This has currently not been examined as it requires systematic analysis of food availability, distribution and predictability between multiple field sites \cite{Lemoine_2022}

Key questions

The key questions, as yet unexplored from the above data are:
This PhD aims to answer the above questions, in doing so predicting how wide scale climate disruption and global change will impact levels of lethality between and within Pan groups, ultimately shedding light on how early Hominin communities may have coped with large scale disruption to food and water supplies.

Methods

This study will focus on the observed behavioural impacts of climate change on western chimpanzees, as multiple long term field sites are set up to observe their behaviour in a variety of habitats, and their latitude makes the seasonal effects of a changing climate more pronounced and easier to observe. After the behavioural adaptions to a changing climate have been broadly described, I will move onto projecting which environmental changes are likely to impact behaviour in other sub-species and make a series of predictions as to how specific climate impacts will affect chimpanzee intra-group cohesion and inter-group conflict in other areas. 

Trends in western African chimpanzee social interactions

Due to their latitude, west African chimpanzees are predicted to feel impacts of climate change, including shorter rainy seasons and longer, more intense dry seasons sooner than central and east African chimpanzee communities - making them an ideal model to study changing social interactions within and between communities. Additionally, IPCC modelling suggests coming large temperature increases in Gabon, where a central chimpanzee study site is located (Loango), making it the ideal location to start testing predictions of social changes caused by changes to climate \cite{ipcc2022}.
The project will first examine seasonal trends in chimpanzee social behaviour at Fongoli, examining in particular the prioritisation of non-kin social grooming behaviour over other activities while under metabolic stress. It will also examine how the frequency, and lethality of intergroup conflict varies by season to examine whether particularly extreme climatic events drive conflict during the dry season over limited resources, or whether lethal raids are conducting during the wet season where the individual costs of conflict are marginally lower.
I will also examine the availability and predictability of water sources across studied communities home ranges by taking extensive temperature readings across sites and estimating water source volume over time. From there I can predict the impact of rising temperatures on water availability during the dry seasons and predict when communities will start to experience metabolic stress. In addition the impact of water availability and rainfall patterns have on food availability, which in some regions may be the limiting resource. Ultimately, this data will be able to draw conclusions on the relationship between inter-group conflict and seasonality and increased temperature over time. I will then model how temperatures and range shifts will impact total available range of chimpanzees in this area, and extrapolate trends in intergroup conflict and intra-group behaviours to 2050.
From there I will test these predictions using the long term behavioural datasets at Taï and Loango, examining whether the observed conserved behaviours in the dry season and trends in intergroup conflict are starting to appear in those communities. Similarly I will then model temperatures and range shifts will impact total available range of chimpanzees in this area, and extrapolate trends in intergroup conflict and intra-group behaviours to 2050.
To project water availability in the future, I will need to examine weather variations in multiple western field sites over time and see which easily measurable environmental conditions correlate with lower water availability (e.g maximum daily temperature, minimum daily temperature, number of consecutive hours over 40°C, etc.). Then using projections of climate change under various emissions pathways, examine how these will impact the number of water sources in these communities to predict when changes to social structures will start to be observed. 

West African chimpanzee study sites  

Taï Chimpanzee Project

The Taï chimpanzee project is located in Cote d'Ivoire following 4 chimpanzee communities for over 40 years. The current relevant research focuses are long term demographic changes, intercommunity interactions and social bonds & cooperation. The communities live in an evergreen rainforest habitat, with 2 wet seasons (March-June; September-October) and 2 dry seasons (July-August; November-February) \cite{Doran_1997}
Cote d'Ivorie is being severely afflicted by climate change - the mean average temperature over the past 5 years is more than 0.2°C hotter than it was the preceding 5 years, and the standard deviation in average rainfall has increased 5% in the same time \cite{group}

Fongoli Savanna Chimpanzee Project

The Fongoli Savanna Chimpanzee project is located in Senegal, and is the northern-most study site of wild chimpanzees in the world. Since 2001, the project has been studying a community of 35 semi-habituated individuals, collecting behavioural data There is one long dry season (November–April) and a short wet season (June–September), with May and October being transitional months when some rain may fall. Maximum temperatures at Fongoli exceed 40°C during the late dry season (Pruetz 2007), and chimpanzees are reduced to between two and four permanent water sources available during the peak of the dry season. Rainfall before 2010 averaged less than 1,000 mm annually, but between 2010 and 2015 rainfall has become more erratic, with some wet years of >1,000 mm and some very dry years.

Central African chimpanzee study sites  

Loango Chimpanzee Project

This study site was established in 2005 in Loango National Park, Gabon. The Loango community is bordered by 5 other chimpanzee communities. The area consists of a mosaic of rivers, swamps, coastal forests, mangroves, savannahs, and secondary and mature forests. Temperatures range between 18 and 32 °C, with the mean minimum and maximum temperatures being 22.7 °C and 27.8 °C, respectively. There is a long rainy season between October and April, interrupted by a short dry season between December and January. The long dry season usually lasts from May to September (Head et al. 2011).

Time schedule for data collection, analysis and thesis

Year 1

The first year will consist of an extensive literature review of chimpanzee sociality and inter-group conflict with a focus on western chimpanzee communities. During this first year I will begin analysis of Fongoli behavioural data to examine long term trends in sociality and conflict, particularly in relation to rising temperature to establish predictions for other field sites. I will travel to Fongoli at the start of the dry season to set up multiple temperature monitors across the site, as well as measuring total water availability across the season. One month into the rainy season I'll return to the U.K. to analyse what has been collected, in combination with the historical datasets. The newly collected data, predictions of future water availability and predicted impacts on intergroup conflict and intra-group cohesion will form the basis of the first year report. 

Years 2 & 3