International Journal of Molecular Ecology and Conservation 2024, Vol.14, No.2, 134-143 http://ecoevopublisher.com/index.php/ijmec 138 6.2 Alterations in thermoregulation and habitat selection Thermoregulation is a critical aspect of reptile behavior that can be significantly impacted by habitat fragmentation. In fragmented landscapes, the spatial distribution of thermal resources can become more clumped, making it more challenging for reptiles to find suitable microhabitats for thermoregulation. For example, the Mediterranean lacertid lizard Psammodromus algirus shows precise and efficient thermoregulation in fragmented habitats, but the cost of thermoregulation is higher in evergreen fragments due to the more clumped distribution of sunlit and shaded patches (Llanos-Garrido et al., 2023). Additionally, the quality of the habitat, rather than the degree of fragmentation, has been found to be a better predictor of lizard distribution, with lizards preferring deciduous woodlands that offer better conditions for thermoregulation and foraging (Teixido et al., 2021). 6.3 Potential for behavioral plasticity to mitigate the effects of fragmentation Behavioral plasticity, or the ability of an organism to modify its behavior in response to environmental changes, can play a crucial role in mitigating the negative effects of habitat fragmentation. Reptiles that exhibit high levels of behavioral plasticity are more likely to adapt to the altered conditions of fragmented habitats. For instance, the demographic model developed to study the impacts of habitat fragmentation on individual fitness highlights the importance of movement behavior traits. Species with high searching propensity and large inherent searching distances can better cope with fine-scale fragmentation by selecting suitable habitats, thereby mitigating the impact on their fitness (Cattarino et al., 2016). Moreover, the adaptability of nocturnal lemurs to dietary changes in fragmented habitats underscores the potential for behavioral plasticity to support survival in suboptimal environments (Hending et al., 2023). Table 1 Standardized index of the breadth of feeding niches of four species of lemur individuals in the core and marginal areas of the Anabohazo and Ankarafa forests in the Sahamalaza-Iles Radama National Park in northwestern Madagascar (Adopted from Hending et al., 2023) Species Anabohazo Ankarafa Core Edge Core Edge Mirza zaza 0.423 0.705 0.585 0.389 Lepilemur sahamalaza 0.000 0.019 0.037 0.107 Microcebus sambiranensis 0.431 0.465 - - Cheirogaleus medius 0.376 0.267 0.138 0.145 7 Case Study: Habitat Fragmentation and the Decline of the Gopher Tortoise (Gopherus polyphemus) 7.1 Background on the Gopher Tortoise and its habitat requirements The Gopher Tortoise (Gopherus polyphemus) is a keystone species native to the southeastern United States, primarily inhabiting upland habitats such as longleaf pine forests, sandhills, and coastal dunes. These tortoises are known for their burrowing behavior, which provides shelter for over 300 other species, making them crucial for ecosystem health (Cooney et al., 2016). Historically, the Gopher Tortoise was associated with the longleaf pine ecosystem, which has been reduced to less than 3% of its original extent due to human activities (Figure 2). The species requires well-drained, sandy soils for burrowing and a habitat with ample herbaceous vegetation for foraging (Tuberville et al., 2014; Blonder et al., 2021). 7.2 Specific challenges posed by habitat fragmentation Habitat fragmentation poses significant challenges to the Gopher Tortoise, primarily through the reduction and isolation of suitable habitats. Fragmentation leads to smaller, isolated populations, which can suffer from inbreeding depression and reduced genetic diversity. For instance, the impoundment of the Chattahoochee River in 1963 created isolated populations on newly formed islands, resulting in genetic bottlenecks and reduced population sizes (Metcalf et al., 2023). Additionally, urban and agricultural development disrupts the connectivity between habitat patches, further exacerbating the risks of population decline (Rautsaw et al., 2018). Fragmentation also increases the likelihood of habitat degradation due to altered fire regimes and human disturbances, which are essential for maintaining the open canopy and ground cover that Gopher Tortoises need.
RkJQdWJsaXNoZXIy MjQ4ODYzNQ==