Raising young from a bird’s eye view – adjusted social interactions keep a male godwit’s brood alive

This blog post is provided by Luke Wilde and tells the #StoryBehindThePaper for the paper “Behavioral adjustments in the social associations of a precocial shorebird mediate the costs and benefits of grouping decisions“, which was recently published in the Journal of Animal Ecology.
Luke received his Masters from the University of South Carolina in 2021 before starting his doctoral research at the University of Wyoming studying behavioral plasticity in migratory mule deer. Luke’s research focuses on how animals leverage behavior and social interactions to optimize lifetime fitness using metabolic and movement-based techniques.

Any parent would agree, it takes a village to raise young and one can never be too careful. Unfortunately for wildlife, baby monitors and dual-action smoke-monoxide sensors aren’t much help in the wild, but watchful eyes can make all the difference. Many species have evolved intricate social networks that facilitate information transfer and allow faster responses to fleeting resources or foes. Telling apart friends and foes is a serious challenge for wild animals and one that the ecological theory hasn’t been fully explored.

The best group is the one that avoids the most costs. So, in the case of grouping with members of one’s own or a different species, choosing who to group with should be based on the current context. Animals do this just fine, but the problem for researchers exists at this dynamic front, where friend and foe can shift and change as time, or development, goes on. In the recent paper, “Behavioural adjustments in the social associations of a precocial shorebird mediate the costs and benefits of grouping decisions” in the Journal of Animal Ecology, we investigated how the shorebird, Hudsonian godwit (Limosa haemastica), adaptively groups with other godwits and short-billed gulls (Larus brachyrhynchus) to minimize predator risk at different times of chick development. With the paper freely available online, this post takes on the male godwit’s perspective to explore how this happens from a bird’s-eye-view:

After three weeks of alternating 12-hour incubation and feeding bouts, the day is finally here. Our male godwit has hatched a nest! As the four youngsters pluck insects from the grasses covering the muskeg bog, he keeps a watchful eye.

An adult male godwit sentinels above the muskeg and black spruce (Photo credit: Casey Weissburg)

He’s migrated to this spot each year, and he knows it well. Lucky for him, his chosen nest territory was well within the colony of gulls. Sure, they are loud and messy, but nothing gets past them. Every eagle (Haliaeetus leucocephalus), raven (Corvus corax), or coyote (Canis latrans) received the sort of welcome only 100+ gulls can provide. Beyond that, each time he arrived for his shift incubating the nest and to relieve his mate, their thunderous calls told him exactly how safe it was to approach the nest concealed in the tall grass lining the muskeg ponds. Once as he came in for his incubation, the gulls called out around where his partner incubated – a sandhill crane (Grus canadensis) was striding through the bog in search of nests to eat. He barreled down towards the crane, alongside other godwits, and flushed the bird right out. Who knows what could’ve happened without the gulls’ alert?!

Godwits will mob predators such as this Sandhill Crane in loosely formed groups (Photo credit: Senner Laboratory)

Nesting was hard, sure, but now the real work begins. His partner will leave in a few days’ time, leaving him with the brood. He won’t leave their side until they can fly, but that isn’t always enough. Shorebird chicks are easy prey and are a favorite snack of the gulls surrounding the young family. The gulls don’t seem interested in him now, but they will be soon. Unlike his young, theirs need constant supplies of regurgitated food. To keep his family alive and together, our godwit will have to get his chicks away from the colony, and fast. But leaving the colony means he won’t have the same early warning system, nor will the bruisers always be there to best would-be predators. There is a lot resting on his scapulars.

Each day, our godwit notices his chicks getting bigger and more mobile. Their mother left days ago, but he has managed to keep all the chicks alive on his own. The other male godwits in the bog have been doing the same, and he’s felt safer with them close by. The gulls seem to be settling down and haven’t bothered him as much as they were. Keeping close – well, within earshot anyways – to the very edge of the colony has meant his chicks could fill their days eating without as much hiding. Getting too close seems to draw too much attention but being too far leaves him feeling blind. He would choose godwits over gulls, but it’s been harder to find the other godwits. Many of the other fathers lost their chicks and have left the bog, joining mates on the mudflats, and preparing for migration. In two weeks’ time, his chicks will be able to leave the bog too, but for now he is stuck with them on his 24-hour duty.
His chicks are already faster than him on the ground and they swim! All it takes is one of his alarm calls after either the gulls or godwits stir up a racket, and they all sprint towards the water or the tall grass.

An adult male godwit vocalizes from the ground while tending chicks (Photo credit: Casey Weissburg)

They are getting flighty too. Just the other day he watched one fly 30 meters across the bog before coming back down. If he can keep this up just a little longer, his whole family will make it out of this. After that, the chicks will have other chicks, throughout the breeding range, to help them make their staggered migration south to the plentiful mudflats he used on his first migration.

Read the paper

Read the full paper here: Wilde, L. R., Swift, R. J. & Senner, N. R. (2022). Behavioural adjustments in the social associations of a precocial shorebird mediate the costs and benefits of grouping decisions. Journal of Animal Ecology, 91, 870– 882. https://doi.org/10.1111/1365-2656.13679

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