An overview of the past, present, and future of the Cuban Boa, Chilabothrus angulifer (Squamata: Boidae)

Abstract


 
 
 
 On oceanic islands, where carnivorous mammals are frequently absent, the niches of large predators are often filled by raptors and reptiles. Cuban Boas (Chilabothrus angulifer), along with Cuban Crocodiles (Crocodylus rhombifer) and large birds of prey, were the top predators in the Cenozoic terrestrial ecosystems of Cuba until the arrival of Homo sapiens in the region about 6,000 years ago. This ecological scenario of large boas in the genus Chilabothrus functioning as top predators in terrestrial ecosystems is repeated on each of the largest islands of the Greater Antilles. The evolution of very large size in the Cuban Boa is best explained as phyletic giantism (Cope’s Rule), although other paleo-ecological selective factors might have maintained or even accentuated the evolutionary trend toward large body size (insular giantism). However, this seems not to be the case for all species of Chilabothrus, since the evolution of a small body size is repeated in several lineages, a phenomenon that is best explained by autamorphic nanism (Island Rule). Unfortunately, the negative effects of humans on natural populations of the Cuban Boa apparently have induced a dramatic reduction in maximum body size even during the relatively short period since the first reliable measurements were recorded in the 19th century. Such a reduction in body size is consistent with that reported for other West Indian reptiles and is probably indicative of rapid evolution in response to a highly modified environment with new selective pressures.
 
 
 

Giant dwarfs: Very large giant tropes Tropidophis melanurus (Squamata: Tropidophiidae), and new maximum size records for the species

“…The size and general body shape of T. melanurus is comparable to that of the Hispaniolan Desert Boa (C. fordii), a small (for the genus; SVL to 860 mm), mostly ground-dwelling species (although it will climb into shrubs) (Tolson and Henderson 1993;Landestoy et al 2021). A similar scenario of convergence has been observed between the gracile semiarboreal species of Tropidophis in Cuba and the Hispaniolan Vine Boas, C. gracilis and C. ampelophis (two strictly arboreal species), which share morphological traits largely associated with arboreality (i.e., slender and laterally compressed bodies, long and distinctive neck, large and protruding eyes) (for reviews see Hedges and Garrido 1992;Lillywhite and Henderson 1993;Tolson and Henderson 1993;Hedges 2002;Pizzatto et al 2007;Rodríguez-Cabrera et al 2016;Díaz and Cádiz 2020;Landestoy et al 2021). Nonetheless, additional morphological, ecological, and behavioral studies of snakes in both genera are required before arriving at conclusions regarding ecological segregation between species.…”

“…1, 3, and 6; adult female observed at La Movida, Santa Clara Municipality, Villa Clara Province). The Giant Trope seems to be the only representative of the generalist Tropidophis ecotype in Cuba (Rodríguez-Cabrera et al 2016, 2020a. Apparently, T. melanurus occupies the niche of medium-sized, nocturnally active constrictor in Cuba.…”

“…Apparently, T. melanurus occupies the niche of medium-sized, nocturnally active constrictor in Cuba. The extensive diversification of Cuban snakes in the genus Tropidophis has been attributed to an ecological barrier that prevented further colonization or in situ evolution of smaller species in the West Indian boid genus Chilabothrus, as happened, for instance, on the neighboring island of Hispaniola, which harbors only one species of Tropidophis but four species of Chilabothrus (Hedges 2002;Rodríguez-Cabrera et al 2016;Landestoy et al 2021). Greene (1980) Fig.…”

Interspecific diurnal refuge sharing in Cuban snakes of the genus Tropidophis (Tropidophiidae)

“…Only generalist or terrestrial ecomorphotypes occur on islands inhabited by Tropidophis except Cuba (for reviews on morphology see Schwartz and Henderson 1991;Hedges 2002). The more specialized semi-arboreal ecomorphotype apparently evolved more than once (Díaz and Cádiz 2020) and is present only where multispecies assemblages occur in Cuba (Rodríguez-Cabrera et al 2016;2021a;2021b;Rodríguez-Cabrera and Blanco Morciego 2021). These semi-arboreal species do not show the high degree of specialization observed in other strictly arboreal snakes from other families (for reviews see Hedges and Garrido 1992;Lillywhite and Henderson 1993;Hedges 2002;Pizzatto et al 2007;Rodríguez-Cabrera et al 2016;Díaz and Cádiz 2020;Landestoy et al 2021).…”

“…

W ith 17 species, all endemic, the Cuban Archipelago has the richest diversity of snakes in the genus Tropidophis (Tropidophiidae) (Hedges 2002;Díaz and Cádiz 2020; Uetz et al 2021). This diversity is reflected in the co-occurrence of several species, probably the result of the evolution of traits that allowed the ecological segregation of three distinct ecomorphotypes (terrestrial, semi-arboreal, and generalist) (Rodríguez-Cabrera et al 2016;2021a;2021b;Rodríguez-Cabrera and Blanco Morciego 2021). Jamaica is the only West Indian island other than Cuba with more than one species of Tropidophis (three), but they have allopatric distributions and phenotypic divergence is minimal (Schwartz and Henderson 1991;Hedges 2002; Powell and Henderson 2012).

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