Piping Plovers are small, endangered shorebirds in Manitoba. Its call is described as a "plaintive peep-lo" which made it the perfect name for this blog as it too is a plaintive call, a Call to Action.

19 August 2012

So what happened to the nest of 7

Well, we're not 100% sure, but here's what we know and what transpired.

We were confident the nest would hatch out sometime in the last week of June so I made preparations to be there at that time.

June 23, Saturday evening - My colleague Alex visited the nest site. At 6:44 PM I received a text from her that said, "Just saw both plovers and checked nest. 5 eggs in the centre of nest, 2 looked to be pushed off to the side a bit."

June 26, Tuesday late afternoon and evening - I set up my spotting scope on the gravel road running adjacent to the ditch and island where the nest was located. From this vantage point, I observed both adult piping plovers. I could only see the top of the cage (exclosure) I had placed over the nest as the vegetation surrounding it had grown to a height of nearly 40 centimetres. I also saw two adult killdeers with a family of four. I estimated the chicks to be eight to ten days old. They were feeding on the far southwest shore of the island near to where the plover nest was located. Anytime the piping plovers got too close to the killdeer chicks the adult killdeers acted most aggressively towards them. They eventually drove them from the island. I watched them fly off in a southerly direction and land on another flooded field. During this time I also observed on the opposite side of the road a raven being buzzed by avocets, blackbirds and a lone eastern kingbird. It was walking in tall grass with its bill gaping open. Eventually, it picked up a large egg of some kind and flew off in the direction of a farmstead with blackbirds in hot pursuit.

As sunset approached, the piping plover pair returned to the island and when I left for the day both adults and the killdeer family were all present and accounted for.

The Island looking west, Whitewater Lake
Photo by K. Porteous

June 27, Wednesday - Although I had planned on checking the nest first thing in the morning, a storm blew through so my friend Brad and I decided to try again later in the afternoon. Upon arriving at the site at about 3:00 PM, I met Ken De Smet, a wildlife biologist with Manitoba Conservation and the Chair of the Manitoba Piping Plover Recovery Program. He had just finished visiting the nest. He reported that there were only three eggs in the nest and with no adults about, it appeared the nest and area had been abandoned.

Three eggs in exclosure - Photo by K. Porteous

June 28, Thursday morning - My friend Brad and I arrived at the plover site early. As we prepared to canoe across the ditch to the island to check on the nest, we observed a female northern harrier (hawk) skimming and hovering only a few feet above the vegetation on the island. She appeared to be very intent on capturing something, but flew off when she caught sight of us on the gravel road. After a short visit to the nest, I sent a text to Alex which read, "Only three eggs in nest. All cold. No chicks, alive or dead, no eggshells, no adults. Only 2 of 4 killdeer chicks left and get this, they swam across the ditch to get away from me! Not sure what happened to the other 4 plover eggs."

Whitewater Lake nest & exclosure looking east
Photo by K. Porteous

Those are the facts. That is what I and my colleagues observed over a six day period. So what happened? I'm afraid I don't know and only have more questions, than answers.

It would appear that four of the seven eggs hatched. This could have been the second clutch of eggs of a re-nest using the original nest site. I'm confident they were not predated as all seven eggs should have been taken and eaten if that was the case. But why were no chicks observed? Could the raven and/or the northern harrier have taken all of them along with two of the four killdeer chicks? As Brad, an accomplished outdoorsman and part-time trapper observed, "Nature can be so cruel."

I'm hoping the outcome was more positive. Having seen the killdeer chicks swim across the ditch, could the adult piping plovers, sensing there was only room for one set of chicks on the island, cajoled their chicks to swim across the water to a safer shoreline away from the island and killdeers. We will never know for sure, but we can hope that that's what happened. We can hope that at least four of the nest of seven survived and are now headed south to the Gulf.