Kiana K. G. Koenen Jillian J. Whitney Kenneth G. MacKenzie Stephen DeStefano Daniel E. Clark 2016 <p><span>While the breeding ecology of gulls (Laridae) has been well studied, their movements and spatial organization during the non-breeding season is poorly understood. The seasonal movements, winter-site fidelity, and site persistence of Ring-billed (</span><i>Larus delawarensis</i><span>) and Herring (</span><i>L. argentatus</i><span>) gulls to wintering areas were studied from 2008–2012. Satellite transmitters were deployed on Ring-billed Gulls (</span><i>n</i><span> = 21) and Herring Gulls (</span><i>n</i><span> = 14). Ten Ring-billed and six Herring gulls were tracked over multiple winters and &gt; 300 wing-tagged Ring-billed Gulls were followed to determine winter-site fidelity and persistence. Home range overlap for individuals between years ranged between 0–1.0 (95% minimum convex polygon) and 0.31–0.79 (kernel utilization distributions). Ringbilled and Herring gulls remained at local wintering sites during the non-breeding season from 20–167 days and 74–161 days, respectively. The probability of a tagged Ring-billed Gull returning to the same site in subsequent winters was high; conversely, there was a low probability of a Ring-billed Gull returning to a different site. Ring-billed and Herring gulls exhibited high winter-site fidelity, but exhibited variable site persistence during the winter season, leading to a high probability of encountering the same individuals in subsequent winters.</span></p> application/pdf 10.1675/063.039.sp120 en The Waterbird Society Fidelity and persistence of Ring-billed (<i>Larus delawarensis</i>) and Herring (<i>Larus argentatus</i>) gulls to wintering sites article