Local Funding Helps Pond Take Shape
Wildlife conservation charity, Froglife has now completed a programme of work to create a wildlife area around an existing pond, with a £500 grant awarded by the WestRaven Big Local Community Grant at the WestRaven community garden in Ravensthorpe.
The creation of the wildlife area and pond area (additional larger pond is part of future work due to take place later this year) is a valuable asset to the community garden by providing an educational tool for local residents and other users of the garden including young people taking part in Froglife’s BBC Children in Need funded Green Pathways project. Froglife aims to teach as many people as possible about the extensive biodiversity and benefits of a simple garden pond and providing habitats for local wildlife.
Green Pathways is a youth project providing practical outdoor activities with young people aged 5-18 in Peterborough, Northamptonshire and the Fenland district. The project supports those with extra difficulties in their lives to improve green spaces for wildlife and people; and learn about and enjoy the environment.
By raising awareness of ponds and demonstrating what a great feature they are in a garden Froglife aims to inspire local people to create their own ponds at home. Froglife also hope to encourage people to get outside and become more active, as this has proven to reduce stress, improve mental health and enhance fitness. This project will benefit local residents as well as teaching good habits to the next generation for a healthier future.
The funds awarded have been used to buy materials to make wildlife homes, provide additional fencing, and enhance the existing fencing around the pond site. It has also been used to purchase two benches so people can sit and relax and enjoy this much improved area. The construction and painting of the wildlife homes, bench and the fencing has all been carried out by young people on the Green Pathways project.
“The children have really enjoyed assembling the benches, and changing them from plain brown to the multi-coloured eye-catching design they are now” said their teacher Adam Billitt
“We got to use a saw and a drill to make a bird box which was great and then we painted pictures on that we thought would attract the birds” said one of the young people
“It’s great to teach the young people new skills and make a huge difference to wildlife and a community at the same time” said Froglife’s Learning Officer
To find out more about the Green Pathways Project visit: http://www.froglife.org/what-we-do/green-pathways/peterborough/
Volunteering at Froglife
Alice recently spent two weeks volunteering full time with Froglife. Here she recounts her experiences.
Day 1 and 2
My two-week long placement at Froglife began with a general introduction to the charity and a tour of the Hampton Nature Reserve. While at Hampton I saw how the reserve was managed to protect threatened native species such as the Great Crested Newt and Bearded Stonewort.
Bearded Stonewort thrives in newly scraped ponds, I saw first-hand the progression of growth in a series of ponds that were created at different times. I also considered the challenges of creating and maintaining ponds in a large and rugged site.
While touring the site I noticed mats placed around the reserve which are used during reptile surveys. I also saw specially created basking pits for reptiles and strategically placed clearings, allowing reptiles to bask on the south bank.
Reserve design is a topic that I have covered extensively at university. The fragmentation of natural environments can isolate populations, which leads to inbreeding and a reduction in the fitness of a species. Hampton Nature Reserve is split by a road. Special tunnels have been built to allow reptiles and amphibians to migrate, and the success of the tunnels is monitored using camera devices. During my visit I was able to view these tunnels and while in the office I am going to be working with the camera data.
Hampton Reserve cannot be accessed by the public but there are still conflicts with the local community such as vandalism and littering. This caused me to reflect on a previous work experience at Walsall Countryside Rangers. In a publicly accessible reserve the local community fly tipped and burned waste causing extensive damage and resulting in an intervention by the fire service. Local community engagement is a complex task faced by any conservation organisation. Froglife is tackling this by increasing its use of social media, and inviting community groups onto the reserve to volunteer.
My time at Froglife will be divided between Hampton Nature Reserve, the main office and community events. While at the office I am going to be working with data from the tunnel cameras and from the long running Toads on Roads project. This project monitors common toads, which migrate along roads during the breeding season and are often harmed by vehicles. Signs and physical crossing assistance can be used to reduce toad fatality.
