Tag: Birds

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Heating by Thomas Klodowsky

blinding hot sun
a t-shirt in February
confused birdsongs

by Thomas Klodowsky

New Jersey, the state I’ve lived in all my life, just experienced the warmest January on record, and any accumulation of snow seems to be a distant hope. NJ is also one of the fastest warming states of the last 50 years. As nice as it’s felt outside (even reaching over 60 F) so far this year, it makes me nervous for what future winters might hold, confusing wildlife, vegetation, and people.

In fact, evidence is already increasing that early and false springs occurring as a result of climate change are detrimentally affecting bird populations in a number of ways, from disrupting migratory cycles to setting them out of sync with key food sources such as caterpillars.

Further reading:

‘NJ experienced a record warm January. What’s the outlook for the rest of winter?’, NorthJersey.com: https://www.northjersey.com/story/news/environment/2023/02/10/nj-had-warmest-january-on-record-what-will-rest-of-winter-bring/69889744007/

‘False Springs: How Earlier Spring With Climate Change Wreaks Havoc on Birds’, Audubon.org: https://www.audubon.org/news/false-springs-how-earlier-spring-climate-change-wreaks-havoc-birds

‘Climate change leaves birds hungry as chicks hatch too late to eat caterpillars’, The Independent: https://www.independent.co.uk/climate-change/news/climate-change-hungry-birds-chicks-late-caterpillars-spring-woodland-flycatchers-a8318366.html

‘Migrating birds can’t keep up with an earlier spring in a changing climate’, CarbonBrief.org: https://www.carbonbrief.org/migrating-birds-cant-keep-earlier-spring-changing-climate/

Author bio:

Thomas Klodowsky is a writer, writing instructor, and proud New Jersey native. You can see what he’s up to at www.thomask.space

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Darwin’s Finches

islands diverging
beaks for seeds and bugs and blood
letters rearranged

Darwin’s finches are a group of 18 species of passerine birds found across the Galápagos Islands (hence their other name of Galápagos finches). The group are a poster child for Darwin’s theory of evolution by means of natural selection. During his voyage on the HMS Beagle he collected specimens from what later turned out to be 12 of the 18 species, although Darwin himself didn’t realise the significance at the time, not realising they were all types of finch (ornithologist John Gould corrected him about the species) and not recording which islands they came from (he was later able to correctly assign them based on the notes of others on the voyage).

As the finches colonised the islands and began to adapt to the varied habitats and food resources available, the different groups diverged from each other, resulting in the separate species we see today. The finches themselves have a huge variety of forms (likely leading to Darwin’s confusion), most notably in their beak shapes and sizes. Their beaks are highly specialised to the food sources available on the different islands, with different species feeding on nuts, seeds, flowers, nectar, leaves, cacti, and invertebrates (including insects, parasites, larvae and spiders).

Perhaps the strangest of all is the Vampire Ground Finch (Geospiza septentrionalis) which feeds on the blood of other birds such as blue-footed boobies and Nazca boobies. It’s theorised that this behaviour evolved from mutualistic behaviours where the finch would clean parasites from the plumage of larger birds. These days their sharp beaks are used to peck their victim’s skin until it starts bleeding and the finches feed on the blood. Their unpleasant behaviours don’t stop there, however, as they steal eggs and roll them into rocks to break the shells, and they’ll also eat guano – excrement from seabirds. Since fresh water is scarce on their home islands (Wolf Island and Darwin Island), they also feed on nectar from Galápagos prickly pear flowers.

Molecular studies of Darwin’s finches suggests that the timing and spatial expression of at least four genes are responsible for the differences in beak structure, alphabetic changes that led to anatomical changes: BMP4 (which encodes Bone morphogenetic protein 4), CaM (which encodes Calmodulin), ALX1 (which encodes ALX homeobox protein 1), and HMGA2 (which regulates the expression of other genes).

A note about the sciku: this sciku has been written using a scale and focussing structure – narrowing in from the vast islands to the beaks to the individual letters of DNA. Have you ever tried writing sciku with a focussing structure? If so, how did you get on? Let us know in the comments below!

Interested instances of evolution in action? Check out this sciku by Prof Matthew J. James on the classic example of evolution, the Peppered Moth: Dark Moths.

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Urban parakeet by Dr Matt Geary

Urban parakeet
Feeds in small parks and gardens
Missing from forests

By Matt Geary

As with many islands around the world, the island of Hispaniola in the Caribbean is home to a number of bird species found only there. Hispaniola is divided between two countries, Haiti and the Dominican Republic. Both countries have experienced severe environmental change since European colonisation, including considerable forest loss and agricultural expansion. Hispaniolan parakeet (Psittacara chloropterus) is hard to find across the Dominican Republic but a considerable population lives in the capital city, Santo Domingo. Our work explores how these vulnerable island endemics use the urban environment.

In 2019, our research team spent three months walking through parts of the city where parakeets are found, counting birds as well as measuring the natural environment around them. They covered 60 1 km2 squares of Santo Domingo, visiting each square three times. As well as looking for parakeets, they recorded sightings of another endemic, Hispaniolan woodpecker, a species which makes cavities in trees where parakeets are potentially able to nest. The team were also on the lookout for parakeet nest sites in trees and buildings.

Hispaniolan parakeet (Psittacara chloropterus). Image credit: Martingloor.

