BTO - British Trust for Ornithology - Non-natives

Breeding Bird Survey

Anonymous — Fri, 02 Feb 2018 11:46:31 +0000

The Breeding Bird Survey is the main scheme for monitoring the population changes of the UK’s common and widespread breeding birds. The survey involves two early-morning spring visits to a 1-km square, to count all the birds you see or hear while walking two parallel 1-km lines across the square.

Breeding Bird SurveyButterfly Monitoring Friday, April 1, 1994 - 00:00

BBS monitors the population changes of 118 breeding bird species across the UK thanks to the dedication of almost 3,000 volunteers who survey their randomly selected 1-km square each spring.

The BTO/JNCC/RSPB Breeding Bird Survey (BBS) is the main scheme for monitoring the population changes of the UK’s common and widespread breeding birds, producing population trends for 118 bird and nine mammal species.

The survey involves a recce visit and two early-morning spring visits to an allocated 1-km square, to count all the birds you see or hear while walking two 1-km lines across the square and record any nest counts for colonial nesting birds in the square.

You can optionally record mammals and visit your square later in the season to survey for butterflies. There is the option to return data on paper, via field recording forms or to submit your data on BBS-Online.

Support the future of our birds

Our surveys are vital. The data they produce help us drive positive change for the UK’s birds.

But increased pressure on funding is putting our surveys and data at risk – which is why we need your support.

Donate today

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Read the latest BBS report

The Breeding Bird Survey started in 1994, and a report is produced every year containing population changes and other results from the scheme.

The 2022 Breeding Bird Survey Report reveals a mixed picture, especially for birds which breed in farmland habitats.

Read the 2022 Breeding Bird Survey report

How to take part

Find out how to request a square and what the survey entails.

Results

Explore the results from the data BBS volunteers provide.

Mammal recording

Find out how to record mammals during your BBS visits.

Count butterflies on your BBS square

Take part in the Wider Countryside Butterfly Survey by making additional visits to your BBS square.

How to enter BBS data online

Instructions and video tutorials on submitting your BBS data.

Download BBS forms

Download and print BBS recording forms instructions and recording forms.

Support the future of our birds

Our surveys are vital. The data they produce help us drive positive change for the UK’s birds.

But increased pressure on funding is putting our surveys and data at risk – which is why we need your support.

Donate today

Take part in BBS - counting for conservation

David White

James Heywood

February – March Forms sent or downloaded
March Reconnaissance visit
Early April – mid May Early visit
Mid May – late June Late visit
May – August Wider Countryside Butterfly Survey
End of August Data entry deadline

Undertake three site visits between April and June - a recce and two morning visits, along with data entry. Able to identify UK breeding birds by sight, song and call. If you have the necessary bird ID skills to take part in the Breeding Bird Survey but want to learn more about survey methods, there are a number of BTO training courses covering this subject.

ongoing Farmland birdsUpland birdsWoodland birdsOther species volunteers

BTO Urban AppealWider Countryside Butterfly SurveyAssessing agri-environment schemes No bbs@bto.org

Waterbird News - Issue 39

NEILCALBRADE — Thu, 02 Nov 2023 12:13:14 +0000

The Cuckoo cohort of 2024 takes flight!

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Tackling invasives: unpicking the definitions

WEBSITEEDITOR — Mon, 16 May 2022 12:00:00 +0000

BTO's Head and Principal Ecologist David Noble breaks down what we really mean by 'invasive species'. Yes

David Noble

Head & Principal Ecologist

David is responsible for the strategic development of BTO’s monitoring programme and associated research, is the main contact for biodiversity indicators, surveys of taxa other than birds, and for conservation initiatives such as BAP and Birds of Conservation Concern.

Lady Amherst’s Pheasant

As well as their effect on biodiversity, non-native species can also have significant impacts on human health and economies, with severe consequences for crops, timber resources or livestock, as well as transport infrastructure such as canals. Control and eradication programmes designed to deal with these pressures are a huge global drain on resources, estimated to cost billions - close to £2 billion annually in the UK alone.

