Over the past few weeks, I’ve learned that there are a number of environmental and social concerns around the farming of cut-flowers- there are questions about pesticide and water use, about the impacts on families and communities, about poaching and introduced pests. But there are also quite a few organizations working to improve the conditions of workers and ecosystems, so I think that changes can be made. Some of that change can come from us, the consumers- we have power to influence what retailers want and how growers conduct their business- and there is more than one way to make our voices heard.
If you want to make sure that you are buying flowers that were ethically and sustainably grown, you can look for certification from one of a number of bodies- some of these sites will let you search for sellers of certified flowers:
• Veriflora
• Fairtrade International
• Florverde
• Flor Ecuador
• Sustainable Agriculture Network
• Fair Trade USA
You can also encourage flower sellers to participate in trade with certified growers through the organizations above and through Ethical Trading Initiative. Since many cut-flowers are grown in developing countries, pushing sellers to demand certified flowers helps both the environment and the workers, but part of the challenge is finding new and better ways to grow flowers- both Rainforest Alliance and Flower Valley Conservation Trust have projects to improve farming methods and expand the reach of sustainable farms.
And you may also want to consider looking into the slow flowers movement, which uses locally-grown, seasonal flowers- there are a number of sites that will help you find local growers:
• Field to Vase
• Slow Flowers
• Local Harvest
Above all, I think we need to get away from expecting that we can get perfect flowers of any type whenever we want them- by accepting flowers with leaf spots and recognizing that the natural world moves through seasons, we can change the pressures growers feel and help them move toward more environmentally- and socially-friendly practices that still allow them to succeed as a business.
In my last post I talked about some of the environmental concerns surrounding the cut flower industry, namely pesticides, water use, and the movement of parasites and diseases. While there are many other facets to growing flowers for bouquets, I want to highlight two other issues, both of which I think we can influence: wildflower harvesting and the social impacts of the flower trade.
While the majority of flowers we buy in stores are raised in greenhouses, it turns out that there is a flourishing trade in wildflowers as accent pieces or filler for bouquets. The challenge is to ensure that the harvest is sustainable. In some cases this means certifying that the flowers were not poached from protected areas– in Australia, for example, there is already a sustainable cut-flower industry for waratah flowers, the emblem of New South Wales, but poachers have been taking the blooms from wild stands even though it is protected (Beckers & Offord 2010). Along monitored transects up to 32% of flowers were lost, and there is concern for future populations because seeds don’t remain viable for a long time and new plants are only recruited to the population after wildfires, so fresh seeds need to be waiting. In other cases, we need to make sure that rates of harvest don’t reduce genetic diversity and outpace rates of growth. One of the challenges within the flower industry in general is that the industry itself has become more streamlined and simplified, with retailers (like Tesco or Sam’s Club) talking directly to growers and fewer, more standard varieties in cultivation, while at the same time there is public demand for novelty flowers (Heywood 2003), so suppliers keep looking to wild plants for the latest new thing. But if we overexploit wild populations and reduce both population size and genetic diversity, those wild stocks may not be able to survive and adapt to natural disasters, changing climates, or other challenges.
And the rapid expansion of cut-flower farming into developing countries has had social impacts. On the positive front, Newman (2002) reported that men and women in Ecuador who worked in the flower industry had less wage disparity between the sexes than workers in other industries, and married men in the flower industry did more housework than men in other industries. On the negative side, because wages can be based on individual production and flowers need attention 7 days a week, people may work long hours without gaining substantial returns, and in Ecuador Korovkin (2003) documented both a trend away from young women starting independent households and less time spent on childcare in general because parents aren’t paid high wages and work overtime. Plus, as I mentioned in my last post, there are high rates of pesticide exposure and, in addition to causing headaches and rashes, researchers have documented that women in the cut-flower industry can have problems with reproductive health (Handal & Harlow 2009).
At the start of this post, I mentioned that I thought we could have an influence on these issues, and I think we can get at both of these, plus the water-use concern, through voicing our opinions about how we want workers and ecosystems to be treated and by being willing to accept flowers that are not perfect, both in appearance and seasonality. A number of national and international organizations have been formed to address issues like pesticide and water use, worker’s rights, and sustainable harvesting of natural resources. Whether looking at Flor Ecuador, the Flower Valley Conservation Trust in South Africa, or the larger global entity of Fairtrade International, there are bodies that monitor and certify whether flowers are farmed in a responsible manner- we just need to pay attention to the symbols (Raynolds 2012). And we need to appreciate flowers with blemished leaves and accept that certain flowers may be unavailable during specific months- changing consumer expectations would allow more farms to utilize organic methods and reduce energy and water waste.
