Despite extensive study of prehistoric human foraging behavior in the Bonneville basin, little is known about human exploitation of birds, as many of these analyses focus on the hunting of mammalian prey and present models of diet breadth that are limited to artiodactyls and lagomorphs. This paper uses the prey choice model of foraging theory to predict the extent and timing of the exploitation of Greater Sage-Grouse (Centrocercus urophasianus)—one of the most common avian prey species—in the basin during the terminal Pleistocene and early Holocene. During this time, increased seasonality depressed populations of artiodactyls—the highest-ranking prey—across the basin, resulting in low encounter rates with human foragers. According to prey model logic, human foragers would have consequently expanded their diet to include lower-ranked prey, such as lagomorphs. Greater Sage-Grouse are likely similarly in rank to larger lagomorph taxa, based on body size and other characteristics, and thus sage-grouse should have also been exploited at this time in proportion to their abundance on the landscape. The paleontological record of sage-grouse from Homestead Cave provides a measure of their abundance on the landscape and shows that they were relatively abundant in the late Pleistocene, then their abundance declined into the early Holocene. If human foragers were indeed exploiting Greater Sage-Grouse relative to their abundance on the landscape during this time, the relative abundance of sage-grouse remains in archaeological sites should decline concurrently. Tests of this prediction with records from Danger Cave and Bonneville Estates Rockshelter demonstrate that this is the case. The tight fits documented between the paleontological and archaeological abundance of sage-grouse during this period strongly suggest that this decline in Greater Sage-Grouse abundance was caused primarily by environmental change, rather than human hunting pressure. However, further study linking local paleoenvironmental histories with paleontological and archaeological records across the remainder of the Holocene can provide insight on the long-term impacts of hunting Greater Sage-Grouse and may thus be useful to inform their modern management.

The Associational Critique posits that extinct megafauna are scarce in North American late Pleistocene archaeological contexts, contrary to expectations of the overkill hypothesis. In an analysis focusing on the period of overlap between humans and megafauna, we revealed that no such underrepresentation of extinct taxa in kill/scavenging sites exists. Instead, we found a single positive trend between paleontological and archaeological occurrences for all megafauna taxa—extinct and extant—a pattern that is consistent with expectations from the prey model of foraging theory (Wolfe and Broughton, 2020). Grayson et al. (2021), while agreeing that such equated timescales should be used, question certain aspects of our analysis and use new datasets to reaffirm the premise of the Associational Critique. However, their analysis is problematic, as they use different criteria to assemble archaeological records for extant and extinct megafauna—more strict for the latter, thereby inflating the archaeological abundance of extant taxa. More critically, by using archaeological and paleontological data that align in time and space, there is no logical warrant for their argument that extinct forms should be underrepresented in kill/scavenging contexts because they "had either already disappeared or were much reduced in abundance by the time people arrived on the landscape" (Grayson et al., 2021). Using archaeological datasets that were assembled using the same stringent criteria and further refined timescales, we again find no support for such an underrepresentation nor the Associational Critique.

At least 37 genera of mostly large mammals went extinct toward the end of the Pleistocene in North America near the time of human arrival, and this general synchrony has long been argued to suggest human hunting (i.e., “overkill”) caused those losses. However, there exist only a few sites that securely document the human utilization of extinct megafauna, and this apparent scarcity—often referred to as the Associational Critique—remains the single most widely-cited, empirically-based objection to overkill. Some explain this scarcity as a function of taphonomic issues and sampling, suggesting few kill sites exist because the period of overlap between people and megafauna was so short. For some time, this argument we call the ‘Taphonomic Rebuttal’ has been challenged by observations that many extinct megafauna have rich late Pleistocene fossil records but are nonetheless poorly represented in archaeological contexts. Such analyses also suggest that surviving (extant) megafauna (e.g., deer [Odocoileus], bison [Bison], moose [Alces]) are overrepresented in archaeological faunas of the period relative to those that would ultimately go extinct. We build on these observations using a foraging theory framework that dictates such comparisons between paleontological and archaeological abundance records must be conducted with samples derived from similar chronological and geographical windows. Approached this way, we find that the number of secure archaeological associations known for any given megafauna taxon scales positively with their paleontological abundance. There is thus no systematic difference in the abundances of extant and extinct taxa in archaeological versus paleontological contexts as previous analyses have suggested, and thus no support for the Associational Critique from these data.

