Scale of declines of UK migratory birds wintering in Africa revealed

Yellow Wagtails have declined in the UK by 43% since 1995. Credit: Andy Hay; rspb-images.com

The migration of millions of birds across the face of the planet is one of nature's greatest annual events. Every spring some species move in one direction, while every autumn those same species move in the opposite one, very often linking continents.

Although these migration patterns are as regular as the seasons, monitoring is revealing that, for some species, fewer birds are making the journey each season as the populations of these birds, including species nesting in the UK, are declining rapidly.

The latest in the annual series of State of the UK's Birds report includes a migratory birds section, including trends for 29 migrant species which nest in the UK in summer and spend the winter around the Mediterranean, or in Africa south of the Sahara Desert. For the first time the recent population trends for these migratory species have been combined into an indicator revealing some marked differences between species that winter in different areas.

Species, such as Whinchat, Common Nightingale, Tree Pipit and Spotted Flycatcher, which winter in the humid zone of Africa -- stretching across the continent from southern Senegal to Nigeria and beyond -- show the most dramatic declines: the indicator for this group of species has dropped by just over 70% since the late 1980s. This contrasts with species, such as Sand martin, Common Whitethroat and Sedge Warbler, wintering in the arid zone (just below the Sahara desert). These species have fluctuated considerably since 1970, but show a less than 20% decline overall.

One of the most dramatic declines is that of the European Turtle-dove with a decline of 88% since 1995. The following species have also declined over the same period: Wood Warbler, 66%; European Pied Flycatcher, 53%; Spotted Flycatcher, 49%; Common Cuckoo, 49%; Common Nightingale, 43%; and Yellow Wagtail, 43%.

Concern about migratory bird species is growing and future editions of the State of the UK's Birds report will contain a regular update to the migratory bird indicator. To understand the changing status of the UK's migratory birds, researchers need to understand more about what's driving these declines. Evidence is currently being gathered from a variety of sources including tracking studies and on-the-ground surveys.

Martin Harper, RSPB Conservation Director, said: 'West Africa is the winter home for many species bird species that breed in the UK. But many of these birds that cross continents are in rapid decline. Their nomadic lifestyle, requiring sites and resources spread over vast distances across the globe makes identifying and understanding the causes of decline extremely complex.

'The problems may be in the UK or in West Africa, or indeed on migration in between the two.'

David Noble, Principal Ecologist at the British Trust for Ornithology (BTO), said: 'We can accurately monitor the patterns of decline in these once-familiar summer breeders thanks to several decades of careful observations by an army of volunteer birdwatchers. More recently, tracking devices have shed light on migratory routes and key wintering areas.

'To take appropriate action, further study is needed to determine the pressures faced in sub-Saharan Africa, as well as breeding here in the UK.'

Colette Hall, Wildfowl & Wetlands Trust (WWT) Species Monitoring Officer, said: 'The length of many bird migrations -- often thousands of miles -- makes it very difficult to pinpoint where and what is causing populations to fall.

'So the more information we can get all along the migration routes -- on land use changes, new infrastructure etc -- the better we can target protection measures. It's important that we help build up the capacity of local bird organisations and volunteers across the world to provide vital information through their own long-term monitoring.'

Alan Law, Director of Biodiversity Delivery at Natural England said: 'It is self-evident that effective conservation of a migratory species requires appropriate measures to be in place at each step of the migratory cycle.

'For some species, there is growing evidence of pressure on breeding success here in England. Our focus therefore is to ensure that well-managed habitats are available in this country so that migratory species can breed here successfully; this work involves close collaboration with land managers both on designated conservation sites and across the wider farmed countryside.'

David Stroud, Senior Ornithologist with the Joint Nature Conservation Committee, said: 'Migratory birds depend on conservation actions in all the countries they move through in the course of their annual cycle.

'The UK is working with these countries to help improve the condition of their critical habitats through its participation in multi-lateral environmental agreements such as the Biodiversity Convention and the Ramsar Convention on wetlands.'

The State of the UK's Birds report also covers the UK's Overseas Territories. The latest evidence reveals mixed fortunes for two important albatross populations in the UK's Overseas Territories. Seventy per cent of the world's Black-browed Albatrosses nest in the Falkland Islands. A population increase here has allowed researchers to downgrade the extinction threat of this species from Endangered to Near Threatened. Sadly, the fortunes of the Grey-headed Albatross has deteriorated as declines have been reported in nesting colonies on South Georgia, which hosts half the world's population.

