Molecular dating largely overturned the paradigm that global cooling during recent Pleistocene glacial cycles resulted in a burst of species diversification although some evidence exists that speciation was commonly promoted in habitats near the expanding and retracting ice sheets. Here, we used a genome-wide dataset of more than half a million base pairs of DNA to test for a glacially induced burst of diversification in kiwi, an avian family distributed within several hundred kilometers of the expanding and retracting glaciers of the Southern Alps of New Zealand. By sampling across the geographic range of the five kiwi species, we discovered many cryptic lineages, bringing the total number of kiwi taxa that currently exist to 11 and the number that existed just before human arrival to 16 or 17. We found that 80% of kiwi diversification events date to the major glacial advances of the Middle and Late Pleistocene. During this period, New Zealand was repeatedly fragmented by glaciers into a series of refugia, with the tiny geographic ranges of many kiwi lineages currently distributed in areas adjacent to these refugia. Estimates of effective population size through time show a dramatic bottleneck during the last glacial cycle in all but one kiwi lineage, as expected if kiwi were isolated in glacially induced refugia. Our results support a fivefold increase in diversification rates during key glacial periods, comparable with levels observed in classic adaptive radiations, and confirm that at least some lineages distributed near glaciated regions underwent rapid ice age diversification.kiwi | Apteryx | New Zealand | glaciation | diversification P leistocene climate cycles resulted in glaciation and the buildup of extensive ice sheets at temperate latitudes during periods of global cooling, followed by recession of ice sheets during brief interglacial periods. These cycles were originally proposed to have fragmented populations, resulting in speciation and the formation of much of today's species richness (1-5).

Using allozymes and mtDNA sequences from the cytochrome b gene, we report that the brown kiwi has the highest levels of genetic structuring observed in birds. Moreover, the mtDNA sequences are, with two minor exceptions, diagnostic genetic markers for each population investigated, even though they are among the more slowly evolving coding regions in this genome. A major unexpected finding was the concordant split in molecular phylogenies between brown kiwis in the southern South Island and elsewhere in New Zealand. This basic phylogeographic boundary halfway down the South Island coincides with a fixed allele difference in the Hb nuclear locus and strongly suggests that two morphologically cryptic species are currently merged under one polytypic species. This is another striking example of how molecular genetic assays can detect phylogenetic discontinuities that are not reflected in traditional morphologically based taxonomies. However, reanalysis of the morphological characters by using phylogenetic methods revealed that the reason for this discordance is that most are primitive and thus are phylogenetically uninformative. Shared-derived morphological characters support the same relationships evident in the molecular phylogenies and, in concert with the molecular data, suggest that as brown kiwis colonized northward from the southern South Island, they retained many primitive characters that confounded earlier systematists. Strong subdivided population structure and cryptic species in brown kiwis seem to have evolved relatively recently as a consequence of Pleistocene range disjunctions, low dispersal power, and genetic drift in small populations. Molecular genetic assays of intraspecific variation over the past 20 years have established the orthodox view that bird species exhibit only weak population structure relative to most other vertebrates (1-3). This finding is expected under population genetic theory because increased dispersal capability via flight should translate into greater amounts of realized gene flow than in less vagile vertebrates (4). However, recent refinements in molecular methods and the development of companion genetic theory and analytical methods have begun to challenge the near exclusivity of this generalization and have spawned a vigorous reexamination of population structure and phylo-

We present the outcome of a century of post-bottleneck isolation of a long-lived species, the little spotted kiwi (Apteryx owenii, LSK) and demonstrate that profound genetic consequences can result from protecting few individuals in isolation. LSK were saved from extinction by translocation of five birds from South Island, New Zealand to Kapiti Island 100 years ago. The Kapiti population now numbers some 1200 birds and provides founders for new populations. We used 15 microsatellite loci to compare genetic variation among Kapiti LSK and the populations of Red Mercury, Tiritiri Matangi and Long Islands that were founded with birds from Kapiti. Two LSK native to D'Urville Island were also placed on Long Island. We found extremely low genetic variation and signatures of acute and recent genetic bottleneck effects in all four populations, indicating that LSK have survived multiple genetic bottlenecks. The Long Island population appears to have arisen from a single mating pair from Kapiti, suggesting there is no genetic contribution from D'Urville birds among extant LSK. The N e /N C ratio of Kapiti Island LSK (0.03) is exceptionally low for terrestrial vertebrates and suggests that genetic diversity might still be eroding in this population, despite its large census size.

SummaryThe population growth of Brown Kiwi Apteryx mantelli was measured under four different management regimes: unmanaged, predator trapping, predator poisoning, and Bank of New Zealand Operation Nest Eggä (BNZONE) -the removal of eggs for artificial incubation and return of resultant subadults to the wild. Life table analysis revealed that high adult mortality (7.3% per annum), caused mainly by domestic dog Canis familiaris and Ferret Mustela furo predation was the critical factor affecting Brown Kiwi populations in central Northland. The 13.8-year life expectancy of adults was only one-third of what can be expected in the absence of these two predators. Predation of Brown Kiwi chicks and juveniles (, 1 kg) by Stoats Mustela erminea and, to a lesser extent, domestic cats Felis catus, was also important. Unmanaged populations declined at 2.5% per annum. Trapping pests in a 200 ha area was largely ineffective, with the population declining by 1.7% per annum. Poisoning pests allowed Brown Kiwi populations to increase at 3.3% per annum. BNZONE proved to be by far the most effective tool, resulting in a 12.5% annual population increase, mainly due to 83% chick survival to six months old, compared with 10% survival in unmanaged sites. There were no observable behavioural problems associated with chicks being reared ex situ, but BNZONE was the most expensive tool and benefited only the Brown Kiwi. This study has helped to develop a range of tools that are now being used to facilitate recovery of populations of all four threatened species of kiwi in New Zealand, and the experimental approach used has wider application in management of other threatened species.

We present 14 microsatellite loci that were isolated from little spotted kiwi (LSK, Apteryx owenii). All loci cross-amplify in all kiwi species currently recognized except for one locus in a single species. Little spotted kiwi exhibited lower variation at these loci (mean number of alleles, H E ) than other kiwi species, despite the markers having been developed for polymorphism in LSK and a far greater number of LSK genotyped than kiwi of other species. Reliable cross-species amplification and polymorphism make these markers promising new tools for the management of New Zealand's threatened kiwi.