So there are problems with cut flowers, but also solutions- in my final post, I’ll see what I can find about how we can make a direct difference.
Works cited:
Beckers, D and CA Offord. 2010. Waratah theft in Brisbane Water National Park- an analysis of the blue paint poaching reduction program. Cunninghamia 11: 287-293.
Handal, A and S Harlow. 2009. Employment in the Ecuadorian cut-flower industry and the risk of spontaneous abortion. BMC International Health and Human Rights 9: 25.
Heywood, V. 2003. Conservation and sustainable use of wild species as sources of new ornamentals. Acta Horticulturae 598: 43-53.
Korovkin, T. 2003. Cut-flower exports, female labor, and community participation in highland Ecuador. Latin American Perspectives 30: 18-42.
Newman, C. 2002. Gender, time use, and change: the impact of the cut flower industry in Ecuador. The World Bank Economic Review 16: 375-395.
I had been a little worried that I wasn’t going to be able to find much research concerning the cut-lower industry, or that, if I did, it would all be about developing new varieties of popular flowers. In fact, I was surprised at the extent of the literature- researchers have been paying attention to multiple aspects of the industry for at least the last few decades. For this week, I’ll concentrate on the issues we might expect when thinking about cut flowers: pesticides, pests, and water use.
Growing beautiful flowers that people want to buy means making sure that they don’t show signs of diseases or parasites– in addition, flowers imported into the US and many other countries must be free of pests when checked at the border (Tenenbaum 2002). Since we don’t eat the imported flowers (generally), there aren’t always regulations limiting how much or what kinds of pesticides are used. A 1979 study testing flowers as they arrived in Miami found that 85% of samples had residue from at least one type of pesticide, and 16 different pesticides were found (Morse et al. 1979). Some of the samples even had levels that could cause reactions in people handling the flowers. According to a 2007 review, roughly 20% of the pesticides (insecticides, fungicides, herbicides, etc.) used for flowers in the developing world are either untested or not allowed for use in the US (Donohoe 2007). Simply saying that growers shouldn’t use pesticides is unrealistic- flowers are big business with sales hitting $30 billion in 2007, and it’s global trade that involves Holland, Columbia, India, Kenya, Malaysia, Mexico, and a number of other locations. But it’s very important to think about these issues- over 84% of workers in Bahong, Philippines reported going into recently sprayed areas (Lu 2005) and people applying pesticides on several farms in Uganda indicated that they did not have much access to protective gear (Munyuli 2014), plus those pesticides don’t just impact the people who work with them- they wash into rivers, affect non-target insects like bees, and can make their way into drinking water.
And it is important to keep floral pests from getting to new places. Chilli thrips are a big problem for rose growers in India and have been found in the US since 2005 (Mannion et al. 2013). Mannion et al.’s (2013) study in Florida found that regular fertilization of roses may make them important hosts for the thrips, which is important information- the thrips may like roses, but they attack at least 112 species of plants, including some that we use for food. Likewise, a fungus originally found in the US, Guatemala, and South Africa showed up on arum lilies in Brazil as a leaf spot disease (Vieira & Barreto 2004). As I’ve mentioned in my posts on invasive species, newly introduced species can overwhelm native communities and even cause species extirpation.
Water-use is another crucial aspect of the cut-flower industry where we face challenges. Fresh, clean water is becoming an ever-more scarce resource around the globe, and growing flowers both removes water supplies and releases water pollutants such as pesticides and fertilizer (Tenenbaum 2002). You might be surprised by the actual water impacts of growing flowers for sale- a study of Kenya’s Lake Naivasha area, where most of the country’s horticulture industry is based, found that the water footprint per rose flower stem was 7-13 liters– this includes both water used by the plant and water needed to absorb and dilute nitrogen run off from the farms (Mekonnen et al. 2012). That is a lot of water. When water use was compared with water input from precipitation and river flow, supply met demand only April-October per year. As might be expected, the lake level has decreased as surrounding horticultural activity has increased, and water quality in the lake has decreased as more and more nutrients are released into the waters.