Day 3
Today I was helping with the Dragon Finder fun day at Lyveden New Bield. This community engagement event involved making masks, pond dipping and a quiz trail. Around 130 people visited and many people asked for more information about upcoming events.
During pond dipping, local children caught and identified a variety of aquatic invertebrates. Particular highlights included a dragonfly larva, a duck leech and damselfly nymphs.
Day 4
Yesterday I assisted with a reptile survey on Hampton nature reserve. This is the first time I have surveyed for reptiles, and I learnt a lot about reptile identification. During the day I saw slow worms, common lizards and grass snakes, at many different life stages. I also saw a wide variety of invertebrates, plants and a wood mouse.
The survey was conducted using a series of mats placed around the reserve. The mats were lifted and any reptiles found underneath were recorded. We also recorded any reptiles found in the immediate area. Any interesting species and potential dangers such as cats were also recorded.
Day 5 and 6
I have spent the previous two days of my placement in the office, familiarising myself with current literature on reptiles and amphibians. I read a particularly interesting paper about the effect of historical and current land use on amphibian populations. Environments with a long history of agriculture often have lower land quality, reducing the diversity of species present. Areas which have a history of local forest cover have a higher level of species diversity, and have more common toads. I also read a paper concerning the introduction of an invasive marsh plant that was destroying the breeding habitat of Fowler’s toads in Canada. There was sufficient adult habitat but the species declined as it was unable to breed successfully. These two papers showed the effects of habitat loss in human altered environments.
I have also increased my knowledge of UK conservation by finding contacts with ecology and herpetology backgrounds. This is to assist Froglife in finding others interested in collaborating with their camera trap research.
During my lunch break I also got the opportunity to visit Froglife’s allotment. Many different community groups work on this site, including young offenders and it has been improved recently by the addition of a new path. While here I have been able to see newly created ponds, and ponds at various stages of construction. This has enabled me to consider some of the challenges of setting up appropriate amphibian environments, such as selecting the right plant species and preventing algal blooms.
Day 7 and 8
Due to the rain yesterday, the butterfly survey was rearranged for today. The survey took place at Hampton Nature Reserve and the sunny weather meant that lots of butterflies were visible. Our team surveyed the entire site for butterflies and moths, this covered different habitat types such as woodland and scrub.
My surveying skills progressed quickly due to the expertise of the other volunteers. I was able to distinguish between different types of white butterfly using the presence of green veins and the colouring of the wing tip. Species such as the small heath, the speckled heath, the small white and the meadow brown were common sightings. We also saw red admirals, commas and peacocks.
Day 9
Today is my last day at Froglife, and I am in the office finishing all of my online tasks.
I am reflecting on the last two weeks and all of the new experiences I have had. It had been three years since I last performed a survey, over the last two weeks I have gained a vast amount of knowledge on reptile and butterfly identification. I have seen my first grass snake and learnt the names of butterflies and plants that I have seen countless times.
While at the office I have improved my computer skills and found some useful websites to gather historic data. I have learnt how to more effectively summarise scientific literature and I have enjoyed expanding my knowledge on reptile and amphibian ecology.
During my time out of the office I have met many new people with different expertise and backgrounds. I have also worked with members of the public, and taught young children about wildlife. The soft skills that I have developed such as living alone in a new city and forming relationships with colleagues will prepare me well for life after university.
Croaking Science: Chemical communication in frogs and toads
Chemical communication in frogs and toads
The use of chemical communication to facilitate courtship in salamanders and newts is well recognised. Since anurans (frogs and toads) predominantly use acoustic cues during courtship, the use of scent has previously been thought of as a less important form of communication. However, studies over the past two decades have shown that chemical cues are more important than was first realised in the lives of frogs and toads.