On a global scale, the problem is particularly dire for island nations; high in endemic species, and low in natural predators and competitors, these isolated landmasses are hugely vulnerable to invasives. A well-known example is the local extinction of nearly all vertebrate species on the island of Guam after it was colonised by the Brown Tree Snake.

However, once you start talking about invasives, definitions can become surprisingly tricky.

Non-native species have been introduced to areas outside their natural range through human intervention.

The Common Pheasant was introduced as a game bird in the UK as early as the 10th Century. Now, close to 40 million are released every year for the hunting season. Tom Streeter / BTO

Hitching a ride with humans

Non-native species are species that have been introduced to areas outside their natural range through human intervention. Synonyms used elsewhere include ‘non-indigenous’, ‘exotics’, ‘introduced species’ and ‘aliens’, many terms coming with slightly negative or uncomfortable social connotations.

Introduction through ‘human intervention' comes in many forms. Many species of plants and animals have been deliberately introduced to Great Britain and Ireland for food (for example, Rabbit), for hunting (Pheasants, Fallow Deer) and for aesthetics (Peafowl). Countless others arrive through escapes from wildlife parks and zoos, as pets or from aquariums, or as stowaways in cargo, food supplies, ship ballast or timber.

The definition also includes species that arrive through their own devices from introduced populations which are established elsewhere, as in the case of Asian Hornet, brought to Europe on wood pallets from China but subsequently flying across to Great Britain. Sacred Ibis occasionally seen but not established in Great Britain may have flown over from the naturalised populations in France, although to date, most have turned out to be recent escapes from parks.

Asian Hornet. Eduardo Gonzales / stock.adobe.com

The Asian Hornet was first recorded in France in 2005 after arriving in wood pallets containing pottery from China. It has since flown across the Channel, with the first British record in 2016.

Established or naturalised populations of non-native species are self-sustaining and self-perpetuating, surviving and breeding without any deliberate human intervention.

Populations of ornamental waterfowl, such as Black Swan, are not considered officially 'established', although they may become so; some pairs are forming free-living populations, albeit with little expansion. Edmund Fellowes / BTO

Putting down roots

The second issue is whether the species is established or synonymously naturalised, by which we mean whether the non-native population is self-sustaining and self-perpetuating. In other words, the population is surviving without any deliberate human intervention (e.g. food or shelter) and is breeding.

This is particularly relevant for plants, where there are hundreds of ornamental or crop species in gardens, parks and agricultural land, but the species is not considered naturalised unless it has established ‘beyond the garden wall’, meaning there are generations of self-sustaining populations in the wild.

This also excludes many waterfowl in city water bodies where they are being supplied regularly with food and shelter, like Black Swan in London’s Regents Park. The definition of establishment is important, despite its murkiness, because hundreds of species – usually single individuals - occasionally escape from homes, zoos or parks despite legislation meant to prevent this, and neither establish nor have much impact. Rogue pythons, Red Panda and even a Hippo which briefly occupied a canal before being recaptured are good examples.

Some escapes, however, are more worrying, because we know that the species has caused significant problems elsewhere, such as Raccoons which are well-established in Germany. The escape pathway is of special concern when the species is commonly kept in groups and escapes may include already breeding individuals.

The global Convention on Biological Diversity defines invasive species as having a negative impact on other biodiversity, the economy or human health.

Little Owl was first reported breeding in the UK in 1879. It is now widely established but has little impact on native biodiversity, the economy or human health, so is not considered invasive. Liz Cutting / BTO

When does a non-native species become invasive?

The other slightly non-intuitive definition is for invasive non-native species.

In Great Britain, we follow the lead of the global Convention on Biological Diversity in defining invasive as having a negative impact, by harming other biodiversity, causing economic damage or by impacting human health. Hence it is not the ecological meaning of invasive (rapidly spreading and colonising new areas or habitats) that is used, but the extent of a species’ negative effect.

