The nest
Many Curlew pairs return to the same territory to nest in year after year. Some nest in the same spot, others choosing a new site each year, often on a different farm to the one on which they nested in previous years. The height of the vegetation and lack of disturbance would seem to be the factors which determine choice of site in which the nest is formed.
The male spins on his breast to form a nest cup for the female to approve, he may make several attempts at this. The nest is just this indentation, but whilst laying and incubating eggs the adults pull grass and throw it, often over their shoulders, possibly to help disguise the nest area. Over time the incubating bird pulls this grass in to make an outer ring to the nest.
The eggs
Eggs are laid over a period of days, often a day apart and sometimes the last egg or eggs can be laid further apart. They are a similar size to a duck egg and in our area vary from khaki green to blue green with brown markings. The colour and marking of eggs can vary in different parts of the country. Our eggs can also vary in size and colour.
Many clutches are of four eggs, although some of three and two have been found. We have had a nest with six eggs in it and believe that two females were laying in the same nest. The eggs are arranged around a centre point to which the narrower end of the egg faces.
Typically, the Curlew lays four eggs. They are arranged in a star shape as above with the narrower end facing toward the middle.
Incubation
Both adults take turns in incubating the eggs. They are hard to tell apart, but when there is a changeover where both birds can be seen at the nest, it is easier to see that the female is larger with a longer bill. The bird not incubating is likely to be away from the nest, but within calling distance. It will alert the incubating bird to potential dangers such as avian predators flying over and if you listen carefully, you may hear alarm calls from time to time.
Migration
In the Curlew Country area birds start returning from their winter roosts as early as February 14th. 
There is some evidence from sightings reported that some birds travel between migratory roosts or even the coast before settling in their usual territories. Winter roosts are wet areas including shorelines, estuaries and inland wet areas where Curlews can probe their long bills to find soil borne invertebrates. Curlew Country birds travel to Cornwall, Wales, the Scilly Isles, Southern Ireland and France. The male usually returns to its nesting territory first and is followed by the female some weeks later.
Territories
Curlews are considered to be territory faithful. Many older rural dwellers recall decades past when they would have been in a meadow where ‘clouds of Curlews and Lapwings rose’ when disturbed, perhaps by a predator. This suggests that historically their ‘territories were much smaller than they are today now their numbers have declined so dramatically. Curlews are loosely territorial. Current work led by Dr Rachel Taylor from the BTO in north Wales has found that Curlew territories are not robust. Curlews will move in and out of territories of other pairs more than had been thought.
In the Curlew Country area, we have observed that Curlews do return to the same territories to breed, but they will use other territories as well especially for foraging. We have found new pairs nesting in territories previously occupied by other birds and interestingly this year, we found one of our headstarted chicks in almost the exact spot in which another pair had nested regularly. This pair then returned and the chick has not been subsequently spotted.
Other waders may nest as colonies, keeping nests close together and co-operating to fend of predators or send out alarms to others in the group. Curlew pairs are loosely colonial, co-operating to fend off predators if close enough and seemingly sometimes social. We have however observed males defending territories with females in strongly.
Fidelity
We have mentioned site fidelity before, but we do know that many of our pairs will nest in almost
the same spot, certainly in the same field if the conditions suit them at the time of choosing a nest site. Curlews are also thought to be partner faithful. We have, through the colour ringing programme, observed several changes in partners. Curlew Cam pair 1 in 2021 is such a pair. The female was until two years before, known to be nesting on a dairy farm a few miles away.
Do the chicks return to the site they were hatched to breed ?
Hi Janet,
The short answer is yes they do. We have had about 15 birds (we know about) return to our study area to breed with wild birds and a growing evidence base that they are replacing adults we have lost to (e.g.) predation in their old territories. What we don’t know is just how widely distributed they now are from their hatch/release sites, as we can’t possibly cover such a wide area with the intensity of survey coverage required to identify returning birds by their colour rings. Fewer birds have returned to breed than we would like, but they may be breeding elsewhere and we just haven’t heard about it yet. One of our headstarted males raised a brood to three weeks old this year, but unfortunately lost it before fledging. This is the third breeding record from that male in Shropshire since his release in 2019.
Do curlews call to unhatched eggs prior to hatching?
Hi Julia,
Yes they do. You can see an adult calling to its pipping eggs here if you skip to 5:01:00 and press play. The chicks will be audibly peeping whilst still inside the egg, which indicates that they are about to hatch.
https://www.youtube.com/watch?v=PFgq3HMDBdM&list=PL5fk0HbrC4lnpUAO3grFoutxNC9J1Ow9V&index=7
Chicks hatch over 2-3 days and once they’ve dried off, the quickest to hatch will start to roam around the nest area looking for food and returning to the nest intermittently for warmth and safety, while the remaining unhatched eggs are incubated. This causes a bit of a dilemma for the parents and they will frequently call to their wandering chicks from the nest. You can see this happening here:
https://www.youtube.com/watch?v=QP-NYD9ZIUA&list=PL5fk0HbrC4lnpUAO3grFoutxNC9J1Ow9V&index=6
This is a very vulnerable time for the chicks, as they are calling constantly and drawing attention from predators, but have not yet developed the skills to stay hidden in the vegetation and are also still rather wobbly on their brand new (untested) lanky legs. Chicks must learn to hide from potential predators in response to the adults vocal warnings, so communication is key for any curlew family to have the best chance of survival and this starts to develop while the chicks are still inside the egg.
The curlews have nested next to drive way
With 2 eggs under tree
But we haven’t seen them for a couple of hours
Is this normal at night
Hi Alan,
It is normal for Curlews to leave the nest at night before they have laid a full clutch and started incubating their eggs. Curlews will lay one egg every approximately 1.5 days until they reach a full clutch and only then will they start to incubate the eggs. A full clutch is usually 3-4 eggs (4 is more common). Once incubation has started one of the adults will stay on the nest overnight keeping the eggs warm, while the other can travel considerable distances to find a shallow pool to feed in — often with other curlews from the area — before returning to relieve their partner from incubation duties at first light. Until incubation has started the eggs are left cold, even if a bird is sitting on and guarding the eggs during the day, they don’t warm them up until they’re ready. Once incubation has started then the eggs will fail to develop if left to go cold for too long.
Hope this helps!
We’re currently in Swaledale and have witnessed a group of over 20 young curlews, we were amazed, is this usual?
Hi Joanne, no it would be very unusual to see large groups of young curlews in May. The earliest a young Curlew would be old enough to be flying and intermingling with other juvenile Curlews would be late June/July. Are you sure they weren’t adult Whimbrels? Peak passage of Whimbrel occurs in May, so it seems likely that is what you saw. Whimbrels are considerably smaller than an adult Curlew with a straighter bill with a hooked end and an obvious stripe on the crown of the head. The bill of a Curlew is longer and more evenly curved.
If you managed to take any photos send them in and we can confirm which species you have.
Hope this helps!