So there are certainly concerns about how cut-flowers are farmed in terms of pesticide and resource use, plus we have to think about the global scale of the trade and all of the chances for nasty parasites and microbes to travel to new locations and wreak havoc. But the cut-flower industry also has social and political components, which I will look at next time. Plus I’ll describe how some groups and individuals have already recognized the environmental challenges and started working to mitigate the impacts.
Works Cited:
Donohoe, M. 2007. Flowers, diamonds, and gold: the destructive public health, human rights, and environmental consequences of love. Human Rights Quarterly 30: 164-182.
Lu, JL. 2005. Risk factors to pesticide exposure and associated health symptoms among cut-flower farmers. International Journ. of Envir. Health Research 15: 161-169.
Mannion, CM, Derksen, AI, Seal, DR, Osborne, LS and CG Martin. 2013. Effects of rose cultivars and fertilization rates on populations of Scirtothrips dorsalis (Thysanoptera: Thripidae) in southern Florida. The Florida Entomologist 96: 403-411.
Mekonnen, MM, Hoekstra, AY and R Becht. 2012. Mitigating the water footprint of export cut flowers from the Lake Naivasha Basin, Kenya. Water Resources Manag. 26: 3725-3742.
Morse, DL, Baker, EL and PJ Landrigan. 1979. Cut flowers: a potential pesticide hazard. Amer. Journ. of Public Health 69: 53-56.
Munyuli, BMT. 2014. Is the cut-flower industry promotion by the government negatively affecting pollinator biodiversity and environmental/human health in Uganda? ISRN Biodiversity 2014: 368953.
Tenenbaum, D. 2002. Would a rose not smell as sweet?: Problems stem from the cut flower industry. Environmental Health Perspectives 110:A240-A247.
Vieira, BS and RW Barreto. 2004. First record of Cercospora richardiaecola causing leaf spots on Zantedeschia aethiopica in Brazil. Plant Pathology 53: 813.
You can find flower bouquets that say they are environmentally responsible, but what does that mean?
When I started thinking about a blog topic for this month, I looked back through the posts from the last few months and noticed that my last four topics have centered on animals. Probably a good idea to show plants a bit more appreciation, and it is February after all- pictures of flowers are pretty common- so I started thinking about how little I know about the conservation challenges faced by flowering plants.
My goal is to look into the cut flower and nursery industry and see if I can get a better sense of how those impact natural communities, but I’m really not sure what I will find, if anything. It may turn out that I spend my time reading about threatened flower species instead, but we will see. I will do my best to keep the focus on the flower industry- definitely going where I have not gone before.
So, if you enjoy looking at, smelling, and handling flowers, hopefully this will be an informative month. If there are any particular elements of the flower industry that you have questions about, let me know and I’ll see what I can dig up.
Over the last few weeks I’ve described some of the problems facing colonial seabirds around the world (and some of them are pretty serious), but I’ve also pointed out that we are making progress at fighting some of these challenges. Birds in general get a lot of attention from researchers and the public- they are charismatic, some of them have adapted well to living side by side with us, and you don’t have to be a scientist to appreciate them- so they are also getting a lot of attention on the conservation front. This is great for seabirds, and also for us because it means that there are many ways we can get involved and help seabird populations.
Looking to help out without leaving the comfort of your computer?
• American Bird Conservancy has a petition to remove feral cats from nesting areas at Jones Beach in New York
• Pacific Seabird Group has a variety of policy letters just waiting for your signature
• You can also donate to a variety of organizations, including BirdLife, Forest and Bird, Alaska Sealife Center, and Southern African Foundation for the Conservation of Coastal Birds
Seen some seabirds on a birding trip?
• Ebird is just waiting to hear about all of the birds you saw
Planning a vacation and wondering if your trip could help birds in some way?
• Audubon’s Project Puffin in Maine has a visitor’s center and the Friends of Maine’s Seabird Islands run an art gallery- maybe Maine should be part of the itinerary
• There is a Caribbean Birding Trail that will help you use your tourist dollars in support of birds
• Trogon Tours and Cape Town Pelagics have single- and multi-day trips to expand your life-list and support conservation efforts
Want to take a more active role in seabird conservation?