It is of course virtually impossible for any non-native species to have absolutely zero impact, but where impacts are considered minimal (as for Little Owl or Red-necked Wallaby in Britain - indeed, 85% of non-native species) they are not considered to be invasive. In some cases, the species may be still too rare to have much impact, but if it is known to be problematic elsewhere, it would be included.

Can a native species be invasive? Yes, but only in the ecological sense, in being able to rapidly colonise and dominate new habitats - Bracken could be described in this way.

Ring-necked Parakeet. Guarav Mittal

The impact of Ring-necked Parakeet on native cavity-nesting species in the UK is still uncertain although it is thought to out-compete Nuthatch and Noctule Bats elsewhere in Europe. The British population of this introduced species are the most northerly breeding parrots in the world.

The cultural value of species such as Reeves' Muntjac and Canada Geese should be weighed against evidence for their negative impact elsewhere. BTO research has revealed Reeve's Muntjac have strong adverse effects on native woodland biodiversity, and high concentrations of geese - with their droppings - can affect water quality. Steve Round / BTO

Can non-native species be beneficial in their new environment?

The damaging consequences of non-native species are clear, and the most cost-effective solutions include promoting awareness to prevent their introduction and spread through bio-security measures. However, the question of whether non-native species can be beneficial is often raised. Evidence of this is rare apart from instances of high cultural value, particularly in urban environments, where much of the public enjoys seeing and interacting with a suite of non-native species such as Ring-necked Parakeet, Canada Goose or Grey Squirrel.

For some of these culturally-valued species, these benefits must be weighed against strong evidence of damage to native diversity (as for Reeves' Muntjac and other non-native – and native – deer on woodland plants, insects and birds) but in other cases, such as for Ring-necked Parakeet, the impact appears still to be a potential threat rather than a current pressure, at least regarding ecological effects.

In general, pragmatism rules: early eradication of new arrivals, such as American Bullfrog, is both more cost-effective and risk-averse than trying to control already widespread and problematic species such as Signal Crayfish or Grey Squirrels.

In Great Britain, there are more than 2,000 established non-native species of animals or plants; of these, 15% are classed as invasive.

Initially present in the UK as an ornamental plant, Water Primrose started to cause severe damage to native biodiversity and waterway transport routes. Its sale is now banned in the UK. jag images / stock.adobe.com

Monitoring and tracking invasive species

In Great Britain, there are more than 2,000 established non-native species of animals or plants. The majority have had minimal impact, but around 15% - the invasive non-native species - have spread and are having a negative impact on biodiversity and/or human health or economy. These are largely the species in the GB Non-Native Species Indicator, which tracks the aggregated geographical spread of these species across the past six decades. Of these established non-native species, the majority (around 75%) are plants, followed by insects, and then vertebrates, with most found in the terrestrial environment.

We know this mainly because of the high effort in biodiversity recording that goes on in the UK, via a plethora of different monitoring schemes, most of them volunteer-based. In addition, a number of particularly problematic species – including Raccoon, Water Primrose and Asian Hornet - are on the ‘alert list’ for Great Britain because their arrival and establishment could cause huge problems for native wildlife, or to human health and our economy.

The public can submit sightings and photos of any of these species through iRecord or the Non-Native Species Information Portal. Non-native species records submitted as part of other monitoring schemes (such as the BTO/JNCC/RSPB Breeding Bird Survey or BirdTrack) are also subsequently forwarded for use to the National Biodiversity Network Atlas and relevant organisations.

Invasive Species Week: get involved!

Invasive Species Week is organised by the National Biodiversity Network (NBN). It is an annual national event to raise awareness of the impacts of invasive species, and how everyone can play a part in preventing their spread, from learning how to be Plant Wise when gardening to looking out for alert species like Asian Hornet. To find out how you can get involved, follow the links above for recording non-native species, visit the GB Non-native Species Secretariat's website, or explore the content below.

