Dados do Trabalho

TÍTULO

EFFECTS OF ROADKILL ON GENETIC DIVERSITY OF TWO SPECIES OF XENARTHRAS

Resumo

Ecosystems fragmentation and habitat loss are threating biodiversity worldwide. This is a problem in small and isolated populations which suffer from genetic consequences, such as loss of genetic variation, reduction of gene flow and inbreeding. The Brazilian Cerrado Biome has become heavily fragmented in the past few decades, in addition, the network of highways crossing the biome have increased this effect and lead to a high number of casualties due to road collisions. Myrmecophaga tridactyla and Tamandua tetradactyla are strongly affected by these anthropic impacts. Overall, it generally believed that males can disperse longer and more often than females within mammals. This means that they are potentially more susceptible to roadkills. To test this hypothesis, we tried to determine sex from roadkilled individuals in the field, but the pilot study showed that this is often not possible in older carcasses. Thus, we identified the sex of road-killed individuals in a region of Mato Grosso do Sul state (N=548, total number considering both species) by molecular tools. The protocol was adapted for Xenarthra from existent protocols and the partial SRY and Zinc Finger genes located only in Y and in both X and Y sex chromosomes, respectively. They were amplified in a polymerase chain reaction (PCR) and the products analyzed in 3% agarose gel. A total of 165 males and 89 females of M. tridactyla were identified, suggesting a sexual bias for roadkilled males (2:1). In the same way, for T. tetradactyla we found 124 roadkilled males and 48 females, in a clear 3:1 unfavorable for males. In contrast, if this roadkill continued, removal of more males than females will surely impact the genetic diversity and can rapidly increase the risk of threatened this population. Also, endogamy and drift genetic can be some of the threatened affect this local population of anteater because a large number of individuals died. It is not possible to know if the removal of all these individuals by roadkill has already promoted genetic changes in the populations of both species. New studies are needed to predict the genetic impacted of the roadkills for the species.

Palavras-chave

Microsatellite, Pilosa, Tamandua, population

Financiamento

Fapesp, Capes, CNPq, Instituto de Conservação de Animais Silvestres (ICA), Foundation Segré, Houston Zoo