Tuesday, 15 May 2012

Where have all the Mallard chicks gone?

Earlier this month we were seeing a few Mallards with their chicks. But since we have been on the River Witham we have only seen one brood between Torksey and Langrick Bridge. We have seen several broods of Grey Lag Geese. On our various walks with the dogs we have seen some evidence of predation of eggs from nests. We have come across quite a few of what appear to be Mallard eggs with holes in the side. Yesterday we watched a couple of Lapwings trying to defend their nest against a very persistent Crow. This is nature in the raw.

Once the eggs hatch Mallard chicks are almost self sufficient. Mother does not feed them, she leads her brood from food source to food source. At the same time she gives some protection from predators and some shelter from the weather. However, whilst being on the water does give some respite from crow's and magpies. Another predator in the form of large Pike will then take some of the chicks. It's nature at its wildest.

I know one nature reserve where due to the privations of crows and magpies who would sit in a couple of large trees near  the centre of the site, watching the meadow land. (Each time they spotted a chick, it would be quickly snatched up to feed their own chicks) The nature reserve actually significantly reduced Ring Plover, Little Ring Plover and Lapwing chick losses by removing the trees. This is positive action that helps to give additional protection to key species.

As we have made our way along the Witham, we have seen vast field after field of monoculture crops. Old seed rape is a bright yellow swath across the land from horizon to horizon. Field boundaries in the form of hedgerows long ago ripped out so that mechanised farming methods would be more efficient. Thereby removing the habitat needed by our wildlife. Pesticides used to kill the insect population. Herbicides used to remove weed species that form part of the food web for our wildlife.

It is a pressure that is maintained all the year round. Including the autumn  winter period after the crops are gathered in. Once upon a time, fields would lay as stubble until next spring. Giving some food and shelter to birds and mammals over the winter. Now they are ploughed and a winter tolerant crop is sown to give a head start for the following spring.

I can remember a time when sparrows were so common they could be seen everywhere our towns and villages were full of them. The population have crashed. The common house sparrow used to nest in gaps below our roofs. Now, we have UPVC soffits designed to keep the birds out. Our gardens are filled with none native species of plants. I know that some people put up nest boxes that they purchase from garden centres. There is a fundamental problem in the boxes. The holes are often far too small for sparrows to enter. Smaller birds such as blue and great tits are the target species.

The environmental changes that have created the change in bird numbers is a very complex process to understand. To get a better understanding of why the environment and habitat for our wildlife is under pressure, have a read at this 28 page overview from the UK-NEA. it's a PDF document. Click Here 

[Note] The UK National Ecosystem Assessment (UK NEA) was the first analysis of the UK’s natural environment in terms of the benefits it provides to society and continuing economic prosperity. Part of the Living With Environmental Change (LWEC) initiative, the UK NEA commenced in mid-2009 and reported in June 2011. It was an inclusive process involving many government, academic, NGO and private sector institutions.

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