Wednesday, May 4, 2016

Swans killed by energy infrastructure this spring

Trumpeter swan killed by transmission lines at Frank Lake (photo by Mike Sturk,
see below for more images)

We are an energy-intensive civilization and whether it is solar and wind or oil and gas, gathering the kind of power we use every day seems to require a lot of man-made infrastructure on the landscape. With the decision on the Chaplin Wind Project looming (the Environment Ministry has called a meeting on May 9th, inviting a select group of conservation NGOs who commented on the Environmental Impact Statement), some news out of Alberta provides a powerful cautionary tale.

While the turbines themselves have to be sited on disturbed lands with little ecological value, this story from Alberta demonstrates that is important to ensure that the associated transmission facilities carrying the electricity away are also sited carefully.

The following story showing that transmission lines are killing Trumpeter swans at Frank Lake Alberta, is based on a report by (and presented here with the permission of) biologist Greg Wagner, one of Alberta's most vigilant defenders of prairie habitats. A big thanks to Greg for bringing this issue to public attention and for letting his words appear in this post.

Frank Lake is, like Chaplin Lake in Saskatchewan, a recognized Important Bird Area. Greg says that it is one of the few Environmentally Significant Areas in the Municipal District of Foothills

It is also a major Ducks Unlimited Canada project, built with funding under the North American Waterfowl Plan. It is arguably the single most important bird habitat area south and west of Calgary.

The lake is also used as a major spring and fall staging area by both Tundra and Trumpeter Swans as highlighted on eBird, which is publicly accessible online. This data also shows that Basin 2, and to a lesser extent, Basin 3, are the most important areas on the lake for spring and fall staging swans. The number of staging Trumpeter Swans has also increased significantly over the last decade as the migration route of this species has expanded eastward.

Despite the areas importance for wildlife, AltaLink has recently built new transmission lines around the lake. These lines, along with historic lines now surround the western half of the lake. It is well known that transmission lines can act as large mortality sources for habitat areas that are used by large numbers of birds such as wetlands like Frank Lake (e.g., Crowder and Rhodes 2001, Rioux et al. 2013). Large less maneuverable birds, with heavy wing loading, like swans, cranes, pelican and herons, are know to be particularly susceptible to transmission strikes, particularly to single top wires.. Both the Alberta Trumpeter Swan Recovery Plan 2012-2017  and the most recent Alberta Trumpeter Swan Status Report indicate that 

"Electrocution and other injuries from collisions with power lines are believed to be the most significant causes of mortality for adult trumpeter swans in Alberta. The Grande Prairie area appears to have the highest recorded number of mortalities with as many as 6-10 confirmed cases each year.” 

Beyersbergen et al. 2009 also observed the following related to the large nesting colony (up to 50,000 pairs) of Franklin’s Gulls at Frank Lake: "There is a large power-line intersecting the colony on Frank Lake. While performing nest counts on the lake, we noticed a number of dead gulls directly under the powerline. No mortality counts from the power-line were conducted so we do not know how many birds die each year due to collision with the line and towers.”

Given the amount of information available on the impacts of transmission lines around wetlands, it is somewhat incredible that transmission lines would be built so close to the lake. The line at the southwest corner of the lake could actually have been set back further from the existing line, which it will replace. Instead it was built closer. Reflective tags have been put on the top wire of the new transmission lines as a means to mitigate collisions. But it is unclear how effective these have been given current mortality levels. AltaLink also conducted radar and visual surveys in tandem on Basin 1 on September 30, and October 12 and 18, 2013 (Stantec 2012). Unfortunately, these studies were done on Basin 1, which receives minor swan use relative to Basin 2, and were done before large numbers of swans arrive at the lake.

Furthermore, it isn’t like there are vast amounts of wildlife habitat in the High River area. Frank Lake is more or less it. The lake could have been easily avoided by transmission line development. After all, the first rule of environmental management is to avoid potential impacts where feasible. It was certainly feasible to avoid putting transmission lines near Frank Lake in this case.