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BTO is a National Biodiversity Network Trust Member. Read more about NBN, and their work on invasive species, on their website.

BTO research suggests that Common Nightingale and Willow Tit are being affected by increasing populations of non-native deer.

Upland Habitat. Mike Toms / BTO

Collaborative 'horizon-scanning' research involving BTO has identified species with the potential to threaten Great Britain's biodiversity.

Featured Publication

Peer-reviewed papers

The potential for analyses of monitoring scheme data to inform about the impacts of invasive on native species

2022 | Pringle, H. & Siriwardena, G.

Biological Invasions

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BTO's Head and Principal Ecologist David Noble breaks down what we really mean by 'invasive species'.

Today is the start of Invasive Species Week - seven days to raise awareness of the impacts of invasive species like Ring-necked Parakeet, Japanese Knotweed, Reeves' Muntjac and Asian Hornet. This week is important: there is a huge body of evidence that non-native species can have strong adverse effects on the environment and other species in their new range. This makes them one of the most significant threats to biodiversity on a global scale, and one that is increasing despite stricter legislation and better practice to prevent their spread.

Grey Squirrel. John Harding / BTO

15 May 2023 no

The potential for analyses of monitoring scheme data to inform about the impacts of invasive on native species

VIOLA.ROSS-SMITH — Tue, 19 Apr 2022 13:40:35 +0000

The Cuckoo cohort of 2024 takes flight!

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Pringle, H. & Siriwardena, G. Biological Invasions 10.1007/s10530-022-02785-8 UK animals and plants are surveyed annually by a wide range of long-term citizen science monitoring schemes, which are designed to detect species’ range, status and population trend. Here we explore whether these data are suitable for detection of ecological impacts of invasive species on native species. While expert horizon scans and risk assessments can identify those non-native species that are likely to turn invasive from ecological knowledge, it would be valuable to monitor such impacts in practice. Monitoring scheme data may support such evaluations. We consider the utility of monitoring data in this context via a series of case studies examining the detectability of impacts of Ring-necked Parakeet, Grey Squirrel and Reeves’ Muntjac on native birds and bats that are potentially vulnerable to their impacts. The results show that monitoring scheme data have the potential to provide novel insight informing the evaluation of invasive effects in a range of contexts, adding to current evidence bases, which typically rely upon ecological principles and evidence from small-scale studies. We found a combination of results supporting the expectation of invasive impacts and those not finding such effects. The latter may partly reflect limitations in data quality, such as issues of co-location of data, sample size, adequately detailed identification of at-risk habitats or locations, and likelihood of incompleteness of data on non-natives. We discuss options to enhance monitoring to support enhanced analyses in the future, but analyses of the data can already provide evidence to assist with the determination of invasive impacts now.

The authors thank all the volunteers who have participated in BBS and BCT, and the survey organisers. BBS is funded by a partnership of BTO, JNCC and RSPB. The authors also thank Philip Briggs and Becky Wilson for providing BCT data and advice, and Niki Newton and Niall Moore for comments on earlier drafts. The authors are grateful to an anonymous reviewer and Guillaume Latombe for their helpful comments and feedback.

Long-term citizen science monitoring schemes are designed to detect species’ range, status and population trends, and are already used to track the arrival and spread of invasive species. However, they could also be a valuable source of data for researchers looking to assess the impact that established invasive species have on native species.

The impact of an invasive species could be revealed through three types of relationships with native species: a status-status comparison, in which the native species is rarer where the invasive species occurs or is more common; a status-change comparison, in which the native species sufferers more declines were the invasive species occurs or is more common; or a change-change comparison, in which more negative population effects are observed in the native species when more positive effects are observed in the invasive.

In this study, the researchers evaluated the possible uses of citizen science data for detecting these ecological impacts of invasive species on native species. Using data from the BTO/JNCC/RSPB Breeding Bird Survey (BBS) and the National Bat Monitoring Programme (NBMP) the researchers conducted four case studies employing different methods of data processing - for example, summarising data over different spatial and temporal scales depending on the taxa recorded.

