Wildfowl & Wetlands Trust (WWT)

Icicles and poo – studying geese in Bulgaria

Anne HarrisonIt’s week six of my trip now and the last few weeks have been eventful. Unfortunately it’s not all good news. The cannon netting team left empty handed on 2 February after a month of setting and re-setting nets in the hope of a successful catch.

Too warm…

As I talked about in my January post only very small numbers of geese were here during the first half of the month. Luckily the onset of colder weather marked the arrival of more birds, so the odds of a successful catch looked set to improve. Nets were dug up and re-laid in a different field – a known favourite feeding area and the location of a successful catch last year. Things were looking up and the geese came within only a few metres of the nets, but no closer…

Then came the cold…

Heavy rain, followed by blizzards, strong gales and extremely cold temperatures down to minus 18 degrees – so cold that the spray from huge waves crashing onto the Black Sea cliffs at Tyulenovo froze into huge icicles! Likewise, the cannon nets froze solid. We awaited a thaw, but this came too late, after the team had returned to UK soil. Digging up those cannons and packing away the nets in the howling icy wind was somewhat exhilarating, despite the fact we didn’t catch.

Fingers, toes and wings crossed for better luck next winter.

The good news is that fitting tags is just one of many aspects to the fieldwork we’re doing for the Safe Grounds for Red-breasts project. I’m here to make sure the methods are put into practice properly, so that we collect good scientific data on which to base conservation measures.

One aspect is to learn how disturbance, particularly from hunting, affects their ecology. Hunting red-breasts is illegal, but greater white-fronted geese are legal quarry and, as the two species usually occur in mixed flocks, disturbance of one inevitably affects the other.

Studying how their distribution changes daily and over the course of the winter, and what types of crops they are selecting to eat, lets us quantify the factors that are important to geese, as well as the effects of disturbance. The data will also be used to map important areas for geese, which could be used as a tool to inform future development in the area, especially of wind turbines.

Goose poo

One of the best ways of looking at how many geese have used one area compared to another is to count their droppings! Because geese eating a particular stand of crop will poo at regular intervals, the number of droppings can be related to the time spent by geese in an area.

We’re using this simple method to get an idea of how much damage geese cause to winter wheat crops in the area. By preventing access to some plots using cages or ‘exclosures’ and leaving others open for grazing, we can compare the final harvest of the crop when exposed to different grazing pressures. Does heavy grazing lead to reduced yield?

We’re also looking at whether there is a correlation between goose use – again measured by counting poo – and proximity to wind turbines, to investigate whether geese avoid feeding in areas close to turbines.

 

Safe Ground for Redbreasts is a partnership between BSPB, WWT, RSPB, Kirilovi Ltd – an agricultural cooperative – and the Shabla Hunting and Angling Association. It has been made possible with the contribution of the LIFE financial instrument of the European Community (No. LIFE 09/NAT/BG/00023)

 


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Weather challenges red-breasted goose research

I’m Anne and have been working at WWT for six years now – I’ve recently started a new role in the Species Recovery Unit after transferring over from WWT Consulting. I’m now spending most of my time working on the Safe Grounds for Red-breasts LIFE+ project, which is the reason I’m writing from a Bulgarian hotel looking out over the Black Sea. I’ll be here in Dobrudzha for two months helping with the various fieldwork activities that are going on here in one of the major wintering grounds of the red-breasted goose.

One of our key objectives is to catch some red-breasted geese and fit satellite transmitters to them, so that we can learn more about their movements here and along their migration routes. However, we’re now two weeks into our month-long mission to catch the birds and so far we’ve had little success.

These small radio tracking devices can be attached to red-breasted geese like a backpack (c) Sacha Dench WWT

These satellite transmitters can be attached to red-breasted geese like a backpack (c) Sacha Dench WWT

Red-breasts can usually be seen here in their thousands at this time of year – over 80% of the world population have been recorded wintering in the area. But no more than 300 birds have been spotted since our arrival in early January, reducing our chances to catch some.

A flock of red-breasted and white-fronted geese in Bulgaria 2011 (c) Sacha Dench WWT

A flock of red-breasted and white-fronted geese in Bulgaria 2011 (c) Sacha Dench WWT

The number of geese wintering in Bulgaria does vary greatly between years. Cold Siberian winters usually force the geese south from Russia and Ukraine to the relatively-warmer wetlands of coastal Dobrudzha in Bulgaria and Romania. This winter has been unusually warm though. The geese, wanting to stay as close to the breeding grounds in the Russian tundra as possible to reduce the length of the return slog north, haven’t been driven as far south as Bulgaria, as they would in extreme (or even normal!) cold weather.

So we have been bracing ourselves daily for the weather forecast, hoping for some colder weather. In between, the catching team from WWT and BSPB has been making dawn trips to locate the few geese there are, as they move from their roosts on the Black Sea, Durankulak and Shabla Lakes to feed in arable fields.

Fortunately, despite the low numbers the birds tend to stay in the same flock, along with the more numerous greater white-fronted geese and they have been using the same few fields sown with winter wheat close to Durankulak.

The WWT/BSPB goose catching team monitoring the fields (c) Sacha Dench WWT

The WWT/BSPB goose catching team monitoring the fields (c) Sacha Dench WWT

Watching the geese in the fields allows the team to detect any signs of predictability in their activity, which will hopefully allow us pinpoint locations to set the cannon nets we use to catch the geese. Puddles in fields, for example, are good locations for catching because geese need to drink during the day.

Setting cannon nets for catching red-breasted geese in 2011 (c) Sacha Dench WWT

Setting cannon nets for catching red-breasted geese in 2011 (c) Sacha Dench WWT

This week the team found red-breasts and white-fronts using puddles in the tyre tracks along a dirt road – seemingly, a good place to set the nets that night. Unfortunately, the next day, although the flock was is the right field, the birds stayed well away from the nets. They were frequently buzzed by white-tailed eagles and peregrine falcons. At that point, they took to the air, and returned to the lake nearby where they took the opportunity to have a drink, which meant they didn’t need to return to the puddles.

Today however, we’ve had good news. Around 2,000 red-breasted geese have been seen, coinciding with a drop in temperature. This bodes well – or at least better – for the next two weeks, so fingers crossed we’ll catch some geese soon.

Flock of red-breasted and white-fronted geese in Bulgaria 2011 (c) Sacha Dench WWT

Flock of red-breasted and white-fronted geese in Bulgaria 2011 (c) Sacha Dench WWT

Winter wheat in Bulgaria (c) Sacha Dench WWT

Winter wheat in Bulgaria (c) Sacha Dench WWT

Safe Ground for Redbreasts is a partnership between BSPB, WWT, RSPB, Kirilovi Ltd – an agricultural cooperative – and the Shabla Hunting and Angling Association. It has been made possible with the contribution of the LIFE financial instrument of the European Community (No. LIFE 09/NAT/BG/00023)

 

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