Eastern Tailed-Blue is a species that has caused a lot of excitement during the MBA. Prior to the project this species was considered uncommon in the Maritimes, and the only records were from southwestern New Brunswick. The first couple years of the MBA seemed to confirm that – the first record for the project was a Grand Manan record from 2011 – the second year of the MBA. Then things started to change.
In 2012 Eastern Tailed-Blue was recorded in eight atlas squares. These were all from New Brunswick, but some were from regions where the species hadn’t been seen before, including Albert and Northumberland Counties. In 2013 Eastern-tailed Blue was recorded throughout the southern New Brunswick and for the first time in Nova Scotia. In Nova Scotia it wasn’t just recorded once, it was found at four different locations! At one site near Debert multiple individuals with little wing wear were present, suggesting the species had bred there. In 2014 Eastern Tailed-Blue was again found at four sites in Nova Scotia, including three new MBA squares, and it was recorded for the first time from far northern New Brunswick (an August record from just south of Jacquet River Gorge Protected Natural Area), and, as I’ve just found out through material submitted recently, on Prince Edward Island!
On September 4, 2014, Mark Arsenault collected the first record of Eastern Tailed-Blue for Prince Edward Island. Given how rapidly the species had spread on the mainland it appeared it was just a matter of time before on was found on PEI.
It will be interesting to see what happens to Eastern Tailed-Blue in the Maritimes in the future. In 2015 there were relatively few Eastern Tailed-Blues reported. 2015 data is still being compiled, but records to date show in Nova Scotia it was only recorded in and around Kentville, and in New Brunswick the it was only recorded at Grand Manan and Fredericton (though I haven’t received records from a couple of major contributors who found many records for the species in the Saint John River valley in previous years).
Director – Maritimes Butterfly Atlas