For each case study, the researchers identified the association between invasive presence or abundance and native species’ responses, and assessed the strengths and limitations of the datasets used. For example, the first study used BBS data covering the same time period and spatial scale, collected using BBS methodology. This made the analysis more robust than that in the final case study, which used data from BBS and the NBMP. As the data had been collected in different surveys, there was less spatial and temporal overlap and the resolution of the BBS data analysis was limited by the survey methodology of the NBMP.

The researchers concluded that data from existing national biodiversity monitoring schemes could be used to assess the impact of invasive species on native ecology, but several limitations do exist in these datasets. Firstly, invasive effects need to be identified rapidly after arrival when the species is still rare or localised, but national-scale monitoring is not likely to collect enough high-resolution data at this early stage to inform eradication programmes. Secondly, abundance data for many groups of interest are lacking, as schemes have focussed on recording simple presence/absence data. Thirdly, many schemes collect data on taxa other than those originally targeted; for example, while BBS has all the advantages that come from a structured, standardised survey, it was not designed specifically for recording mammals and therefore may report more ‘false absences’ than a specialist mammal survey due to differences in mammal and bird detectability.

In order to enhance analysis options, the researchers suggest combining the data quality of structured surveys (such as BBS) with the data quantity of unstructured schemes (such as opportunistic recording), and encouraging counts of individuals (or cover measures for plants)rather than simple presence/absence data.

Effect of a joint policy statement by nine UK shooting and rural organisations on the use of lead shotgun ammunition for hunting common pheasants Phasianus colchicus in Britain

VIOLA.ROSS-SMITH — Wed, 24 Feb 2021 09:39:51 +0000

The Cuckoo cohort of 2024 takes flight!

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Green, R.E., Taggart, M.A., Pain, D.J., Clark, N.A., Clewley, L., Cromie, R., Elliot, B., Green, R.M.W., Huntley, B., Huntley, J., Leslie, R., Porter, R., Robinson, J.A., Smith, K.W., Smith, L., Spencer, J. & Stroud, D. Conservation Evidence There are significant negative effects of exposure to spent lead ammunition on wildlife and human health. A joint statement was issued by nine UK shooting and rural organisations on 24th February 2020 intended to encourage a voluntary transition to non-lead shotgun ammunition within five years “in consideration of wildlife, the environment and to ensure a market for the healthiest game products”. We dissected carcasses of wild-shot common pheasants Phasianus colchicus sold or offered for human consumption in Britain in the shooting season between 1st October 2020 and 1st February 2021 to recover shotgun pellets. The principal metallic element composing one pellet from each bird was identified using inductively coupled plasma atomic emission spectrometry. The results showed that 99% of the 180 pheasants from which shotgun pellets were recovered had been killed using lead shotgun ammunition, compared with 100% in a much smaller study conducted in the 2008/2009 shooting season. We conclude that the shooting and rural organisations’ joint statement, and their subsequent promotional actions, have not yet had a detectable effect on the ammunition types used by shooters supplying pheasants to the British game market.

BTO and COVID-19

WILLIAMSKELLORN — Mon, 19 Oct 2020 12:17:41 +0000

17 Jan 2022

This statement was updated at 09:00 on 17.01.2022.

Volunteers can currently undertake surveys in most/all parts of the UK so long as they are careful to follow relevant guidance.

The spread of COVID-19 (Coronavirus) has had a significant impact on our lives, and on the monitoring and survey work to which we contribute. It is likely to continue to have an impact on our activities for some time. BTO continues to take the threat seriously, with utmost concern for the health and well-being of our staff, volunteers and members, and those landowners and communities with which we interact.

