we research species that move outside of their native distribution
Our research focuses on the ways biological invasion work and how it alters ecosystems
Cities provide unique opportunities for non-native species to establish and are also one of the main drivers of exotic species introductions.
Behavioural traits are key for exotic species to survive when in novel environments as it shifts fast according to changing conditions.
When an invader establishes in a given area it changes the community that surrounds it, often promoting native populations decline.
Invasive species tend to be more tolerant to climate changes, in global warming scenarios they are expected to be even more successful.
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FORAGING BEHAVIOUR OF A NATIVE TOPMINNOW WHEN SHOALING WITH INVADERS
July 3, 2019
Individuals join a group when the benefits of doing so outweigh the disadvantages. Typically, groups are composed by individuals of the same species, as sharing the benefits with relatives dilutes the disadvantages of being part of a group. However, mixed species shoals do occur in the wild. The Mexican Goodeidae are a clade of viviparous topminnows endemic to Central Mexico. Survival of most species is under threat, with some already extinct in nature. Causes of decline include the introduction of exotic species. These include viviparous topminnows of the Family Poeciliidae, such as the Trinidadian guppy (Poecilia reticulata Peters, 1859), as well as the twospot- (Pseudoxiphophorus bimaculatus Heckel, 1848) and porthole livebearer (Poeciliopsis gracilis Heckel, 1848), both native to the Mexican costal slopes but frequently translocated to the central Highlands. Guppies and goodeids readily associate with each other, and guppies entering such associations improve their foraging efficiency. This has been hailed as evidence of a social skill that favours the establishment of viable guppy populations across the globe. It is as yet unknown whether this improvement in guppy foraging efficiency comes at a cost for the interacting goodeids. Here, we investigated how sharing resources with poeciliid invaders affects the foraging efficiency of the goodeid twoline skiffia (Skiffia bilineata Bean, 1887). We measured the time it took them to locate food and the total time spent eating when part of a mixed species shoal that included either a species of exotic poeciliids (guppies, twospot- or porthole livebearers), or another goodeid (Goodea atripinnis). We also measured foraging efficiency of twoline Skiffia in single-species (conspecific) shoals as a control. We found that the total foraging time of twoline skiffias is reduced when shoaling with guppies and twospot livebearers compared to when associating with conspecifics. We provide evidence to support the idea that native species’ fitness is reduced when invaders with similar ecological requirements occupy their habitats.
HABITAT USE BY THE INVASIVE EXOTIC EURASIAN COLLARED-DOVE (STREPTOPELIA DECAOCTO) AND NATIVE DOVE SPECIES IN THE CHAMELA-CUIXMALA REGION OF WEST MEXICO
June 11, 2018
Invasive species are one of the main threats to biodiversity, and anthropogenic disturbance facilitates their entry and establishment. In this study, we assessed the presence and abundance of the invasive Eurasian Collared-Dove (Streptopelia decaocto) along a habitat gradient where this species interacts with native doves and pigeons. We found Eurasian Collared-Doves only in habitats modified by human activities, occurring more frequently in urban areas than agricultural fields. Sites with Eurasian Collared-Doves were highly dominated by this species, displaying less diverse dove communities, suggesting that the presence of this invasive species could be a factor contributing to a reduction of dove diversity. Effective management actions are essential to preserve biodiversity in human-modified habitats such as urban areas, and even more so if exotic invader species are present. Controlling Eurasian Collared-Doves’ further dispersion could be beneficial to native dove communities in a wide range of habitats.
BIRDS FROM THE BURGH: BIRD DIVERSITY AND ITS RELATION WITH URBAN TRAITS IN A SMALL TOWN
June 7, 2018
The global tendency towards urbanisation results in habitat transformation, and even replacement, for many species. However, properly managed, urbanised areas can contribute in promoting biodiversity conservation. Urban planning and management for biodiverse cities can use information on the ecological relationships that occur within its limits to meet their goals. Most studies on the topic have been carried out in large cities, but we know much less about the ecology of smaller cities and towns. In this study, we assessed bird species diversity and density within St Andrews, a small town in Scotland’s Southeast coast, and explored relationships between urban and geographical traits, and bird diversity. We recorded 29 bird species, 5 of which (i.e. Common Wood-pigeon, Columba palumbus; House Sparrow, Passer domesticus; European Robin, Erithacus rubecula; European Herring Gull, Larus argentatus and Blackbird, Turdus merula) composed more than half of the total bird records. Elevation, number of passing pedestrians and distance to the nearest coastal border were the variables that best explained variation in bird species richness. According to our estimate, there were over 11 000 bird individuals within the town in the surveyed space and time, i.e. 26.2 birds per hectare or 0.7 per person. This information could be useful for future environmental policies design to make urbanised environments more hospitable for the biota, so we can promote biodiverse environments. It can also help connect people with nature and facilitate positive human–avian interactions.