Introducing House Martin Support Suffolk

This year SBG are launching a new project – House Martin Support Suffolk (HMSS).
Following on from the success of Save Our Suffolk Swifts (SOSSwifts) we are turning our
attention to their also red-listed cousins. As we know hirundines – Swallows and Martins,
are often a confusion species with Swifts, especially when feeding together in mixed flocks
early after arrival from migration or in inclement weather where they are drawn to these
spots. House Martins are facing similar threats; habitat change, changes in building design,
availability of invertebrate prey, but also unique threats including availability of mud to
build their natural nests, and in dry summers, especially on sandier soils the risk of nests
falling down during the breeding season. Birds breeding on PVC fascias and soffits have
been shown to have much lower breeding success – with nests more likely to collapse.
HMSS is raising awareness of House Martins in a world changed by humans; the threats they
face, their ecology and how people, including homeowners, farmers and landowners, can all
help. We are also joined by House Martin expert Martin Tickler who recently gave a very
entertaining and informative talk to SBG members at Hintlesham Community Centre in
April.

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Looking for Swifts. Swallows and Martins

House Martins from Europe and western Asia winter in Africa south of the Sahara but there
are also records from India (Ali and Ripley 1972). They return in late March or early April to
join Swallows, Sand Martins and Swifts over lakes, ponds and meres picking insects from the
air and the water’s surface. They feed to gain strength for nest building and raising the
chicks that will join them over the same pools and meres in late summer and autumn. Until
the end of the 18 th Century educated gentlefolk and clergy with time to spare for the study
of nature were obliged to record in their diaries only what they could see within the limits of
their parish boundaries. Swifts, Swallows and Martins gathering over ponds in autumn
simply disappeared. With no one inclined to follow and map their progress they were
believed by some? to dive into the depths to spend the winter sleeping in the mud before
re-emerging the following spring.

In our time of instant on-line information and a library of ID guides even the most casual
observer of birds will tell you that some birds migrate and the seasons of their arrival and
departure, but the same observer might not be able to tell you whether they are looking at
a Swallow or a House Martin. It takes only a little practice to pick out the long-winged
Swifts with their scimitar silhouettes, the stubby pale brown sand martins and the glossy
blue House Martins and Swallows. Look again at the long tail streamers of the Swallows and
compare with the House Martins flashing their shirt-tails, their white rumps easily picked
out even on dull cloudy days.

A thousand pellets of mud and a safe place to build a nest

House Martins are semi-colonial, more accurately semi-social as some nest collectively in
groups, while others may nest singly. They used to breed on coastal and inland cliffs as they
still do in places like North West Scotland and Malham Cove in North Yorkshire. Like Swifts
and Swallows, they have largely abandoned traditional nest sites to exploit our own built
environment of vertical surfaces, garage caves, eaves and towers. But Swifts belong to the

sky and build their nests from feathers and spiders webs while Swallows and Martins are
tied to the earth. They build their nests from pellets of mud pecked from the edges of
ponds, muddy trackways and hollows while Sand Martins nest in burrows scraped into river
banks, cliffs and quarries.

It can take a pair of House Martins two weeks and up to a thousand mud pellets to build a
new nest. A supply of mud has to be close by so that the mud pellets don’t dry out before
the birds can glue them in place with a spit of saliva. House Martins nest in colonies and
pairs can raise two or three broods of young during the course of a breeding season which
can last into September/October. Both birds share parental duties but the female is
responsible for most of the incubation and brooding. There are records of young House
Martins helping to feed a second brood (Menzel 1984); raising two broods will help to
ensure that enough juveniles survive to maintain the population and usually occurs in old
nests in good condition or artificial nests if they are available when the birds return in the
spring.

The four to five white eggs are laid at daily intervals but in bad weather laying can be
suspended by a day or more (Hund 1976) and will hatch after 14 -16 days, although the
hatching can be delayed by bad weather when the adults leave the eggs unattended for
long periods. As the chicks grow they gather at the lip of the nest hole waiting for the adult
birds to feed them. With their sleek cap and white bibs, they look like waiters angling for
tips, pushing through the kitchen door to greet a generous patron. They are usually ready
to fledge after around 22-23 days. Bad weather can lead to nestlings dying of starvation,
although like Swifts they can survive on their fat reserves while also becoming torpid for a
few days (Prinzinger and Seidle 1986,1988).

 

 

 

 

 

 

 

 

 

 

 

 

House Martins are in trouble

House Martins still glide over ponds and meres, sometimes so close to the water’s surface
that they might be imagined to suddenly dive beneath the surface, or risk being snatched by
Jenny Green Teeth, a water sprite invented by anxious mothers to scare children away from
deep water. We dismiss the foolishness of our ancestors for believing that birds hibernated
at the bottom of ponds with fairy tale monsters but in our intolerance of untidy nature, of
bird droppings and mud nests and declining insect populations we risk making fairy tales of
Swallows and House Martins.

