Higher maximum temperature increases drinking frequency in mountain gorillas (Gorilla beringei beringei) – Increased by that?
A field study at the frontier in Conservation Science, determined that gorillas drink more water when it’s hot.
Introduce
Water has many essential roles for animals, such as a medium for chemical reactions to take place, a carrier of metabolic products and waste products, and as a lubricant and shock absorber.Robbins, 1983; Jéquier and Constant, 2010). In addition, water plays an important role in thermoregulation (National Research Council, 2003; Mitchell et al., 2009; Jéquier and Constant, 2010; Withers et al, 2016). Maintaining water balance is a major homeostatic goal and is critical to growth, reproduction, and survival.Karasov and del Rio, 2020). Water requirements are influenced by a number of factors, such as climatic conditions, diet and metabolic rate (Robbins, 1983; Jéquier and Constant, 2010; Karasov and del Rio, 2020).
Terrestrial animals obtain water from food (prepared water), water metabolized by the oxidation of macronutrients, and through drinking water (Robbins, 1983; Jéquier and Constant, 2010). Most animals depend on free water sources, but some can get most of their water needs from converted and preformed water (Withers et al, 2016). Understanding how animals obtain and use water is especially important in the face of climate change, as increasing global temperatures and more extreme weather events are predicted to affect water availability. availability and may have a negative impact on the animal’s ability to maintain homeostasis (Hetem et al., 2014; Fuller et al., 2016; Zhang et al, 2019).
Increased temperature leads to increased evaporative cooling demand, especially in heat collectors, which require water (National Research Council, 2003; Withers et al, 2016; Mitchell et al., 2018; Karasov and del Rio, 2020). To compensate for the loss of water at high temperatures, animals often increase their water consumption (Adams and Hayes, 2008; Dias et al., 2014; Harris et al., 2015; Mella et al., 2019; Chaves et al., 2021). Animals may also increase their water intake during dry periods, which coincide with the highest temperatures in some areas (Harris et al., 2015; Mella et al., 2019). In addition, the water content of the feed may be lower during periods of low rainfall and therefore the animal may need additional water intake when drinking (Fuller et al., 2016). Animals may also favor water-rich foods to replenish preformed water during periods of little rain (Ciani et al., 2001; Sato et al., 2014).
Reduced water availability has been shown to increase mortality in some species (Cayton and Haddad, 2018; Riddell et al., 2019; Young et al., 2019; Campos et al, 2020). In contrast, tropical forest species can get most or all of their water requirements from their diet (Karasov and del Rio, 2020). However, increased temperature can lead to increased drinking of water as a means of thermoregulation and avoidance of dehydration (Dias et al., 2014; Chaves et al., 2021). Tracking changes in water-drinking behavior could be an early warning indicator of the effects of climate change as the duration of dry spells and temperatures increase.
A significant proportion of primates (22%; 134 out of 604) are predicted to be vulnerable to the effects of drought (Zhang et al, 2019). Furthermore, primate habitats are predicted to experience 10% more warming than the average global temperature increase, with 86% of primates likely to experience an increase in temperature. maximum above 3°C by 2050 (Graham et al., 2016; Carvalho et al., 2019). Areas of higher elevation also have faster temperature increases than regions of lower elevation (Wang et al., 2016). Given the vulnerability of primates to dry spells, it is important to look for indicators of physiological stress in endangered species, such as changes in water use due to climate change (Chapman et al., 2006; Bernard and Marshall, 2020).
Understanding how endangered mountain gorillas obtain and use water is particularly warranted as they are vulnerable to extinction for a number of reasons. Only about 1,000 individuals remain on two small isolated mountaintop islands, Uganda, Rwanda and the Democratic Republic of the Congo, covering an area of about 784 km2.2 (Eckardt et al., 2019; Granjon et al, 2020). The mountain gorillas’ slow-living history limits their ability to evolve beneficial adaptations that are better suited to new climates quickly enough to mitigate the harmful effects of climate change. Queen (Robbins, 2011). Mountain gorillas are also geographically constrained as human pressure around their current habitat makes it impossible for them to disperse to other areas (Robbins, 2011).
Mountain gorillas usually get enough water from the vegetation they consume, and they rarely drink water (Schaller, 1963). The water content of alpine gorilla food, with most food containing 60 to 90% water (Rothman et al., 2006; Grueter et al., 2016), with little seasonal variation (within species) in the Virunga Volcano (Watts, 1998). The mountain gorilla habitat is characterized by a two-modality distribution of precipitation (heavy rainfall in March-May and lighter rainfall in September-November), with temperature being mainly a function of of altitude and little seasonal variation (Polansky and Robbins, 2013; Seimon and Phillips, 2015; Diem et al., 2019; Eckardt et al., 2019). Both Uganda and Rwanda are experiencing the effects of climate change with increasing temperatures and frequency of extreme weather events (Safari, 2012; McGahey et al., 2013; Tenge et al., 2013; Nsubuga et al., 2014; Nsubuga and Rautenbach, 2018). An average annual temperature increase of about 2.1°C has been recorded over the past 5 decades (McGahey et al., 2013; Nsubuga and Rautenbach, 2018). Future projections suggest this trend is likely to continue, with an increase of 1 to 2.5°C between 2000 and 2050 (Tenge et al., 2013; Nsubuga and Rautenbach, 2018). Furthermore, with precipitation becoming less seasonal, with both increasing precipitation over time and increasing during dry spells, the trend is likely to continue into the future (Kizza et al., 2009; McGahey et al., 2013; Diem et al., 2019; Salerno et al., 2019; Ojara et al, 2020).
To investigate whether changes in climatic conditions might influence mountain gorilla water drinking patterns, we examined water drinking behavior from 2010 to 2020 in two mountain gorilla populations remaining and correlate this with local maximum temperature and precipitation. We tested the prediction that mountain gorillas drank more frequently during hotter and drier periods. After observing a remarkable difference in water intake frequency between the two populations, we compared the water content of key foods between the two mountain gorilla populations to see if this could explain the difference. differences in their behavior.
https://www.frontiersin.org/articles/10.3389/fcosc.2022.738820/full
Of course to get funding, this framework is needed.
There is no doubt that the direct effects of climate change will likely be a bigger problem for species living in more arid environments that face reduced access to adequate amounts of water. existing or predefined water sources (Fuller et al., 2016; Cayton and Haddad, 2018; Mitchell et al., 2018; Wessling et al., 2018; Riddell et al., 2019; Young et al., 2019; Campos et al, 2020). There are still many directions of future research on this topic to better define the increased temperature risk for mountain gorillas. However, the study highlights that climate change can have negative consequences even for tropical forest mammals, which regularly derive nearly all of their water from tropical forests. diet food. This may be especially true for endangered species in small isolated populations prone to drought and extinction.
https://www.frontiersin.org/articles/10.3389/fcosc.2022.738820/full