• Seattle Audubon’s next Puget Sound Seabird Survey is February 6th and they would welcome your help
• If you are near Moss Landing, CA, the annual Mud Stomp to help create nesting habitat for western snowy plovers is coming up- register by March 29th
• Birds Caribbean has regular monitoring surveys, including right now until February 3rd
• Many of the organizations listed above also have volunteer and intern programs, as do the Kauai Seabird Habitat Conservation Program, the Maui Nui Seabird Recovery Project, Isles of Scilly Seabird Recovery Project, and the African Penguin and Seabird Sanctuary
Much like the seabirds themselves, this is a wide-ranging list of opportunities to get involved with seabird conservation, and I’m sure there are many other options I haven’t mentioned- if you feel like your area or interest isn’t represented here, a great place to start is by contacting your local Aubudon group- they are bound to have ideas!
In my post last week I talked about three of the big challenges facing colonial seabirds: habitat loss, invasive species, and changing food resources. I spent the last few days reading about ways to combat these problems, plus gaining insight on other issues related to seabird survival. The good news is that we are continually getting better information about what effects seabird populations, and often we can do something to help. The bad news is that they face a laundry list of problems.
Brown pelicans seem pretty happy to use the pond in front of a newly constructed back marsh area which will eventually fill in with plants and add area to a barrier island
When it comes to habitat loss, while we can’t always stop it in the first place (limiting development of an area is one thing, stopping sea level rise is totally different…) we have had success at creating new habitat for seabirds to use. Here in Louisiana (and elsewhere) material from dredging canals and harbors has been used by terns and skimmers (Mallach and Leberg 1999) since it is initially bare of vegetation- the problem, of course, is that plants eventually fill in the area, so the process needs to be repeated to keep creating habitat. Just about every island that I work on has had some type of restoration project and a variety of bird species, including brown pelicans, least terns, and spoonbills use these areas for nesting. And we’ve been able to create nesting habitat on a tiny scale as well– African penguins dig their own burrows, but islands that have been harvested for guano don’t have enough material for that, so the birds nest on open ground which puts eggs and chicks at risk from predators, high temperatures, and rain. When researchers put out artificial nest boxes on Robben Island, South Africa, penguin nesting success went up (Sherley et al. 2012).
We’ve also had some success at addressing the issue of invasive predators. Off the western coast of Mexico, eradication efforts starting in 1996 had removed invasive predators and herbivores (who trample soil and denude landscapes) from 26 islands by 2008 (Aguirre-Muñoz et al. 2008). By starting with islands that had smaller areas and fewer invasive species, projects helped build up knowledge for more complex situations. By 2008 at least 201 bird colonies had been protected at a cost of $58 per hectare for each invasive species removed- not bad, right? Of course, these successes depend on keeping those invasives from coming back, so educational campaigns were the next step in the process so that local people moving between the mainland and islands don’t reintroduce any species. A recent review of threatened seabird species suggested that, of 968 islands with threatened seabirds, 37% had invasive species (Spatz et al. 2014), so we’ve got a ways to go, but we’re definitely developing more effective strategies at removing the threat of invasive predators and herbivores.
The problem of changing food resources is a bit trickier to tackle. To begin with, some of those changes are happening in response to global changes in climate, so that’s a long-term process. In addition, we’re not exactly sure how flexible some birds are at changing foraging strategies or how they will compete with each other. There is an EU proposal to end fishery discards by 2019- previously discarded fish would be retained for use (Bicknell et al. 2013). While this would make the fisheries more sustainable, it would mean that birds currently utilizing discards would not have that food resource anymore. Generalists will probably be just fine- there are, after all, other fish in the sea. But specialists might be in trouble if the stocks they depend on have already been depleted. And there is concern that gulls and skuas may turn to more egg and chick predation. So, we’re going to have to see how this pans out.
Another seabird issue that was mentioned several times in the literature was light-induced mortality, especially for fledglings. For nocturnal species, urban lights can be disorienting and may draw birds away from the coast and into urban environments. In Hawaii, shearwater mortality has been reduced through dampening the lights by putting shields around them and a “Save Our Shearwaters” campaign which rescues and releases birds (Duffy 2010). Similarly on Reunion Island, a rescue program plus public education has reduced mascarene petrel mortality (Corre et al. 2003).
So seabirds are facing big challenges and we are getting better at understanding and meeting those challenges. Although some of these problems may seem very far away from us, there are bound to be ways that we can contribute to seabird conservation. In my final post of the month, I’ll take a look at our options.
