The adult loon population continues to thrive at Madge Lake, although fewer chicks than expected are being seen, according to the 2016 loon initiatives and survey report issued recently by Doug Welykholowa of Madge Lake, chair of the Yellowhead Flyway Birding Trail Association Loon Initiatives Committee (YFBTA LIC).
“It is difficult to draw conclusions as to why there appear to be fewer chicks surviving than we expect, as there are numerous factors that will affect successful production of young,” the report says. “Predators, weather and what appears to be increased boating activity all likely play a role, but we have no definitive empirical data to tell us the significance of each.
“The health of the lake itself doesn't seem to be a problem, as other species, such as grebes and ducks appear to be increasing in numbers each year.
“Where we lack critical data is in how many nests are actually occupied and how many eggs are laid, in order to draw meaningful conclusions on chick production and survivability.
“We are not currently capable of doing a proper nest search and egg count,” the report said. “This would be an excellent topic for possible research grants.”
The YFBTA LIC conducted its annual loon survey at Madge Lake over the spring and summer months of last year.
“We also worked on a number of other initiatives involving education and information about the common loon with the Duck Mountain Provincial Park interpreters,” it said.
Last spring the ice was off the lake about three weeks earlier than it has in recent years, it said. This allowed the various migratory birds, including loons, Canada geese, grebes, ducks and
mergansers to gain access to their nesting grounds early.
As with the other species, the loons established their territories and began nesting much earlier that in recent years.
Studies throughout Canada and the northern United States indicate that young adult loons don’t return to their breeding grounds until they are three to five years old, and won’t breed until they are four to six years old. This results in a number of non-breeding adults living on the lake in groups, but not establishing or occupying specific territories.
Also according to this research, only 50 per cent of the loons that establish specific territories will attempt to breed in any given year, laying an average of two eggs per nest if they are successful. Unsuccessful attempts and high egg and chick mortality result in about a 50 per cent survival rate for juveniles by the end of the season, much lower than other waterfowl species such as geese, ducks and grebes.
Madge Lake has averaged 26 observed loon territories from 2014 to 2016.
“We can expect about 12 pair to attempt to breed. Those attempts should produce an average of 10 -12 surviving juveniles per year. This number will, and has varied each year, but seems to be borne out by our data over the last six years.
“Adult loons often leave their territory during the day to feed in other locations. If a pair has established a territory, we often only see one bird on the water in that particular territory, if the other is off feeding elsewhere.
“Determining an exact count for the lake requires multiple surveys in any given period in order to catch all the birds in their territories. As we are very weather dependent, this has been somewhat difficult to do with only the one boat. Each year, we hope to get other cottage owners with boats to help us out by doing their own independent surveys, and providing us with the results for us to correlate.
“So far we have been unsuccessful in recruiting assistance, except for occasional spot reports by individuals,” the report said, adding that the topic will again be raised at the next cottage owners’ meeting in July.
With regards to counting eggs, nests cannot easily be spotted from the lake itself, and one would need to use a canoe or kayak over every bit of shoreline in every territory in order to locate nests and establish accurate egg numbers, it said “This is something that is beyond our limited capabilities, but might be a subject for a future research grant.
“We have also noticed that some birds appear to be hiding their chicks in areas that are difficult to get to with power boats. This is based on observations of loon pairs where no chicks are spotted, but where these pairs exhibit the same type of nervous, protective behavior throughout the summer that loons with chicks display.
“Occasionally we then observe these same birds later protecting juveniles at the end of the season in their established territories.”
The report said that 2016 provided the committee with the second year of discovering juveniles in late July and August, with parents that were consistently displaying nesting behaviour.
“However, it is too early to draw any definite conclusions, so we will continue to study this phenomenon.
“Loons that have previously established territories on Madge will normally return to the same spot, unless something has happened to disrupt the pair, or if undesirable changes to the territory have occurred.
“Each year we have noted about a 25 per cent change in territories, with the old ones being abandoned or modified and new ones established. This may be a result of old pairs not returning, and new pairs establishing a new territory, or established pairs abandoning one area for another.
“We have also noted some modifications to the rough boundaries of older territories each year, based on where each pair tends to frequent.
This year we observed that 3 old territories from 2015 were abandoned and that three new ones were established. The abandoned territories were initially occupied in early June, but were abandoned by early July. Most of the others showed some changes to location and size.
“Of the 26 occupied territories observed in 2016, 19 of the territorial pair consistently displayed nesting behaviour throughout the summer, a slight increase over the previous two years.
“We found only five new chicks on the lake over the June/July period. In August we found an additional three juveniles with adults that had been observed displaying nesting behaviour in June and July. All eight of the young survived the season. An additional four juveniles were noted in mid-September, and were likely fly-ins from other areas. By this time, all adults had departed the lake.
“This year we again noted large numbers of unpaired adults feeding on the lake. Up to 30 birds at a time were observed on any given day, with gaggles of up to 17 birds feeding and frolicking together. Average counts of adults were 59 in July and 62 in August. These numbers include both territorial birds and unpaired groups.
“It should be noted, however, that on any given count day, we would often see only one loon of a particular territorial pair.
“Extrapolating our figures, the lake was averaging about 70 to 80 loons throughout the summer, including the 26 territorial pairs and the unpaired groups. This is consistent with last year’s count.
“One change that we have noticed in overall adult loon behaviour over the last three years is that adults appear to be hiding their chicks in areas such as dense reeds or downed trees where we can’t easily find them, more so than in the past. This has made it harder for us to spot the chicks/juveniles than in the past. It appears to be more prevalent in areas where the boat traffic is higher. Further surveys should tell us if this a significant trend in the future.”
In addition to the annual Madge Lake Loon Survey, the LIC continues to work on a number of other projects, the report said. A grant of $1,500 from the Saskatchewan Fish and Wildlife Development Fund for new loon awareness signage for boat launches within the park, and nesting area marking buoys has been completed. The highway grade aluminum signs were placed at the three boat launches on Madge and at Jackfish and Batka lakes. The park staff is looking after the placement of these signs.
“Using the leftover funds from the sign production, we constructed and deployed loon nesting warning buoys near the three most vulnerable nesting sites. These buoys will be emplaced annually in late May/early June, and will be removed in mid-July once chicks are large enough to survive large boat wakes. The intent is to keep power boats from approaching these areas too closely, in order to protect eggs and young chicks from drowning in boat wakes.
“This year, loons successfully produced chicks in two of the three sites where we emplaced buoys. On a few occasions we observed these loons using the buoys as cover whenever a boat came close to them. The third site is promising, but has yet to result in a successful observed hatching.
“All comments we received regarding the buoys were very positive.
“We will continue to work with the park staff to improve awareness of nesting loons on Madge Lake through information provided by the park interpretation program, brochures, signage and via reports to the cottage owners,” the report says.
