while Jake had three favorite spots--under the table if I was in the kitchen, or in his chair or sometimes at my feet when I was at my desk. Several times a day I have noticed Jake trotting down into my office, going around the corner of my desk, looking around as if searching for something. On Monday I noticed him once with his head up over the edge of Rem's bed (which is elevated), sniffing the air back and forth. Never noticed him do that before. And then certainly the last 2 days--not sure about Monday--he has spent a lot of time lying on the floor near Rem's bed. Not looking at it--in fact, facing away--not looking depressed, just licking his paws or holding his squeaky or whatever he might usually do while lying somewhere. But I don't think he ever lay there before.
Wed. morning I changed the cover on Rem's bed so that the one Rem had last slept on was no longer there. Wed. evening, Jake got up on the bed and started the nesting thing, where he digs and pushes and grunts and growls at the bedding, which I have seen him do maybe a couple of times on Rem's bed in the whole time we've been in this house (19 months). But he didn't lie down--hopped off again and went on his way.
I don't think he's been in his own chair at all this week, which is where he usually nests enthusiastically and then settles in. He's mostly been right at my feet under the desk or under the table when he's not near Rem's bed.
The action that hit me the hardest was last night at agility class. I've almost always had Rem's and Jake's classes one right after the other, sometimes one first, sometimes the other. Usually the first dog doesn't want to get back in the car because he knows I'm going to get the other dog out to do agility. Last night, after Jake was done, I walked him back to the car, and he didn't want to get in as usual, even though there had been no Rem driving up with us. When he did get in, he stuck his head way out, moving his nose back and forth and up and down just an inch or two, scenting the air, looking towards Rem's seat. Then he stuck his head between the two front seats, and checked both seats. Looked in the back of the car. Looked everywhere again. Not frantically, just looking, mostly not moving his feet, just his head and more his nose. Stood there, air scenting, nose up and back and forth and all around, before he finally turned back towards me. Jeez.
My general impression is that he's been snugglier and hanging tighter to me.
Tika I think is also hanging closer. For example, usually she goes upstairs and rests on my nice down comforter whenever I'm not doing anything interesting, or in good weather lies on the deck to scout the yard. Although the last few days have been nice, she has mostly been hanging in the house. Right now she's been lying on the floor behind my chair--where Remington often used to lie. Did that yesterday, too.
In bed, Jake's place is on the side directly to my left, Rem's was at the left foot of the bed, Tika's right next to my feet on the right. Made it crowded for both her and me. I'm hoping to move her over to where Rem slept, but I don't want to push it. Monday morning and again this morning, while my brain was still in the stage of deciding whether to wake up, she has stepped across me, turned and turned and turned--not quite all the way over to where Rem slept--and then at the last minute stepped back to her usual spot to lie down. Never has done that before; stayed away from the boys' sleeping spots.
The usual wake-up ritual has her stretch out up my right side so I can rub her with my right hand while skritching Jake with my left. Twice in the last 3 days she has stepped across me and stretched out on Jake's side, which she's also never done before. I've moved her back so she's not between us.
I haven't so far seen any signs of changes in who's in charge or how they interact with each other, although I wonder whether Tika's actions aren't showing signs of taking over Rem's spots--