Works cited:
Aguirre-Muñoz A, Croll DA, Donlan CJ, Henry III RW, Hermosillo MA, Howald GR, Keitt BS, Luna-Mendoza L, Rodríguez-Malagón M, Salas-Flores LM, et al. 2008. High-impact Conservation: Invasive Mammal Eradications from the Islands of Western México. AMBIO – J. Hum. Environ. 37:101–107.
Bicknell AWJ, Oro D, Camphuysen K (C. J., Votier SC. 2013. Potential consequences of discard reform for seabird communities. J. Appl. Ecol. 50:649–658.
Corre ML, Ghestemme T, Salamolard M, Couzi F-X. 2003. Rescue of the mascarene petrel, a critically endangered seabird of réunion island, indian ocean. The Condor 105:387–391.
Duffy DC. 2010. Changing seabird management in Hawai’i: from exploitation through management to restoration. Waterbirds 33:193–207.
Mallach TJ, Leberg PL. 1999. Use of dredged material substrates by nesting terns and black skimmers. J. Wildl. Manag. 63:137–146.
Sherley RB, Barham BJ, Barham PJ, Leshoro TM, Underhill LG. 2012. Artificial nests enhance the breeding productivity of African penguins (Spheniscus demersus) on Robben Island, South Africa. Emu 112:97–106.
Spatz DR, Newton KM, Heinz R, Tershy B, Holmes ND, Butchart SHM, Croll DA. 2014. The Biogeography of Globally Threatened Seabirds and Island Conservation Opportunities. Conserv. Biol. 28:1282–1290.
Over the last week I’ve gotten something of an around-the-world tour of seabird conservation- some of the papers have been reviews, which means that they combine information from as many studies as they can and provide a broad view of trends, while others were targeted at specific species. No matter which way you look at things, seabirds are facing some serious challenges- habitat loss, invasive species, changing food resources– but not every seabird species is in the same boat, so I think it’s worth looking at both sets of literature. (And I’d like to point out that there is an entire journal, Waterbirds, devoted to these species, so there are lots of people investigating these issues.)
These royal and sandwich terns nest in colonies on the edge of vegetation near the beach- once the chicks hatch, they form a creche on the sand where adults guard them
Given current rates of sea level rise, it’s probably not surprising that nesting seabirds are finding themselves in more and more restricted locations. Certainly here in Louisiana continued availability of nesting sites for pelicans and certain tern species is partially due to human efforts to restore island and marsh locations (Visser and Peterson 1994)- in my own study sites I have seen marsh areas expanded by adding a shell berm behind an island and then filling in the enclosed area with sediment and I have seen tons of sand piped onto eroding beaches. Because certain species prefer bare sand and shell areas for nesting (for example, black skimmers here in the Gulf or little terns in the Mediterranean), these birds automatically have limited nesting options because habitat that is bare this year could start filling in with vegetation the next. This is a natural process at the mouth of any river as sediment is deposited and then colonized by vegetation, but we’ve put some extra pressures on these systems. Researchers in the Po Delta of Italy suggested that accelerated loss of nesting habitat due to sea level rise and human use of the same areas means we should be continually creating new little islets for birds to use (Fasola and Canova 1996). In the Chesapeake Bay area, improved prevention of storm breaches at some islands has limited the creation of new tidal shoal areas for nesting (Brinker et al. 2007). And habitat loss isn’t connected to just nesting opportunities– Kittlitz’s murrelets in Alaska forage in areas directly around glaciers, perhaps because the mixing of horizontal water layers concentrates food resources (Kissling et al. 2007), so disappearing glaciers means less foraging habitat.
