Weather effects on birds of different size are mediated by long‐term climate and vegetation type in endangered temperate woodlands

Abstract

Species occurrence is influenced by a range of factors including habitat attributes, climate, weather, and human landscape modification. These drivers are likely to interact, but their effects are frequently quantified independently. Here, we report the results of a 13‐year study of temperate woodland birds in south‐eastern Australia to quantify how different‐sized birds respond to the interacting effects of: (a) short‐term weather (rainfall and temperature in the 12 months preceding our surveys), (b) long‐term climate (average rainfall and maximum and minimum temperatures over the period 1970–2014), and (c) broad structural forms of vegetation (old‐growth woodland, regrowth woodland, and restoration plantings). We uncovered significant interactions between bird body size, vegetation type, climate, and weather. High short‐term rainfall was associated with decreased occurrence of large birds in old‐growth and regrowth woodland, but not in restoration plantings. Conversely, small bird occurrence peaked in wet years, but this effect was most pronounced in locations with a history of high rainfall, and was actually reversed (peak occurrence in dry years) in restoration plantings in dry climates. The occurrence of small birds was depressed—and large birds elevated—in hot years, except in restoration plantings which supported few large birds under these circumstances. Our investigation suggests that different mechanisms may underpin contrasting responses of small and large birds to the interacting effects of climate, weather, and vegetation type. A diversity of vegetation cover is needed across a landscape to promote the occurrence of different‐sized bird species in agriculture‐dominated landscapes, particularly under variable weather conditions. Climate change is predicted to lead to widespread drying of our study region, and restoration plantings—especially currently climatically wet areas—may become critically important for conserving bird species, particularly small‐bodied taxa.

Improving Restoration Programs Through Greater Connection With Ecological Theory and Better Monitoring

“…This is particularly critical as the recovery of ecosystems or populations of particular species may take a prolonged period, especially if past levels of human disturbance and environmental modification have been substantial (Majer et al, 2013;Palmer et al, 2016). In the case of the restoration programs in the temperate woodlands, the value of replanted areas as refugia for birds (including species of conservation concern) during droughts only became apparent after prolonged monitoring spanning more than a decade (Lindenmayer et al, 2018b).…”

Revegetation and reproduction: do restoration plantings in agricultural landscapes support breeding populations of woodland birds?

“…We used spring bird survey data collected over 12 years (see Lindenmayer et al 2018c) to select a subset of 21 long-term monitoring sites: 12 plantings (1.3-7.7 ha), six similarly-sized woodland remnants (2.1-5.8 ha), and three large, intact remnants ("reference" sites >44 ha) (Figure 1). Plantings were aged between 12 and 25 years.…”

“…Studies examining woodland bird responses to restoration plantings typically use pattern data such as presence and abundance to infer habitat quality. Previous research has offered insights into colonisation and extinction patterns (Barrett et al 2008;Mortelliti and Lindenmayer 2015), changes in bird community composition in plantings over time (Mac Nally 2008;Lindenmayer et al 2016Lindenmayer et al , 2018cDebus et al 2017), and occupancy trends relating to site type, habitat structure, and composition (Martin et al 2011;Munro et al 2011;Ikin et al 2018). However, do patch attributes have the same influence on breeding success as they do on site occupancy?…”

Spatiotemporal effects of logging and fire on tall, wet temperate eucalypt forest birds

“…In this study, we focused on three traits; body mass, movement patterns, and diet. These traits are important in explaining responses to altered natural disturbance regimes and the impacts of human disturbance, including for birds in other Australian ecosystems (Lindenmayer et al 2018a. Body mass is linked to abundance, energy use, and geographic range size (Calder 1984, Schmidt-Nielsen 1984, Lomolino and Perault 2007, and to the risk of species decline across taxonomic groups, with global analyses suggesting that large-bodied vertebrates are at particular risk of decline (Tilman et al 2017).…”