During the breeding season of frogs and toads, the male will often form amplexus with the female and to help facilitate a grip on the female’s back, male frogs develop keratinized, often spiny nuptial pads on their thumbs and forearms. Glands are present below the surface of the nuptial pads and these release a secretion onto the keratinized surface of the nuptial pads. It has been proposed that these produce glue-like substances to enhance the male’s grip on the female. In addition, they may also act as attractant pheromones for reproduction. A recent study on the common frog (Rana temporaria) has shown that these chemicals serve a purpose in reproduction. Willaert et al. (2013) have found that chemicals known as amplexins are secreted at the surface of the male’s nuptial pad, probably during amplexus. The small spines on the male’s nuptial pad causes wounds on the female and these may allow the secreted molecules to seep directly into the female’s circulatory system. Such a direct delivery of protein pheromones into the circulatory system is only known from some species of plethodontid salamanders from North America. In these species, males develop a special gland during the breeding season which they use to rub pheromones into the female’s skin. It is therefore possible that delivery of pheromones through the skin is more common than initially thought within anurans.
Chemical communication may be used to serve different purposes during courtship in anurans. The anuran family Hyperoliidae (reed frogs) is common in sub-Saharan Africa, Madagascar, and the Seychelles, and consists of over 200 species in 18 genera. Reed frogs develop a colourful gular patch on their vocal sac during the breeding season. The vocal sac is used to produce advertisement calls and results from experimental work on reed frogs by Starnberger et al. (2013) has shown that the colourful gular patch produces pheromones (Figure 1). This study confirmed the presence of volatile pheromones in the gular patch on the vocal sac of reed frogs from several of the genera known at present including the most species-rich ones (Hyperolius, Afrixalus, and Heterixalus). Starnberger et al. (2013) propose that the male produces volatile substances that are emitted while he is calling and these circulate in the air to attract females, and/or to keep rival males at a distance. Male reed frogs often call from females in mixed groups with other closely related species. Starnberger et al. (2013) propose that advertisement calls alone may not be sufficient for females to sufficiently identify males from their own species. Therefore the additional chemical cues emitted in the form of pheromones may aid in species recognition.
Male dwarf African clawed frogs (genus Hymenochirus) have also been observed to have an ability to attract females using pheromones. Members of this genus are highly aquatic and endemic to central Africa, occupying slow-moving water bodies within areas of rainforest. As with many other male frogs and toads, individuals within the genus Hymenochirus possess skin glands during the breeding season. The importance of these has remained unknown for many decades. However, Pearl et al. (2007) have found that the breeding glands of male dwarf African clawed frogs (Hymenochirus sp.) release a mate-attractant chemical. In an experimental y-maze, females showed a positive response to water housing males and to water containing homogenized breeding glands. Results from this study were among the first to demonstrate a mate-attractant function for anuran breeding glands. Since many anuran species possess breeding glands, these results suggest that pheromone communication could be more widespread among frogs and toads than previously believed.
Since this discovery in 2007, further research has focused on searching for other anurans which use chemical signals. In the Mantelline subfamily of Mantellid frogs, males have enlarged femoral glands that cluster on their ventral thighs (Figure 2). An analysis of macroglands from several Mantelline species by Veneces et al. (2007) found species specific differences in the volatile compounds. The authors suggested that the chemicals help the frogs identify individuals of the same species in multi-species choruses. These and similar studies are adding to our knowledge and understanding of how anurans use chemical signals. The chemical systems used by amphibians are varied and complex and future research should look at further investigating the use of chemicals in anuran reproduction.
References
IUCN SSC Amphibian Specialist Group. 2014. Hymenochirus boettgeri. The IUCN Red List of Threatened Species 2014: e.T58154A18396612. http://dx.doi.org/10.2305/IUCN.UK.2014-3.RLTS.T58154A18396612.en. Downloaded on 08 September 2017.
Pearl, C.A. Cervantes, M., Chan, M., Ho, U., Shoji, R. and Thomas, E.O. (2007) Evidence for a mate-attracting chemosignal in the dwarf African clawed frog Hymenochirus. Hormonal Behaviour, 38 (1): 76-74.
