TOAD CONSERVATON Saving toads in Henley-on-Thames Angie Julian (ARG UK/OxARG), Angelina Jones, John Sumpter (Henley Toad Patrol) www.arguk.org
The Henley-on-Thames toad crossing • Situated on the A4155 Henley-Marlow Road near Henley Business School. • Toads crossing for around 8 weeks from early Feb onwards (weather dependent). • 90 volunteers on the database (from 18 - >70 years). • 2- 25 volunteers per night. • In 2018: 6,021 toads, 681 frogs and a record-breaking 496 smooth newts were transported. • To find out more contact Angelina Jones (amtjones@googlemail.com).
Toads migrate from their winter hibernation grounds through woodland to reach their ancestral breeding pond in early Spring
Toads cross the busy A4155 on their journey – this coincides with ‘rush hour’ on a busy alternative route from Reading/Henley to Marlow and the M40
Toads migrate from their winter hibernation grounds through woodland to reach their ancestral breeding pond in early Spring
Sinsch, Ulrich. (1988). Oecologia. 76. 390-398.
Followed by the females
Males arrive first
Too many males? •
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A greater number (ratio of 2-10:1) of males migrate to the breeding ponds, arriving earlier and staying longer than females. Intense competition can result in ‘toad balls’ – where a single female is mobbed by multiple males. Sometimes the female drowns. This could be exacerbated if large numbers of males, are placed in the breeding pond near to the females.
Toad ball copyright John Baker
Toad patrollers can reduce the impact of over-amorous males by separating males and females in different buckets, and releasing animals at different locations.
Distances vary from 100 m – 1.5 km (max)
Summer migrating toads typically meander
Late Spring – summer post breeding migration
Long-distance slow migration of adults back to summer foraging grounds, in rough pasture, woodland, scrub, hedgerows and field margins, and wildlife-friendly gardens
What about juvenile toads? • Toadlets leave ponds from June – August to live and forage on land. • Mass toadlet movements can be seen if weather conditions are right (typically rain after a dry period)
Toadlets copyright Nicola Morris
Toadlets can often be spotted in long grass and other sheltered spots in late September, up until the frosts of early October.
Summer movements
Short, meandering daily excursions – foraging for food (bugs and grubs)
Pre-breeding/autumn migration
Some adult toads start the migration back towards their ancestral breeding pond during the autumn
Onset of colder (drier) weather (< 5-6°C) brings a halt to these movements and toads remain in sheltered places or semi-buried in leaf litter over winter
Winter resting sites
Once temperatures warm, reaching > 5°C during late Jan â&#x20AC;&#x201C; March migration to breeding ponds resumes. Spring migrating toads move quickly and in straight lines
Interventions –Toad Patrols Volunteers patrol road side verges from dusk onwards on ‘warm and wet’ (> 5°C) spring evenings collecting toads (and other amphibians), and transferring them across the road in buckets to allow them to reach their breeding (spawning) ponds.
Amphibians copyright Nicola Devine
Not just toads!
GCN copyright Julian Smart
Annual toad numbers at Henleyon-Thames Number of toads crossing each year (1999 - 2018)
14000 12000 10000 8000 6000 4000 2000 0 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Interventions - A Temporary Barrier • Create a temporary barrier to prevent the toads crossing the road using inexpensive plastic sheeting and wooden posts • Put up for the toad crossing season only –late Jan– April (with landowner permission) • Volunteers patrol every night collecting amphibians from the barrier and transferring them across the road
IMG_0041 (1).MOV
Interventions - A Temporary Barrier
Safer for toads and toad patrollers!!
The fate of the returners? • Highlighted as an issue by the Henley patrol • 1,500 returning toads collected by patrollers in 2018 (1,000 in 2017) • Many others will have perished. • Is this a factor in the overall declines seen? • Some mitigating factors - later in the year with lighter nights, so toads crossing after rush hour • Installation of a second barrier was problematic as it blew down
Interventions- Toad tunnels Traditional narrow gauge toad tunnels did not work well because: • Although initially successful (2,750 toads used the two Henley tunnels in 18 nights when first installed in 1987), the narrow tunnels soon became blocked with road silt and leaves (not regularly maintained). • Usage was improved by using fencing to funnel the toads to the tunnel entrance. However, toads do not use the tunnels at all now. • Very costly – and may also involve closing a busy road during installation Langton T.E.S. (1989) Proceedings of the Toad Tunnel Conference, Rendsburg, Federal Republic of Germany, 145-152.
Interventions - Pond Creation (also great for other amphibians and invertebrates)
• Creating two new ponds to deter the toads from crossing the road • Ponds need to be large and deep to attract toads – a major capital project – cost ~ £25,000 (funding from Biffa) • Slow up-take by the toads as the desire to go to the ancestral pond is so strong – volunteers have seeded the new ponds with 440 toads (includes 150 pairs) in 2018 to encourage them to breed. • Successfully attracted breeding frogs and smooth newts, and their numbers have increased significantly.
Two new ponds
Interventions â&#x20AC;&#x201C; Improve habitat around the breeding pond Paddock Wood (KRAG, Kent) toad patrol â&#x20AC;&#x201C; believe that improving the terrestrial habitat around the edge of Putland Pond is deterring the toads from crossing the busy adjoining housing estate roads in search of foraging and hibernation spots (Steve Songhurst, KRAG).
Thank you for listening