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Leah Gray

@leahgray.bsky.social

45 followers 13 following 6 posts

PhD researcher studying the effects of agricultural land management on breeding wading birds. 🪶🌄

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Leah Gray @leahgray.bsky.social · Apr 2

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🔬Next steps: DNA Barcoding and beyond

•Identifying predators from field signs was not always possible.
•We're piloting DNA metabarcoding to ID predators from chick remains.
•Analysis is ongoing—more insights to come as we uncover more about the early lives of wader chicks

Leah Gray @leahgray.bsky.social · Apr 2

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🌱 Growth & Habitat Effects

•Chick growth was highly variable across areas. Some chicks reached fledging condition weeks earlier than others.
•Chicks grew faster fields which were cattle-grazed, and wetter.
•Fields with standing water supported the highest growth.

Pictures showing the growth of 2 chicks. The chick raised in cattle grazed, wet field shows much higher growth and development than the chick raised in dry, sheep grazed field.

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Leah Gray @leahgray.bsky.social · Apr 2

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🐦‍⬛Who are the predators?

•Analysis of 23 predated chicks showed a range of predators, with no single dominant predator.
•This included: stoats, rodents, corvids, gulls & raptors.

A pie chart showing the cause of mortality of 23 recovered lapwing chicks. There is no one single dominant predator species. Rat = 2, stoat = 3, raven = 3, great black-backed gull = 1, short-eared owl = 3, avian unknown species = 10, not predated = 3

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Leah Gray @leahgray.bsky.social · Apr 2

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📊 Survival Results

•Only 5 out of 71 chicks monitored survived to 30 days. This is exceptionally low compared to previous years.
•This was likely linked to prolonged cold, wet weather in 2024 leading to poor survival conditions.
•Predation was the dominant cause of mortality (47/49 chicks)

Box plot showing the no of days survived of lapwing chicks across 5 different sites of varying habitat: marshland reserve, lochside reserve, low density mixed grazing, high density sheep, low density cattle grazing. There are no significant differences in survival between site, or reserve status.

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Leah Gray @leahgray.bsky.social · Apr 2

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📌Background & Aims

•Breeding waders are in critical decline across Europe, linked to agricultural intensification & predation.
•Orkney is a stronghold for several wader species, but populations remain threatened.
•We radio tagged 49 Lapwing chicks to study survival rates.

Schematic showing 3 species of wader and their estimated rate of decline over 3 generations (IUCN estimates). Eurasian oystercatcher = greater than 40%, Northern lapwing = 30-49%, Eurasian curlew = 30-49%

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Leah Gray @leahgray.bsky.social · Apr 2

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🔍Investigating drivers of wader chick survival on Orkney

Lapwing chicks face high mortality—our radiotracking study in 2024 explored survival rates, habitat effects & predation risks. What did we find? 🧵#BOU2025 #ornithology

Picture of a lapwing chick with a small radiotag attached to the back. Map of mainland Orkney above showing the location of study sites, which are in various areas across the island.

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