Predation and Culling – Cormorants, Gulls, Buzzards and Bee-eaters
A few days ago, I read the string of comments on our local Nextdoor about the ducklings spotted on Alexandra Park lake, and their sad demise. Later, some were calling for justice and the culling of the possible perpetrators. Others were more stoical and said “well that’s life, it’s tough out there.”
I thought I would pen a piece in response.
Part 1 – Survival
Large Broods Ensure Survival – Blue Tits
Last May we were lucky enough to catch the fledging of a nest of Blue Tits. We saw eight youngsters emerge from their nest box and fly clumsily into the nearest low tree, and from there begin their inevitably short lives.
It was likely the pair of adult Blue Tits would then go on to raise a second brood for the year. Twenty plus young for a pair of Blue Tits is not uncommon in a year, and certainly seems a lot for a pair of adults to raise in a single season. Obviously the reason is that few of them will survive their first few weeks or months. These vulnerable little birds, like the Mallards on Alexandra Park lake, need to produce a lot of young in order to ensure they themselves are replaced as a pair of breeding adults, when they eventually die.
Even Predators Are Vulnerable
This outcome of the evolutionary process doesn’t just apply to those lower down in the food chain. The top predators are also vulnerable, but in different ways.
Last week we found a Tawny Owlet sitting silently on a log under its nest, while its sibling sat there watching from way up.
Tawny Owls normally leave the nest well before they can fly, and using their strong beaks and claws, they climb into the upper canopy of the trees where their parents will continue to feed them for many weeks until they have perfected the skills of flight and hunting. In the autumn the parents will drive them out of the large woodland territory, and the youngsters are on their own. Sadly, about eighty percent of them will die by next spring, many from starvation.
It’s Mainly About Territory
Tawny Owls are fiercely territorial. They keep the same territories year on year. Their territories are large, anything up to 50 to 60 acres of woodland, and are defined by nesting spots and food supply. No other Tawny Owls will be allowed in.
By definition, all the best spots are taken as established territories by these long-lived birds, and the young ones have to find somewhere outside of an established territory, with a reliable food supply, if they are to survive long. Few do – and those that manage it will then try to attract a mate, or move on and find an existing territory to replace an adult bird that has died.
Yes, it is tough out there, even for the big guys.
Part 2 – Culling those we don’t like
The problem with this argument is that there is always somebody out there who will adore the creature you seem to most despise; or someone who hates the creature you most like.
The Buzzard
One of the birds we most enjoy watching local to home are Buzzards. They are the most extraordinary of birds. Their sheer flying ability is there to amaze – you can see them over Combe Valley Nature Reserve.
In early spring the male and female strengthen their pair bond through a wonderful display of aerobatics. The male will fly slowly with deep wing beats low across the tree line, rise quickly on a thermal to an immense height, and then put his wings back and dive at incredible speed. The female will follow and he will dive towards her when she may then flip, touching claws and then separating. On a clear warm spring day this beautiful display can continue for 30 minutes or more.
The Persecution of Birds of Prey
Since the advent of guns, large birds of prey have been indiscriminately persecuted by game keepers. They seem to offer too much competition for the precious game (See previous blog: 60 million game birds released for shooting each year: https://woodcockwood.com/the-release-of-pheasant-and-red-legged-partridge/).
In the past, the Buzzards favoured food during spring was young rabbit. At times, wild rabbit has been an important source of food for country people, but also a great menace to crops. In its infinite wisdom the Ministry of Agriculture introduced myxomatosis to reduce the rabbit population. It succeeded wonderfully. The rabbit population plummeted.
The Buzzard, adaptable as ever, had to find new food sources, and yes, very occasionally they took young game birds, along with squirrels, mice, voles, frogs, worms and anything else remotely catchable and edible. But of course, the occasional game bird chick promotes them to number one enemy of game keepers. Illegal persecution continues.
We love them, and some people hate them, irrational and extraordinary as it may seem.
European Bee-eaters
The European bee-eater must be the most exotic looking of all European nesting birds. They live in small colonies and nest in burrows excavated in sand banks. The young from previous years will often assist their parents in raising the current brood.
They live entirely on insects, mainly on bees and wasps, and have developed superb hunting techniques to ensure they themselves are not stung. Now who could hate such beautiful birds, and want rid of them? Yes, beekeepers of course! And as difficult as it is to imagine, in the past (and possibly even now) they were persecuted. Among other ways, they were trapped with nooses strung across the nesting holes.
Cormorants
A few weeks ago there was a discussion on Nextdoor about the Cormorant spotted on Alexandra Park lake, and elegant birds they are. It was a pleasure to see it sitting so boldly on the concrete pier, opening its wings to dry them following a dive into the lake. Like me, many of you appreciated the view.
Who hates Cormorants? Many fishermen I’m afraid. In 1981 it became illegal to kill them without a licence, but you can apply for a licence and either shoot them or destroy their nests and eggs in order to safeguard course fishing stocks. You don’t have to look far on the internet to discover the acrimony of the arguments for and against this practice!
And now to our Herring Gull
The Herring Gull is our archetypical seagull. Where would Hastings be without the sound of their call and the sight of this magnificent grey and white bird (Latin name: Larus Agentatus – the silver gull), perched on the seawall, foraging along the tideline, and I suppose yes, tearing at plastic refuse bags left in the street.
They are everywhere, and as much part of Hastings as the fishing fleet, the tourists, and everything else we love so much.
