The latest news, photography and seasonal wildlife highlights

GOLDEN WONDER

Seen here on a branch in a cloudforest in Ecuador, golden tanagers are found in Andean foothills and subtropical regions across an arc in South America that spans Bolivia to Venezuela.

As the name suggests, they are mostly a bright golden yellow, with black streaks on their backs and black ear patches.

IMPALING IMPALAS

Impala rams fight for mating rights in Amboseli National Park, Kenya, using horns measuring up to 90cm long.

Exhausted by these skirmishes and distracted by raised testosterone levels, rams – which can weigh up to 76kg – are more vulnerable to predators such as lions during mating season

Richard Pallardy

A new study warns that a rare forest ecosystem in South America may be under threat – from a voracious wild pig species imported from Europe. Native to the slopes of the Andes Mountains in Chile and Argentina, the monkey puzzle tree (Araucaria araucana) has sometimes been called a 'living fossil' because of its resemblance to fossils from the Late Triassic period, more than 200m years ago.

After years of illegal logging, the tree was declared Endangered in 2013. Now wild boar, originally shipped from Germany around 1950 and released as prey for hunters, may pose a growing threat, according to the authors of a study published in PeerJ Life and Environment. Wild boar can cause major damage to delicate ecosystems because their foraging habits frequently disrupt the growth of native plantlife. By deploying camera traps in the monkey puzzle forests of Villarrica National Park in Chile, researchers were able to make the first ever density estimate for wild boar in South American temperate forests. The results showed about 1.4 individuals per km² – lower than in the species' native range. But even small numbers of boar may cause long-lasting effects, the researchers say.

In the case of monkey puzzle forests, the boar disrupt the seedlings, which take up to 40 years to reach reproductive age. "Wild boar feed on the seeds, impacting the regeneration of this forest in a way that we do not yet fully understand," says the study's co-author Oliver Keuling, senior researcher at the University of Veterinary Medicine in Hannover, Germany.

There are few controls on the boars. While pumas do feed on them, human interventions such as trapping are in the early stages. The authors say that more monitoring is necessary to ascertain the long-term effects of their activity. 

Monkey puzzle forests offer wild boar little else to feed on – except their seeds, say researchers