Many species recovery programmes use pedigrees to understand the genetic ancestry of individuals to inform conservation management. However, incorrect parentage assignment may limit the accuracy of these pedigrees and subsequent management decisions. This is especially relevant for pedigrees that include wild individuals, where misassignment may not only be attributed to human error, but also promiscuity (i.e. extra-pair parentage) or egg-dumping (i.e. brood parasitism). Here, we evaluate pedigree accuracy in the socially monogamous and critically endangered kakī (black stilt, Himantopus novaezelandiae) using microsatellite allele-exclusion analyses for 56 wild family groups across three breeding seasons (2014–2016, n = 340). We identified 16 offspring where parentage was incorrectly assigned, representing 5.9% of all offspring. Of the 16 misassigned offspring, three can be attributed to non-kakī brood parasitism, one can be assigned to human error, but others cannot be readily distinguished between non-monogamous mating behaviours and human error. In the short term, we advise the continued use of microsatellites to identify misassigned offspring in the kakī pedigree, and to verify non-kakī brood parasitism. We also recommend the Department of Conservation’s Kakī Recovery Programme further evaluate the implications of pedigree error to the management of this critically endangered taonga species.
Bar-tailed godwits (Limosa lapponica) were counted throughout New Zealand and on the east coast of Australia during the 2019–2020 austral summer, in the first attempt to assess the total population of the subspecies baueri on the southern hemisphere non-breeding grounds. Survey coverage in New Zealand was nationwide (158 sites surveyed); surveys in Australia covered 314 sites between Great Sandy Strait in southern Queensland, and the Gulf St Vincent in South Australia. Areas north of Great Sandy Strait were either partially counted or were not visited over this survey period. Partial surveys were excluded from the survey results. The total number of godwits counted was 116,446. If allowance is made for an additional ~10,000 birds expected to have been present in northern Queensland (based on previous surveys), the total population of baueri in New Zealand and Australia would have been about 126,000. The 2019 breeding season was very successful, with the highest recorded number of juvenile birds since 2011 and 2012.
Accurate long-term monitoring of a threatened species’ population size and trend is important for conservation management. The endangered yellow-eyed penguin (Megadyptes antipodes) is a non-colonial breeder. Population monitoring of the subantarctic population has focused on beach counts rather than nesting birds. Here, we combined intensive nest-searching and counts of transiting penguins on Enderby Island, Auckland Islands, over 3 years to establish the relationship between count numbers and breeding birds. Morning beach counts of transiting penguins were extrapolated to estimate breeding population for the entire Auckland Island group from 2012 to 2017. Breeding numbers varied considerably between years, but overall did not appear to be declining in the short term. Breeding birds at the Auckland Islands averaged 577 pairs annually over the three ground-truthed breeding seasons, similar to the lower estimate of 520–680 pairs from the last survey in 1989, but less than the higher estimate of 650–1,009 pairs generated from that survey. Direct comparison of beach counts indicated a large decline, but these may be more prone to uncertainty. Large variations between years indicated variable breeding effort. The Auckland Islands (particularly Enderby Island) represent 37–49% of the total breeding population for yellow-eyed penguins, indicating the importance of the subantarctic populations for the species. We recommend ongoing monitoring, including mark-recapture methods, for future population estimates. At least 50% of the individuals in an area should be marked to reduce confidence intervals of estimates.
Between 2014 and 2018 a mark-recapture/ resighting study was conducted to ascertain the size of the population of New Zealand storm petrel (Fregatta maoriana) at their breeding grounds on Hauturu, Little Barrier Island, New Zealand. A total of 415 New Zealand storm petrels were captured and marked with individual colour bands using acoustic playback and night-time spotlighting on Hauturu. Two mark-recapture models were developed using the recaptures of banded birds on land and the at-sea resightings of banded birds attracted to burley on the Hauraki Gulf near Hauturu. The land- based model suggests a current population of 994 (range 446–2,116) individuals whereas the at-sea model suggests an estimate of 1,630 (range 624–3,758) individuals. The discrepancy between these models likely lies in the bias of on-land captures towards juvenile birds constituting >50% of birds caught. We consider the at-sea model most representative of total population size. Logistic population growth models anchored by on-land and at-sea population estimates suggest pre-rat eradication populations of New Zealand storm petrel of 323 and 788 individuals respectively.
The results of biannual national wader counts done during winter (June–July) and early summer (November– December) by the Ornithological Society of New Zealand (OSNZ)/Birds New Zealand from 2005 to 2019 are compared with similar counts done in 1983 to 1994. Although the national wader counts continued 1995–2004 the coverage was insufficient to enable comparable analyses; however, reference is made to some sites that were counted continuously since 1983. At least 1,567 counts at 74 sites nationally resulted in 3,977,228 waders of 39 species being counted. The numbers of most species have declined since the 1983–1994 surveys, particularly evident in the northern hemisphere migrants, with the numbers of some species down by 50% or more. Such changes in numbers are likely to be a true reflection of the declining populations rather than changes in the counting effort. Some native species are faring better, mostly as a result of numerous community-led wader protection projects for northern New Zealand dotterels (Charadrius obscurus aquilonius) and variable oystercatchers (Haematopus unicolor).
More than 3,500 Holocene bones, representing at least 853 individual birds, have been recovered on the uninhabited subantarctic Auckland Islands, south of New Zealand. Today this island group has a rich seabird and land-bird fauna, although there have been at least four bird extinctions (a duck, two petrels and a plover) due to predation by introduced mammals and hunting by humans. The Holocene bone fauna, overwhelmingly from sand dunes on Enderby Island, is dominated by seabirds still found at the island group (particularly diving petrels Pelecanoides spp., southern royal albatrosses Diomedea epomophora, and prions Pachyptila spp.). Remains of all endemic taxa (apart from the Auckland Island tomtit Petroica macrocephala marrineri) were recovered from the deposits. All the taxa known to have gone extinct at the island group have now been recovered in Holocene bone deposits, except for the shore plover (Thinornis novaeseelandiae). The deposits indicate also that the abundance of other species has changed. For example, both the eastern rockhopper penguin (Eudyptes filholi) and white-chinned petrel (Procellaria aequinoctialis) are common in the Enderby Island deposits but are rare on the island today, and the Auckland Island rail (Lewinia muelleri) is present as bones in these dunes but has no historical records from the island. This information on the prehistoric distributions of birds will assist the management of the avifauna of the Auckland Islands, which is currently the subject of a major ecological restoration programme.