Known swan mortality at Frank Lake over the last two years is as follows:

  • 19 March 2015, three carcasses found under transmission line at basin 1 of Frank Lake. These all appeared to be Trumpeter Swans, but this could not be confirmed because the carcasses were lying on thin ice (see attached pictures taken by Mike Sturk ). A Snowy Owl carcass was also found under the transmission line (See page 15 of this issue of the Western Producer)
  • Two splashes of white feathers, including large primaries, with no carcass present were found near the blind at Basin 1 in Spring 2016 before 4 April. Another splash of white feathers, with no carcass present was also found under the transmission line on the north side of Basin 1 at this time. Splashes of white feathers were found around all other carcasses at Frank Lake.
  • 4 April 2016 – one Trumpeter Swan found dead under the transmission line at basin 1 west of the blind (see article from High River Online)
  • 11 April 2016 – two Trumpeter Swans found dead under the transmission line at basin 3 of Frank Lake (see photos below).
  • 12 April 2016 – three Trumpeter Swans found dead under the transmission line in NE23-18-28-W4M west of basin 2 of Frank Lake (see photos below)
  • 14 April 2016 – another Trumpeter Swan carcass was found under the transmission line at basin 3. No photo taken.
  • 29 April 2016 – one injured Trumpeter Swan observed at the observation point north of the blind at Basin 1. The bird had a difficult time walking on land, and laboured to get into the water. A dead swan, presumably the same bird, was found at the same location the next day (see photo below).
  • Transmission line strikes have potentially killed eleven swans at Frank Lake during spring migration in 2016. This level of mortality is higher than the level of transmission strike mortality previously reported for the Grande Prairie area.

This level of mortality is probably much higher. The dead swans and feather splashes that were found were situated in publicly accessible areas around the lake, or in fields that could be observed from roads and trails around the lake. Such areas probably represent 10% of the area around the lake traversed by transmission towers. Simple extrapolation suggests that the actual level of mortality could be ten times higher. Predators could also have removed carcasses before the were detected.

At least 1,250 swans staging at Basin 2 also took daily, if not twice daily, trips to a field to the southwest in SW13-18-28-W4M. These birds would have had to travel through two separate sets of transmission lines. However, because these lines were located on private land and away from roads, there is now way to ascertain how many birds might have died from transmission line strikes at this location.

The loss of swans at Frank Lake is sad. The recovery of the Trumpeter Swan from about a hundred birds to thousands of birds is one of the great North American wildlife conservation triumphs. The sight of several swans staging at Basin 2 is truly stirring and has huge ecotourism potential. But the birds now face new risks from obviously silly land use decision making.

Farmers in southern Alberta have a saying about AltaLink - “AltaLink would rather do things wrong and apologize later rather than doing things right in the first place. This certainly applies in the case of the swans at Frank Lake. But, as long as Berkshire Hathaway is making a profit, things will probably work out. Yes, that was sarcasm.

Sincerely yours,

Greg Wagner, B.Sc.
President and Senior Wildlife Biologist
Athene Environmental Limited

Greg's concerns seem very reasonable to me and coincide with the science in a study released this spring in The Condor, a peer-reviewed journal of international repute, which says

"Given that all infrastructure types result in direct loss or fragmentation of habitat and may affect the distribution of predators, indirect effects mediated by these mechanisms may be pervasive across energy facilities. When considered together, the direct and indirect effects of renewable energy facilities, and the transmission lines serving these facilities, are likely cumulative. Ultimately, cross-facility and cross-taxon meta-analyses will be necessary to fully understand the cumulative impacts of energy infrastructure on birds. Siting these facilities in a way that minimizes avian impacts will require an expanded understanding of how birds perceive facilities and the mechanisms underlying direct and indirect effects."

All images below by Greg Wagner and Mike Sturk:

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