It is vital that our staff, volunteers and members continue to follow the latest government advice in order to prevent the spread and transmission of infection. The monitoring work undertaken by BTO staff and volunteers makes a valuable contribution to society and to their own mental well-being, but these are exceptional times and the government advice provides the framework by which we should direct our activities. People across society are having to make sacrifices, and it is important that we, as volunteers, continue to do our bit by following government advice and supporting the efforts to bring an end to this pandemic.

The health of yourselves and your families and friends is important. If you or those close to you are impacted by the virus, we wish you a swift recovery. You should not feel that you have to carry out surveys this year if you have any concerns about the health and safety of yourself or other people.

BTO offices and working arrangements

We have put steps in place to minimise disruption to our work and core charitable activities and have produced a risk assessment (PDF 823kb) for our offices. Please note that most of our staff are still working from home, but can be contacted by email or through our website. We have put in place mechanisms to enable people to contact the BTO over the telephone and our online sales operation remains open.

Participating in BTO surveys

BTO’s senior leadership team continues to review published legislation, government guidance and other relevant advice for England, Scotland, Wales, Northern Ireland, the Isle of Man, Channel Islands and Republic of Ireland. We also continue to consult with JNCC, the relevant Statutory Agencies or responsible bodies, and NGO partners about the implications for our volunteer surveys.

It is vital to understand that the guidance presented here represents the latest interpretation of the legislation received by BTO from the relevant government departments. For your own benefit, in terms of disease transmission we urge volunteers to carefully assess the risks posed by their fieldwork. Given the potential risk of the spread of new variants, guidelines could quickly change again and there is likely to be greater onus on individuals to be responsible for minimising risk to themselves and others.

Our current position, as of 17 January 2022, is as follows:

You may take part in surveys, provided you follow any current government restrictions and guidance for England, Northern Ireland, Scotland, Wales, Isle of Man, Bailiwick of Jersey, Bailiwick of Guernsey as appropriate, and our survey-specific guidance below.

Survey work and coronavirus

No volunteer should undertake survey work if displaying symptoms of Covid-19. If volunteering is undertaken, volunteers should follow all government guidance in their geographic region, and appropriate health and safety procedures at all times.

The health of our volunteers is very important to us, as are our relationships with the landowners who so generously allow us onto their land. No volunteer should feel under pressure to carry out fieldwork if they do not feel comfortable doing so, or if they are concerned about the impacts of carrying out survey work on relations with landowners or other members of the public. Please be sensitive to the feelings of landowners and your impact on local communities at this time and help foster good relationships with local communities for the future. Inconsiderate actions will be damaging for all of us. As with all fieldwork, please ensure that you have appropriate landowner permission to visit.

Useful links

England: https://www.gov.uk/coronavirus / https://www.legislation.gov.uk/uksi/2021/364/contents/made

Wales: https://gov.wales/coronavirus

Scotland: https://www.gov.scot/coronavirus-covid-19/

Northern Ireland: https://www.nidirect.gov.uk/campaigns/coronavirus-covid-19

Republic of Ireland: https://www.gov.ie/en/campaigns/c36c85-covid-19-coronavirus/

