The Role of Zoos in Monitoring Urban Biodiversity

Biodiversity conservation in large cities is extremely important as it contributes to the conservation of nature and improves the quality of life for urban residents. Zoos play a key role in this process, acting as research centers that collect data on species’ behavior and ecological needs, helping to understand the impact of urbanization on biodiversity. In addition to providing habitats for wild species, zoos serve as educational centers and offer important green spaces for the conservation of local species, thereby enhancing awareness of the importance of biodiversity conservation.

Various studies are conducted in Zagreb to collect data on species and develop measures for their protection and conservation.

As part of this project, two studies were conducted:

Project Title: Nesting Pairs of Hooded Crows (Corvus cornix) in the City of Zagreb
Authors: Dr. Luka Jurinović, M.Sc. Biology; Louie Taylor
Collaborators: Sanjin Hadžalić, Dario Starić
Project Duration: April 2018
Status: Completed
Species: Hooded Crow (Corvus cornix)
IUCN Red List Status: Least Concern (LC)
Croatian Red List Status: Least Concern (LC)

Hooded crow, a common resident of urban areas, is one of the most abundant nesting birds in Zagreb. Its adaptability to urban environments and opportunistic feeding habits contribute to its successful survival. It nests in open areas with tall trees, often in parks and along forest edges, with the breeding season lasting from late March to mid-June.

This study involved counting the nesting pairs of hooded crows in Zagreb, revealing a 27.67% increase over the last ten years. Data on the abundance of hooded crows is presented in the Bird Atlas of Zagreb (Kralj et al., 2015), where the city is divided into one-kilometer quadrants. The atlas consolidates data from 2003 to 2015, prompting this study to recount quadrants surveyed ten or more years ago for insight into population trends.

In April 2018, active nests were counted in 32 quadrants. Results showed significant increases in several areas, particularly in the Dubrava-Čulinečka and Srednjaci quadrants, indicating the adaptability of hooded crows in urban environments.

Authors: Dr. Luka Jurinović, M.Sc. Biology; Louie Taylor
Project Duration: March 2018
Status: Completed
Species: Grey Heron (Ardea cinerea)
IUCN Red List Status: Least Concern (LC)
Croatian Red List Status: Least Concern (LC)

Grey Heron is a distinctive bird often found in wet urban areas, including parks and riverbanks. This species nests high in trees, usually in colonies. The population of grey herons in Croatia is increasing, with over 3,000 pairs currently present. There are more than 60 heron colonies in Croatia, the largest of which is located in Maksimir Park.

On March 28, 2018, a survey of grey heron nests was conducted in the Zagreb Zoo. Using a truck-mounted crane with a maximum reach of 22 meters, a total of 26 nests were recorded on 14 trees. Unfortunately, due to technical limitations and adverse weather conditions, not all nests were accessible for detailed monitoring. A follow-up survey on May 17, 2018, focused on ringing the chicks, but many nests remained inaccessible due to the same constraints.

Summary:

The research on urban biodiversity in Zagreb highlights the crucial role of zoos in monitoring and preserving local wildlife. By acting as research centers and educational hubs, zoos collect data on species behavior and ecological needs, which is essential for understanding urbanization’s impact on biodiversity. Two specific studies focused on the population trends of the hooded crow and the grey heron, revealing significant increases in their nesting pairs, thus underscoring the importance of urban habitats for these species.