Risk of Agricultural Practices and Habitat Change to Farmland Birds

Abstract

ABSTRACT. Many common bird species have declined as a result of agricultural intensification and this could be mitigated by organic farming. We paired sites for habitat and geographical location on organic and nonorganic farms in Ontario, Canada to test a priori predictions of effects on birds overall, 9 guilds and 22 species in relation to candidate models for farming practices (13 variables), local habitat features (12 variables), or habitat features that influence susceptibility to predation. We found that: (1) Overall bird abundance, but not richness, was significantly (p < 0.05) higher on organic sites (mean 43.1 individuals per site) than nonorganic sites (35.8 individuals per site). Significantly more species of birds were observed for five guilds, including primary grassland birds, on organic vs. nonorganic sites. No guild had higher richness or abundance on nonorganic farms; (2) Farming practice models were the best (∆AIC < 4) for abundance of birds overall, primary grassland bird richness, sallier aerial insectivore richness and abundance, and abundance of ground nesters; (3) Habitat models were the best for overall richness, Neotropical migrant abundance, richness and abundance of Ontario-USA-Mexico (short-distance) migrants and resident richness; (4) Predation models were the best for richness of secondary grassland birds and ground feeders; (5) A combination of variables from the model types were best for richness or abundance overall, 13 of 18 guilds (richness and abundance) and 16 of 22 species analyzed. Five of 10 farming practice variables (including herbicide use, organic farm type) and 9 of 13 habitat variables (including hedgerow length, proportion of hay) were significant in best models. Risk modeling indicated that herbicide use could decrease primary grassland birds by one species (35% decline from 3.4 to 2.3 species) per site. Organic farming could benefit species of conservation concern by 49% (an increase from 7.6 to 11.4 grassland birds). An addition of 63 m of hedgerow could increase abundance and richness of short distance migrants by 50% (3.0 to 4.8 and 1.3 to 2.0, respectively). Increasing the proportion of hay on nonorganic farms to 50% could increase abundance of primary grassland bird by 40% (6.7 to 9.4). Our results provide support for alternative farmland designs and agricultural management systems that could enhance select bird species in farmland. RÉSUMÉ. De nombreuses espèces d'oiseaux ont décliné en raison de l'intensification des pratiques agricoles, mais ces déclins pourraient être atténués grâce à l'agriculture biologique. Nous avons apparié des sites (habitat et situation géographique) sur des fermes biologiques et des fermes non biologiques en Ontario, Canada, afin de tester des prévisions a priori d'effets sur l'avifaune dans son ensemble, 9 guildes et 22 espèces d'oiseaux, en relation avec des modèles candidats testant les pratiques agricoles (13 variables), les caractéristiques locales de l'habitat (12 variables) ou les caractéristiques de l'habitat qui influencent...

Past, Present and Future of Hay-making Structures in Europe

“…In the White Carpathians (Slovakia) important areas have been purchased by nature conservation authorities and restored to species-rich hay meadows [66]. Because of the declines in grassland bird populations across North America, many State and federal agencies are making efforts to gear management towards preservation of grassland bird populations, particularly in a landscape context [67,68]. Understanding existing traditional grassland management could greatly help to improve the ability to preserve biodiversity and cultural value in traditionally managed farmlands, which could be supported by subsidies [4,69].…”

Organic farming benefits birds most in regions with more intensive agriculture

“…In North America, most studies have been confined to single states or provinces (e.g. Beecher et al, ; Freemark & Kirk, ; Kirk & Lindsay, ; Kirk, Lindsay, & Brook, ; Quinn et al, ). Here, we address the lack of cross‐regional studies of organic farming effects on wildlife in North America by asking whether organic farming could benefit birds across three Canadian provinces (Saskatchewan, Ontario and Québec, spanning a distance of c .…”

“…We combined previously published datasets of bird point counts on organic and conventional farms in Saskatchewan and Ontario in 1990 (see Freemark & Kirk, ; Kirk & Lindsay, ; Kirk et al, ) with unpublished bird observations collected on organic and conventional farms in Québec in 1991. Previously published work on these data included mostly multi‐species, multivariate statistical analyses examining avifaunal abundance and composition in relation to farm type, farming practices and local land cover.…”

Falcon Nest Occupancy and Hatch Success Near Two Diamond Mines in the Southern Arctic, Northwest Territories

“…We recognize differences in biology and diet occur among falcon species but this should not preclude using a species guild to examine indirect effects from sensory disturbance (e.g., Ammon and Stacey 1997, Aitken et al 2002, Pavel 2004, Kirk et al 2011. A set of a priori predictions based on previous findings in falcons and other birds of prey were considered to meet the study objective.…”