If you know anything about me, you know that I love long term environmental data sets. They are necessary to track patterns and changes in these patterns over time. This is especially important in terms of conservation for monitoring population numbers. It is so exciting to contribute to the “history” of studies.
Part of the deal of going to do field work in Haida Gwaii with a seabird researcher who had spent many field seasons in the area (I would have found 0 Cassin’s auklets without him), was to help him with his long term seabird occupancy surveys. Of course I said yes, I was looking for any excuse to stay there longer!
After spending time on the east coast of the Haida Gwaii archipelago to find Cassin’s auklets for my project, we set sail (on a real sail boat) for the west coast. After roughing it in tents, it was a treat to be able to stay on the boat and have the waves rock us to sleep! (Also a bonus to have someone else cook for us). Besides going around the archipelago in the north or the south, the quickest route to the other side is through the Burnaby Narrows, a 50m wide waterway separating the two big islands of the archipelago. We had to time our departure perfectly, in order for the boat to make it through the Narrows before the tide was too low. The intertidal zones were full of life, including kelp dancing with the waves and sea stars covering the rocks. Luckily we beat the tide and arrived in Englefield Bay, where we spent the next week conducting seabird occupancy surveys on the small islands in the area.
The occupancy surveys were conducted across transects that had been used three times since 1986 for the same surveys. Conducting surveys along the same transects in multiple years allows for comparison between years to track any changes that occur. The surveys started with me sitting at the very edge of the cliff (don’t tell Health and Safety) as the researcher climbed up with the yellow measuring tape trailing behind him to the other side of a plot. Although the plots were only 5m by 5m, due to the dense vegetation and fallen logs, he would disappear up the rugged and slippery terrain with the measuring tape as my only life line.
Once the perimeter of the plot was set up, we would check for signs of burrow occupancy by seabirds within the plot. This included sticking my hand in holes in the ground to check if chicks or eggs were inside (luckily there was never anything unexpected in them -as much as I like snakes, I think I would be very startled if I touched a snake in the hole!). We also used our sense of smell to detect the not so nice smell of the seabird “latrine” that many species leave at the entrance to their burrows. We would then repeat this survey for plots every 30m along the transect to the other side of the island. The first occupied burrow I found contained a fork-tailed storm-petrel. This was super exciting for me as I did my fourth year Honours project on this species but had never seen one in the wild (my field work for that project consisted of traveling to the Royal Ontario Museum in Toronto -still exciting but less outdoors!).
In addition to burrow occupancy, we noted any feathers or pieces of egg shell that would indicate a bird had been there at some point. Many times we would find raccoon scat near a pile of feathers or cracked egg shell. Predation by raccoons has been very detrimental to the seabird populations in this area. Repeating surveys along the same transects can give us an idea of occupancy over time. Based on the 4 repeated surveys, there appears to have been a decrease of over 50% in the number of occupied burrows since 1986.
Although the addition of this season’s data with not many seabirds “home” in their burrows does not paint a pretty picture, it was a great experience to be part of a long term survey that can influence real conservation decisions.