# Evidence of Avian Predation on a Critically Endangered Elasmobranch, the Halavi Guitarfish (Glaucostegus halavi), in the Red Sea

## TL;DR

Ospreys are preying on a critically endangered guitarfish species in the Red Sea, highlighting a new ecological threat.

## Contribution

First documented evidence of osprey predation on Halavi guitarfish, revealing a previously unknown ecological interaction.

## Key findings

- Six predation events observed, including direct photographic evidence of ospreys carrying guitarfish.
- Shallow water habitats may increase guitarfish exposure to avian predation despite reducing risk from other predators.
- Citizen science reports are currently the primary source of evidence for these interactions.

## Abstract

The Halavi guitarfish (Glaucostegus halavi) is a Critically Endangered but poorly studied batoid found in the northwestern Indian Ocean. Its trophic ecology, both as predator and prey, remains largely undescribed. This note reports evidence of osprey (
Pandion haliaetus haliaetus
) predation on early lifestage Halavi guitarfish in the northern Red Sea. The six predation records presented here suggest that sheltering in shallow water may increase exposure to avian predation even as it reduces exposure to predation by other fish. Of these records, one represents direct photographic evidence of a successful predation attempt, showcasing an osprey carrying a guitarfish in its talons, while the remaining observations provide indirect evidence consistent with predation. The remains of two individuals were discovered in osprey nests, and two more individuals were found desiccated above the shoreline with organs removed. Another Halavi guitarfish, captured alive, exhibited wounds consistent with talon marks from an avian predation attempt. These occurrences were documented across six islands in the Al Wajh lagoon from 2020 through 2024 and suggest that osprey–elasmobranch interactions remain largely undocumented in the scientific literature, with most evidence currently emerging from opportunistic citizen‐science reports. Further investigation (potentially using biochemical markers such as stable isotopes) is needed to better understand the ecological implications of these events.

We report six cases of suspected and confirmed osprey predation events on early lifestage Halavi guitarfish in the Al Wajh lagoon, northern Red Sea. These observations provide rare evidence of avian‐elasmobranch interactions in the region, and suggest that the use of shallow habitats may increase exposure to osprey predation. Together, these highlight a poorly documented risk for one of the most threatened batoid species.