City life alters the gut microbiome and stable isotope profiling of the eastern water dragon (Intellagama lesueurii)

Abstract

Urbanisation is one of the most significant threats to biodiversity, due to the rapid and large‐scale environmental alterations it imposes on the natural landscape. It is, therefore, imperative that we understand the consequences of and mechanisms by which, species can respond to it. In recent years, research has shown that plasticity of the gut microbiome may be an important mechanism by which animals can adapt to environmental change, yet empirical evidence of this in wild non‐model species remains sparse. Using an empirical replicated study system, we show that city life alters the gut microbiome and stable isotope profiling of a wild native non‐model species – the eastern water dragon (Intellagama lesueurii) in Queensland, Australia. City dragons exhibit a more diverse gut microbiome than their native habitat counterparts and show gut microbial signatures of a high fat and plant rich diet. Additionally, we also show that city dragons have elevated levels of the Nitrogen‐15 isotope in their blood suggesting that a city diet, which incorporates novel anthropogenic food sources, may also be richer in protein. These results highlight the role that gut microbial plasticity plays in an animals' response to human‐altered landscapes.

Shades of grey: Coat-colour dependent effect of urbanization on the bacterial microbiome of a wild mammal

“…Urbanization clearly affected the eastern grey squirrel microbiome. This result is consistent with findings from birds [21,[23][24][25][26], reptiles [30], humans [51,52], insects [53], plants [54], and wild mammals [29]. Unlike previous studies, we demonstrate that convergence occurs across cities, but also that substantive variation exists both between and within cities.…”

“…Inconsistencies of urban effects are likely attributable to; 1) city-specific variation (most studies to-date have focused on populations residing within a single city); 2) differences in the operational definition of urbanization; 3) differences in the how host species interact with the urban environment. For example, among vertebrates, consumption of human food resources is hypothesized to be the primary driver of microbiome variation [24,26,30,31]. Dietary variation is likely an important contributor to urban microbiome variation for some wildlife, but not all species rely on human food subsidies to the same extent [32].…”

Shades of Grey: Host Phenotype Dependent Effect of Urbanization on the Bacterial Microbiome of a Wild Mammal

“…Urbanization clearly affected the eastern grey squirrel microbiome. This result is consistent with ndings from birds [21,[23][24][25][26], reptiles [30], humans [51,52], insects [53], plants [54], and wild mammals [29].We further demonstrate that convergence occurs across cities, but also that substantive variation exists both between and within cities. For example, the variation explained by city-scale urbanization was comparable to the variation explained by land class heterogeneity within a single city (campuses, suburban parks, urban forests).…”

“…Inconsistencies of urban effects are likely attributable to; 1) city-speci c variation (most studies to-date have focused on populations residing within a single city); 2) differences in the operational de nition of urbanization; 3) differences in the how host species interact with the urban environment. For example, among vertebrates, consumption of human food resources is hypothesized to be the primary driver of microbiome variation [24,26,30,31]. Dietary variation is likely an important contributor to urban microbiome variation for some wildlife, but not all species rely on human food subsidies to the same extent [32].…”

Microbial symbiosis and coevolution of an entire clade of ancient vertebrates: the gut microbiota of sea turtles and its relationship to their phylogenetic history

“…Investigations into the microbiota of reptiles, including sea turtles, are limited to studies describing microbial communities [16][17][18][19][20][21][22][23][24][25][26][27][28][29], factors that influence their composition [30][31][32][33][34][35][36][37][38][39][40][41][42][43], and how they affect host physiology [8,9,[44][45][46], but investigations into the influence of phylogenetic factors affecting microbiota composition in this taxon are rare. Irrespective of the potential host-phylogenetic signal in microbiota composition at a broad taxonomic level, it has been shown that at a more individual level, diet, captivity, geography, and feeding regime all influence the microbiota [9,17,32], and that fermenting bacteria are important for digestion in herbivorous species [47].…”