Many nestlings produce faeces that are surrounded by a membrane. These so-called faecal sacs are white with a dark, pointy end. Nestlings signal to their parents that they are about to defecate, e.g. by lifting their bottom. This allows a parent to pick up the sac straight from a nestling’s butt and remove it to keep the nest clean. Nestlings usually produce a faecal sac immediately after being fed, but if they fail to do so, the parents peck their bottom to encourage defecation. Parents sometimes eat the faecal sacs instead of removing them. Nestlings stop producing sacs when they leave the nest.
Never mess with bombardier beetles! The beetles are famous for their explosive way of defending themselves. If threatened by predators, the beetles eject a 100°C hot chemical spray from their anus which is accompanied by a popping sound. For toads, beetles are usually a tasty snack. But bombardier beetles know how to fight back, even from the inside of a toad’s stomach. By releasing their boiling hot spray, toads are taught a painful lesson and made to regurgitate the feisty beetle.
Nymphister kronaueri is a tiny, reddish-brown beetle native to Costa Rica. It lives exclusively among the nomadic army ants of the species Eciton mexicanum. This tiny beetle has found an unusual and rather lazy way of transport. Whenever the ant colony moves on, the beetle attaches itself with its mandibles to the waist of an ant, hitchhiking all the way. It makes the ant look like it has two abdominal segments, one above the other. It’s a quite dangerous ride though – army ants are aggressive predators, dismembering and consuming other insects, spiders, and even scorpions. Looking like an ant’s butt helps reduce the chance of being detected. Photo by Daniel Kronauer
The illegal ivory trade causes elephant populations to diminish at an alarming rate. To access the tusks, poachers kill elephants by either poisoning or shooting them. In March 2018, Singaporean authorities seized more than 60 bags of ivory worth around AUD$3.3 million from a Vietnam-bound ship. Conservation biologist Samuel Wasser extracted DNA from the elephant tusks and compared it to DNA he had previously collected from elephant dung across Africa. As a result, Wasser was able to pinpoint exactly where the animals had been killed, and he discovered that ivory shipments came from a few poaching hotspots. This was valuable information in the fight against ivory poachers and corrupt wildlife rangers.
In Alaska, defecating brown and black bears, not birds, are the main distributors of berry seeds. By dispersing the seeds through their scat, bears unintentionally promote the growth of the berry‐producing shrubs that feed them. The scat of a single bear can contain tens of thousands of seeds. The seeds are then further spread by small mammals which bury them in the ground. Brown bears disperse the most seeds. During the summer months when their diet switches from berries to salmon, black bears temporarily take over the role of main seed dispersers. A drastic reduction in bear numbers in Alaska would very likely cause a reduction in berry‐producing shrubs, changing the ecosystem.
Phytoplankton plays a vital role in marine ecosystems. Apart from being a food source for marine animals, it removes carbon dioxide from the atmosphere through photosynthesis. Phytoplankton needs iron to grow. Whale poo is very rich in iron, containing 10 million times as much as seawater. Over the last century, commercial whaling has reduced the number of whales dramatically, starving the oceans of the necessary iron and decreasing the plankton’s capability to remove carbon dioxide from the atmosphere. Protecting whales and restoring their populations should therefore be an important goal for governments.
Over the last decade, bed bugs have re-emerged in the developed world. They can now be found even in 5-star hotels. They live in bedding and under mattresses and feed on blood. They hide during the day but emerge during the night to feed on their sleeping host. Their faeces appear as clusters of tiny spots and contain histamine, a chemical known to cause allergic reactions such as asthma, itchiness, sneezing and watery eyes. There are treatments available to get rid of bed bugs, but their poo can remain in mattresses, carpets and furniture upholstery long after the bugs are gone.
Every year, around 236,000 tonnes of microplastics (tiny fragments of plastic from broken down plastic bags, bottles and other plastic products) end up in our oceans. Researchers have long feared that these microplastics could enter the food chain, eventually being ingested by humans eating fish and other seafood. A 2017 study in the UK examining poo samples of seals and mackerel found proof that microplastics are indeed transferred from prey to predator. Scientists at Ghent University in Belgium claim that shellfish lovers eat up to 11,000 plastic fragments in their seafood every year. Plastic in our oceans has become a global crisis. It is expected to outweigh fish by 2050.
Outbreaks of the crown-of-thorns starfish are a major threat to the health of reefs. The masses of starfish eat the corals and cause their destruction. One way to tackle the problem is to try to cull them, which is not an easy task. Another option is to identify the fish species that feed on the starfish and protect them to increase their numbers. Previously, fish were caught and cut open to inspect the content of their intestine to see whether they contained any crown-of-thorns starfish remains. A new, non-invasive and non-lethal approach is to collect fish poo and examine it to see whether it contains starfish DNA.