Chough report: July 2022

By Charlotte Dean

A successful start to the month: Catch ups!
The start of July brought more ‘catch ups’ at the Sorel aviary. Great success as we caught five ‘choughlets’ in the space of two days – we really must have found them off guard! The most recent chicks in the ‘catch up’ belonged to Lee & Caûvette (one), Percy & Icho (one), Green & Pyrrho (two) and Bo & Flieur (two). Only three were left (see below).

Bidding farewell
This month we said goodbye to our second valued team member for the chough project this year. Jane, a fellow chough enthusiast and a chough field volunteer with Durrell who has dedicated five years of her life to the chough project. It’s sad for her time to be over on the project, like the other staff and volunteers who have been involved in the past but, with time comes growth and new career opportunities. They may be relocating but I’m sure they will miss the chatter within our wild flock. If you are a chough enthusiast, don’t forget that you can help by reporting your sightings of any choughs seen around. Anthony Morin took these wonderful photos at Les Landes:

Harvest season
There are eight species of small mammal in Jersey including four rodents. The choughs’ aviary is more active with rodents in different seasons of the year. At current, it is quite clear that, with all the harvesting being carried out in the surrounding fields, there is a greater abundance of rodent activity as of late. This can pose a problem through diseases they may carry and the holes they create around the overall structure of the aviary itself. A few of the small mammals that have been spotted in Sorel are protected under the Wildlife (Jersey) Law 2021 including the Jersey bank vole Myodes (Clethrionomys) glareolus caesarius, lesser white-toothed shrew Crocidura suaveolens and Millet’s shrew Sorex coronatus. The best way for us to keep the rodents out of the aviary is by reinforcing any entry and exits by repairing aviary netting, covering over holes and, the main factor, keeping any food at the aviary out of reach and/or secured in rodent-proof containers.

This July, Jersey was officially considered to be in a drought. A drought in Jersey is confirmed by 15 consecutive days without measurable rainfall. The last measurable rainfall recorded occurred on Saturday 2nd July. Jersey is known for its limited underground reserves of water and no links to external water networks; therefore, it is important for Islanders to preserve water were possible. Anyone who is environmentally conscious will tell you that we should be using water wisely on a daily basis regardless of the weather; but it is even more important to when the Island is in a drought. There are many ways in which homeowners can reduce their water waste; here are some examples:
• If its yellow, let it mellow – resist the urge to flush a toilet unless completely necessary
• Taking shorter showers, using plugs in sinks to avoid running taps for long periods of time
• Only using the washing machine and/or dishwasher when at full capacity
• Not washing your car (including the ‘choughmobile’) or leaving sprinklers on the grass as often
• Installing ‘low-flow’ equipment to all your water outputs
• Fix your holey clothes instead of throwing them out for new plus shopping in charity shops.

Ok, scrap last month’s “hottest day of the year”
Last month in Jersey we saw soaring temperatures of 33.1°C. However, on Monday 18th July, this was beaten by a scorching temperature of 37.9°! The highest temperature recorded in Jersey previously had been 36°C; this occurred 19 years ago. As summer is still in full swing, we worry what August’s temperatures will bring as things are only getting hotter with global warming. At the Sorel aviary we usually provide just the one water source for the choughs but with these rising temperatures, more water has been provided. The choughs, adults and chicks were all seen gular fluttering at the feed of the 18th; however, it was good to see that they were lining up next to the water trays to make use of the water provided in the aviary.

The last three chicks
It was nearing to the end of the month, and we still had three more un-ringed chicks left to catch up. By this point in chick catch ups; the chicks are getting clever. The choughs know that, when two keepers come to the aviary, they need to be extra cautious, especially those that have been captured recently. But it brings me great joy to state that we caught the last three chicks all together, so now all the chicks that have fledged this year have been captured and colour ringed. We are scheduling a licensed ringer to place Jersey metal rings on the chicks sometime next month. We’ve not seen any more chicks arrive at the aviary now, so our fledged chick count for this year is a very respectable 16. Which is certainly nice as during our Ronez Quarry visit we only counted 14 chicks in the five accessible nests of our breeding pairs.

Table 1. A comparison of chicks found in nests at Ronez Quarry (plus one pair from Plémont), to the number of chicks that have fledged to the aviary this year. 

Study charts global decline of great black-backed gull

From BirdGuides

A newly published study has estimated that the global great black-backed gull population has almost halved within the past four decades.

Using the most recent population counts from across the species’ range, Sam Langlois Lopez and his colleagues analysed population trends at a global, continental, and national scale between 1985 and 2021.

Their results confirmed recent concerns among conservationists that great black-backed gull has been faring badly at both local and regional scales, with widespread declines noted across its North American and European range. The global population is estimated to have declined by up to 48% over the study period from an estimated 291,000 breeding pairs in 1985 to 152,000-165,000 breeding pairs in 2021.

