Trophic ecology of an introduced top predator (Felis catus) on a small African oceanic islet (Santa Luzia, Cabo Verde Islands)

Abstract

Studies on feral cat diet offer important ecological information and are the first step towards determining their impact upon endangered species. However, in comparing seasonal changes in diet with seasonal prey availability, the scarce amount of research into oceanic islands worldwide must be considered when deciding if a specific population is actually affected by cat predation. Cat diet was analysed on Santa Luzia (Cabo Verde Islands) since this invasive predator is considered one of the main threats to native endangered species that require conservation measures. These previous studies were carried out in different seasons, providing contrasting results, skinks being more preyed upon in the rainy season and mice in the driest periods. To check these different results, we focussed on how cat diet varied seasonally in response to changes in prey abundance. Saurians were the most important prey group, followed by mice, invertebrates and birds. No seasonal differences were, however, observed in the different prey groups consumed, saurians being the main prey in both seasons. All cases reflected their respective abundances. Results corroborate the generalist and opportunistic trophic ecology of feral cats, providing important information to assess their impact on prey populations and design future eradication programmes.

Trust your guts? The effect of gut section on diet composition and impact of Mus musculus on islands using metabarcoding

“…For instance, in this study, we did not consider the impact that this rodent can have on vertebrates. However, we know that in Cabo Verde, mammal invaders already contributed to the extinction of endemic species (Mateo et al, 2005 ; Medina et al, 2021 ), therefore, it is important in the future to access the impact that M . musculus has on seabirds and terrestrial and marine reptiles.…”

“…For instance, in this study, we did not consider the impact that this rodent can have on vertebrates. However, we know that in Cabo Verde, mammal invaders already contributed to the extinction of endemic species (Mateo et al, 2005;Medina et al, 2021), therefore, it is important in the future to access the impact that M. musculus has on seabirds and terrestrial and marine reptiles. Further studies on other islands, particularly in Seychelles, show that the prevention, eradication, and control of rodents would very positively affect government revenues even after discounting the costs of such actions (Mwebaze et al, 2010).…”

“…Therefore, all non‐volant terrestrial mammals were introduced during the past 550 years, when the first Europeans arrived in the archipelago. These invaders already caused a great impact contributing to the extinction of endemics, such as the Cabo Verde giant skink Chioninia coctei (Duméril & Bibron, 1839), and the extirpation of the giant wall gecko Tarentola gigas (Bocage, 1875) on Santa Luzia Island (Mateo et al, 2005 ; Medina et al, 2021 ). From the rodent invaders, mice are the most widely distributed occurring across all inhabited and even some uninhabited islands of the archipelago (Hazevoet & Masseti, 2011 ).…”

Characterization of an extinct seabird colony on the island of Santa Luzia (Cabo Verde) and its potential for future recolonizations

“…This species was largely dependent on seabird colonies, feeding on eggs and chicks (Bocage 1896;Mateo 2012), and the disappearance of these seabird colonies may also have contributed to its extinction. Recently, Medina et al (2020) showed that on Santa Luzia, feral cats have also turned out to be a serious threat to reptiles, which represent more than 70% of their diet (in terms of consumed biomass).…”