"Starry, starry... mole?"

The star-nosed mole, Condylura cristata, is the only member of the genus Condylura and can be found in the wet lowlands of eastern Canada and in the north-eastern states of the USA, typically near to lakes, rivers and streams. The mole is small, with adults being no longer than 20cm and weighing up to a maximum of 55g; and are are instantly identifiable by the tentacle appendages protruding from their nose.

The 22 fleshy tentacles of the star-nosed mole give the species its name and are believed by some scientists to be able to detect the electrical currents emanating from their prey. However, many scientists doubt this as there is little empirical evidence to support this idea.

Unlike other species of mole, which are able to see (albeit with only limited success), star-nosed moles are completely blind. Therefore, they rely exclusively on their nose tentacles in order to detect food, such as worms, insects and crustaceans; and to navigate their way around dark tunnels and other environments. As such, their tentacles are extremely sensitive to touch stimuli and odorants and possess around 25, 000 Eimer's organs per cubic centimetre. This is much higher than in any other species of mole and their tentacles' star-shaped arrangement appears to be an adaptation that allows them to keep soil from entering their nose and to eat very small prey quickly. In fact, they are able to eat prey extremely quickly and are the fastest foragers in the animal world, taking on average of 227 milliseconds to decide whether an item is edible and to consume it. This decision making and response ability is so fast that it is at the limits of the speed of neuronal conduction!

Like other species of mole, the star-nosed mole digs shallow tunnels through the earth when foraging, which helps them to evade their predators, which include owls and hawks and to find many subterranean species of prey, such as worms. Their tunnels can be as long as 270 metres and often exit underwater, with the mole being a surprisingly good swimmer; being able to forage along the beds of rivers, lakes and streams. Interesting, star-nosed moles are also able to smell underwater, which they accomplish by breathing bubbles of air onto objects that they are interested in and then by inhaling these bubbles to carry the scents back through their nose.

Little else is known about the shy species of mole, except that it shows no preference to day, night or twilight activity (which is unusual) and remains active throughout the winter. It is also believe that star-nosed moles live in colonies, as many are frequently seen fairly close together.

Fatal white-nose syndrome spreads through the USA

White-nose syndrome is a fungal disease that has killed more than 5.5 million bats in Northern America, with the infection being fatal  in almost every case. The disease was first recorded in New York in 2006 and despite the extensive efforts to control the disease since then, it has spread through 20 states in the USA and 4 Canadian provinces.

White-nose syndrome, caused by the fungus Geomyces destructans, is characterised by a white growth on a bats nose, ears, wings and tail. Other symptoms include weight loss and abnormal behaviour, such as diurnal activity.

The disease is caused by a common European fungus that oddly, doesn't kill bats in Europe. This has led scientists to believe that the fungus has either changed somehow in America, which gives it its fatal effects or that bats in Europe have a local immunity to the fungus that is not found in American populations, which protects them from the disease. It is hoped that if European bats have immunity to the fungus, it can lead to the formation of a vaccine for their cousins in America, helping to reduce the fatal effects of white-nose syndrome.

The main problem with the fungus is that it prefers to grow in dark, damp climates such as those found in caves. Obviously then, it easily spreads to any bats that are living in an infected cave and the fungus can wipe out entire colonies at a time. Catching the disease is particularly likely over winter when the bats are hibernating and sadly, many die in their sleep without even knowing that they were ever infected.

Recent studies in America have found that at least half of their bat species are at critical risk from the disease and face being wiped out. This is of great concern to the USA since resident bat populations are great controllers of pests and keep the populations of crop-damaging insects down, saving the US agriculture industry an estimated US$3.7 billion a year!

Thus, efforts to eradicate or mitigate the effects of the disease are underway and the US government plans to puts procedures in place in airports and in logistics companies that will hopefully slow or stop the spread of the disease, buying scientists more time to deal with it.

Species conservation: simple right?

You may think that conserving a particular species is easy, assuming that all you have to do is stick a few individuals into a zoo, breed them and then release their babies back into the wild. However, you'd be wrong and it is actually much more complex than this, with lots of unpredictable factors that only become apparent once a conservation scheme has been launched. The conservation of the black-footed ferret, Mustela nigripes, in the USA helps to highlight just this.

The black-footed ferret is a small mustelid, from the same family as European and Siberian polecats, such as weasels that were historically found across most prairie grasslands in the USA. However during the mid 20th century, the population of the ferrets began to decline and by the 1960s they were considered rare. In response to this, they were listed as endangered under the Endangered Species Act of 1973 and a conservation scheme was developed in order to help save the species. However, this took far too long and by the time conservationists were ready to implement the plan, the ferret had disappeared, seemingly becoming extinct. By chance, the species was rediscovered in Wyoming in 1985 and conservationists leapt into action to remove 6 ferrets from the wild, placing them into a captive breeding program. 

The black-footed ferret, Mustela nigripes

However, the initial excitement of capturing the ferrets soon turned into despair. Two of the captured ferrets carried canine distemper, a disease to which the ferret is unusually susceptible to and, as a result, all of the ferrets died. This meant that 6 new ferrets had to be removed from the wild for breeding, further reducing an already small population. Very small populations of a species are a major issue for conservation because the population soon becomes inbred, meaning that deleterious alleles of genes begin to build up and they lose genetic diversity. This problem, which is known as inbreeding depression, means that the species suffers from greatly reduced fitness and is less able to cope with environmental changes; thus, becoming much more likely to fall extinct.

Therefore, removing 6 additional ferrets from the population was of great concern to conservationists, especially because the wild population continued to decline. Around this time, it was discovered that the population of black-tailed, Gunnison's and white-tailed prairie dogs, the main diet of black-footed ferrets, was also decreasing due to the Sylvatic plague. With horror, conservationists realised that the main reason black-footed ferrets were going extinct was because its main source of food was declining - they should have been trying conserve the prairie dogs all of this time, rather than the ferret itself. However, by now the distribution of prairie dogs had fallen to only 2% of its historical geographical range, due to both the plague and the actions of farmers, who wrongly believed them to be pests. To make matters worse, conservationists couldn't merely focus on saving the prairie dogs because only 4 black-footed ferrets now remained in the wild!

The now endangered Gunnison's prairie dog, Cynomys gunnisoni.

To try and preserve both species, the decision was made to pull the remaining black-footed ferrets from the wild and add them to the breeding program, whilst applying the burrows of prairie dogs with a poison that would kill fleas, the vectors (carriers) of the Sylvatic plague. It was hoped that this would be sufficient to help their populations to recover. At the same time, just to be sure, they launched an education campaign in order to change the long-held beliefs of farmers that the prairie dogs were pests and that they had to be preserved, or else they could become extinct.

Fortunately, the populations of both species are now beginning to recover, even though they are both still rare. The black-footed ferret has been a particular success, with kit (baby ferrets) reintroduction schemes running since 1991. However, the species may not have been so fortunate and the case study highlights the importance of identifying why species are declining in the first place. Ironically, by trying to save the black-footed ferret, we could have easily driven it to extinction as we did not fully consider the complicating factors of the ecosystem and the full impact of humans on the ferret. This is a lesson that needs to be learnt for new species conservation schemes, elsewise they could fail, at great expense to conservation funds.