Birding the Nanaimo River Estuary

We headed up to Nanaimo over the weekend for a spot of mid-island socialising and I managed to squeeze in stops on Saturday at Quennell Lake and the Nanaimo River estuary for a bit of birding.
The lake, and adjacent field, was absolutely alive with wildfowl. 
On the water I counted over 2,000 mallard. Scattered among them were smaller numbers of other species including northern shoveler, pintail, gadwall, lesser scaup, ring-necked duck, common merganser, hooded merganser, bufflehead, wood duck, American wigeon and common goldeneye.
Around 20 American coot were also present, but strangely not a single teal.

Trumpeter swans

A large herd of swans were roosting and feeding in the, as yet unflooded, field immediately north of the lake. A small number were on the lake itself. I counted approximately 230 trumpeter swans and found a single tundra swan among them. None were ringed, or bore neck collars. There were only 12 young birds among them... sign of a poor nesting season?
Also in the area were several hundred Canada geese (no Cackling geese found with them) and 14 greater white-fronted geese. An adult northern shrike was showing well and a juvenile northern harrier was quartering the fields between the lake and the Crow & Gate (where, incidentally we enjoyed a fine roast beef and Yorkshire pudding dinner on Saturday evening...).

We then moved on to the Nanaimo River estuary. I really miss birding at this place, and I was delighted to be back on my old local patch. Better still, I had the place to myself.
There were 4 trumpeter swans on the river and a further 6 flew in. Up near the bridge the annual arrival of Barrow's goldeneye had taken place with well over 50 birds present.
Down at the estuary, I scanned from the raised platform and soon found an adult female northern harrier sat up on a post. As I checked the area for other interesting birds I noticed a very late barn swallow flying over the marsh. I watched it for some timeas it actively flew up and down the water's edge.
As seems to be the case when the salmon are running, there were scores of bald eagles sat out around the the estuary.
After a short while, I walked out onto the marsh, (optimistic as ever, I was secretly hoping to relocate the Gabriola Island snowy owl...) and soon came across a single western meadowlark.

Scanning the distant posts I spotted a short-eared owl (pictured, with customary crapness) and within a couple of minutes was watching a second one as it hunted over the saltmarsh, occasionally drawing attention from the local ravens.  
I checked the hedgerows for sparrows and such, but it was relatively quiet. Among a group of dark-eyed juncos, I could only see song, golden-crowned and white-crowned sparrows.
A second adult female northern harrier appeared, and for a while both birds were hunting in the same area.
As I headed back to the car a short-eared owl sailed across in front of me - maybe it was one of the birds I'd seen earlier, but I suspect it was actually a third owl as it came in from a different direction.

Seeing as I mentioned snowy owl - are we seeing the first signs of an 'invasion' year? There have been three reports from different areas of Vancouver Island in the past week, and as with other tundra breeders, snowy owl populations are closely tied to lemming/vole cycles. Has this been a boom year for Arctic rodents? Might we see yet more snowy owls on the island in the coming months, and will other northern migrant predators be more plentiful too?

Time will tell...!