Since the 1950s, global changes such as deforestation and urbanization have affected animals and plants in different ways. Sometimes they suffer through human development, and sometimes humans produce situations that allow novel organisms to thrive.
      
Due to a dramatic increase in travel and trade, animals and plants have also crossed into new territories, creating new ecological categories of ‘invasive’ and ‘native’ species. Most conservation efforts are aimed at destroying the former and protecting the latter, though increasingly, more ecologists are conceding that these categories are fluid and unstable.

In When Worlds Collide, ICZ exposes a variety of collisions in Taiwan, Greece and Germany: between nature and the city, invasives and natives. Sometimes these result in violent encounters: competition, predation and extinctions. Other times these interactions result in a new, precarious balance, and a destabilizing of categories of foreign and local, noxious and useful.

All over the world, migratory birds are affected by urban developments that threaten their natural habitats. Besides habitat loss, glass buildings are also a threat as girds often crash into them. In Athens, Greece, ICZ spotlights the work of ANIMA, a non-profit wildlife protection centre that rehabilitates injured birds found in the city. A selection of x-rays of dead or injured birds show the ways in which humans and human developments have harmed these creatures. For example, broken wings indicate that they have collided with a building or a vehicle; white spots are bullets, meaning that these birds have been shot.

In Hamburg, Germany, ICZ examines how nature has encroached into the urban environment by spotlighting the collection of Dr. Herbert Weidner (1911-2009), a scientist who dedicated his career to pest insects, meticulously documenting their habitats and habits.

Arguably, his painstaking study of what he considered harmful creatures, and the calculations economic costs of the damage they cause to human property, were carried out with the meticulous scientific attention accorded to more traditionally valued species.

Finally, in Taiwan, the ICZ explores the contradictory ramifications of human development and intervention in the natural world, as well as the uneasy states of coexistence between introduced and native species. For example, in Chiayi, the government gives out NT$5 for every invasive lizard turned in to the authorities, a scheme that ended up costing the local government NT$2,163,000 in 2017 to maintain the numbers of the invasive population. From the bird refuge centre Wild Bird Society of Taipei, the ICZ collects DIY cardboard boxes which are used to transport injured birds. Battered and punctured with breathing holes, these artefacts are eloquent statement about the wildlife casualties in the city as well as the human gestures to save and rehabilitate them.