Barbara Frei

University of Ottawa

Postdoctoral researcher

Biology

2017

McGill University

Ph.D.

Natural Resource Sciences

2014

McGill University

M.Sc.

Natural Resource Sciences

2009

Postdoctoral research scholarship

Fonds de recherche Nature et Technologies

Postdoctoral research scholarship

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https://www.ontario.ca/page/bobolink-and-eastern-meadowlark-recovery-strategy-executive-summary

The Bobolink (Dolichonyx oryzivorus) and Eastern Meadowlark (Sturnella magna) both rely upon grasslands for breeding, have similar breeding distributions in Ontario, often co-occur in the same fields, have similar population trajectories, and face similar threats. Because of these relationships, the two species are represented within a single recovery strategy.
Prior to European settlement in eastern North America, Bobolinks and Eastern Meadowlarks nested in native prairies, savannahs, alvar grasslands, beaver meadows, burned-over areas, and areas cleared for agriculture by First Nations. Although most such habitat was destroyed following European settlement, the two species quickly adopted newly-created surrogate grasslands – primarily pastures and hayfields – as nesting habitat. Indeed, were it not for the creation of these agricultural habitats for livestock, the two species may well have disappeared from large parts of their original range.
Though still common and widespread, the Bobolink and Eastern Meadowlark were recently designated as threatened species in Ontario, primarily as a result of strong population declines that have been occurring in Ontario and across most of their breeding ranges. Population losses in Ontario have been occurring over much of the last half century. Over the most recent 10-year period, it is estimated that the Bobolink population in Ontario has declined by an average annual rate of 4 percent, which corresponds to a cumulative loss of 33 percent. Over the same period, Eastern Meadowlark populations have declined at an average annual rate of 2.9 percent (cumulative loss of 25%).

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Low Fecundity of Red-Headed Woodpeckers (Melanerpes erythrocephalus) at the Northern Edge of the Range

The Red-headed Woodpecker (Melanerpes erythrocephalus) is a threatened bird species undergoing continued population declines across most of its range. Despite the conservation concern, there are few published studies on the species’ fecundity. We examined the nesting phenology, clutch size, and fledging success of Red-headed Woodpecker nests in southern Ontario and northern New York, where population declines are especially pronounced. We calculated the fecundity of the Red-headed Woodpecker populations from fledgling numbers and nest survival estimates. We found that nest phenology and clutch sizes were similar to those reported in other studies for the species. Red-headed Woodpecker nests monitored using video inspection had an unusually low fledging success (39%), and an average fecundity of 0.43 female fledglings per female per year. The fledgling success and fecundity for the monitored Red-headed Woodpecker population was lower than that reported by other published studies on Melanerpes spp., as well as for other genera of woodpeckers. The fecundity was also below the minimum threshold needed to offset mortality for the species, when compared to a majority of minimum fecundity values estimated from the literature. We suggest low fecundity for Red-headed Woodpeckers at the northern edge of their range may be the chronic condition of sink populations, or a more recent phenomenon for small populations approaching local extinction.

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Maladaptive Habitat Use of a North American Woodpecker in Population Decline

Rapid anthropogenic habitat changes can lead to non-ideal habitat use by animals, often resulting in lower fitness and population declines. An extreme case of use and fitness mismatch is an ecological trap where habi- tat quality cues are disjointed from the true quality of the habitat. Species primarily associated with anthropogenically altered habitat, such as red-headed woodpeckers (Melanerpes erythrocephalus), may be especially vulnerable to use and fitness mismatch as they encounter novel environ- mental challenges. We investigated multi-scale habitat use and nesting success of red-headed woodpeckers to assess their vulnerability to mis- matches between use and fitness as a result of non-ideal habitat use across multiple scales. We found that habitat characteristics that promote feeding potential such as canopy openness and greater dead limb length appeared paramount and were consistent in use across several spatial scales although reproductive fitness suffered. This contrasts with the assumption that habi- tat use by nesting birds should instead favor predation avoidance at smaller scales to improve reproductive fitness and suggests that maladaptive, food- based habitat use by red-headed woodpeckers in southern Ontario may result in ecological traps for the species. Whether due to poor habitat choices or costly ones in favor of feeding potential, it is vital to consider this behavior in conservation and management plans for this and similar species. We suggest multi-scale habitat use studies that consider fitness outcomes are critical for species-at-risk in human-modified landscapes

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