Atlantic Salmon

Every autumn salmon return from the sea to mate in our British rivers. One of autumns greatest spectacles is seeing them leap up waterfalls to reach their spawning grounds. But this spectacle could be in trouble. In recent years there have been many alarming reports of declining numbers of salmon. In August the salmon are coming back from their feeding grounds way out in the atlantic. They will travel to the most northern tip of Scotland and other parts of the U.K. The salmon have to leap fast to get up the waterfalls, they do this by tucking their pectoral fins (these are located just behind their gills) in when they leap. They do this to make them as streamline as possible enabling them to make a successful jump. Their pectoral fins are then pushed back out to cushion the blow for when they fall back into the water. For this a swollen fast flowing river is essential for the salmon to be able to leap up the waterfalls. They also need deep water so they can have a good long swim up before they jump. The brown salmon that you may see have been in the river since spring waiting for the river to be swollen by the autumn rains, the silver salmon have come straight into the river from the atlantic. The movement of these fish has created a massive fishing industry that dates back for hundreds of years. The Atlantic salmon used to be fished very commonly, but now only a few fishing boats remain. The salmon are caught as they return back from the open ocean, when they are looking for their spawning ground rivers. But local fishermen  believe that the number of salmon are actually increasing. Last seasons catch was the best for the fishermen for over two hundred years. So are all the reports of the species being in trouble a myth, if the local fisherman's accounts are true. The St andrews university have been monitoring the local fisherman`s catches for over a decade. Their results show that although the quantity isn`t a problem the quality of the salmon is. The weight is the first thing that's important, the second is the fat reserves that have been stored up. All of the fish need this for their energy, to get up the river, spawn and then back out to sea. Low fat reserves mean less energy for the salmons migration  up the rivers. Size is an issue to, in 1997 the average size of salmon was about 29% higher than today, the salmon are a third smaller now than they were fourteen years ago. Large fish produce more eggs than smaller fish, so if the size of the females are a third down then the amount of eggs being deposited in fresh water is down aswell. It appears though the research being done, their numbers might be up but their physical quality(thats for their ability to reach their spawning grounds and mate) is definatly going down. The obvious reason is climate change, oceans warming and the salmon are migrating out to the norweigen sea. Their disrtibution of their food seems to be changing beacause of the ocean temperature. They are arriving in the right place but the food isn`t there. What can we do about it? In short probaly not a great deal, but we can maximise the quality of their fresh water habitats. Manage these habitats better, making sure the adults have every oppurtunity of spawning so the rivers can produce as many juveniles as possible. Only time will tell if the change in the quality of salmon through our management of fresh water habitats will make them bettter fish for the future. They are in urgent need of conservation.

Hedge Fund.

When it comes to our autumn harvest for our birds there can`t be a richer picking than our hedgerows. In the U.K we are lucky to have masses of them. If you were to line them all end to end they would stretch twenty times around the planet. They are a very rich habitat, replicating a woodland edge they can contain as many as six hundred different species of plants and trees.Many of which produce fruit and berries. During the winter time, birds would do best by eating seeds and insects. The problem is they have to find them and handle them. But berries occur in vast numbers and are easy to spot. In one square metre of hawthorn hedge there can be up to ten thousand berries. Its the bright red against the green background that makes them easy for the birds to spot. They get lots of energy from berries, one hundred grams of blackberries equals fifty calories, one hundred grams of elderberries equals seventy calories and there are as many calories in ivy berries as are in a decent sized chocolate bar. So that's what the birds get out of the hedgerow, but what about the plants? They are demonstrating a fantastic example of co-evolution. These plants have put energy and resources into producing the berries. They have invested so in return the seeds get dispersed, the birds eat the berries and then digest them but not the seed inside. They then fly many miles, the seed then passes through them to germinate somewhere else, not in competition with the parent plant. The seed then colonises another area. Zoochory is what this is called. So if any farmers read my blog, its so important for our hedgerows to be left in the autumn for the birds. Eighty% of our farmland birds rely on our hedgerows for food and for shelter and nesting. If we cut the hedges to early the plants will not be able to establish a longer growth pattern, meaning they will not be able to produce the fruit that is so vital for our farmland birds in autumn.

Magpies-do they have an effect on our small birds?

Should magpies be culled?

Magpies like the rest of the crow or corvid family which include rooks, jays, ravens, choughs, and nutcrackers are all known for their intelligence and adaptability. But theres no getting away from it that they are unpopular with some people because they raid nests taking eggs and chicks. Magpie numbers have doubled since the 1970`s where we have seen farmland and garden birds suffer dramatic declines. Is there a link-are magpies responsible? Do magpies make any difference to the overall survival rates for our songbirds? No, magpies and crows have lived alongside our farmland and garden birds for thousands of years. Songbirds can deal with there presence . The way they deal with it is by having more chicks to make up for any numbers they may have lost. They are the masters of probability, because they know that by having lots broods and chicks they can deal with the predators. But some gamekeepers might not agree, larson traps are used on some estates to trap magpies and other corvid members. Which are then killed humanely. Gamekeepers control the amount of magpies and crows where they keep game birds(grey partridge and pheasants) because they say they(magpies and crows) have a damaging effect on their game birds. But the B.T.O  looked at thirty song birds species, which are prey species and seven predator species. Both predators on adult birds, hawks and kestrels and also predators on nestlings and eggs of songbirds-magpies,crows and grey squirrels. There were very few significant relationships between the growth in the predator population and the decline in the songbird population. From this evidence magpies have little or no effect on overall populations of songbirds. Songbird survival trust isn`t convinced that predation can be dismissed entirely. They don`t pretend its the major factor necessarily . Habitats,nest sites and food supply are as likely as predation. Predation is a major factor that hasn`t been looked at properly. More likely though the decline is down to farming and land use practices than predation. Even though song bird survival aren`t satisfied, everything else that i have read say the decline is down to habitat issues rather that predation. It seems predation can be a problem at a local level. The r.s.p.b control magpies and crows on some of there reserves. In some cases the numbers of songbirds have fallen to such a low because of changes in habitat that a predator such as a magpie or a sparrowhawk can be the final straw because the population of songbirds will be low anyway.There is a lot of evidence to say that magpies and crows have no overall effect on our songbird population. Magpies will always raid nests to survive . I think though that nature will find its own balance and that the magpie is a scapegoat because as humans our emotions take over,