Isle of Man: https://covid19.gov.im/

Bailiwick of Jersey: https://www.gov.je/Health/Coronavirus/Pages/index.aspx

Bailiwick of Guernsey: https://covid19.gov.gg/

The BTO Team

Yes

Norfolk Bat SurveyBirdTrackBreeding Bird SurveyGarden BirdWatchGarden Wildlife HealthWoodcock SurveyBird Ringing SchemeBird Atlas 2007-11Heronries CensusNest Record SchemeWaterways Breeding Bird SurveyWetland Bird SurveyNesting NeighboursTawny Owl Point SurveyTawny Owl Calling SurveyGarden Bird Feeding SurveyEnglish Winter Bird SurveyCuckoo Tracking ProjectEnglish Farm Woodland Bird SurveyGardenwatchBreeding Waders of Wet Meadows Northamptonshire (VACANT)ArmaghAvonBenbecula & the UistsBordersBrecknockBTO Wales OfficerCaithnessDerbyshire (South) (VACANT)DurhamEssex (Northwest) (VACANT)FermanaghHampshireHuntingdon & Peterborough (VACANT)Inverness (East & Speyside)Inverness (West)Islay, Jura & ColonsayIsle of ManChannel Islands (Jersey)Kincardine & DeesideKirkcudbrightLanark, Renfrew & DunbartonLancashire (South) (VACANT)Leicestershire & RutlandLincolnshire (East)Lincolnshire (North)Lincolnshire (South) (VACANT)London (South)LothianNorfolk (Northeast)Norfolk (Northwest)Norfolk (Southeast)Nottinghamshire (VACANT)OrkneyOxfordshire (South)RadnorRoss-shireRum, Eigg, Canna & MuckShetland (VACANT)SomersetStaffordshire (North)Staffordshire (South)TyroneWarwickshireWigtown (VACANT)Wiltshire (North)Wiltshire (South)Yorkshire (Hull)Yorkshire (Northwest) (VACANT)Yorkshire (Richmond) (VACANT)Glamorgan (Mid)Glamorgan (South)Staffordshire (West)HerefordshireCardiganPembrokeshireClevelandMontgomery (VACANT)Oxfordshire (North)Yorkshire (York)GloucestershireClwyd (West)Yorkshire (Central) (VACANT)CornwallGwentMeirionnyddYorkshire (East)BerkshireCambridgeshire (VACANT)Cheshire (Mid)Isles of ScillyThe WirralYorkshire (Bradford)CarmarthenDownBTO Northern Ireland OfficerSussexCaernarfonBedfordshireMoray & NairnMerseyside (VACANT)London (North)NorthumberlandCumbriaDerbyshire (North) (VACANT)SuffolkArgyll (Mainland, Bute & Gigha)Clwyd (East)Antrim & BelfastLancashire (East)Fife & KinrossManchesterLondonderryWorcestershireBuckinghamshireGlamorgan (West) (VACANT)Cheshire (North & East)Cheshire (South)Devon (VACANT)Birmingham & West MidlandsDorsetPerthshireYorkshire (Leeds & Wakefield) (VACANT)Essex (South) (VACANT)Yorkshire (Southwest)Norfolk (Southwest)Lincolnshire (West)SutherlandLancashire (Northwest) (VACANT)AberdeenKentSurreyHertfordshireDumfriesSkyeAyrshire and CumbraeArgyll (Mull, Coll, Tiree & Morvern)ShropshireYorkshire (Northeast)Channel Islands (Guernsey)Isle of WightEssex (Northeast)Yorkshire (Southeast)AngusCentral ScotlandLewis & HarrisAngleseyMarine region away from landIsle of ArranIsle of May

Invasion of freshwater ecosystems is promoted by network connectivity to hotspots of human activity

VIOLA.ROSS-SMITH — Thu, 02 Jan 2020 17:28:00 +0000

The Cuckoo cohort of 2024 takes flight!

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Chapman, D.S., Gunn, I.D.M., Pringle, H.E.K., Siriwardena, G.M., Taylor, P., Thackeray, S.J., Willby, N.J. & Carvalho, L. Global Ecology and Biogeography 10.1111/geb.13051

Aim

Hotspots of human activity are focal points for ecosystem disturbance and non‐native introduction, from which invading populations disperse and spread. As such, connectivity to locations used by humans may influence the likelihood of invasion. Moreover, connectivity in freshwater ecosystems may follow the hydrological network. Here we tested whether multiple forms of connectivity to human recreational activities promotes biological invasion of freshwater ecosystems.

Location

England, UK.

Time period

1990–2018.

Major taxa studied

One hundred and twenty‐six non‐native freshwater birds, crustaceans, fish, molluscs and plants.

Methods

Machine learning was used to predict spatial gradients in human recreation and two high risk activities for invasion (fishing and water sports). Connectivity indices were developed for each activity, in which human influence decayed from activity hotspots according to Euclidean distance (spatial connectivity) or hydrological network distance (downstream, upstream and along‐channel connectivity). Generalized linear mixed models identified the connectivity type most associated to invasive species richness of each group, while controlling for other anthropogenic and environmental drivers.

