The discovery of widespread parasite extinctions in ancient bird droppings has revealed a hidden crisis affecting endangered species everywhere. Researchers from the University of Adelaide, Manaaki Whenua-Landcare Research, and the University of Auckland have made this groundbreaking find by analyzing faeces dating back over 1500 years.

Their study, published in Current Biology, shows that more than 80% of parasites detected in kākāpō poo prior to the 1990s are no longer present in contemporary populations. Nine out of 16 original parasite taxa disappeared before the 1990s, when the endangered parrot came under full-population management. An additional four were recorded as lost in the period since.

According to Dr. Jamie Wood from the University of Adelaide, “parasites are increasingly appreciated for their ecological importance.” They play a crucial role in ecosystems, helping with immune system development and competing to exclude foreign parasites that may be more harmful to their hosts. However, their dependence on living hosts makes them susceptible to extinction.

The phenomenon of coextinction, where a parasite goes extinct alongside its host, often occurs at a faster rate than for the host animal itself. Predictive models indicate that parasites may go extinct before their hosts during this process as opportunities to transmit between host individuals diminish. This has significant implications for faunal declines and parasite communities.

Lead author Alexander Boast from Manaaki Whenua-Landcare Research was surprised by the degree of parasite loss in kākāpō populations, stating that “the level of parasite loss was greater than we had expected.” The study suggests that endangered species everywhere may possess fractions of their original parasite communities.

As we reckon with the impacts of biodiversity loss, Dr. Wood emphasizes the need to give due attention to parasitic life. Global rates of climate change, ecosystem modification, and biodiversity decline continue to rise, making it increasingly urgent to recognize and understand the downstream impacts on dependent species like parasites, mutualists, or predators.

Documenting parasite extinction, how quickly it can unfold, and estimating the number of presently threatened parasites are key first steps toward a “global parasite conservation plan” and supporting informed predictions for past, present, and future parasite losses.

The Amazon rainforest has long been a haven for biodiversity, but recent research has revealed a previously unknown scale of turtle populations in one of its most remote regions. A University of Florida research team, led by post-doctoral researcher Ismael Brack, has developed an innovative method to count wildlife using drones that has confirmed the world’s largest known nesting site for the threatened Giant South American River Turtle.

The researchers used a combination of aerial imagery and statistical modeling to document more than 41,000 turtles gathered along the Guaporé River. Their findings were published in the Journal of Applied Ecology and offer a new tool for conservationists seeking to monitor vulnerable animal populations with greater precision.

“We describe a novel way to more efficiently monitor animal populations,” said Brack. “And although the method is used to count turtles, it could also be applied to other species.”
The project began with researchers from the Wildlife Conservation Society (WCS) in Brazil, Colombia, and Bolivia, who are monitoring the Giant South American River Turtle, which is threatened by poachers who sell its meat and eggs. The turtles are exceptionally social creatures, and females congregate each year in July or August to nest in the Guaporé River sandbanks between Brazil and Bolivia.

Brack met WCS scientists at a conference, where they shared how they use drones to count the turtles. They create orthomosaics, highly detailed, high-resolution composite images made by stitching together hundreds of overlapping aerial photographs. Counting animals shown in orthomosaics is a quicker, more accurate, and less-invasive approach than counting animals from the ground.

However, the method alone doesn’t account for the fact that animals sometimes move during observation. Together, researchers from UF and WCS developed a method that improves counting accuracy by eliminating multiple sources of error, including double counts (the same individual counted multiple times) and missed individuals.
Researchers used white paint to mark the shells of 1,187 turtles gathering on an island sandbank within the Guaporé River. Over 12 days, a drone flew overhead on a meticulous back-and-forth path four times a day and snapped 1,500 photos each time. Using software, scientists stitched the photos together, and researchers reviewed the composite images.
They recorded each turtle, if its shell was marked and whether the animal was nesting or walking when photographed. Equipped with this data, they developed probability models that account for individuals entering and leaving the area, observed turtle behaviors, and the likelihood of detecting an identifiable shell mark.

The models revealed several potential sources of error that could arise from traditional orthomosaic-based counts, according to the study. Only 35% of the turtles that used the sandbank were present during drone flights. And on average, 20% of those detected walking appeared multiple times in orthomosaics – some as many as seven times.
Observers on the ground counted about 16,000 turtles, according to the study. Researchers who reviewed the orthomosaics but didn’t account for animal movement or shell markings counted about 79,000 turtles. When they applied their models, however, they estimated about 41,000 turtles.

“These numbers vary greatly, and that’s a problem for conservationists,” Brack said. “If scientists are unable to establish an accurate count of individuals of a species, how will they know if the population is in decline or whether efforts to protect it are successful?”

The study describes ways to adapt and apply the approach to conservation efforts involving other species surveyed by drone-derived orthomosaics. Past monitoring studies have involved clipping seals’ fur, attaching high-visibility collars to elk, and marking mountain goats with paintball pellets to keep track of animal movement during counts.

The research team plans to perfect monitoring methods by conducting additional drone flights at the Guaporé River nesting site and in other South American countries where the Giant South American River Turtle gathers, including Colombia and possibly Peru and Venezuela. “By combining information from multiple surveys, we can detect population trends, and the Wildlife Conservation Society will know where to invest in conservation actions,” Brack said.

A recent study by Assistant Professor Shermin de Silva and her coauthors at the University of California San Diego has shed light on the dangers of human interactions with wildlife. The research highlights the risks associated with feeding wild animals, including the habituation of these creatures to humans, which can lead to territorial conflicts, disease transmission, and even death.

In Sri Lanka’s Udawalawe National Park, de Silva studied 18 years of elephant-tourist interactions and found that the elephants have developed “begging” behavior. These animals are becoming increasingly dependent on sugary treats and human food, which is not only detrimental to their health but also poses a significant risk to humans.

The researchers observed that several people have been killed or injured, while at least three elephants have died as a result of these interactions. The study also noted that the close proximity between humans and animals increases the risk of disease transmission to the creatures.

In India’s Sigur region, study coauthors Priya Davidar and Jean-Philippe Puyravaud observed feeding interactions with 11 male Asian elephants, four of which died from suspected human causes. One elephant was successfully rehabilitated and returned to natural foraging behavior.

The researchers emphasize that many people, especially foreign tourists, underestimate the power and ferocity of wild animals like Asian elephants. They mistakenly believe these creatures are tame and docile, like domestic pets.

To mitigate these risks, de Silva recommends that feeding bans should be strictly enforced. She also encourages responsible tourism practices, where visitors respect wildlife boundaries and refrain from feeding or approaching animals in their natural habitats.

By understanding the dangers of human interactions with wildlife, we can take steps to protect both humans and animals alike. It is essential to recognize that wild animals are not pets, but rather powerful creatures that deserve our respect and caution.