Declines in House Martin numbers led to their being added to the UK Red List in 2020. These
declines have been most severe in the south and east of Britain. The draining of wetlands,
the removal or infilling of ponds and drier springs have contributed to a serious problem for
Swallows and Martins. No mud to build their nests! Even where there is a supply of mud,
modern houses often have no eaves or very shallow eaves which practically exclude House
Martins from nest building. If they do build they are often exposed to more predation, while
plastic soffits installed during renovation make it difficult for mud pellets to stick and hold.
Birds that build nests on PVC as opposed to brick, concrete or wood have much lower
breeding success, with nests more likely to collapse on the PVC substrate. If located on a
secure surface the same pair might return to their old nest the following year and renovate
it with fresh mud for a new season. But for some householders the droppings that pattern

the walls or hard surfaces beneath the nests are untidy, messy and unhygienic, while the
owners of older buildings see them as a threat to their structure and preservation. House
Sparrows will also displace House Martins from their mud nests and this can impact on a
local scale but this natural and opportunistic behaviour can only be worsened by the
deliberate destruction of House Martin nests.

The Wildlife and Countryside Act 1981 (as Amended) makes it an offence for anyone to
intentionally kill, injure or take the eggs of a wild bird, or destroy their nests while in use or
being built. Unfortunately, the law does not protect nests in winter when they can be
knocked down without any legal repercussions. The destruction of seemingly abandoned
nests might be dismissed as a lesser moral crime with no harm done if there are no eggs or
chicks, but the destruction of a single nest or a whole colony means that birds seeking their
old nests find only a bare wall and then expend energy already depleted by their long
migration, collecting mud pellets to start again. The situation is made worse by some pest
control companies offering advice to householders who want to discourage House Martins.
Droppings are easily removed with a hosepipe or brush, or caught in pots placed on the
ground, or on a board fixed to the wall beneath the nest cups. If a board is used to catch
the droppings it should be fitted 2m below the nest cups so that it doesn’t serve as a perch
for predators to pick off adult birds flying to and from the nest, or a platform for nest
predators to reach for eggs or chicks. Older buildings will likely have offered safe purchase
for House Martin nests for centuries. It would seem unlikely that it would take 300 years for
a House Martin’s dry mud nest to tumble a yeoman’s cottage!

The HMSS is currently trialling 3-D printed artificial House Martin nest cups designed by the
project group, printed by Scott Fairburn and painted by Chris Keeling – this is on six existing
colonies across Suffolk. Scott has already developed a side line producing 3-D printed bird
decoys for SBG, the RSPB and the Lowestoft Kittiwake Group at his shoe repair and key
cutting shop ‘Mr Cobbler’ in Felixstowe. In addition to artificial nests, HMSS will work with
farmers and landowners to encourage the restoration of old ponds with wider field margins
supporting wild flowers and the insects that feed adult House Martins and chicks. Opening
gaps in vegetation to expose mud on the edges of ponds and farm reservoirs will mimic
trampling by livestock, providing mud for nests while also creating micro-habitats for
insects. Creating so-called ‘mud pies’ (muddy puddles that are kept wet while martins are
nest-building) in your garden or farm yard will also have the same effect, a perfect example
of small-scale wilding on the farm, or even in your own garden. We will report back in a
future bird report on their success. We are also encouraging survey and monitoring efforts
of breeding sites – please do send your records to SBG, so that we can get an up-to-date
picture of their populations.

HMSS, alongside organisations such as SWT Farm Advice Team and Operation Turtle Dove
are also offering advice to landowners and farmers. In particular, both organisations are
working with farmers giving advice on pond creation and restoration, with gently sloping
sides, giving benefit to a wide range of wildlife, providing an abundance of invertebrate prey
and also nest-building material. Where possible the creation of ‘mud pies’; an artificially wet
area with mud, will also further help birds access building materials. It is difficult to think of
hot summers after the wet winter we’ve had, but particularly on our sandier soils this is a

problem. Wildflower rich habitats or wetland enhancement projects, particularly with
scrapes will also provide insect rich feeding habitat and will be encouraged.

Can you help? Please visit the SBG website or Instagram page for further information if you
would like to know more about our 3-D printed House Martin nests, creating ‘mud pies’ for
nest building and other ways to welcome House Martins, please visit the Suffolk Bird Group
website, or Instagram for House Martin talks and events or pick up one of our information
leaflets at the next SBG indoor meeting. We hope to see you at one of our events soon!

Please also get in touch with housemartins@suffolkbirdgroup.org

References

Ali, S, and Ripley, S D (1972) Handbook of the Birds of India and Pakistan. Vol. 5. Oxford
University Press, Oxford
Hund, K (1976) Beobachtungen, insbesondere zur Brutbiologie, an oberschwabischen
Populationen der Mehlschwalbe. Orn. Mitt. 28: 169 - 78
Menzel, H (1984) Die Mehlschwalbe. Neue Brehm-Bucherei No. 548 Ziemen, Wittenberg
Lutherstadt
Prinzinger, R, and Seidle, K (1986) Experimental proof of torpidity in young House Martins,
Delichon urbica. J. fur Orn. 127: 95-6

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House Martin photos by Andy Johnson