Results

Connectivity to humans generally had stronger positive effects on invasion than all other drivers except recording effort. Recreation had stronger influence than urban land cover, and for most groups high risk activities had stronger effects than general recreation. Downstream human connectivity was most important for invasion by most of the groups, potentially reflecting predominantly hydrological dispersal. An exception was birds, for which spatial connectivity was most important, possibly because of overland dispersal capacity.

Main conclusions

These findings support the hypothesis that freshwater invasion is partly determined by an interaction between human activity and species dispersal in the hydrological network. By comparing alternative connectivity types for different human activities, our approach could enable robust inference of specific pathways and spread mechanisms associated with particular taxa. This would provide evidence to support better prioritization of surveillance and management for invasive non‐native species.

Associations between gamebird releases and general predators

VIOLA.ROSS-SMITH — Wed, 26 Jun 2019 15:47:20 +0000

The Cuckoo cohort of 2024 takes flight!

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Pringle, H., Wilson, M., Calladine, J. & Siriwardena, G.M. Journal of Applied Ecology 10.1111/1365-2664.13451

1. The release of more than 40 million captive-bred Pheasants and Red-legged Partridges in Britain annually represents a significant addition to the potential food resource base for predators and scavengers. If this extra food availability subsidises predator populations, gamebird releases could increase predation pressure on other wild birds, affecting their populations.

2. Using three extensive datasets, we examined the spatial relationships between reared and free-roaming gamebirds (Pheasant Phasianus colchicus and Red-legged Partridge Alectoris rufa), and explored spatial and temporal associations between these gamebirds and five species of avian predator (Buzzard Buteo buteo, Jay Garrulus glandarius, Raven Corvus corax, Magpie Pica pica, and Hooded Corvus cornix and Carrion Corvus corone Crows combined) in lowland rural Britain.

3. Patterns of spatial variation in the abundance of free-roaming gamebirds across Britain appear to be largely determined by gamebird releases, over and above any effects of land-use or habitat. Predominantly positive associations between gamebird abundance (both reared and free-roaming) and the abundance and inter-annual population growth rates of predators tested suggest that large-scale variation in avian predator populations may be positively affected by gamebird releases.

4. Synthesis and applications. The positive associations between large-scale gamebird release and predator populations shown here may have implications for prey populations that contrast with previously reported findings of positive effects of game management on wider biodiversity. Overall impacts of gamebird releases are likely to be determined by complex interactions between multiple factors, including induced predation pressure, better understanding of which would be possible with compulsory recording of releases and numbers of predators killed. Restriction of releases warrants further investigation and consideration as a potential conservation tool for wild bird populations.

This work would not have been possible without the vast amounts of data collected by volunteers.

This work was funded by Mark Constantine.

What effect might annual releases of non-native gamebirds be having on native biodiversity?Population change of avian predators and grey squirrels in England: is there evidence for an impact on avian prey populations?Environmental correlates of breeding abundance and population change of Eurasian Curlew <em>Numenius arquata</em> in Britain

Population estimates of wintering waterbirds in Great Britain

VIOLA.ROSS-SMITH — Fri, 08 Mar 2019 11:08:02 +0000

The Cuckoo cohort of 2024 takes flight!

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Frost, T.M., Austin,G.E., Hearn, R.D., McAvoy, S.G., Robinson, A.E., Stroud, D.A., Woodward, I.D. & Wotton, S.R. British Birds

Evaluating spatiotemporal trends in terrestrial mammal abundance using data collected during bird surveys

MIKETOMS — Sat, 04 Aug 2018 09:56:51 +0000

The Cuckoo cohort of 2024 takes flight!

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Massimino D., Harris S.J., Gillings, S Biological Conservation 10.1016/j.biocon.2018.07.026