What are the impacts of infrastructure on migratory species?

Infrastructure development fragments and destroys habitat and creates barriers to the movements of species, thereby isolating populations and preventing access to essential resources such as food and water, causing die-offs and reduced fitness. Infrastructure also causes direct injuries and mortality through collisions as well as disturbance and pollution. The loss of ecological connectivity leads to genetic isolation, leaving smaller populations more vulnerable and prone to local extinction. Infrastructure development may cause other indirect impacts such as increased killing of wildlife due to easier access.


 Ecological connectivity

Migratory species are dependent on being able to move freely over long distances to find the best forage or escape harsh weather events. Their movements are a critical element of their ecosystem and disrupting them also puts other species at risk. Ecological connectivity, the unimpeded movement of species and the flow of natural processes that sustain life on Earth, is therefore essential for the survival of migratory species. Through the Gandhinagar Declaration (COP 13, Gandhinagar, 2020), CMS Parties reaffirmed their commitment to maintaining and restoring ecological connectivity as one of the priorities for the Convention. The Declaration also calls for ecological connectivity to be effectively reflected in the post-2020 global biodiversity framework.



 What should CMS Parties do?

In line with Article III.4.b) of the Convention, CMS Parties shall endeavour to prevent, remove, compensate for or minimize, as appropriate, the adverse effects of activities or obstacles that seriously impede or prevent the migration of the species.




Actions Under CMS




Energy infrastructure (e.g. dams, wind farms, powerlines)



Marine infrastructure (e.g. ports, sea defences, offshore wind farms, oil platforms)



Linear infrastructure

  • Fences, railways, roads, pipelines and canals create significant barriers to the movements of migratory mammals. Under the Central Asian Mammals Initiative (CAMI), 14 Central Asian countries are coordinating efforts to implement effective mitigation measures and ensure that species such as the Saiga Antelope, the Asiatic Wild Ass or the Mongolian Gazelle can continue to move freely across the Central Asian steppes and deserts.
  • A Linear Infrastructure Working Group was established under the CMS Scientific Council to review available guidelines and standards and to identify areas for further assistance to the Parties under the CMS framework.



Other types of infrastructure

  • The Scientific Council will review the types of infrastructure that have not been addressed under CMS and are of relevance to the conservation of CMS-listed species.






Examples of Conservation Action on the Ground

Addressing the Impact of Linear Infrastructure on Migratory Species



 Removal of fences in Mongolia

Fences along the Trans-Mongolian Railway in Mongolia constitute a complete barrier for Asiatic Wild Asses, Saiga Antelopes, Goitered Gazelles and Mongolian Gazelles as well as Wild Camels. Thousands of Mongolian Gazelles died in 2017 along the fence because they could not cross and escape the harsh winter weather.

To address this challenge, guidelines to mitigate the negative impacts of linear infrastructure in Central Asia was developed under the CAMI. Based on the guidelines, the Government of Mongolia developed national standards, which put in place wildlife-friendly measures for all development projects. In addition, the Government in cooperation with the Mongolian railway company and partners, modified and partly removed the fence along the Trans-Mongolian Railway in a pilot project. Asiatic Wild Ass, as well as Mongolian Gazelles, were already found to use those gaps in the fences and successfully cross the railroad, rediscovering former range areas.


 Wind turbines and migratory birds

Soaring birds, especially birds of prey, are highly susceptible to collision with wind turbines. Thus, the BirdLife International UNDP/GEF Migratory Soaring Birds (MSB) Project aims to integrate conservation of soaring birds into key sectors of society through partnerships and strategic alliances with businesses, NGOs, governments, and international organizations. Under the project, the Soaring Bird Sensitivity Mapping Tool was developed, collating data on 96 soaring bird species. Through the free online web tool, users can delineate the boundaries of a prospective wind farm and quickly generate the relevant soaring bird data. In this way, the tool helps inform decisions on the safe siting of new developments, such as wind farms, ensuring that negative impacts on soaring birds are minimized. 

The sensitivity mapping techniques developed under the MSB project have recently been successfully applied in the Strategic Environmental Assessment for Wind Power and Biodiversity in Kenya. The tool has revealed that there are large areas of economically viable wind potential in Kenya of low or manageable biodiversity risk, with only 17 per cent of economic wind areas classed as very high sensitivity for species and sites such as Important Bird and Biodiversity Areas (IBAs).


 Towards Bird-friendly Powerlines in Egypt

As a member of the Energy Task Force, Egypt is championing the assessment and mitigation of the risk of collision and electrocution from powerlines for migratory soaring birds in the Rift Valley/Red Sea Flyway. Under the national component of the Migratory Soaring Birds project in Egypt (MSB project), the impact of electric power grids within the wind farms was assessed in 2018 and 2019 at the Gabel Al Zayt bottleneck site, where the terrain presents significant challenges for the installation of high-voltage powerlines. A preliminary assessment indicated an overall minimal casualty rate of 0.19 birds/km/season assessed for the studied segments of power lines. The distance from the coast has been identified as a primary factor affecting the level of casualties, with the orientation of power lines in relation to the dominant migration direction of birds as another potentially important factor.

In response, the following actions have been taken: cooperation between MSB Project and Egyptian Electrical Transmission Company regarding modifying powerlines in the flyway; further investigation on the application of mitigation measures on existing powerlines; and the provision of practical guidance for mainstreaming biodiversity considerations in new powerline planning.


 Power line mitigation: Saving the Spanish Imperial Eagle

A long term conservation initiative in the Andalusia region in Spain has shown how simple remediation techniques and redesign of power lines can positively impact one of the world’s rarest raptors, the Spanish Imperial Eagle. In 1990, the Andalusian government approved the regulation of a new power line design that aimed to minimise the impact of electrocution on bird populations in the region. Since 1992, a total of 20,000 dangerous pylons were made safer along 5,000 km of power lines in Andalusia. Mitigation measures included construction of new pylons with suspended insulators, avoiding the use of pylons with an exposed loop of wire above the insulator and ensuring that new power lines were constructed away from breeding areas.

Retroactive mitigation measures included replacing exposed insulators with the suspended type and installing protective systems on pylons to prevent birds coming into contact with wires. In the Doñana National Park, a 96 per cent reduction in electrocution mortality rates was observed in the decade after the policy change. In the wider Andalusia region, a 62 per cent reduction was seen, despite a continuous increase in the amount of overhead power line construction.

The population of Spanish Imperial Eagles in Andalusia has increased from 22 pairs recorded in the early 1970s to 122 pairs recorded in 2020. This is a practical example of how mitigation measures implemented on a regional level have resulted in a positive shift of demographic trends of one of the most endangered raptors in the world.