Goldies mark the end of the season

With the longest incubation period of all waders we study, Golden Plover chicks, after around 28 days, finally hatched!

Luck so far has been dismal with hatching, but still will be some survivors of this breeding season 2012, but not enough to do telemetry with them this year. After around 30 days living on the tundra feeding on small arthropods and berries, Golden Plover chicks will be probably also the last ones to fledge and depart from the breeding grounds.

Golden Plover chicks newly hatched

During the first days after hatching, adult waders will brood their Young until they can thermoregulate. In the case of Golden Plovers, both the male and the female share these task, but after around two-three weeks just males will protect and stay together will the chicks until fledging.

This year we were very lucky to observe brooding waders and we would like to share it with you here.

Dunlin

Today, Paula and Juan are going back home. Johannes and Dafne will stay 10 days more to monitor the last few active nests that remain.

It has been a very challenging field work season where we have faced the incredibly variable tundra ecosystem.  Thanks all of you for following the blog and your encourage comments. We will see us back next year hoping for a better breeding season 2013!

 

Colour-marked Dunling male alarming

New life on the tundra!

We are in luck..!  More than two weeks later than last year, on the 10th of July we had the first wader hatchlings overthetreeline!

Some wader nests have survived until hatching in this odd breeding season with a very high predation pressure. The first wader hatchlings on the tundra have been a clutch of four Ruff and a Dunlin nest where just one hatched at the time of the visit, with still three eggs more about to hatch in the next few hours. Still some nests are hopefully hatching in the next days or weeks.

Ruff chick

Tiny surface-living arthropods are the main food resource for wader chicks on the tundra. In these last days we are having the peak of arthropod abundance, matching perfectly with the first hatchings, but how long will it last this late season?, will be enough food left for the last hachlings? and will they have time to fledge before the first snow fall?. This year more than others they have a very tight schedule.

Dunlin nest with one freshly hatched chick

Dunlin chick

Predators win

What can we say after seeing the picture of the mountains this last week?….predators win!

They predate 70% of the Golden plover nests we had located in the study area in just few days. Due to the long period with snow cover in the area, predators had more chances to find wader nests. It is also important to mention that last year was a peak of lemmings (our good friend that is missing now), which made breeding of predators succesful last seasson, increasing their numbers in the area.

Plovers are hanging around together, in flocks of up to 100 individuals, ready to departure southwards at any moment…there is nothing else to do in the mountains…lets try next year (they may think…). We also think the same, due to this odd season we don’t have nothing else to do here. It is pretty sad to see the tundra like this. In previous years, normal situation would be the ground plenty of chicks everywhere of different species…Although we will have some, it will have to wait at least one more week…

We will come back next year with full batteries to try to recover some more light-loggers and do monitoring of chicks.

Back home

In phalaropes, the females leave the area just after laying the eggs – leaving the male behind to take care of the brood. Therefore, we only capture males…They are often very tame, as shown by this individual that was happily keeping its eggs incubated while we were watching it from only two meters!

A very tame male keeping its eggs warm.

Yesterday, we went up to Gelmetje to capture Red-necked Phalaropes. We caught four individuals in total, of which the last bird had a big surprise in store: it was already wearing a ring! Checking the ringing forms of earlier years, it turned out to have been ringed as a tiny chick (weighing less than 5 grams) last year in the same area. Now, it was a fully grown male, breeding its own eggs!

This male Red-necked Phalarope was ringed last year as a chick!

So, this tough little bird was back home again. I (Rob) will be back home in about a week – I will start my southward migration today. Hope you have been enjoying the blog, and hope to see you next year at the Overthetreeline blog!

First logger in the hand!

After one month of intense field work looking for Golden plover nests of individuals with geolocator, we finally got the first one back..!

Watch the video here!

Light-logger attached to a colour-ring

This tiny unit has been attached to a colour-ring of the bird for a year and will give us information about migration patterns in the non-breeding season.

Due most probably to the late snow melt, fewer waders finally seem to breed this year in Raurejaure area making it more difficult to find nests of colour-ringed Golden Plovers with light-loggers. The ones that decided to breed have a very high predation rate on their nests forcing us to find them before they get predated and have the chance of retrapping to retrieve the valuable logger.

This has become a true race between predators and us, who will finally win..?

A summer “night” on the tundra

Old acquaintances

One of the firsts posts, from 3 June, reported a few sightings of colour-ringed Golden Plovers. Since then, we have searched the study areas intensively for returning individuals, recognizable by colour-rings and/or geolocators. Resightings of individuals provide information on, for example, survival rates and site tenacity. In the case of birds ringed as chicks, it also shows natal philopatry – a term for the return of individuals to (the vicinity of) their birthplace. We are of course particularly interested in all individuals equipped with geolocators, as the data stored in these tiny devices will show us their whereabouts during the non-breeding season… To read the data however, we have to retrap them – but they need to be relocated first!

Previous years, we not only colour-ringed Golden Plovers, but also Dunlins and Long-tailed Skuas. Furthermore, Golden Plovers, Long-tailed Skuas and a few Red-necked Phalaropes were equipped with geolocators.

Until now, more than 20 Golden Plovers ringed as adults have been seen this season, most of them breeding in the same territory as last year. Also, several Dunlins have been resighted, but not all of the ringed individuals.

Due to the late snow-melt this year, we had to wait a long for the Red-necked Phalaropes to start breeding activities up on the tundra. Only since the last few days we have been able to search for them, which has not produced any resightings (yet!). Hopefully, we can report the return of these birds in the next week!

One of the resighted colour-ringed Long-tailed Skuas.

