Long-term changes in the breeding biology of a New Zealand bellbird population suggest plasticity in life-history responses to ecological restoration

摘要: Ecological restoration projects provide excellent opportunities to study how animals adapt their life−history strategies in response changeable environments. A fundamental way can optimise reproductive success changing conditions is trading−off aspects of breeding system. The New Zealand bellbird (Anthornis melanura) has had a long−term presence on the small island, Tiritiri Matangi Island (Tiri), spanning island′s degraded agricultural past its current extensively restored state. We studied biology this population assess have responded over time Tiri. compared data (2012−2016) bellbirds with from between 2001−2010 (including Baillie, 2011, Cope, 2007), and 1977−1978 (Anderson Craig, 2003), prior restoration. also explored associations abiotic/biotic factors for most recent period (2012−2016). Our main finding was that clutch size significantly declined mean 3.6 2.4 eggs per nest decline correlated increasing density. This consistent density dependent effect, although further are required empirically test conclusion. Overall, earliest spring laying dates were late August latest extended January, all chicks fledged by end February. Nest 47% (range 40 − 54%) across 2012−2016, falling within similar range as previous studies. found little effect year, weather, parental age or morphometrics success. observed directional change patterns investment 2012−2016 ; parents persisted raising single broods rather than abandoning re−nesting raise larger broods. These results suggest bellbirds9 traits plastic local which provides an advantage when repopulating regenerating habitat.