Although recent research of the faunal and floral remains of the Bonneville basin has increased our knowledge of biotic change at the end of the final regression of Lake Bonneville, our knowledge of avifaunal change during this period remains poorly understood. This study focuses on the bird remains from the lower strata (especially Stratum I) of Homestead Cave, the only site in the Bonneville basin that provides a substantial, well-dated avifaunal record dating to the terminal Pleistocene and early Holocene. Analysis of the entire Stratum I avifauna produced a sample of 4613 identified specimens; the fauna is dominated by aquatic taxa including ducks, grebes, gulls, and shorebirds. Terrestrial taxa are also well represented, most notably by Greater Sage-Grouse (Centrocercus urophasianus). We examine change in the taxonomic composition of the Bonneville basin aquatic avifauna as anticipated from previous research and find significant declines from 13.1 to 9.5 cal ka BP in piscivorous or deep-water taxa, such as diving ducks and Aechmophorus grebes. Our analysis captures the transition from the freshwater conditions associated with the terminal regressive phase of Lake Bonneville to the warmer hypersaline context that has characterized Great Salt Lake for much of the Holocene. We also document a dramatic loss of Greater SageGrouse across this period. This similar to 4000-year record of avifaunal change may prove useful in modern conservation efforts, most notably for that of Greater Sage-Grouse, as xeric conditions are forecasted to increase in the future.

Although recent research of the faunal and floral remains of the Bonneville basin has increased our knowledge of biotic change at the end of the final regression of Lake Bonneville, our knowledge of avifaunal change during this period remains poorly understood. This study focuses on the bird remains from the lower strata (especially Stratum I) of Homestead Cave, the only site in the Bonneville basin that provides a substantial, well-dated avifaunal record dating to the terminal Pleistocene and early Holocene. Analysis of the entire Stratum I avifauna produced a sample of 4613 identified specimens; the fauna is dominated by aquatic taxa including ducks, grebes, gulls, and shorebirds. Terrestrial taxa are also well represented, most notably by Greater Sage-Grouse (Centrocercus urophasianus). We examine change in the taxonomic composition of the Bonneville basin aquatic avifauna as anticipated from previous research and find significant declines from 13.1 to 9.5 cal ka BP in piscivorous or deep-water taxa, such as diving ducks and Aechmophorus grebes. Our analysis captures the transition from the freshwater conditions associated with the terminal regressive phase of Lake Bonneville to the warmer hypersaline context that has characterized Great Salt Lake for much of the Holocene. We also document a dramatic loss of Greater Sage-Grouse across this period. This ~ 4000-year record of avifaunal change may prove useful in modern conservation efforts, most notably for that of Greater Sage-Grouse, as xeric conditions are forecasted to increase in the future.

The Gambier Islands (French Polynesia) are noted for their extreme deforestation and low biodiversity in the post-European contact period. We report on the archaeological and palaeoecological investigation of a stratified rock shelter (site AGA-3) on Agakauitai Island, revealing a sequence of environmental transformation following Polynesian colonisation of the archipelago. Radiocarbon dates indicate use of the rock shelter from the 13th to the mid-17th centuries, followed by a sterile depositional hiatus, and then final early post-contact use (late 18th to early 19th century). Zooarchaeological analysis of faunal remains indicates rapid declines in local populations of seabirds, especially procellariids, as well as later increases in numbers of the introduced, commensal Pacific rat (Rattus exulans). Macro- and micro-botanical evidence documents transformation of the island's flora from indigenous forest to one dominated by economic plants and fire-resistant taxa. A multi-causal model of dynamic interactions, including nutrient depletion due to seabird loss, most likely accounts for this dramatic ecological transformation.Resume Les iles de l'archipel des Gambier, en Polynesie francaise, sont notamment connues pour leur deforestation extreme et leur faible biodiversite dont temoignaient deja les ecrits des premiers occidentaux. Nous presentons ici les resultats d'un projet de recherche portant sur l'etude archeologique et paleoecologique d'un abri-sous-roche stratifie (site AGA-3) sur l'ile d'Agakauitai. Nos travaux demontrent une sequence de transformations environnementales qui debuterent immediatement apres la colonisation Polynesienne de l'archipel. Les datations radiocarbone indiquent que cet abri fut utilise continuellement entre le 13(eme) et le milieu du 17(eme) siecle AD. Suite a une interruption de l'occupation marquee par un depot sterile, l'abri est finalement reutilise au cours de la periode post-europeenne (fin 18(eme) - debut 19(eme) siecle). L'analyse zooarcheologique des restes fauniques demontre un rapide declin des populations locales d'oiseaux marins, en particulier les procellariides, ainsi qu'une augmentation plus tardive du nombre de restes de rat Pacifique (Rattus exulans), une espece commensale introduite par les Polynesiens. L'etude des restes micro- et macrobotaniques documente egalement la transformation de la flore de l'ile en demontrant une evolution du couvert vegetal passant d'une foret indigene a un environnement domine par les plantes a valeur economique ainsi que des taxons resistants au feu. Le modele d'interactions dynamiques a plusieurs facteurs ici propose, integrant notamment la perte de nutriments consecutive a la disparition des oiseaux marins, constitue a present l'explication la plus plausible a cette dramatique transformation ecologique.