I’ve mentioned the challenges posed by invasive species many times- with seabirds we are often looking at birds that nest on the ground or in burrows or crevices, so invasive predatory mammals represent a particular threat. When breakwaters connected an island off the coast of Chile with the mainland, a variety of land mammals, including rats and rabbits, made the journey across (Simeone and Bernal 2000)- when feral dogs took up residence, they killed at least 35 adult Humboldt penguins. A study on Reunion Island suggested that the introduction of cats had had massive impacts on the endemic Barau’s petrel- they calculated that 10 cats could kill up to 900 petrels in a year and 58% of recorded kills were adult birds, which makes it an even bigger issue (Faulquier et al. 2009). Why does the high number of dead adults make it worse? Seabirds tend to be long-lived species that are slow to mature and have small clutches (maybe 1-2 eggs)- like us, they are k-selected species. Since chicks fall victim to a variety of deaths, including predation, starvation, and weather-related mortality, a pair of breeding adults typically needs to have several different breeding seasons before they succeed in raising two young which can replace them. Another few seasons are needed to raise enough young to expand the breeding population. When adults experience high mortality, there aren’t enough new breeders to make up for the losses. Of course, when predators are numerous enough, it doesn’t matter if they don’t focus on adult birds- a study in British Columbia found that introduced rats living near a colony of nesting ancient murrelets were feeding almost exclusively on eggs and chicks, with probably some vegetation thrown in (Hobson, Drever, and Kaiser 1999). Not surprisingly, the population of murrelets had dropped more than 90% in less than 4 decades.
When it comes to finding adequate food for themselves and their chicks, many seabirds face a world that is changing. Increased water temperatures connected to the North Atlantic Oscillation are linked to more herring and less capelin in the North Atlantic- more herring seems to have a positive effect on several guillemot species, but is not a good situation for kittiwakes who depend more on capelin (Sandvik et al. 2005). Since sea temperatures are predicted to increase in the future, we may also see that herring populations expand at the expense of capelin, and that scenario, with different fish species, has also played out in the Gulf of Alaska (Osterblom et al. 2008). Why are dietary substitutions a concern? If the fish being substituted do not meet the dietary requirements of the birds or their growing chicks, adult survival and nesting success may be compromised (in the same way that eating only lettuce because hornworms got your tomatoes, eggplants, and peppers, is probably not going to give you all of the nutrients from vegetables that you need). And seabirds are also impacted by our fishing activities. In previous posts I’ve talked about sustainable seafood (see All at Sea), so I’m not going to get into all of that here, but our fishing gear, such as long-lines and gillnets, can catch or trap and drown birds, and overfishing of some stocks had has a negative impact on chick survival, for example with Atlantic puffin and herring stocks in Norway (Tasker et al. 2000). At the same time, it’s important to point out that many bird species have also figured out that our fisheries are a good source of food, since unwanted catch is thrown back- at least 23 species were documented using bycatch off the coast of Patagonia by Yorio & Caille (1999), so it’s not all bad.
Seabirds face other threats, too, such as hunting or egg-collecting, but the big ones revolve around habitat loss, predation from invasive species, and changes in fish stocks. As you can imagine, researchers, in addition to documenting these issues, have been investigating possible solutions and options for supporting seabird populations around the world. For my next post, I’ll dive into that literature.
Works cited:
Brinker DF, McCann JM, Williams B, Watts BD. 2007. Colonial-nesting seabirds in the Chesapeake Bay region: where have we been and where are we going? Waterbirds 30:93–104.
Fasola M, Canova L. 1996. Conservation of gull and tern colony sites in northeastern Italy, an internationally important bird area. Colon. Waterbirds 19:59–67.
Faulquier L, Fontaine R, Vidal E, Salamolard M, Le Corre M. 2009. Feral cats Felis catus threaten the endangered endemic Barau’s petrel Pterodroma baraui at Reunion Island (Western Indian Ocean). Waterbirds 32:330–336.
Hobson KA, Drever MC, Kaiser GW. 1999. Norway rats as predators of burrow-nesting seabirds: insights from stable isotope analysis. J. Wildl. Manag. 63:14–25.
Kissling ML, Reid M, Lukacs PM, Gende SM, Lewis SB. 2007. Understanding abundance patterns of a declining seabird: implications for monitoring. Ecol. Appl. 17:2164–2174.
Osterblom H, Olsson O, Blenckner T, Furness RW. 2008. Junk-food in marine ecosystems. Oikos 117:967–977.
Sandvik H, Erikstad KE, Barrett RT, Yoccoz NG. 2005. The effect of climate on adult survival in five species of North Atlantic seabirds. J. Anim. Ecol. 74:817–831.
Simeone A, Bernal M. 2000. Effects of habitat modification on breeding seabirds: a case study in central Chile. Waterbirds 23:449–456.
Tasker ML, Camphuysen CJ (Kees), Cooper J, Garthe S, Montevecchi WA, Blaber SJM. 2000. The impact of fishing on marine birds. J. Mar. Sci. 57:531–547.
