By Mike Renzella
The Haldimand Press
CALEDONIA—Nestled underneath the old Argyle Street Bridge in Caledonia is a colony of Cliff Swallow birds that has been called one of the largest in Ontario. With plans in motion to replace that bridge with a new structure, activists are raising the alarm bell about the fate of this colony.
Cliff Swallows are aerial insectivores, and although they are not currently listed as an endangered species, they are under threat due to environmental issues. Their current home under the Argyle Street Bridge is an ideal environment to flourish. The concrete foundation of the bridge provides a solid base for the colony to build their mud nests on, and the wide variety of insects along the surface of the Grand River beneath gives them a reliable food source.
The new bridge, scheduled for 2023, would be steel. A study conducted by the Arkansas Journal of Science, out of Henderson University, showed that Cliff Swallows struggle to build nests on steel structures, raising concerns for some locals about the Cliff Swallow population in Caledonia.
“If the bridge design is not amended to ensure the continuation of this significant colony, it means another bridge on the Grand River that is now uninhabitable for Cliff Swallows, because the Cayuga bridge has already hurt this population on the Grand River,” said George Naylor, one of the proponents behind an online petition to save the colony. “This also doesn’t take into account the benefit these birds bring. The Grand River area has a pretty rich flying insect population, which is why the birds are here in these numbers in the first place, and these birds eat a lot of insects.”
Naylor says he has been in contact with the Ministry of Transportation (MTO), the Canadian Wildlife Service (CWS), and MPP Toby Barrett about this situation, and is hopeful that with enough attention drawn to it that changes can be made before it is too late.
Brandon Clim, Spokesperson for Environment and Climate Change Canada (ECCC), explained how the government organization got involved.
“ECCC was informed of the Argyle Street bridge replacement project in the fall of 2020 through Birds Canada, which was made aware of the project by a citizen that was concerned about the project’s potential impact on nesting Cliff Swallows. ECCC does not have specific information or studies regarding Cliff Swallow at that site,” said Clim.
He elaborated on the suggestions CWS made to the MTO: “ECCC suggested design options that could allow for future nesting of Cliff Swallow on the new bridge structure. This is consistent with the mandate of the Canadian Wildlife Service within ECCC to conserve migratory birds, which flows from the Migratory Birds Convention Act and the Migratory Birds Regulations.”
“ECCC recommended that the MTO investigate whether a spray coating could be applied to the steel girders that would allow for nesting Cliff Swallows to affix their nests to the bridge, given that they do not typically attach nests to steel girders because they are too smooth,” continued Clim. “Providing places on the bridge with 90° junctures of a vertical wall and a horizontal overhang will help provide nesting habitat for Cliff Swallow.”
The MTO has also publicly acknowledged that discussions have taken place regarding the colony.
Paola Bonilla, Communications Coordinator for the MTO, stated, “The MTO continues to have ongoing communication with the CWS about this project, the Cliff Swallow colony, and the measures that are included in the construction contract to mitigate potential impacts.”
She elaborated on how the MTO makes determinations involving work that could disrupt a colony: “MTO projects follow the Class Environmental Assessment (EA) process and MTO obtains all necessary permits and approvals in accordance with current legislation from regulatory agencies in advance of construction. Cliff Swallows are not a listed species at risk under either the Ontario Endangered Species Act or the federal Species at Risk Act, but are protected under the Migratory Birds Convention Act. MTO projects consider all protected species and MTO construction contracts include specific measures to be undertaken to allow work to proceed while mitigating potential impacts to migratory birds.”
She stated that although the MTO has considered nesting opportunities for the colony, no further changes are scheduled to be implemented to the design of the new bridge at this time. She added that the MTO has observed Cliff Swallows nesting on MTO structures with similar design features.
Naylor spoke about why local residents should be concerned and consider adding their voices to the petition: “The area around Caledonia will be poorer and less diverse from the wildlife perspective, as has already happened in Cayuga. You don’t have to know birds to appreciate the sight of hundreds of these agile little flyers hawking insects over the river.”
He mentioned how the new bridge design goes against guidelines from the Ontario Significant Wildlife Habitat Guide, which states that Cliff Swallow colonies containing eight or more nests should be considered significant and must be protected. Naylor stated an MTO report showed dozens of nests along the bridge.
“Aerial insectivores such as Cliff Swallow have declined significantly since the 1970s and CWS supports efforts to help conserve these species. You can find more information on the decline of aerial insectivores on the Birds Canada website,” summed up Clim.
For those interested in learning more about how a steel structure will impact the colony, the study conducted by the Arkansas Journal of Science is available to read in full at scholarworks.uark.edu. The petition had almost 11,400 signatures as of press time and can be found at change.org by searching Caledonia Cliff Swallow.
