Understanding the link between environmental and climatic fluctuations and changes in hominin populations and their distribution is one of the major challenges facing archaeologists and palaeoanthropologists. One notable key demographic event is the expansion of Homo sapiens (‘Modern Humans’) and the extinction of Neanderthals in Eurasia between 50,000 to 30,000 years BP (Higham et al. 2014). The exact causes of Neanderthal extinction are still widely debated, but one widely considered theory is that Neanderthals were less able to cope with rapid climate change in this period than Modern Humans. Within this context the overall aim of this thesis is to investigate the potential of microfaunal remains to provide high resolution and localised records of the environment and climate experienced by Neanderthals and Modern Humans using Shanidar cave in the Zagros mountains of Iraqi Kurdistan famously excavated by Ralph Solecki in 1951-1960. The project analyses 2592 microfaunal remains collected in renewed excavations at the site (2015-2018) from a stratigraphic sequence dated from c.85,000 to 30,000 years ago including from sediments adjacent to Neanderthal skeletal remains dating to c.75,000-50,000 years ago and overlying sediments associated with Baradostian archaeology assumed to be associated with Modern Humans. A variety of methods is applied to the material: taphonomic studies of breakage and digestion patterns of teeth and long bones to investigate the role of different predators in the formation of the assemblage; species presence and absence; changes in species abundance; shape change in the Arvicoline component using geometric morphometric methods; and changes in Arvicoline tooth enamel thickness. The sequence is dominated by one species, Microtus c.f. socialis, and displays a relatively constant taphonomic signature, though breakage from rockfall increases in the upper section of the stratigraphic sequence. The study indicates that the broad environmental conditions remained relatively constant throughout the sequence, with no major faunal turnover, though smaller fluctuations in community composition occurred. The smaller fluctuations indicate that the conditions in the earliest part of the sequence were relatively humid and vegetated, and that conditions became progressively arid, with occasional periods of humidity. The sequence has allowed some inferences to be drawn about the link between environment and hominin occupation of the cave. It appears that Neanderthals and Modern Humans preferentially occupied the cave, and in the case of Neanderthals more intensively, when environmental conditions were humid, with more vegetation. There are hints that Modern Humans were also able to occupy the site at times when conditions were harsher, though both groups are absent in the most arid periods. The findings of this thesis emphasise the importance of investigating local environmental signals in addition to global signals, as the former may provide a different perspective on the conditions experienced by past individuals and populations.