Visser JM, Peterson GW. 1994. Breeding populations and colony site dynamics of seabirds nesting in Louisiana. Colon. Waterbirds 17:146–152.
Yorio P, Caille G. 1999. Seabird interactions with coastal fisheries in northern Patagonia: use of discards and incidental captures in nets. Waterbirds 22:207–216.
As we start 2016, I’m trying to be more conscious of conservation issues that I interact with on a regular basis but might not really spend a lot of time contemplating in detail. For example, I know that carbon dioxide emissions are a major cause of global warming, so I try to turn off lights when they aren’t in use and put on an extra layer when it’s cold outside to reduce energy consumption, but it took me a good chunk of time to really think about how many freezer bags I use once and then toss when I’m storing and then cooking food.
Spoonbills are beautiful birds that seem a bit wary of human presence- perhaps they have a good reason?
So much of my work concerns systems on the very edges of Louisiana- barrier islands and beaches that are constantly changing and being lost a bit at a time to erosion, subsidence, and sea level rise. I focus on the carnivores that survive in this dynamic landscape, but many more people are interested in the colonial seabirds that nest and/or winter on the shore- pelicans, terns, plovers, egrets- many different birds with a variety of food sources, behaviors, and habitat needs. But all of them utilize a coastal zone that is steadily disappearing- they share what remains with predators, prey, and lots of human activity. Under those conditions, it seems reasonable to wonder how they are faring, so this month I will be looking at the survival of colonial seabirds here in Louisiana and around the world.
Based on my time in the field, I know that some seabird species like to nest in trees and shrubs, while others prefer beach areas. I also know they can be very loud, messy, and quick to defend the colony if they feel threatened. I know that Louisiana regularly surveys colonies and wintering areas to count birds and nests, and there are several island and beach restoration projects in the areas where I work which were created, in part, to provide more or better nesting habitat- all of this attention suggests that there are concerns about colony survival. Certainly I have seen some nesting islands all but disappear over the course of three years in the field under the constant onslaught of wind and water, so I can understand the concern. But is it all about nesting locations or places to rest on the beach? What about food supplies, invasive species, or seclusion from humans?
This month I want to better understand the issues facing colonial seabirds where I live and around the world, to really consider the situation facing birds I see all of the time and what I can do to strengthen their hand.
It’s easy to pay attention to the spiders around you when their webs are this obvious!
In my previous post I said I was going to look into ways to get involved in spider conservation- I’ve done that, and there are definitely ways to get involved, but not in the same numbers that I usually see with other conservation topics. My guess is that spider conservation is both relatively new and working against generally negative public attitudes toward spiders.
So what can you do to get involved? How up close and personal do you want to get?
• Perhaps you’d prefer to keep them at a distance? You can donate to support Ladybird spider conservation in the UK or to support black purse-web spiders in Canada
• Looking to better recognize the spiders in your garden and give them a place to live?o There are a number of on-line resources for spider identification, including for spiders in southern Africa, the US Midwest, and Europe, just to name a few
o Buglife provides information on wildlife-friendly gardening, including projects
o Canadian Wildlife Federation has suggestions for specific plants that will support goldenrod spiders
• Perhaps you enjoy spending time in caves and want to limit your impact on cave-dwelling spiders and other wildlife? Check out the Southeastern Regional Association of the National Speleological Society’s info on cave conservation
• Want to hang out with spider experts and learn from them?
o In Australia the Friends of Mount Majura are hosting a Spiders at Night walk on January 8 (spending more time with spiders could be a New Year’s resolution…)
o The American Arachnological Society’s next big meeting is in Colorado in July
• Thinking you’d like to do a bit more to contribute to conservation science?
o The British Arachnological Society has a spider and harvestmen recording scheme that needs public participation
o There’s also a spider survey in Colorado looking for help
I know that, in other posts about ways to contribute to conservation efforts, I have usually provided a longer list with a greater variety of opportunities- I’m sure there are more spider-centric activities out there, it just takes a bit more digging. And maybe, if there isn’t one near you to connect with, this coming year is the perfect time to start something- contact a local university, zoo, or nature center, and see where the conversation leads!
As I mentioned in my last post, we are still very much in the beginning stages of understanding spider conservation. At this point, it may be that we can really only speak to general trends, rather than specific conservation situations, but certainly we’ve got a starting point.
