Research - Written by Olivia Maillet

Central Ontario in summer can be very hot, humid, and buggy. Especially in Prince Edward County, native vegetation such as prickly ash, the host plant for Giant Swallowtail butterflies, creates a dense, tangly maze of leaves and thorns. While this isn’t always so pleasant for us to traverse, the spiky forests, fields and wetlands of Prince Edward County support a wide variety of breeding bird species, which rely on these habitats to nest and raise young.

Since 2021, PEPtBO has participated in the Monitoring Avian Productivity and Survivorship (MAPS) program, a collaborative effort among banders across Canada and the U.S. to collect long-term data on North American bird species. Like our migration monitoring, we capture, band, measure, and release birds, which are sometimes recaptured later in the season or in future years. Recapture data is especially useful because it can be used to infer breeding locations, timing, recruitment of young into the population, and annual survival.

PEPtBO operates five MAPS sites on private and public lands across Prince Edward County. Each MAPS site consists of 10-12 nets set up >50 m apart to sample a variety of birds in different habitats. We visit each site on a rotating schedule seven times throughout the summer, beginning in early June and ending in early August. Our MAPS program monitors approximately 600-900 individuals of 40-60 species each year. Our sites fall broadly into five habitat type categories: alvar, forest, wetland, grassland, and sand dunes. Below is a summary of the habitat type and featured species breeding at each site.

Alvar

Our alvar site includes dry, rocky fields of prickly ash, red cedar, and a floodplain marsh. Local breeders include Brown Thrasher, Black-billed Cuckoo, Magnolia Warbler, and Eastern Towhee.

“*Oh Sweet Ca-na-da Ca-na-da Ca-na-da*” is a mnemonic for the song of the White-throated Sparrow

This striking sparrow species breeds in much of Canada’s forests and exists near the southern edge of its range in Prince Edward County, favouring the coniferous trees of the county that appear to mimic the more northern boreal forest. Ninety-seven percent of White-throated Sparrows reside in Canada, representing a very high degree of responsibility for Canada. Since 1970, White-throated Sparrows have declined by approximately 15% according to Canada’s State of the Birds Report. At the southern edge of its range, PEPtBO has a unique opportunity to collect important breeding and survival data for this species.

Forest

Our forest site consists of mixed red cedar and shrub fields, flooded old-growth forest, all near the north shore of Lake Ontario. Local breeders at this site include Baltimore Oriole, American Redstart, Rose-breasted Grosbeak, and Black-and-white Warbler.

Due to the high canopy and dense forest at this site, we observe and band several species of warblers here. One of the more common species is the American Redstart. The American Redstart is an abundant and widespread species of warbler that breeds in much of North America. Unlike most forest bird species, their populations have remained approximately the same since 1970 and in some areas, such as southern Ontario, show signs of increases. Eighty percent of their global population resides in Canada, representing a very high degree of responsibility for Canada to protect their habitat and populations. MAPS data has been used by scientists to understand the connectivity between breeding and wintering populations, which can be a key indicator for resilience to change.

Wetland

Our wetland site includes not only small wetlands and ponds, but also mixed red cedar and prickly ash, and nearby old-growth forests. Forests along the edge of these small wetlands and regenerating fields support a variety of species such as American Woodcock, Nashville Warbler, Field Sparrow, Swamp Sparrow, and Song Sparrow.

Early in the morning, we hear the beautiful and complex song of another local breeder, the Wood Thrush. The Wood Thrush is a bright, cinnamon-coloured thrush with a white belly and black spots. It breeds in the deciduous forests of eastern North America, with only 4% of its global population breeding in Canada. The Wood Thrush has experienced steep declines in areas including central Ontario, of approximately 80% since 1970, likely due to habitat loss and fragmentation. We hope that our continuous monitoring of Wood Thrushes during the breeding season will contribute to future research on this declining species.

Grassland

Our grassland site is characterized by grassy regenerating agricultural land and old deciduous forest near a large wetland along Lake Ontario shoreline. These regenerating agricultural lands support local breeders such as Grasshopper Sparrow, Indigo Bunting, Eastern Meadowlark, and Red-winged Blackbird.

With a quiet, insect-like buzz given from close to the ground, Grasshopper Sparrows often go unnoticed. These small, cryptic sparrows have declined by approximately 70% since 1970 due to habitat fragmentation and degradation. They are especially vulnerable to loss of habitat due to agricultural practices, but can return to regenerating lands such as our grassland site. Collecting productivity and survival information about uncommon and declining species is especially important in the context of land use change. Restoring lands and co-existing with biodiversity are important for bird conservation on a global scale.

Sand Dunes

Our site with the most unique habitat includes sandy dunes with grasses, a small wetland, and a tall pine plantation, supporting local breeders such as Gray Catbird, Common Yellowthroat, Eastern Kingbird, and Common Grackle. Many species at this site are common, generalist species, capable of breeding in the harsh environments of dry sand dunes under the hot sun.

One such species is the Eastern Kingbird, which can be found breeding at small ponds and wetlands within the dunes. Eastern Kingbirds are aerial insectivores, meaning they obtain food for themselves and their young by catching insects in the air. Due to climate change and pesticide use, aerial insectivores in general have declined, and Eastern Kingbirds have declined by 34% since 1970. While common, Eastern Kingbirds are rarely banded at PEPtBO during migration due to their behaviour, so MAPS allows us to monitor their population through banding and recapturing breeding birds.

Many bird species, including aerial insectivores, are declining due to loss of insects and lost, fragmented, or degraded breeding habitat. Although human activities continue to endanger countless species and their habitats, conservation efforts such as land stewardship offer a glimmer of hope for population recovery. Recent analysis suggests that in the last 10 years, Eastern Kingbird populations have increased and with the support of conservation actions, could reach their population goal by 2050.

These kinds of estimates of population change presented in Canada’s State of the Birds Report are derived from a variety of large datasets, including our migration monitoring data submitted to the Canadian Migration Monitoring Network. Species-wide estimates of population change enable scientists and other stakeholders to identify goals for conservation action. Research programs like MAPS not only help us monitor species that are otherwise very hard to detect, but also tell us more specific information about breeding bird populations and how to conserve them.

Our MAPS program monitors and reports on breeding birds on public and private lands Prince Edward County. You can be a part of these efforts to co-exist with the natural world and restore bird populations by becoming a steward of the land and protect habitat for birds, insects and other wildlife. Get involved by supporting local land trusts, naturalist groups, and conservation organizations. Make your property a safe haven for breeding birds by planting native trees, plants, and making your windows bird safe.

Monitoring Avian Productivity and Survivorship (MAPS) at PEPtBO