The State of the UK's Birds report is available online at: http://www.rspb.org.uk/Images/state-of-the-uks-birds_tcm9-383971.pdf

Source: BirdLife International

Managing reefs to benefit coastal communities

Fishing. Credit: Josh Cinner

Coral reefs provide a range of benefits, such as food, opportunities for income and education, but not everyone has the same access to them, according to a new study conducted by the ARC Centre of Excellence for Coral Reef Studies at James Cook University.

The researchers examined how people from 28 fishing communities in Madagascar, Kenya, Tanzania and Seychelles benefit from the marine environment.

For many years conservation in developing countries has been based on the assumption that improvements in ecosystem conditions, such as increasing coral reef fish biomass, will benefit the community as a whole.

But Dr Christina Hicks, a social scientist, says this is approach is too simplistic.

"Increased supply tends to benefit the elite, not the community as a whole," Dr Hicks says.

"We need to look at the social and economic access mechanisms that would enable a wider group of people to benefit from reefs and then develop policies based on that information," she says.

Study co-author Professor Josh Cinner from the Coral CoE says the focus on increasing the supply of benefits isn't enough.

"We need to pay more attention to how that benefit is distributed and how it is accessed by different people within a community," Professor Cinner says.

The researchers argue that policy makers need a more inclusive approach to managing coral reefs, which includes a focus on improving wellbeing.

"We tend to focus on economic growth because it is easy to measure, but this should be greatly expanded to include the way people can share in the benefits that flow from reefs," Dr Hicks says.

Source:  ARC Centre of Excellence in Coral Reef Studies.

You can hear the coral reefs dying, experts say

A lionfish in an Indonesian reef. Credit: Image courtesy of University of Essex

You can hear the sound of former bustling coral reefs dying due to the impact of human activity, according to new research from the Universities of Essex and Exeter.

Coral reefs are amongst the noisiest environments on our planet and healthy reefs can be heard using underwater microphones from kilometres away.

However, scientists have found that coral reefs impacted by human activity, such as overfishing, are much quieter than protected reefs, which can have a big impact on the fish and invertebrates which rely on the reefs for survival.

Led by Dr Julius Piercy, from the University of Essex, the study, which also involved the University of Derby, involved taking acoustic recordings of coral reefs with different levels of protection around islands in the Philippines. The research found that the noise produced by the few remaining resident fish and crustaceans on unprotected reefs was only one third of the sound produced at bustling, healthy reef communities

This is particularly important to the larval stages of reef fish and invertebrates, which spend the first few days of their life away from reefs and use sound as an orientation cue to find their way back. With less sound being produced at impacted reefs, the distance over which larvae can detect habitat is ten times less, impacting on the replenishment of future generations needed to build up and maintain healthy population levels.

"In an environment where underwater noise plays such an important role in the population dynamics of coral reefs, it is alarming to find such a large effect of human impact on the natural acoustic environment," explained Dr Piercy. "This puts reef sound in the spotlight for the people who manage coral reef ecosystems on two counts. Firstly, that they might need to consider reef sound as an integral part of the design of marine protected area networks to ensure that there is sufficient recruitment of larvae within and between reserves and neighbouring reefs. Secondly, this study shows sound can be useful in monitoring the health of coral reefs."

With growing evidence demonstrating the direct impacts of human-made noise on aquatic life, these findings highlight additional indirect human impacts -- such as overfishing and landscape development -- on natural underwater sounds.

Dr Steve Simpson, from Biosciences at the University of Exeter, added: "Taking sound recordings is a cheap, fast and objective way to get a broad idea of whether a reef is in a good condition or not. While it cannot replace detailed visual surveys conducted by snorkelers or divers, it gives a good account of the cryptic and nocturnal species missed in visual census, and quickly provides a general picture of the state of coral reefs without requiring time-consuming surveys and extensive training."

The researchers also found that reef sounds can be detected further away than predicted, increasing previous estimates of the likely detection zone for recruiting larvae and increasing the potential importance of reef sound in attracting new fish and crustaceans to coral reefs.

The study highlights the need to further characterise reef soundscapes and identify acoustic cues that larvae tune into when seeking a suitable home. Dr Simpson said: "We still know very little about what sounds these animals are listening to and it is likely to be very different between species. Combined with recent findings that fish dislike the smell of impacted reefs (another homing cue used by the larvae), there is a real need to understand how human impacts can indirectly affect the success of future generations of reef organisms."

Source: University of Essex