Flushing distances of ferruginous hawks nesting in rural and exurban New Mexico

Abstract

As natural environments become increasingly modified by humans, land managers should devise plans to protect sensitive species from human activities that disturb these species. We explored behavioral responses of nesting ferruginous hawks (Buteo regalis) to an approaching human in areas where the level of human activity on the landscaped varied. Contrary to other reports, hawks were aggressive in nest defense and female hawks defended nests more aggressively than male hawks. Adult hawks decreased nest‐defense intensity as nestling age increased but increased intensity with consecutive human visits to the nest. Flushing distance was considerably higher than that documented in other studies and was negatively related to degree of urbanization. We found that a distance of 650 m prevented 95% of nest‐attending ferruginous hawks from flushing in response to human intruders; thus we recommend establishing a spatial buffer of this distance or greater to minimize adverse effects of human activities on hawks nesting in New Mexico. © 2011 The Wildlife Society.

Habitat urbanization and its effects on birds

“…In urban areas enhanced levels of bioaccumulation of heavy metals has already been demonstrated in many common bird species, e.g. in the House Sparrow Passer domesticus (Swaileh & Sansur 2006, Kekkonen 2011, Bichet 2013, the House Wren Troglodytes aedon or the American Robin Turdus migratorius (Hofer et al 2010). The detrimental, synergistic effects of such pollutants on birds' physiology is also documented by several studies (e.g.…”

“…MØller 2008), even in relatively sensitive raptor species (e.g. Keeley & Bechard 2011). However, an important caveat is that FID is usually measured as a reaction to approaching humans (e.g.…”

Size of Specially Protected Forest Sites for Raptors: What Size of These Sites Should be for Protect the Raptor’s Breeding Territories?

“…Для близкого вида -королевского канюка (Buteo regalis) в Нью-Мехико (США) опре-делена FID в среднем (M±SE) 486±40,4 м для взрослых канюков на гнёздах в сель-ских районах и 340±30,7 м -вблизи го-родов (Keeley, Bechard, 2011). В Монта-не средние показатели FID определены в 202,8±157,4 м (n=87, медиана -160, предел 75 % вспугиваний -280 м, 90 % -430 м, 95 % -532 м от гнезда) (Van Horn, 1993), по более ранним исследованиям -170 м от гнезда (n=9) при беспокойстве пешеходом, 95 м (n=10) -на мотоцикле, от 75 до 200 м -на машине, причём при подъезде на машине остановка вызывала реакцию вспугивания на большем рассто-янии от гнезда (в среднем 140 м), чем без остановок (в среднем 90 м), при транзит-ных проходах на машине птица покидала кладку в среднем на дистанции 65 м, при прямом подъезде в направлении гнезда -в среднем 144 м (Ensign, 1983).…”

“…Исследование в Нью-Мехико пока-зало, что в сельской местности дистанции в 648 м и в городской местности 480 м пре-дотвращают вспугивание 95 % гнездящихся канюков, на основании чего, чтобы свести к минимуму неблагоприятные последствия деятельности человека на гнездящихся ко-ролевских канюков в Нью-Мехико, авто-рами рекомендован буфер 650 м или не-сколько больший (Keeley, Bechard, 2011).…”

Survival of Juvenile Ferruginous Hawks in Utah

“…Predation of juvenile hawks has received little attention as a potential limiting factor of raptor populations, probably because raptor parents are capable of injuring or killing potential predators, and most raptor species exhibit nest defense behavior (Newton 1979, Keeley andBechard 2011). Instead, reproduction in Ferruginous Hawks (Buteo regalis) and other raptors has been assumed to be food-limited due in part to their extended period of parental care (Newton 1979(Newton , 1991.…”