The losses have been most pronounced in North American populations, where the species may have declined by up to 68% since 1985. Although faring comparatively better, European populations have still decreased by up to 28% over the same period.

While there were populations that showed growth between 1985 and 2021, these tended to be smaller and/or were present within a larger state or country where most populations declined. Most increases were recorded in populations on the periphery of great black-backed gull’s range, or in areas that have been recently colonised. These include Spain, Germany and The Netherlands in Europe, as well as North Carolina and Virginia in the US.

The reasons for the decrease are not clear, although are suspected in part to be related to a reduction in the availability of discards from the fishing industry, as well as an overall decline in food availability in the natural environment.

As a result of the findings, Langlois and his colleagues recommend that great black-backed gull should be uplisted from Least Concern to Vulnerable on the IUCN Red List of Threatened Species under criterion A2 (an estimated reduction in population size of more than 30% over three generations).

Read Global population and conservation status of the Great Black-backed Gull Larus marinus here 

Why you should have more sympathy for seagulls

Why you should have more sympathy for seagulls – and how to stop them stealing your chips

From Madeleine Goumas in The Conversation

On a summer’s day at the beach, the sound of seagulls is part of the ambience. But what about when they’re in the middle of a city, or when they’ve just taken your lunch? Not a lot of people like seagulls. They’re loud, messy and quite partial to whatever you’re eating. As annoying as they may be, their reputation for brash behaviour masks a different story.

There are many different species of gulls. The birds most people think of as seagulls, the ones with silver backs and pink legs, are herring gulls.

They’re the species most likely to nest on houses and steal your chips. Because these gulls are increasingly nesting in urban areas, people see them more often. Although it might seem like there are plenty of them, the population is decreasing. Gulls that nest in natural places rather than manmade structures are in dire straits.

All seven gull species that breed in the UK are of conservation concern. Herring gulls are on the UK red list, the highest level of concern.

Some people believe the availability of food from landfills had artificially boosted the number of gulls in previous years, but in reality food poisoning from feeding at landfills as well as culling has contributed to their decline.

A different view

Gulls get a lot of hate for swooping at people, either to get food or when protecting their chicks. Madeleine Goumas thinks people would be more understanding if they imagined themselves in the position of a gull. Most of us were pretty lucky to be born human, and we sometimes take things like food and safety for granted. Gulls can’t rely on a steady supply of food from the supermarket, or know that you aren’t going to hurt their chicks, which both parents diligently care for.

When a female and male pair up, they tend to do so until death. Each pair defends a nesting and foraging territory. The loud calls they make might seem annoying and pointless, but it is the gulls’ way of telling others where their territories lie.

Gulls are what is known as kleptoparasites. They steal food from each other and from other species. This is not unusual in birds but gulls are unusual in that they take food from humans. This is risky behaviour. An animal the weight of a bag of sugar is massively disadvantaged against a human. In fact, only a small minority of gulls are bold enough to do it.

People perceive gulls as greedy. They seem to gobble up anything they can find in one big gulp. But what they’re actually doing is storing food in their crop, a pouch that functions in a similar way to a shopping bag, from which food can be eaten later. From a gull’s point of view, if you don’t take the food that’s in front of you, you might go hungry. It is a result of need, not greed.

They don’t have it in for you, they are trying to find enough food to survive. A study found these clever birds have learned a complicated process to make sea squirts safe to eat. A herring gull has even been observed using bread to bait fish.

Making sense of gulls

Gulls living in towns are very adaptable and savvy. They even learn patterns of human activity to decide where and when to forage. A few years ago Madeleine started a research project to understand gulls’ food-related interactions with humans. She had noticed gulls would often snatch food from people by catching them unaware. Previous research showed several bird species are attentive to human gaze and she wondered if gulls pay attention to where people are looking and prefer to approach food when they aren’t being watched (Project C-Gull).

Madeleine designed a study to test this idea, and timed how long it took gulls to peck at a sealed bag of chips she had placed on the ground in front of herself – once when she was looking at them and once when she was looking away. She found gulls took longer to peck at the chips when she was watching them. Madeleine also found gulls are attracted to food they have seen humans handling, probably because they have learned we often leave food waste lying around.

What does this mean for our interactions with gulls? Well, we can reduce unwanted encounters by disposing of our food waste properly. If we choose to eat our food in a gull hotspot being vigilant will help: look for where gulls are and watch them. Check behind you, sit under an umbrella or by a high wall so that gulls can’t swoop in from out of your sight.

Gulls’ behaviour may seem bad, but we have a lot of scope to change it without resorting to extreme measures. Gulls are making the best of a bad situation caused by our own activities, and our towns may be their last refuge.