Wednesday, February 16, 2011

The 2011 Brant Monitoring Season Is Underway!

Since the Spring of 1999,
I have worked as a contractor, monitoring Brant in the Parksville-Qualicum Wildlife Management Area here on Vancouver Island. I generally spend 5-7 days a week from mid February to late April, counting Brant, noting how many juveniles are in each flock, recording every flight disturbance, it's severity, and it's cause, reading led bands, and assessing how fat or skinny each banded bird is. The Brant which pass through here each Spring are virtually all Pacific Black Brant (Branta bernicla nigricans) although we do see a few Western High Arctic, or "Grey-bellied Brant" each year. The Pacific Black Brant which stage here are migrants on their way north tho the breeding grounds. Most will have spent the winter in Baja California, Mexico. They stop here to load up on the roe of Pacific Herring, which is abundant most years, and helps them to load fat in a relatively short period of time. Like most birds, Brant have an incredibly high metabolism, and they must spend most of each day eating, just to stay alive. To actually gain weight for migration, they switch from their normal vegetarian diet of sea weeds, algae, and especially eelgrass, and begin eating the roe of the Pacific Herring, which washes up on beaches here after storms, sometimes in strand lines meters wide.
In general, Brant which stage in this region have been declining for years, and are a conservation concern. As such, the Canadian Wildlife Service has funded a local monitoring project since 1988, aimed at monitoring the population in an effort to discover whether there are any conservation activities which might help this population. Research in this area has shown that Pacific Black Brant suffer more disturbance from human activities, than any other species of goose, and that the disturbance rates in this region are amongst the highest known anywhere. This leads to the Brant here suffering from not getting enough to eat. They simply spend too much time burning calories trying to get away from walkers, dogs, kite fliers, surfers, clam diggers, joggers, etc, etc, etc. It just never seems easy for these birds. Because this is a tourist area with some of the best beaches on the east coast of Vancouver Island, people flock here, just like the birds do. It's a bad situation, but we are making progress, slowly.
This week I started my first Brant monitoring surveys of 2011, and despite horrific rain and wind, it's been a great week. On Monday I counted 483 at Rathtrevor Provincial park, which is a very good count for this early in February. Each year the Spring migration seems to creep up a little bit earlier. When I started back in 1999, we didn't even start looking for Brant until the last week of February. Climate change? Who knows.
Today was terribly stormy, and I think most of the Brant were staying offshore, as they do sometimes during periods of foul weather. I could only find 137 today, and got soaked to the ass trying. Better weather is coming, but not for at least a month. Brant surveys at this time of year are generally miserable, wet and cold. Did I mention the rain?


motherwort said...

How do you count birds? Is the count an estimate or an actual number? I have never understood how one keeps track of individual birds.


Abu Anka said...

We use different methods, depending upon the number of birds and the types of species involved. With the Brant, what I generally do is make a general estimate of the flock when I first arrive on site. I then count each bird one by one using a hand tally clicker. Having done this for so long, I can accurately count a flock of about 1000 birds in less than five minutes, with an accuracy of 98% or beter. And then afterwords, by comparing my initial estimate to the actual number counted, I can stay on top of how accurate my estimates are, and adjust accordingly. When we do encounter a flock that is larger than about 5000 birds (this rarely happens with Brant here, but certainly does with other species) I would estimate the total flock, and then estimate in blocks of 100 birds, and then multiply those accordingly. Doing it this way is far less accurate, but over the years I have been able to check my estimates now and then by actually counting up the individuals with a hand tally clicker. There was a flock of Greater Sacup in Baynes Sound one Spring that I estimated at 18,700 birds. I then counted with block estimates and got 17,800 birds. When I counted the individuals I came up with 19,162 birds. Of course, there is no way to ever know exactly how many birds there really are in a flock this large. The key is in always doing the counts in the same way, so that even if you are off a bit, you are always off in the same fashion.