When a forest becomes a city, are hummingbirds enjoying gardens good enough?

Abstract

Presence data for some hummingbird species demonstrates that cities are good living spaces across the Americas. Monitoring hummingbird populations in big cities shows that some species could be very abundant in highly transformed environments. Individuals are managing to face interaction with human activities. On the other hand, forest specialists or species less tolerant to habitat disturbance have become rare or completely absent from cities or other environments modified by humans, such as peri urban suburbia or agricultural landscapes. Hummingbirds are particularly challenging animals to monitor with marking methods, their metabolic requirements and small bodies can not hold heavy targets or electronic devices for telemetry. Even ring marking could be considered not completely adequate. Xalapa is a medium size city located in central east Mexico where cloud montane forest used to extend. Two hummingbird species (Pampa curvipennis and Saucerottia cyanocephala) associated with cloud forest are becoming abundant city species and have been observed feeding from several exotic plants and nesting in highly perturbed environments such as human houses. The third aim of my PhD project is to gain a better understanding on how hummingbirds are coping with human environments when forests are highly transformed and cities become attractive providers of nectar. Some research questions to address are: How cloud forest hummingbirds respond to human presence: exotic plants and artificial feeders? Arecities becoming ecological traps? Can we identify if urban populations are behaving differently towards humans than forest ones? (Tolerant to noise, cars or people when feeding). At what point of environmental transformation will species disappear from their habitat forests? Are native individuals from cities also able to return to forest or an ecological segregation could be going on among our backyard gardens? I present preliminary ideas to discuss these topics in order to set a monitoring method to explain why forest hummingbirds are now living in cities