Gambier Group fossil avifaunas: Tables

TABLE 1. Measurements (mm) of exemplary specimens of extant taxa PSRO (Pseudobulweria rostrata, NMNZ O.24691), PTLE (Pterodroma leucoptera SAM B31271a), and PTHE (Pterodroma heraldica NMNZ O.24691) compared to summary statistics of specimens (see *) listed as Pseudobulweria sp. indet. from two Gambier Group sites (Onemea and Nenega-Iti). Abbreviations: TL, total length, except for tibiotarsi, where length is from the proximal articular surface; PW, proximal width; DW, distal width; MDWS, tibiotarsus distal minimum width shaft; Mdws, tibiotarsus craniocaudal depth shaft at minimum width point; Am-a, angulus medialis to acrocoracoideus; Am-cs, angulus medialis to cotyla scapularis; Cs-a, cotyla scapularis to acrocoracoideus; Cs-fah, cotyla scapularis to facies articularis humeralis; MSW, humerus mid-shaft dorsoventral width; Msw, humerus mid-shaft craniocaudal depth; DCW, distal condylus width.

TABLE 2. Summary statistics (X, mean; Min minimum; Max maximum; n count) of measurements (mm) of bones listed as Puffinus magn. P. bailloni from three sites in the Gambier Group (Onemea TAR-6, Nenega-Iti AGA-3 and Kitchen Cave KAM-1). Gambier specimens used: see * in specimen list in Systematics section; gavia is P. gavia SAM B.55367; assimilis is P. assimilis kermadecensis (NMNZ O.23972, 24230, 24229, 15912, 23986, 24229, 24381, 24382, 15911). Standard length measurements are presented for P. assimilis kermadecensis to show how much smaller this taxon is than the P. gavia specimen used to identify the Gambier bones to genus. As discussed under nomenclature, the Gambier size-based taxon used here could include Puffinus bailloni dichrous, P. bailloni gunax, P. auricularis myrtae and P. assimilis kermadecensis, which all have broadly overlapping size distributions (Marchant and Higgins, 1990; Pyle et al., 2011). However, our data presented here for P. assimilis kermadecensis suggest it is a smaller bird than the Gambier birds were. Abbreviations: TL, Total length; PW, proximal width; DW, distal width; TSW, tibiotarsus minimal shaft width; ML, angulus medialis to processus acrocoracoideus; M-cs, angulus medialis to cotyla scapularis; Cs-a, cotyla scapularis to processus acrocoracoideus.

TABLE 3. Summary statistics of measurements (mm) of Nesofregetta fuliginosa from Kitchen Cave, Gambier Group (KAM-1). Specimens used: see * in specimen list. Abbreviations: DW, distal width; SW, minimum shaft width; SD, shaft depth at point of minimum SW; PW, proximal width; TL, Total length.

TABLE 4. Summary of data for bird bones identified from each site in this study, showing NISP (MNI), where NISP is the Number of Identifiable Specimens and MNI the Minimum Number of Individuals, determined separately for each layer and summed for the site. Taxa in brackets are not necessarily different from those more precisely identified. † is extinct.

TABLE 5. Past and present distribution of birds in the Gambier Group. Data is from this study (bold) with additional data for Aukena, Mangareva and Kamaka from Steadman and Justice (1998) in non-bold text. Species status is from Thibault and Cibois (2017), B, breeding; H, historic record; M, migrant; e, extirpated; E, extinct; v, visitor. MNI is between brackets. MNI for the data from Steadman and Justice (1998) is derived by the separate additive treatment of each layer and sub-layer, but because elements were not reported to side, MNI for an element within a stratum is assessed by dividing the reported number by two, so 4 humeri would be MNI=2. Taxa in brackets are not necessarily different from those more precisely identified. Taxa in bold are introduced species. † means extinct, †B is extinct breeding population.

1. We consider it most likely that this specimen identified by Steadman and Justice (1998) belongs to the taxon identified here as Pseudobulweria sp. indet.

2. The bones referred by Steadman (2006) to Puffinus lherminieri were identified before separation of that Atlantic Ocean taxon from the Pacific birds, so they would now be listed in our taxon Puffinus magn. P. bailloni. Puffinus bailloni is a common breeding bird in the Gambier Group but the similar sized P. auricularis myrtae is a likely visitor to the area and would not be distinguished on bones.

3. We consider it more likely (as discussed above) that the bones referred to Alopecoenas (=Gallicolumba) nui by Steadman and Justice (1998) from Kamaka Island belong to the same taxon as those we refer to Bountyphaps sp. cf. obsoleta, so they are included here.