The 26th field season on East Limestone Island is brought to a close with more sunshine and seabirds!

The second to last week of our season was spent in Gwaii Haanas around the Hotsprings Island area completing our second survey of Black Oystercatchers (BLOY). We were very lucky to have extremely calm waters and sunny skies, allowing us to get to everywhere we needed to go – it was even hot too! During this survey we scan the shoreline for Black Oystercatchers, looking for both breeding pairs and non-breeding birds. Having completed this same survey route earlier in the season, we were aware of lots of breeding adult pairs with eggs; now it was time to search for chicks! The chicks are difficult to find: fast and sneaky, they know how to find the best cracks to hide in and boulders to hide under when predators fly over-head, or walk into their territories! Much of our time was spent searching for these chicks in known territories, watching and listening for clues from the adults as to where their chicks might be.

We discovered 43 chicks and 27 eggs, and two new territories. During the first survey this year, we had found 177 eggs, but not all eggs hatch to become chicks and not all chicks survive, due to predation by Bald Eagles and Common Ravens. Luckily BLOY are long-lived, and always willing to try again next year! At one territory on Faraday Island that had not been used for 6 years, a breeding pair had built a new scrape. One member of the pair had a blue band on its right leg, indicating that it was banded in 2006 as a chick, so is now 9 years old. We were also excited to see the same two banded Laskeek Bay BLOY that we had sighted on the first survey. E4 was seen again with a big group of non-breeding birds on Murchison Island, and A6 (a 2 year old bird who had been building a scrape last survey!) was seen on the opposite side of Alder Island to its territory, but still apparently paired up.

Beautiful weather to accompany rewarding monitoring!

Most of the chicks in wildlife trees at East Limestone Island have fledged and we have been enjoying watching cavity nester chicks. The Red-breasted Sapsuckers and Hairy Woodpecker chicks follow behind their parents, learning how to hunt for invertebrates and eating insects from holes their parents have made.  Interestingly, woodpeckers find prey within wood by listening. Wildlife tree 109 is the only wildlife tree we are still monitoring on the island, where Red-breasted Sapsuckers are feeding their chicks. However, they now feed their chicks more infrequently; although you can hear them peeping, the adults may not come to feed the chicks for periods of a half hour or more. Wildlife tree 109 was first active in 2006, and has been active every year since 2011 with nesting Red-breasted Sapsuckers!

This year we completed a Cassin’s Auklet Census, a survey conducted every four years to count the number of active burrows on East Limestone Island. We found 101 active Cassin’s Auklet burrows! We also have 4 chicks in nestboxes at Lookout Point and the East Coast. This is lower than last year (7 chicks in nestboxes), but the number has varied a lot since the nestboxes were built in 2010 (1 chick in 2010, 6 in 2011, 2 in 2012, 7 in 2013). It is good to see that there are still some adults raising young on Limestone after the deaths of so many Cassin’s Auklets this winter, likely due to changes in food availability from warmer than average sea surface temperatures.

With the Ancient Murrelet season over we have completed our last gathering ground count and packed up the funnels for another year.  We continue to monitor for raccoons using remote cameras (4 at various locations around the island), but since finding a headless Ancient Murrelet in Crow Valley, we have not found any other evidence of raccoon presence on ELI.  We are now fairly certain that what we thought might be raccoon predation was actually predation by river otters, which are a common sight along the shorelines of ELI.

An update on chicks in Laskeek Bay, and in Gwaii Haanas too!

On the night of June 8th, we completed our Ancient Murrelet monitoring with a total of 42 chicks. This was a disappointingly low number of chicks as the last few years there have been over 100 chicks (112 in 2014, 136 in 2013, 110 in 2012). We are not sure why the numbers are so much lower this season, but monitoring next season will hopefully give us an indication as to whether it is just a one-year anomaly (possibly due to warm ocean temperatures) or if the habitat around the cabins on ELI is no longer suitable for breeding Ancient Murrelets. Our evening gathering ground counts and nightly point counts indicate that there were still many adult Ancient Murrelets coming to the island at night. Maybe they have not be able to breed this year, but it is good to see that they are still in the colony, socializing and making plans for next year! At Funnel 4 in North Cove, our infrared cameras captured 11 chicks, a similar number to last year (10 chicks), but much lower than 2013 (41 chicks). It will be interesting to explore why these low numbers have occurred and to see if the chick numbers will recover next year.

On June 7th, we found a beheaded Ancient Murrelet in Crow Valley, on the south shoreline of ELI. This could indicate predation from a raccoon, as raccoons will often only eat the head of their bird prey. Since then, we have searched Crow Valley for other evidence of raccoon predation and have found a few other Ancient Murrelets that we suspect were eaten by a raccoon. We have also completed a night-time low tide spotlight survey and have set up a second baited raccoon camera in Crow valley, but have not located a raccoon on East Limestone Island thus far.

In full swing with Ancient Murrelets, Cassin's Auklets and Project Limestone!

We have been monitoring the Cabin Cove ANMU funnels since the night of May 7th, as we do each year. We also have a camera set up in funnel 4 again, to monitor the last remaining funnel that survived the blowdown in North Cove. Unfortunately, our ANMU chick numbers at the funnels have been very low to date. As of the night of May 28th, we have a total of 39 chicks in Cabin Cove; last year we had 104 chicks on this same date. The camera in North Cove has captured pictures of 10 chicks so far. Information from biologists with the Canadian Wildlife Service suggests that Ancient Murrelets in other colonies in Haida Gwaii are nesting later than usual, so we are interested to see how long the chicks continue to arrive at our funnels this year. Each year we continue monitoring until there are two nights in a row with zero chicks; this usually happens around the beginning of June, but the date varies quite a bit, and one year the crew was still staying up at night waiting for chicks until the 22th of June!

Whether last winter’s die-off of Cassin’s Auklets, thought to be caused by above average sea temperatures along the west coast of North America that decreased their food supplies, affected Ancient Murrelet populations is not known. However, there are similar foods found in both Cassin Auklet and Ancient Murrelet diets. We have done the first check in our Cassin’s Auklet nestboxes, and found that there are a similar number of eggs and chicks to last year. Last year there were 7 chicks; this year so far we found 2 chicks and 4 eggs.