No abstract

Anthropogenic disturbance may cause birds to flush and relocate, abandon breeding sites, experience increased nest failure, or fledge fewer young. Ground‐based military activities are of particular concern for ground‐nesting birds because of the increased risk of nest destruction and trampling of vegetation. We investigated how different intensities of disturbance from ground‐based military training affected reproductive ecology of Bachman's sparrow (Peucaea aestivalis) from 2014–2016, on Fort Bragg Military Installation, North Carolina, USA. We designated 2 training intensity regimes and monitored sparrows at 6 observation areas, 3 in high‐intensity training areas (i.e., foot traffic every 1–3 days) and 3 in low‐intensity training (i.e., foot traffic <1 per month) areas. We compared seasonal productivity metrics and daily nest survival between training intensities. Additionally, we compared male sparrow relative abundance and micro‐habitat use between high‐ and low‐intensity training areas. We monitored 106 male territories and located 110 nests opportunistically and by tracking telemetered female sparrows. We used fixed‐radius point counts to estimate relative abundance in each observation area and measured vegetation composition and structure at a subset of 10 locations in each male territory. Seasonal productivity metrics, daily nest survival, relative abundance, and vegetation composition and structure at male locations did not differ between areas with high and low military training intensity. In 2015, 1 sparrow nest was trampled by military personnel, but ≥1 nestling force‐fledged and the nest was considered successful. Bachman's sparrow nesting ecology was not affected by intensity of ground‐based military training activity, likely because activity was sufficiently dispersed across the landscape, even in high‐intensity training areas. We recommend ground‐based training attempts to minimize ground vegetation destruction by dispersing large groups and traversing variable routes when in forested uplands. © 2018 The Wildlife Society.

No abstract

Fledgling ecology remains understudied for many passerine species, yet information about the fledgling life stage is critical for understanding full‐annual life cycles and population recruitment. We examined the survival, habitat selection, and movements of fledgling Bachman’s Sparrows (Peucaea aestivalis) in a longleaf pine‐wiregrass (Pinus palustris‐Aristida stricta) community managed with frequent prescribed fire. We captured and marked 36 fledglings on the day of fledging and used radio‐telemetry to relocate them daily until independence during three breeding seasons (2014–2016). We visually confirmed the status of fledglings as live or dead during daily relocations and determined causes of mortality. We measured vegetation characteristics at fledgling locations and compared them to the characteristics of vegetation at the locations of adult males. We used a Known Fates analysis in Program MARK to estimate fledgling survival, and generalized linear mixed effect models to determine habitat selection. Estimated fledgling survival until independence was 0.31 (SE = 0.08), with most mortality during the first 4 d post‐fledging. Fledglings with longer wing chords had higher rates of survival than those with shorter wing chords, possibly due to an increased ability to evade predators. Fledgling movements were restricted primarily to natal territories. Fledgling Bachman’s Sparrows were located in areas with greater woody plant, forb, and grass cover and less bare ground than available in natal territories. Similar to fledglings of other songbirds, understory woody and herbaceous plants appear to provide critical cover for fledgling Bachman’s Sparrows, and maintenance of such cover should receive consideration in management plans for longleaf pine communities.

No abstract