Vintage nests: Birds turning trash into treasures

Sadly, plastics and litter have become part of the urban and often rural environment. It can be found almost everywhere and in any form – ranging from plastic bags to broken traffic cones. We consider it trash, however, for some birds, it is a jackpot. Often, litter is creatively included during nest building by these intelligent animals, whereby they turn trash into treasures. A fairly popular example is the incorporation of cigarette butts, wherein the butts seem to act as insect repellent. It is also suggested that anthropogenic matter increases nest structure and creates a slightly warmer microclimate, which is favorable for breeding (James Reynolds et al., 2019). So, the use of anthropogenic materials doesn’t seem to be all negative, but it is definitely not entirely positive either.

How have birds acquired the behavior of gathering non-natural material?

Since this display is relatively new, not much is known yet about the general pattern of the behavior. However, Jagiello et al. (2019) suggested that when the natural habitat changes, a decrease in natural nesting material may occur. This is especially the case on land. The pollution and transformation of their habitat affect how organisms behave. As a consequence, it drives the birds to search for alternative options – and plastic debris seems to fulfill the job too. The “availability hypothesis” suggests that birds choose the materials based on their abundance, without it having any adaptive significance (James Reynolds et al., 2019). The notion that the composition of nest materials changes depending on the availability of those materials is supported. So, the birds seem to not give a ‘flying feather’ about what kind of nest material they use.

All in all, while this may seem like a cool novel adaptation, this does not suggest that people should throw their litter next to the bins during March and April with the intention of providing additional nest material for birds. The litter could possibly have a toxic effect in the long run on chick development or the overall health of the animal. Furthermore, cases of entanglement and strangulation are also not uncommon, portraying a bittersweet picture of these remarkable nests (James Reynolds et al., 2019). The images of the bird nests that are spreading can be seen as both sad, revolting, and oddly fascinating. Hopefully, the nests will serve as a powerful reminder of the impact we have on mother nature.

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References

Jagiello, Z., Dylewski, Ł., Tobolka, M., & Aguirre, J. I. (2019). Life in a polluted world: A global review of anthropogenic materials in bird nests. Environmental Pollution, 251, 717-722.

James Reynolds, S., Ibáñez-Álamo, J. D., Sumasgutner, P., & Mainwaring, M. C. (2019). Urbanisation and nest building in birds: a review of threats and opportunities. Journal of Ornithology, 160(3), 841-860.

Featured image: © Ben Keen, some rights reserved (CC-BY)