Decline in distribution of the takahePorphyrio (= Notornis) mantelli: a re-examination

Ancient and modern scats record broken ecological interactions and a decline in dietary breadth of the critically endangered kākāpō parrot (Strigops habroptilus)

Threatened animal taxa are often absent from most of their original habitats, meaning their ecological niche cannot be fully captured by contemporary data alone. Although DNA metabarcoding of scats and coprolites (palaeofaeces) can identify the past and present species interactions of their depositors, the usefulness of coprolites in conservation biology is untested as few endangered taxa have known coprolite records. Here, we perform multilocus metabarcoding sequencing and palynological analysis of dietary plants of >100 coprolites (estimated to date from c. 400–1900 A.D.) and > 100 frozen scats (dating c. 1950 A.D. to present) of the critically endangered, flightless, herbivorous kākāpō (Strigops habroptilus), a species that disappeared from its natural range in Aotearoa-New Zealand (NZ) after the 13th C. A.D. We identify 24 orders, 56 families and 67 native plant genera unrecorded in modern kākāpō diets (increases of 69, 108 and 75% respectively). We found that southern beeches (Nothofagaceae), which are important canopy-forming trees and not an important kākāpō food today, dominated kākāpō diets in upland (c. >900 m elevation) habitats. We also found that kākāpō frequently consumed hemiparasitic mistletoes (Loranthaceae) and the holoparasitic wood rose (Dactylanthus taylorii), taxa which are nutrient rich, and now threatened by mammalian herbivory and a paucity of dispersers and pollinators. No single dataset or gene identified all taxa in our dataset, demonstrating the value of multiproxy or multigene datasets in studies of animal diets. Our results highlight how contemporary data may considerably underestimate the full dietary breadth of threatened species and demonstrate the potential value of coprolite analysis in conservation biology.

Novel Conditions in Conservation Translocations: A Conservative-Extrapolative Strategic Framework

In response to anthropogenic threats, conservation translocations are increasingly used to combat species' population and range declines. However, moving animals outside of their current distribution can mean introducing them to novel conditions, even in the case of reintroductions to formerly inhabited areas due to ecosystem changes following extirpation. This exposure to novel conditions introduces uncertainty that can undermine decision making for species conservation. Here we propose two strategies, which we define as conservative and extrapolative, for approaching and managing novelty and the resulting uncertainty in conservation translocations. Conservative strategies are characterised by the avoidance and removal of novel conditions as much as possible, whereas extrapolative strategies are more experimental, allowing exposure to novel conditions and monitoring outcomes to increase understanding of a species' ecology. As each strategy carries specific risks and opportunities, they will be applicable in different scenarios. Extrapolative strategies suit species in recovery which can afford some experimental management, or species facing novel and emerging threats which require less traditional translocations, such as assisted colonisations. We provide examples, applying our framework to two endemic New Zealand species with long histories of translocation management: tuatara (Sphenodon punctatus), a reptile and takahē (Porphyrio hochstetteri), a flightless bird.

A phylogenetic analysis of the Gruiformes (Aves) based on morphological characters, with an emphasis on the rails (Rallidae)

The order Gruiformes, for which even familial composition remains controversial, is perhaps the least well understood avian order from a phylogenetic perspective. The history of the systematics of the order is presented, and the ecological and biogeographic characteristics of its members are summarized. Using cladistic techniques, phylogenetic relationships among fossil and modern genera of the Gruiformes were estimated based on 381 primarily osteological characters; relationships among modern species of Grues (Psophiidae, Aramidae, Gruidae, Heliornithidae and Rallidae) were assessed based on these characters augmented by 189 characters of the definitive integument. A strict consensus tree for 20,000 shortest trees compiled for the matrix of gruiform genera (length = 967, CI = 0.517) revealed a number of nodes common to the solution set, many of which were robust to bootstrapping and had substantial support (Bremer) indices. Robust nodes included those supporting: a sister relationship between the Pedionomidae and Turnicidae; monophyly of the Gruiformes exclusive of the Pedionomidae and Turnicidae; a sister relationship between the Cariamidae and Phorusrhacoidea; a sister relationship between a clade comprisingEurypygaandMesselornisand one comprisingRhynochetosandAptornis; monophyly of the Grues (Psophiidae, Aramidae, Gruidae, Heliornithidae and Rallidae); monophyly of a clade (Gruoidea) comprising (in order of increasingly close relationship)Psophia,Aramus,Balearicaand other Gruidae, with monophyly of each member in this series confirmed; a sister relationship between the Heliornithidae and Rallidae; and monophyly of the Rallidae exclusive ofHimantornis. Autapomorphic divergence was comparatively high forPedionomus,Eurypyga,Psophia,HimantornisandFulica; extreme autapomorphy, much of which is unique for the order, characterized the extinct, flightlessAptornis.

In the species–level analysis of modern Grues, special efforts were made to limit the analytical impacts of homoplasy related to flightlessness in a number of rallid lineages. A strict consensus tree of 20,000 shortest trees compiled (length = 1232, CI = 0.463) confirmed the interfamilial relationships resolved in the ordinal analysis and established a number of other, variably supported groups within the Rallidae. Groupings within the Rallidae included: monophyly of Rallidae exclusive ofHimantornisand a clade comprisingPorphyrio(includingNotornis) andPorphyrula; a poorly resolved, basal group of genera includingGymnocrex,Habroptila,Eulabeornis,Aramides,CanirallusandMentocrex; an intermediate grade comprisingAnurolimnas,Amaurolimnas, andRougetius; monophyly of two major subdivisions of remaining rallids, one comprisingRallina(paraphyletic),Rallicula, andSarothrura, and the other comprising the apparently paraphyletic ‘long–billed’ rails (e.g.Pardirallus,Cyanolimnas,Rallus,GallirallusandCabalusand a variably resolved clade comprising ‘crakes’ (e.g.Atlantisia,LaterallusandPorzana, waterhens (Amaurornis), moorhens (Gallinulaand allied genera) and coots (Fulica). Relationships among ‘crakes’ remain poorly resolved;Laterallusmay be paraphyletic, andPorzanais evidently polyphyletic and poses substantial challenges for reconciliation with current taxonomy. Relationships among the species of waterhens, moorhens and coots, however, were comparatively well resolved, and exhaustive, fine–scale analyses of several genera (Grus,Porphyrio,Aramides,Rallus,LaterallusandFulica) and species complexes (Porphyrio porphyrio–group,Gallirallus philippensis–group andFulica americana–group) revealed additional topological likelihoods. Many nodes shared by a majority of the shortest trees under equal weighting were common to all shortest trees found following one or two iterations of successive weighting of characters. Provisional placements of selected subfossil rallids (e.g.Diaphorapteryx,AphanapteryxandCapellirallus) were based on separate heuristic searches using the strict consensus tree for modern rallids as a backbone constraint.

These analyses were considered with respect to assessments of robustness, homoplasy related to flightlessness, challenges and importance of fossils in cladistic analysis, previously published studies and biogeography, and an annotated phylogenetic classification of the Gruiformes is proposed.