Tag: Conservation

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Tool of the future?

Environmental

DNA: Conservation

tool of the future?

 

Conservation efforts depend on the knowledge of species distribution patterns and population size estimates in order to know what needs protection and the subsequent impacts of conservation efforts. But there are a number of difficulties association with biodiversity monitoring techniques, including issues to do with correct species identification and invasive methods.

Environmental DNA – “genetic material obtained directly from environmental samples (soil, sediment, water etc.) without any obvious signs of biological source material” – could be a non-invasive and easy to standardise method of biodiversity monitoring. The advances of next-generation sampling technologies has meant individual or multiple species (through DNA metabarcoding) can be detected from such environmental samples quickly and cheaply.

Thomsen and Willerslev (2015) provide a thorough review of the main findings, future potential and limitations of eDNA for biodiversity monitoring and conservation. They document the successes of eDNA so far and discuss pitfalls such as contamination, inhibition, errors, interpretation and problematic reference DNA databases.

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Black and white cat-foot

Black and white cat-foot.

Your numbers are rising but

your home shrinks and splits.

 

The giant panda (whose Latin binomial name literally means black and white cat-foot) is a poster species for animal conservation yet recently the IUCN Red List downgraded the species from endangered to vulnerable based on an increase in adult population since 1988.

Despite this population increase there remains concern for the future of the species. A study by Xu et al (2017) using remote sensing data suggests that both the total amount of available giant panda habitat and the average size of habitat patches (an indication of habitat fragmentation) have decreased substantially. Whilst total area and habitat patch size have shown signs of an recovery since 2001, they still remain below 1988 levels (1.7% and 13.3% lower respectively).

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Fungal culprit

Fungal culprit of

amphibian genocide –

Innocent scapegoat?

Amphibian populations are in the midst of a pandemic, the spread of chytrid fungus devastating species around the world. Conservationists have pointed a finger of blame at African clawed frogs: they are hosts of the fungus, have a degree of immunity and have spread around the world due to their use in research laboratories and hospitals.

The circumstantial evidence seems damming but research by Tinsley et al (2015) into long-standing UK populations suggests otherwise. Native amphibian species present alongside populations of African clawed frogs were not infected with chytrid fungus, despite the African clawed frogs themselves carrying it. What’s more, the African clawed frog populations have been present for decades yet surveys revealed continued high native species abundance. If fungal transmission from African clawed frogs were an issue then such levels of native amphibians would be unlikely.

It seems then that African clawed frogs may be scapegoats after all.

Interested in African clawed frogs? Check out these other Xenopus sciku: ‘Clawed frogs indicate‘, ‘Have frog, will travel‘, ‘Xenopus enrichment‘ and ‘Reservoir or predator‘.

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Ghost ponds by Roy McGhie

After many moons,

even when buried alive –

Zombies in ghost ponds!

A study in Norfolk has shown that historic ponds infilled by agricultural activity, even after over 100 years have passed, maintain viable aquatic plant propagules. These ghost ponds can have the potential to restore locally extinct species assemblages. Alderton et al, 2017.

Roy McGhie works for the North Yorkshire Moors National Park as a Countryside Manager. He has a strong background in environmental conservation and education, and plays a mean game of tennis. You can connect with him on LinkedIn here. If you enjoyed his sciku, check out his other poems A Heady Mixture, Fluttering By At Dusk and Hedgerow Snuffling.

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Can herbivores relax?

My how big you are!

and yet your range contracts. Can

herbivores relax?

 

As the human population around the world expands, the impact we have on wildlife increases due in part to more land being used for habitation or agricultural purposes. Large carnivores are particularly vulnerable to anthropogenic threats such as loss of prey base and human-wildlife conflict (often to do with livestock).

Wolf & Ripple (2017) created and analysed large carnivore range maps from present and historical (~AD1500) data. They found that large predators historically occupied 96% of the world’s land area whereas now they occupy 34%. A number of species have suffered an decline in range of over 90%, including the red wolf (99.7%), Ethiopian wolf (99.3%) and the tiger (95.3%). Overall the greatest range contractions occurred in South-eastern Asia and Africa.

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Bumblebees bumble

Bumblebees bumble

Towards one third extinction

One bee, Two bee, Oh!

 

There are 260 known species of bumblebees globally many of which are important pollinators, particularly in agriculture. A phylogenetic study of ~43% of these species has revealed that approximately one third of the species are declining. The Thoracobombus subgenus which accounts for 64% of species tested is particularly vulnerable, as are species of bumblebee with small geographic ranges. Arbetman et al, 2017.

 

Interested in bumblebees? Check out this sciku on bumblebee cognition: Bumblebee football.

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How small the harvest

How small the harvest

for sustainability,

this cream-coloured gold.

 

Illegal poaching and the ivory trade have decimated African elephant populations, but could ivory be harvested sustainably at a level to both maintain the species and satisfy the trade?

By modelling a reference population of African elephants, Lusseau & Lee (2016) show that only a very small amount of ivory can be harvested sustainably without endangering the species and that this amount is well below the current demand. They comment that ‘any overexploitation very quickly runs the risk of driving elephants to extinction’.

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No saturation

Aliens spreading,

their invasion continues.

No saturation.

 

Increased globalisation over the past 200 years has helped to spread flora and fauna species around the world, with some non-native species disrupting local habitats to a devastating degree. Despite efforts to mitigate such invasions, the rate of alien species establishment appears to be increasing and no saturation point has been observed. Seebens et al, 2017.

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Unhappy Whio

Unhappy Whio –

Your populations estranged,

split by the Cook strait.

 

The rare blue duck (named the Whio in Maori after the male call) is found on the North and South islands of New Zealand. The genetics suggest that the populations on the two islands diverged in the late Pleistocene, with very limited gene flow since. The current conservation strategy not to translocate individuals between the populations is therefore sensible so as to avoid potentially negative issues arising from crossing distant genetic pools. Grosser et al, 2016.

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Perfect storm

Spreading fungal scourge

salamanders succumbing

perfect storm draws near.

 

Many of the world’s amphibians are under threat from a chytrid fungus (Bd), particularly in the tropics where it is driving many amphibian species towards extinction. More recently a sister species (Bs) has been observed in Western-European salamanders. Observations of a salamander population across two years following initial detection of Bs suggest a rapid population collapse with little recovery. Bs also has an increased transmission strategy over Bd and may behave as a “perfect storm” as it spreads through European populations of salamanders. Stegen et al, 2017.