Packham worked with the group Wild Justice, calling for general licenses allowing the slaughter of so-called 'pest species' including pigeons and crows, to be revoked.
As a result of the campaign the government's advisors for the natural environment, Natural England, has revoked general licenses - under which farmers could kill birds on their land without seeking permission. Now, individuals must apply for permission.
'Delighted to win'
In a statement on released on Wednesday, Wild Justice said: "We haven't changed the law, we have merely shown that the current system of licensing of killing of certain species of birds, developed and administered by a statutory wildlife agency, is unlawful now and presumably has been for decades.
"We are delighted to have won this legal case. What sort of world is it where the statutory body with responsibility for wildlife protection is operating a bird-killing licensing scheme that is unlawful? Millions of birds are killed each year under the terms of the General Licences and many of these deaths will not be justified."
Licensing used appropriately
The Royal Society for the Protection of Birds was happy with the change, with its Director for England, Chris Corrigan, saying: "This is a positive step in the right direction. We need an open and transparent system of licensing that everyone can be confident in, and is being used appropriately.
"It is important that licenses are only issued when there is no other option, and when non-lethal alternatives have been exhausted. Any new system that Natural England now develops should be based on this principle."
Angry blood sports fans and farmers
But the move has angered blood sports enthusiasts and some farmers, with the latter claiming that if they can't slaughter birds like magpies and Canada Geese, they will be unable to protect public spaces and crops.
Packham believes those who are angry about this resolution are behind the dead birds.
Earlier today, he tweeted and image of the birds, with the words: "This was my gate this morning (it was vandalized) Police & lawyers have been informed."
He tagged pro-blood sports pressure group the Countryside Alliance, as well as the National Farmers Union, and Farmers Weekly among others in the Tweet, asking them whether they condone this behavior.
Additionally, Packham has faced criticism from the blood sports and farming fraternities for his campaigning, as they say he should remain impartial. One farmer launched a petition calling for Packham to be fired by the BBC following Natural England's decision.
It says: "As an employee of the BBC, Chris Packham should remain impartial and keep his views and beliefs to himself. However, he is the face of many anti-hunting campaigns and uses his celeb status as a platform to push his anti-hunting agenda, he has made his goal to ban all kinds of hunting, and country sports and pursuits and I feel he is no longer fit to work for the BBC."
At the time of writing, the petition has more than 80,000 signatures.
In addition, Farmers Weekly has launched a poll asking 'Should the BBC sack outspoken Springwatch presenter Chris Packham?' At the time of writing, 72 percent of respondents said no.