Ravens, Risk, and Rethinking Nest Protection at Ormond Beach
- Power to the Plover
- Apr 8
- 3 min read
Updated: Apr 8
Published 4/8/26
Protecting western snowy plovers starts with a simple question:
What is the leading cause of plover nest failure, and how can we minimize it?
This question extends to many of the other endangered species in threatened coastal ecosystems. The video below illustrates our challenge.
Once ravens learn where plovers are nesting, they return repeatedly—searching, watching, and exploiting opportunities with remarkable efficiency.
Ravens are highly intelligent and persistent predators
The Scale of the Problem
Between 2016 and 2025, Ventura Audubon monitored 480 snowy plover nests across more than 200 acres of habitat. Just over one-third of these nests failed (179 total).
Of those failed nests:
74% were lost to predation
Remaining losses were due to abandonment, tides, wind, or human-related impacts
We documented eight predator types: corvids (ravens and crows), skunks, coyotes, squirrels, opossums, loggerhead shrikes, great horned owls, and mice.
58% of predation events were attributed to corvids
Of all predator species, ravens alone account for the largest share of nest losses.
Ravens are the most significant predator impacting nesting success
Predator Exclosures Are One Strategy
To reduce egg loss, site managers sometimes use mini-exclosures (MEs)—wire cages placed over nests to prevent larger predators from accessing eggs. These have been used at Ormond Beach during periods of elevated corvid predation. This is a relatively low-cost, short-term strategy used during periods of elevated predation pressure.
At first glance, MEs appear effective and they enable nests to hatch. But ravens are intelligent and resourceful, and have demonstrated that they can beat MEs. They can easily find ME's and routinely monitor them, harass adults, and take chicks as they emerge. In some cases, they have learned to defeat the cages entirely.
MEs may protect eggs in the short term, but they do not reduce predator pressure—and may not prevent loss.
Unintended Consequences of Intervention
At Ormond Beach, a diverse predator community interacts with these structures in unexpected ways.
Some predators rely on scent, others on visual cues—meaning that MEs can inadvertently make nests easier to locate.
MEs also do not exclude all predators:
Smaller predators (such as squirrels and mice) can pass through the mesh
Larger predators (such as skunks and coyotes) can dig under or displace cages
Owls and loggerhead shrikes target adults—either knocking over cages or accessing birds through the mesh
In a complex predator community, single-point solutions can create more problems
Adult Survival Matters Most
While protecting eggs is important, the long-term health of the population depends on something else:
Adult survival
Snowy plovers can re-nest if a clutch is lost. But if an adult bird is killed, that reproductive potential is gone.
Some interventions—particularly those that increase visibility or constrain movement—can unintentionally increase risk to adults.
From protecting individual nests to reducing predator pressure across the landscape.
A New Approach
To address this challenge, Ventura Audubon is partnering with Ornilogic and USFWS to pilot a non-lethal approach that targets raven behavior directly.
This technology has been used successfully to reduce raven predation on desert tortoise nests by exploiting an aversion to green light in corvids.
Rather than reacting to predation, this system aims to:
Disrupt raven activity
Prevent repeated nest targeting
Encourage long-term avoidance of nesting habitat
Looking Ahead
The footage in this post highlights both the challenge—and the limitations of current tools.
Moving forward, the goal is not just to protect nests, but to change the conditions that make predation so effective in the first place.
For our April 14, 2026 Speaker Program, Tim Shields with Ornilogic will introduce this emerging approach and what it could mean for the future of snowy plover conservation at Ormond Beach—and for nesting beaches across the region.
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