Well, for those of you calling for a major culling, sadly this may be unnecessary. Herring Gull numbers are in serious decline even without the help of culling. As our towns expand along the coast and become busier than ever, so the natural breeding sites for the seabirds has decreased, and fish stock reductions have forced it to find other food sources.
In spite of its adaptability the Herring Gull is now a red listed bird – “ … Recent Breeding Population Decline (1981-2010), Recent Winter Population Decline (1981-2010), Recent Breeding Range Decline (1981-2010), Recent Winter Range Decline (1981-2010)” 1 and along with so many other Red Listed birds, in a generation’s time may well be a rarity, and what a loss that would be.
Species Extinction
The Herring Gull disappear? It is difficult to believe I know. But then when I was a lad, I would not have believed the humble House Sparrow and Starling would be birds at risk in UK – birds that now may require special conservation measures to ensure their survival.
Be careful what you wish for, as they say!
NOTES:
1 British Trust For Ornithology, BirdFacts Herring Gull – https://app.bto.org/birdfacts/results/bob5920.htm.
What a fabulous set of pictures – I so enjoyed these and your informed words of information and support to go with them. Thank you for taking the time and pointing out interesting links. Noticing the bird life around Hastings, above the country park and on the rocks out to sea is a joy. There are two fulmars and two starlings nesting in the cliff near me – it is fun to watch them bonding and protecting the area- including knocking a peregrine sideways one day!
Watching them must be quite special, especially if they have to tackle the odd peregrine or two. It’s surprising how powerful birds like the peregrine don’t always have it their own way!
I notice you refer to the loss of “natural” nesting sites for the herring gulls. But they don’t need them: rooftops, gulleys, flat roofs and especially chimneys give them loads, and conveniently next door to the human rubbish they are largely feeding on.
I do wonder if there are perhaps two groups of these gulls starting to emerge: the ones living on the beach or nearby and foraging there (eg for the shellfish they drop on the beach or prom from a great height) and those which have developed the special “skill” of identifying bags with something edible in them and then tearing them apart, plus descending in large numbers on the parks where people obligingly throw bread at them. Given the chance, they will then attack and kill ducklings and other wildlife there. They are also very good at begging, and some will bang on windows with their enormous beaks until they are rewarded with food. Others hang around cafe tables for the scraps either thrown down or foraged, and the athletes among them will swoop down and grab food from cafe tables or people’s hands.
Not forgetting those people who make a point of feeding whole families of herring gulls, which means they are largely domesticated.
I would like to see some evidence that these birds are declining in numbers. If that is true it must be because we are getting better at protecting our edible rubbish, eg with wheelie bins. Which is a good thing!!!! (unless you love living with rubbish strewn everywhere and the rats having a field day).
I love my wildlife but there has to be some kind of balance otherwise the species we favour and feed take over from others.
Interesting comments Barbara.
The Herring Gull is basically a bird of cliffs and rocky outcrops, which is where its main populations live. But it is a highly adaptable and intelligent bird, and since about the 1930s in UK it has taken to using builds as a nesting site, which is obviously very recent in evolutionary terms.
It has also adapted its diet to scavenging food scraps. This adaptation of course, is in line with the changing habits of people. In the 1930s in UK such vast quantities of food wouldn’t be discarded in the way it is now, nor would people have used plastic bags. And so the Herring Gull’s behaviour has, in a sense, kept pace with our own changing habits.
It’s an interesting point you make about the individuals that have learned particularly clever (or annoying) techniques for acquiring food from people, and passing these techniques on to their offspring. Do they warrant being seen as a subgroup of specialists. I suppose the answer lies in how adaptable that group is when the town’s tourist industry closes down during the winter, or as now, during lockdown. Is that group disadvantaged in anyway, or does it just return to its natural feeding habits? I’m not sure if this question has been studied in any detail. I suspect the answer is that they readily change back. But over a longer period than two or three generations of birds, the situation may be different.
In towns we only see a small sample of the overall population of this bird, and we see plenty of them. But the main population stress is in its traditional breeding areas. Bird Life International estimate that the population has declined by about 30% over the last 30 years. It is vulnerable to new fishing techniques and by-catch. It also appears vulnerable to off shore wind farms, but presumably the main cause of declining numbers is loss of colonial breeding areas and decreasing fish stocks.
Our perception of their numbers in towns probably distorts the overall picture of their population strength.
Having said all of this, they are a very widespread breeding gull. Their overall numbers do not warrant them being Amber or Red Listed, but their recent decline in number is real and continues.
(http://datazone.birdlife.org/userfiles/file/Species/erlob/summarypdfs/62030608_larus_argentatus.pdf)
Last year we saw a peregrine drop like a missile and take a young Herring Gull from a neighbouring flat rooftop nesting area in the Filsham Road area. Though we watched out for it, we only saw it fleetingly once more, and sadly it seems to have moved to more promising hunting grounds so far this year.
The Herring Gull is larger than the Peregrine, and is a powerful birds, but obviously taken by surprise and with such force, it can do nothing. They’re once in a life time events to see!
Yes, herring gulls are very adaptable and clever. It’s true, they are not seen much in some parts of the country but they still should not be on the Red or Amber list if that is to maintain any credibility.
I now think the minority group of them are seeking fish and shellfish on and off the beach while others are living much like rats, off the humans’ rubbish. Some are also paddling for worms on open grass, possibly from both groups. But there is a huge amount of deliberate feeding : chips and white bread especially.
I don’t think we should feed wild animals though I am hypocritical as I restock my bird feeders for the small ones and do my best to keep the cats out of the garden. Humans eh?