Being a non-breeding year for Long-tailed Skuas, this season is rather problematic when it comes to resighting of this species. Nevertheless, six colour-ringed adults and the old metal-ringed bird (see the blogpost from 11 June) have been resighted, most of them within their previous years’ territory. Although it seems that virtually all Long-tailed Skuas have left the study areas, there are still occasional sightings of flocks roaming over the tundra. We will keep our eyes open for any colour-ringed birds!

Colour-marked Golden Plover resighted in the study area

Breeding starts on the tundra

Snow cover has been reduced to 50% in many parts of the study areas and finally waders seem to start breeding. However, the still high snow cover in some parts force waders to nest on small snow-free patches making it easier for predators to detect them giving rise to a very high predation rate on nests.

Red Fox photographed in Bjorkfjället last season 2011

The high number of predators around make it even more difficult to find nests before they get predated. Large number of Red fox (Vulpes vulpes) tracks and droppings but also the observation of several individuals hanging around the area, Wolverine (Gulo gulo) tracks, the encounter with a Stoat (Mustela erminea) and many of their winter nests found, recognized by the skins and underfur of the rodents they kill, in a no-lemming year like this, make predators have mainly one target: nests!

Rock Ptarmigan on snow

Mainly Golden Plover nests have been found so far but also other species nests aswell. For the first time since we are coming here in 2008, we have found two Ptarmigan nests, one of a Willow Ptarmigan (Lagopus lagopus) and another of a Rock Ptarmigan (Lagopus muta). We have seen many individuals around in previous years in the study areas and also chicks but never found a nest before!

Rock Ptarmigan nest with 7 eggs

Also Temminck´s stint (Calidris temminckii), Redshank (Tringa totanus), Ruff (Philomachus pugnax) and Dunlin (Calidris alpina) nests have been found so far but few with a complete clutch. As soon as snow melt, snow-free patches are progressively used for nesting.

Ruff in flight

Dotterel foraging on a snow-free patch

Dotterels and Ringed Plovers are also seen in the study areas but few nests have been found in previous years. Maybe their anti-predator tactics that use against us for finding their nests also work with other ground-living predators.

Ringed Plover

Phalarope count and food in the fridge!

Most of the ponds up on the tundra are still frozen. Species dependent on them are therefore still waiting for them to thaw. Among them are Red-necked Phalaropes. This is a small wader that feeds mostly swimming and winters on the ocean. There is a huge flock of phalaropes feeding (and waiting…) at the lake near the village. Today we counted little over 300 individuals! Arctic Terns were surface dipping between them. What would they be feeding on?

Arctic Tern on the ice

Up on the tundra, small arthropods start to emerge. While the snow cover is still around 80% in some parts of the study area, mainly rove beetles (Staphylinidae) increasingly are seen on the snow following air channels created by penetrating shrubs to forage on microarthropods, such as springtails (Collembola) and mites (Acari). These tiny creatures climb from the ground upwards, through little pores of the snow cristals. Higher up in the food web, waders feed on these tiny invertebrates. Maybe birds with longer bills have an advantage finding food at an early stage on the tundra where most parts are cover by snow or ice layers, probing the snow with their bill to catch the hidden invertebrates.

Temminck´s stint foraging on the snow

The old bird returns

After a long drive from the Netherlands, today was my first chance to cross the treeline in search of Long-tailed Skuas. Earlier reports were not hopeful: although there were skuas around, they did not show territorial behaviour. Observations today gave the same picture: only very few birds present, and those that were present were not territorial at all. No alarm calls, nothing. Although they were approachable down to about 15m, they flew really, really far away after flushing. So it seems like it is going to be a non-breeding year, which means that I have to wait another long, long, long year before I get another chance of retrapping the birds with geolocators…

Still, there was something very interesting about the first Long-tailed Skua I saw. The bird was perched on a large rock, located where a ringed bird has been defending its territory in every year since I have been here (2007). Even before that, the bird has probably been occupying this territory for a long time, as it had been ringed in 1997 at exactly the same place. Although I could not read the entire code on the ring, it must have been this old bird, as this is the only one who is wearing its metal ring on its left tarsus… As it was already an adult in 1997, it must now be around 20 years old!

The old skua, which was ringed in 1997 at the same place.

Other goodies today were three Dotterels, four Ptarmigans, a Willow grouse, a Hen Harrier… and a Brown Frog jumping about on the snow!

Chillin’ poikilotherm.

Life on the Tundra

After some days of non-stop raining, we came up again to Raurejaure and Gelmetje study areas. Higher temperatures and rain have helped to reduce the snow cover creating a mosaic-like landscape on the tundra where more and more waders and skuas are observed on the increasingly abundant snow-free patches.

Slowly the spring starts up on the tundra but still breeding is just on their first stages where most birds are struggling to feed on scarse tiny arthropods and Crowberries waiting for the snow to melt on their territories.

Raurejaure study area from Gájsátje

In Gelmetje, waders are a little bit more advanced in their breeding duties than in the other areas. On the 7th of June we found the first wader nest over the treeline! This nest was found in the laying period with two cryptic eggs to reduce predation. Eventually up to four eggs will be laid and later incubate by both sexes for about 28 days.

Golden Plover nest with two eggs

On the 6th of June in Giehplejávrrie we had a very nice observation of a Stoat (Mustela erminia)  running restless over the snow  and  later going away from us with a Lemming on its mouth.

These little predators live here throughout the year and moult the fur twice a year being completely white in winter except for the tail-tip that remains black.

Stoat moulting to summer fur

Stoat with its prey, a Lemming