# Avian Haemosporidian Infection in Wildlife Rehabilitation Centres of Portugal: Causes, Consequences, and Genetic Diversity

## TL;DR

This study found that malaria parasites are infecting birds in Portuguese wildlife rehabilitation centers, affecting their recovery and survival.

## Contribution

The study identifies new malaria parasites and host-parasite interactions in birds, highlighting their impact on rehabilitation and conservation.

## Key findings

- 30.3% of birds in rehabilitation centers were infected with avian haemosporidians.
- 30% of infected bird species had no prior records of malaria parasites.
- Infected birds required longer rehabilitation periods, increasing costs and reducing survival.

## Abstract

Over thirty percent of bird species are undergoing population declines and are threatened with extinction in Portugal. Several reasons have been proposed to explain this decrease, such as the impact of human activities on natural environments and pathogens affecting the health of wildlife, domestic animals, and humans. Wildlife rescue and rehabilitation centres play an essential role in the conservation of endangered species. Despite wildlife rehabilitation centres providing valuable information on disease prevalence and transmission, the information on haemosporidian infection is still very scarce for birds admitted in these centres. In this study, we discovered new malaria parasites in birds admitted to wildlife rehabilitation centres in Portugal. We also revealed infection in bird species that were previously unknown to be infected with malaria parasites. Birds admitted to rehabilitation due to debilitating disease were more frequently infected with malaria. Furthermore, we demonstrate that the malaria infection extends the required period for medical treatment in these birds, which imposes additional economic costs for the rehabilitation and reduces the survival probabilities of the bird. These findings stress the importance of the study of malaria parasites in wildlife rehabilitation centres, also helping to design protocols and interventions to preserve endangered species.

In the last decade, over 40% of bird species in Europe have experienced poor and bad conservation status, with more than 30% of bird species in mainland Portugal threatened with extinction. Along with anthropogenic factors, parasites and pathogens such as avian haemosporidians have been suggested to be responsible for these avian population declines. Wildlife rehabilitation centres play an essential role in species conservation and preservation. Moreover, animals admitted for rehabilitation can provide valuable information regarding transmission and pathogenicity of many diseases that affect wild birds that are rarely sampled in nature. However, reports of haemosporidians in captive birds are still limited. Here, we explored the prevalence and genetic diversity of avian haemosporidians in 89 birds from 29 species admitted to rehabilitation centres in Portugal, showing an overall infection prevalence of 30.3%. The prevalence of infection was higher in Strigiformes and in birds admitted to rehabilitation centres due to debilitating diseases. Remarkably, 30% of the infected bird species have not been found to harbour malaria parasites in preceding studies. We detected 15 different haemosporidian lineages infecting a third of bird species sampled. Notably, 2 out of these 15 detected haemosporidian lineages have not been obtained previously in other studies. Furthermore, we also identified nine new host–parasite interactions representing new host records for these haemosporidian parasites. Finally, our results revealed that birds infected with haemosporidians require longer rehabilitation treatments, which increase the economic costs for rehabilitation and may impair their survival prospects. These findings emphasise the importance of integrating haemosporidian infection considerations into rehabilitation protocols, highlighting the challenges posed by these infections in avian conservation and rehabilitation, including economic and logistical demands.