Starnberger, I., Poth, D., Peram, P.S., Schulz, S., Vences, M., Knudsen, J., Barej, M.F., Rödel, M-O., Walzl, M. and Hödl, W. (2013) Take time to smell the frogs: vocal sac glands of reed frogs (Anura: Hyperoliidae) contain species-specific chemical cocktails. Biological Journal of the Linnean Society, 110 (4): 828–838, https://doi.org/10.1111/bij.12167.
Willaert, B., Bossuyt, F., Janssenswillen, S., Adriaens, D., Baggerman, G., Matthijs, C., Paulsels, E., Proost. E., Raepsaet, A., Schoof, L., Stegan, G., Treer. D., Van Hoorebeke, L., Vanderbergh, W. and Van Bocxlaer, I. (2013) Frog nuptial pads secrete mating season-specific proteins related to salamander pheromones. The Journal of Experimental Biology, 216: 4139-4143.
Vences, M., Walh-Boos, G., Hoegg, S., Glaw, F., Spinelli Oliveira, E., Meyer, A. & Perry, S., 2007. Molecular systematics of mantelline frogs from Madagascar and the evolution of their femoral glands. Biological Journal of the Linnean Society, London, 92: 529–539.
Woodley, S. (2015) Chemosignals, hormones, and amphibian reproduction. Hormones and Behaviour, 68: 3-13.
Inspired by Nature: Snakes!
Froglife Volunteer and Wildlife Artist, Samantha Marais, is adding to her ongoing species drawing collection this month with the UK Snakes.
Grass Snake (Natrix natrix)
Grass Snakes are found throughout England and Wales but are absent from Scotland. They’re quite often seen in gardens, especially those with ponds which the snakes can hunt in. Grass Snakes are quite timid, often feigning death if disturbed; alternatively they may excrete a foul-smelling liquid. They are our longest native snake and can reach 150cm. Find out more.
Adder (Vipera berus)
Adders are found throughout Britain, right up to the north of Scotland, but their secretive nature and camouflaged markings mean they often go unnoticed. This can sometimes be a good thing – as the only venomous snake in the UK they have often been persecuted in the past. Adder bites are painful but rarely fatal and usually only occur if the snake is disturbed or deliberately antagonised. Adders are a sturdy looking snake and are easy to distinguish from the other native species. Find out more.
Smooth Snake (Coronella austriaca)
The Smooth Snake is the UK’s rarest reptile and is only found on the heathlands of Dorset, Hampshire, Surrey and West Sussex. Their name comes from the fact the scales are smooth and flat, unlike the Grass Snake’s and Adder’s scales which have a ridge down the middle. They are a shy, secretive snake. Find out more.
Croaking Science: Biparental care and the evolution of monogamy in amphibians
Biparental care and the evolution of monogamy in amphibians
Monogamy, the mating system of only having one partner at a time, is generally rare within the animal kingdom and largely restricted to birds. Social monogamy is applied to pairs that remain together throughout their lives, but do not necessarily mate exclusively with one partner. Approximately 90% of birds are described as socially monogamous for although these pairs will remain with the same partner for life, many will seek to mate with other partners. Genetic monogamy, which refers to exclusive mating between two pairs, is rare within vertebrates. For example, only 25% of socially monogamous bird species are actually genetically monogamous. The evolution of genetic monogamy has been of interest to biologists for many decades and it is thought that biparental care, where both parents look after the offspring, has been an important factor in driving the evolution of monogamy. In species where biparental care is crucial for the offspring survival, working together results in greater survival of the young and greater reproductive output.
Parental care is generally rare within the amphibians and paternal care is considered to be the first form of parental care to have evolved. This is in contrast to birds and mammals, where maternal care appears to have evolved first. Within the amphibians parental care is often associated with tropical terrestrial species, particularly poison dart frogs belonging to the genus Ranitomeya. After females have laid their small clutches of eggs the males often carry the eggs to phytotelmata (pools of water in the axils of tree-dwelling plants) and exhibit egg-guarding. Biparental care has subsequently evolved where by females may lay non-fertile (or trophic) eggs in these small bodies of water to feed developing larvae. Known as trophic feeding, this form of maternal care has been reported from a range of terrestrial breeding tropical frog species and within the Ranitomeya, is associated with larvae developing in very nutrient poor, small bodies of water.
