February was a month of two halves, weather-wise, the first being cold, grey, and overcast for most of us, while the second was much milder, but also much more unsettled. Last month we learned that January was "officially" the warmest on record, with temperatures 1.75C (3.15F) above pre-industrial levels as the inexorable rise to 3C (5.4F) continues.
Speed Read of the Month
This month sees the introduction of a new species profile to the website: an overview of the natural history of the Red-billed chough (Pyrrhocorax pyrrhocorax). This species represents a rare conservation success in Britain, the population having recovered from local extinction in the West Country in the 1970s and having bred successfully every year since 2002.
News and discoveries
Diversity drama. Red squirrels are a well-known conservation subject here in Britain, with scientists and conservation charities alike working hard to preserve and restore fragmented and declining populations in the face of ever-increasing habitat loss, pollution, disturbance, and introgression of grey squirrels. Despite being a stronghold for the species in the UK, a recent study by scientists at the University of Edinburgh mapped the entire genetic code of 106 animals from Scotland and Formby, only to find that, as a species, the red squirrel's level of genetic diversity is lower than some of the world's most endangered animals, including the Iberian lynx and Amur tiger. It seems that movement across Scotland is restricted by a variety of natural and man-made barriers, from mountains to cities, which has created isolated populations. The north-east of Scotland remains one of the only areas where the animals can freely move between the north and south. If we look to translocate squirrels across these barriers to boost genetic diversity, this genetic analysis will likely prove invaluable in identifying suitable candidates.
Sealed with a fish. We've all heard the (now inaccurate) expression "plenty more fish in the sea", but our oceans and seas are vast, and fish distribution is not even. Indeed, most of the world's fish biomass exists in the appropriately named "twilight zone" (or mesopelagic zone), a layer of the ocean that extends from 200 down to 1,000 meters (650 ft. to just over half a mile deep). We know very little about this zone because it's extremely difficult to study, but recent suggestions that this zone could soon be exploited as a fishery have prompted scientists to try and understand how stock depletion could impact ocean health. Now, a decades-long study of Año Nuevo Natural Reserve's elephant seal (Mirounga angustirostris) population, incorporating more than 350,000 observations of over 50,000 individuals, is helping us measure fish abundance across the twilight zone in the Pacific where these pinnipeds feed. Data from the study indicate that body condition and breeding success of the seal population correlates with fish mesopelagic fish abundance, offering a much more accessible window on this world.
Invasive identification. Invasive non-native species, those introduced into habitats in which they did not evolve, are a long-standing problem and are one of the top five threats to global biodiversity, and some estimates suggest they cost the global economy nearly £2 billion a year. What's worse, once established, these species can be extremely difficult and costly to remove or control. A new study, currently in press with the Journal of Biogeography, led by the Invasion Science Research Institute at the University of Florida, has developed a new "Environmental Resistance" modelling approach that helps scientists and governments understand what makes a habitat attractive to invasive species (e.g., soil type, human disturbance, etc.) and allows them to predict potential patterns of spread. The hope is that a better understanding of invasive species and their new environment can only help develop more appropriate and effective management strategies.
Wilding win. There's a lot in the news about the damage humans are inflicting on the environment and the biodiversity freefall our species appears to be presiding over, so it's worth taking a moment to acknowledge success in the field of conservation. Last month, a collective of local environmental groups, funded by Hackney Council, the Environment Agency, and the Mayor of London, reported significant increases in biodiversity at Hackney Marshes in Greater London. Three years of creating habitats through activities such as coppicing, installing dams, and creating log piles, has seen species such as kestrels, mice, voles, shrews, and weasels rebounding. The site still faces pressure from human disturbance, particularly from boat parties and dog walkers, but this illustrates what can be accomplished in a short amount of time.
For a round-up of Britain's seasonal wildlife highlights for early spring, check out my Wildlife Watching - March blog.