Icon mould, and have been secured in the tennis-ball nests working with a garden-tie that passed by means of the centre of every egg; this produced it challenging for nest predators to totally get rid of eggs from the nests. Black rats, like other mammalian predators, are exceptional at distinguishing compact differences in complicated chemical odour cues [42, 55, 56] and use scent to hunt for eggs at night. We simulated prey scent using quail (Coturnix japonica) odour. The quantity of odour used was constant in between web sites, and therefore any differences in egg survival would have resulted from variations in black rat density rather than modifications in prey cue. Every nest was deployed within the field with an added domestic quail egg and about 10 g of quail manure to provide semirealistic olfactory cues for predators (see [42]). The quail manure was stored frozen and applied only when in the begin in the experiment; treating manure this way will not alter its attractiveness to black rats (see [56]). All nests and eggs have been handled working with latex gloves to limit any confounding anthropogenic odours and to decrease olfactory recognition by potential nest predators. This experiment was carried out in two blocks of two weeks on six websites at a time (two websites per treatment) in Austral spring, 2011. We deployed 36 nests on each site (36 points per website; 12 internet sites in total; four removal and eight unmanipulated sites) and left nests in location for 14 days; this is the average incubation period for New Holland honeyeaters [57], and the common incubation period for other small neighborhood birds for instance QS11 site fantails, robins and honeyeaters [58]. As the average territory size to get a New Holland honeyeater pair is 528.3 m2 [59], and birds have been observed to nest 25 m apart [60], our deployment of 1 nest per 20 m x 20 m (i.e. 400 m2) is within the upper limit on the natural expected density. We deployed nests in suitable habitat 1.5 m above ground, inside the standard array of nest heights for New Holland honeyeaters [61], as well as the similar height definition that we utilised to define arboreality for bush and black rats. We classified appropriate nesting habitat as a tall shrub or tree with a well-covered nesting region, along with a vertical branch or patch of branches where the nest could be stably secured. We secured nests to trees and inspected them soon after 1, two, 4, eight and 14 days or till the nest was attacked. A predation occasion was defined when the quail egg was either broken or missing and/or the plasticine egg was disfigured. If we located that only the quail egg had been attacked, then we classified the predator as `unknown’. In all other cases, we inferred the identity in the nest predator by (i) examining bite marks on the plasticine eggs, (ii) generating visual comparisons of bite marks together with the conformation of teeth in reference skulls, (iii) comparing bite marks with images caught on infra-red cameras (ScoutGuard1 SG550V-5MP Compact Trail Security Camera) in pilot trials, and (iv) using earlier research as guides [40, 62]. Essentially the most prevalent bite marks that we identified included those from birds, common brushtailPLOS A single | DOI:ten.1371/journal.pone.0156180 June 13,five /Nest Predation by Commensal Rodentspossums (Trichosurus vulpecula), widespread ringtail possums (Pseudocheirus peregrinus) and rodents. We couldn’t distinguish in between bush rats and black rats utilizing bite marks.Statistical analysesWe analysed all data applying the statistical programs JMP1 version PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/21106918 9.0.0 [63] and R version 2.4.1 [64], and tested model fits for.