Recent research has shown that where biparental care has evolved in amphibian species, this has also resulted in the evolution of genetic monogamy. Prior to 2010, social and genetic monogamy had not been recorded in any species of amphibian. However, research by Brown et al. (2010) documented that social and genetic monogamy occurs in the mimic poison frog (Ranitomeya imitator) (Figure 1). This species occurs in north-central Amazonian Peru, in the regions of Loreto and San Martín and occurs in rainforest habitats between 200 and 1,200 m (Figure 2). Following courtship, the female mimic poison frog lays arboreal clutches of 1–3 eggs on understorey vegetation. The male guards the egg clutches and transports individual tadpoles on their backs to small phytotelmata. The female then lays trophic eggs into the water to provide food for the developing larvae. In an experimental study, Brown et al. (2010) found that 11 out of 12 pairs investigated showed genetic as well as social monogamy by the use of molecular markers. However, the closely related R. variabilis shows no monogamy and is highly promiscuous. In this species the male provides parental care but the female does not provide trophic eggs. Pairs preferred larger pools for tadpole deposition which contain higher levels of nutrients so additional trophic feeding by the female is less required (Brown et al., 2008). It appears that small pool size with low nutrient levels is crucial in driving the evolution of biparentral care and monogamy in species of poison dart frogs. Brown et al. (2010) experimentally confirmed the importance of trophic feeding by showing that tadpoles denied trophic eggs had lower growth rates than controls. Further experiments by Tumulty et al. (2016) demonstrated a significant reduction in reproductive success when males were removed after tadpole deposition, establishing the importance of male care for tadpole growth and survival throughout development. Therefore, because R. imitator breeds in small, low-nutrient waterbodies, both males and females are required to provide parental care. This requirement for active parental care from both the male and female appears to have driven the evolution of genetic monogamy and stable pair bonds in this species.
Many studies have shown that there are many advantages to biparental care but the high occurrence of extra pair matings, particularly in birds, indicates that there are many genetic advantages to having more than one mate. Therefore, why is the poison mimic frog so exclusively monogamous? The answer seems to lie in the importance of both male and female parental care in the pair bond. Experimental work on species where both partners are crucial for the survival of the young show that monogamy is strong, whereas in species where one partner is not obligatory, the level of monogamy is often weaker. This correlation suggests that genetic monogamy may be favoured when both male and female care is required for offspring survival. Results by Tumulty et al. (2016) indicate this to be the case in R. imitator, which has low rates (8.3%) of extra pair matings.
Overall, the biparental care hypothesis for promoting evolution of monogamy is gaining support from a variety of taxonomic groups and results from recent studies indicate that R. imitator shows a highly stable and cooperative long-term association between male and female and both care mutually for their offspring. The selection for long-term biparental care, as required by the demands of small, low nutrient pool size has driven the evolution of social and genetic monogamy in R. imitator.
References
Tumulty, J., Morales, V. & Summers, K. (2014) The biparental care hypothesis for the evolution of monogamy: experimental evidence in an amphibian. Behavioral Ecology, 25 (2): 262–270.
Brown, J.L., Morales, V. & Summers, K. (2008) Divergence in parental care, habitat selection and larval life history between two species of Peruvian poison frogs: an experimental analysis. Journal of Evolutionary Biology, 21: 1534–1543.
Brown, J.L., Morales, V. & Summers, K. (2010) A key ecological trait drove the evolution of biparental care and monogamy in an amphibian. The American Naturalist, 175 (4): 436-446.
IUCN SSC Amphibian Specialist Group (2014) Ranitomeya imitator. The IUCN Red List of Threatened Species 2014: e.T56378936A43715994. http://dx.doi.org/10.2305/IUCN.UK.2014-1.RLTS.T56378936A43715994.en. Downloaded on 11 August 2017.