Spiders are particularly sensitive to vegetative structure, meaning how tall and thick vegetation is, as well as which plant species are present, and part of that sensitivity seems to relate to how they respond to unstable environments. Hogg and Daane (2011) found that, while non-native spiders tended to have a relatively constant abundance throughout California vineyards, native spider abundance decreased with distance from the surrounding woodlands. They suggested that the more stable conditions in the woodlands provided better habitat for native spiders. A study in Switzerland also suggested that more stable habitats, such as sections of land that are left fallow for several years, may provide important over-wintering habitat for spiders who later spread into adjacent disturbed areas (Schmidt et al. 2008).
The horizontal streaks of silver are from spiders riding the wind in western Kentucky- ballooning in December…
Those fragments of undisturbed, or less-disturbed, habitat may be very important in maintaining spider diversity over the long-term– a study in Brazil found that local spider abundance was generally low across the study area and suggested that spiders may be slow, overall, to recolonize areas (Pinto-Leite, Guerrero, & Brazil 2008). In South Africa, Gaigher and Samways (2014) found that natural habitat fragments were relatively rich in rare spider families and species. Getting out of those refugia and into new areas is another important part of the spider diversity puzzle. When roadsides in France with and without hedgerows were compared for spider abundance and species diversity, the presence of hedgerows was significantly tied to the group of spider species found in a location (Le Viol et al. 2008). Spiders that use their own locomotion to disperse were more common in roadsides with hedgerows, while spiders that hitch a ride on animals or the wind were more common in roadsides without them. (Hunting method was also connected to vegetation- webs in places with hedgerow, ground foragers in places without them.) If the presence of hedgerows can influence the spider community so much, it’s worth thinking about all of the ways that we (and other forces) alter the vegetation around us.
So, let’s say that a spider species has been negatively impacted by a change in vegetation- can we do something to reverse that trend? If loss of plant structure and leaf litter is the issue (meaning, do we mow and till the area?), we can set aside strips as refuges and, if the field has several distinct zones of vegetation, try to set up tracts that are perpendicular to the plant zones (Cattin et al. 2003). If the issue is invasion by alien vegetation, a study from South Africa suggests that physically removing the plant makes an immediate difference (Mgobozi, Somers & Dippenaar-Schoeman 2008). However, if that removal program uses surfactant sprays to apply herbicides to plants, we need to rethink our strategy- a study in New Zealand found that, while the herbicides used to control invasive lupins were not fatal to spiders, the surfactants used to get the herbicides to stick to plants had a spider mortality rate of about 30% (Evans, McCaw & Beggs 2009).
The strategies mentioned above are ones that can be used on a variety of scales, from entire preserves to one’s own back yard- there probably other ways we can support spider species, too, so my final post for the month will look in that direction.
Works cited:
Cattin, M-F, Blandenier, G, Banasek-Richter, C and L-F Bersier. 2003. The impact of mowing as a management strategy for wet meadows on spider (Araneae) communities. Biol Conserv 113: 179-188.
Evans, AM, McCaw, J and W Beggs. 2009. Could herbicide used to control alien weeds be harming threatened New Zealand spiders? J. Appl. Entomol. 133: 767-770.
Gaigher, R and MJ Samways. 2014. Insect Conserv and Diver 7: 470-479.
Hogg, BN and KM Daane. 2011. Ecosystem services in the face of invasion: the persistence of native and nonnative spiders in an agricultural landscape. Ecol. Appl. 21: 565-576.
Le Viol, I, Julliard, R, Kerbiriou, C, de Redon, L, Carnino, N, Machon, N and E Porcher. 2008. Plant and spider communities benefit differently from the presence of planted hedgerows in highway verges. Biol Conserv 141: 1581-1590.
Mgobozi, MP, Somers, MJ and AS Dippenaar-Schoeman. 2008. Spider responses to alien plant invasion: the effect of short- and long-term chromolaena. J. Appl. Ecol. 45: 1189-1197.
Pinto-Leite, CM, Guerrero, AC and TK Brazil. 2008. Non-random patterns of spider species composition in an Atlantic rainforest. J. Arach. 36: 448-452.
Schmidt, MH, Rocker, S, Hanafi, J and A Gigon. 2008. Rotational fallows as overwintering habitat for grassland arthropods: the case of spiders in fen meadows. Biodivers Conserv 17: 3003-3012.
