Raptor resource use in agroecosystems: cover crops and definitions of availability matter

Abstract

The populations of many species of raptors that forage in agroecosystems have declined as agriculture has intensified. Cover crops are a recent trend in areas of intensive row-crop agriculture in the Midwestern United States that could positively affect raptors by increasing the abundance and distribution of raptor prey. We assessed the habitat use of two raptors, American Kestrel (Falco sparverius) and Red-tailed Hawk (Buteo jamaicensis), and tested for use of areas near cover-cropped fields. We conducted 1184 km of roadside transects in 2018 and 2019 in west-central Indiana and recorded 191 detections of our focal species. We constructed resource selection functions within a use-availability design to evaluate raptor habitat use with a series of weighted logistic regression models. For each species, we fitted models at two scales (transect and landscape) and with two definitions of available points (completely random and random subject to perch constraints). American Kestrels were strongly associated with cover-cropped agricultural fields. Red-tailed Hawks were strongly associated with woodlots. Scale did not greatly affect the inclusion of habitat variables into top models for either species. Random models identified potential perch sites, whereas constrained random models identified more subtle habitat preferences not included in the random models. For American Kestrels, constrained models revealed reduced use of woodland perches and increased use of perches near cover-cropped and conventional agricultural fields. For Red-tailed Hawks, constrained models revealed habitat associations, particularly reduced use of utility lines and human development, that were absent or de-emphasized in random models. Modeling resource selection with constrained random availability will work best for well-studied species with discrete, easily mapped habitat features. If damage to commodity crops by rodents in cover-cropped fields is a concern, raptor management should focus on kestrels and could include erection of artificial perches, nest boxes, and enhancement of permanent herbaceous habitats for hunting. Utilisation des ressources par les rapaces dans les agroécosystèmes : les cultures de couverture et la définition de la disponibilité importentRÉSUMÉ. Les populations de nombreuses espèces de rapaces qui se nourrissent dans les agroécosystèmes ont diminué avec l'intensification de l'agriculture. Les cultures de couverture, une tendance récente dans les zones de cultures intensives en rangs du Midwest des États-Unis, pourraient avoir un effet positif sur les rapaces en permettant d'augmenter l'abondance et la répartition de leurs proies. Nous avons évalué l'utilisation d'habitat de deux rapaces, la Crécerelle d'Amérique (Falco sparverius) et la Buse à queue rousse (Buteo jamaicensis), et testé l'utilisation des zones près des champs de cultures de couverture. Nous avons inventorié 1 184 km de transects en bord de routes en 2018 et 2019 dans le centre-ouest de l'Indiana et noté 191 détections de nos espèces cibles. Nous avons ...

Ferruginous Hawk movements respond predictably to intra‐annual variation but unexpectedly to anthropogenic habitats

“…This increased the size of their home‐ranges. Irrigated croplands provide perches, low vegetation density and high rodent populations for some raptors during certain parts of the year (Panek & Hušek 2014, Ng 2019, Zagorski & Swihart 2021). As Ferruginous Hawks are rodent specialists (Schmutz & Fyfe 1987, Giovanni et al .…”

“…This increased the size of their home-ranges. Irrigated croplands provide perches, low vegetation density and high rodent populations for some raptors during certain parts of the year (Panek & Hušek 2014, Ng 2019, Zagorski & Swihart 2021. As Ferruginous Hawks are rodent specialists (Schmutz & Fyfe 1987, Giovanni et al 2007, Ng 2019, we suspect that the cropland they were using may be an anthropogenic subsidy for these birds, Specifically, we suspect that they were exploiting agricultural areas with high-density prey populations or increased hunting opportunities, as has been seen for other raptors (Panek & Hušek 2014, Herring et al 2020.…”

Farmers’ perception of the ecosystem services provided by diurnal raptors in arid Rajasthan

“…It involves regular monitoring of pests, and their natural enemies ( Ehler, 2006 ). Raptors play an effective role in controlling damage to crops by feeding on pests ( Peisley, Saunders & Luck, 2017 ; Gorosábel, Bernad & Pedrana, 2022 ) and are important part of IPM ( Zagorski, 2019 ). The rodent population can be controlled by conserving raptors ( Antkowiak & Hayes, 2004 ), constructing nest boxes ( Paz Luna et al, 2020 ) or by erecting artificial perches ( Kay et al, 1994 ), which in long term will also lower the cost of farming inputs on pesticides and rodenticides ( Machar et al, 2017 ).…”

Ring‐necked pheasant nest site selection in a landscape with high adoption of fall‐seeded cover crops

“…Corn‐soybean dominant systems present many challenges to wildlife (Best 1983, Santelmann et al 2006), along with a range of additional environmental challenges related to soil and water conservation (Tilman et al 2001, Renwick et al 2008). In the agricultural community, in‐field conservation practices such as fall‐seeded cover crops are being implemented in an effort to improve water and soil outcomes in corn‐soybean systems (Cates et al 2018) and may also provision habitat for wildlife (Wilcoxen et al 2018, Zagorski and Swihart 2021).…”