Research results shared at Field Naturalists’ meeting

Long Point was one of the focus areas for two researchers who were recipients of the Harry B. Barrett Bursary. Bursary recipients Josh Pickering and Andrew Kramarenko presented their research findings at the November meeting of the Norfolk Field Naturalists.

By Lisa Timpf

The November meeting of the Norfolk Field Naturalists featured presentations by two recipients of the Harry B. Barrett Bursary.

Bursary recipients Josh Pickering and Andrew Kramarenko shared their research findings with the 30-plus attendees at the event.

Pickering studied the effect of deer population management on vegetation and bird communities in Long Point. He noted that deer were extirpated in Norfolk in 1870, but reintroduced after that. Over time, due to lack of predators and other factors, deer became over-abundant in the area.

A deer cull in 1989 brought the population back down to a healthy level. Pickering reviewed data collected over the past 30 years at Long Point to determine how the drop in deer population impacted both the forest understory (trees and shrubs growing between the forest canopy and the forest floor), and the birds that live in Long Point. His research may be helpful for future efforts related to deer population management and bird conservation.

As an example, Pickering showed an image of a white cedar tree whose lowest branches were two metres off the ground. Normally, he noted, white cedars have branches right down to ground level, but the effect of too many deer is that they eat a lot of understory shrubbery and plants, to the detriment of other wildlife.

Pickering’s research shows that in the 30 years since the deer population was reined in, the understory has grown back. On Long Point, native plant species increased in abundance, and there was a greater diversity in plant species as the forest recovered from over-browsing.

Pickering also investigated how this change in vegetation affected bird populations. Since 1991, the gradual recovery of the understory has resulted in a 44 per cent increase in foraging and nesting spots for birds. This change particularly affects species that depend on shrubbery for places to eat and nest.

As Pickering expected, data showed that some species increased in frequency seen, while others declined. For reasons unrelated to deer impact, some bird species dropped off the map. Pickering noted that a number of other factors affect bird populations, including climate change, urbanization, and pollution of land and water. Nonetheless, maintaining the deer population at a healthy level is one step that can be taken to give birds a fighting chance.

Kramarenko discussed his research on the quality of vegetative food sources for waterfowl in areas that have been affected by invasive species. One invasive species of particular interest, and one that has a huge impact on areas favoured by waterfowl, is Phragmites australis. This fast-spreading plant invades waterfowl habitats, choking out other food sources. Phragmites australis is difficult to get rid of, with treatment methods including burning, mowing, and application of herbicides.

Kramarenko’s research involved the use of a forage quality index developed in the United States, and he noted the difficulties in applying this index in Long Point, because the index fails to account for native species here in Ontario. He is working on developing a relevant index for our particular environment.

Kramarenko’s preliminary results suggest that within two years of removing Phragmites australis from a particular site, the quality of vegetative food sources for waterfowl improves. Kramarenko noted that vigilance is needed to ensure that the invasive plant does not re-establish itself in these areas. If so, the benefit would be lost.

Pickering and Kramarenko both tipped their hats to the Harry B. Barrett Bursary Fund for supporting their research. The bursaries are awarded by the Norfolk Field Naturalists from a fund created in 2018 to honour Harry B. Barrett. Barrett made significant contributions to education, and to the protection and enjoyment of Norfolk County’s natural heritage.

Barrett was, among other honours, the Charter President of the Norfolk Field Naturalists, a Life Member and Director of the Long Point Bird Observatory, and co-founder and director of the Long Point Biosphere Reserve.