The population in the city is certainly large. We counted around 1500 birds at a communal roost site in the city centre and saw lots of birds on our surveys. We found that parakeet distribution within the city was related to the number of different tree species within the square and saw more parakeet groups where there were more small greenspace patches. This suggests Hispaniolan parakeets are using street level green spaces like small parks and gardens for foraging rather than relying on large areas of vegetation. We only found three locations where parakeets were nesting, all of which were previously know – one palm tree and two communal roosts in buildings.

This species certainly needs some support across the island of Hispaniola and we hope that by improving our knowledge about this population, which may be the largest remaining, we can help to improve the outlook for the species as a whole. Our work continues on this species and other Hispaniolan endemics. @AndreaThomen is putting the miles in with survey work across the island for her PhD research so we hope to have much more to report in the near future.

Further reading: Geary, M., Brailsford, C.J., Hough, L.I., Baker, F., Guerrero, S., Leon, Y.M., Collar, N.J. and Marsden, S.J., 2021. Street-level green spaces support a key urban population of the threatened Hispaniolan parakeet Psittacara chloropterus. Urban Ecosystems, pp.1-8. https://link.springer.com/article/10.1007/s11252-021-01119-1

Dr Matt Geary (https://mattgeary.github.io/) is a Conservation Ecologist working in the Conservation Biology Research Group at the University of Chester. Twitter: @MattGeary

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Owls of the Eastern Ice by Jonathan Slaght – Book Review

a fish owl
on an icy river bank
grabs more than fish

by Jon Hare.

Jonathan Slaght’s book “Owls of the Eastern Ice” is part natural history and part adventure story. The natural history focuses on Blakiston’s fish owl, the largest living species of owl. The adventure focuses on Dr. Slaght’s research on the Blakiston’s fish owl in the Primorye territory of Russia – a rugged region in the Far East bordering the Sea of Japan, North Korea, and China. The region is home to Amur tigers, Asiatic bears, masu salmon, and Blakiston’s fish owls. The region is also home to villages, logging companies, and loners – all living off of the land.

Dr. Slaght’s task is to understand the owl and then develop a conservation plan that the logging companies and local communities can support. This is a well written narrative that is as much a story of the human condition as it is a description of the work necessary to better understand and conserve the fish owl.

Slaght, J.C. 2020. Owls of the Eastern ice: A quest to find and save the world’s largest owl. New York: Farrar, Straus and Giroux, 368 pp. ISBN: 9781250798718

Dr. Jon Hare is a scientist who works in Woods Hole, Massachusetts. His research background is fisheries oceanography and climate change impacts on marine fisheries. Check out Jon’s previous sciku ‘Varves’, ‘Cobwebs to Foodwebs’, ‘Signs of Spring’ and ‘Glacier Mice‘.

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Pickled – Not Pickled

Hidden, protected.
Ancient bird beneath acid,
DNA preserved.

DNA from extinct species can be hard to get – obtaining bone or tissue samples is tricky and degradation of those samples over time can result in vast swathes of the genome missing or heavily fragmented.

Yet, as a new study by Oswald et al (2019) suggests, there are circumstances where samples can be remarkably preserved across hundreds and even thousands of years.

The study used bones found in Sawmill Sink, a blue hole in the Bahamas. The Sawmill Sink has a top layer of fresh water, a hydrogen sulfide layer and then a bottom layer of saltwater. The hydrogen sulfide layer forms a barrier that limits UV light and oxygen from getting to the lower saltwater. As a result, the various bones found on floor of the blue hole are remarkably well preserved.

Oswald et al (2019) were able to recover a nearly complete mitochondrial genome from a 2,500 year old bone of an extinct bird species – Caracara creightoni. Genetic analysis of the ancient DNA suggests that the species is sister to a clade containing the Northern Crested Caracara and the Southern Crested Caracara, birds of prey in the Falconidae family found in Central and South America. The work highlights the huge potential for similarly recovered fossils to illuminate our understanding of species and populations in the past.

The title of this sciku is Pickled – Not Pickled. This refers to the hydrogen sulfide layer in Sawmill Sink which forms sulfuric acid where it comes into contact with the fresh water layer above, making it extremely hard for divers to get through and discover the bones beneath. Whilst the bones themselves were not in the sulfuric acid, they were preserved by it making them in essence pickled whilst not actually being pickled.

Original research: http://dx.doi.org/10.1016/j.ympev.2019.106576

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Small and spherical

Small and spherical,

the eggs of forest blue tits.

Urban differences.

 

Populations of many species live in different environments that provide varied resources and have differing selection pressures. Research by Bańbura et al (2018) investigated the eggs of blue tits living in a forest environment compared to a nearby urban park.

The researchers found that urban-dwelling blue tits produced eggs that were on average 5% larger than their forest-dwelling counterparts, and the urban eggs were less spherical as well. These differences are potentially the result of blue tit diets in each environment – the forest is caterpillar-rich but calcium-poor whilst the urban park is the opposite, with 5-6 times the density of snails which have calcium-rich shells. The smaller, rounder forest egg shape requires less calcium compared to the less spherical urban egg shape.

Original research: http://dx.doi.org/10.1186/s12983-018-0279-4

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You aren’t one of us.

Help! Help! Predator!

Guys, why aren’t you helping me?

You aren’t one of us.

 

Jackdaws respond to anti-predator calls to join the caller in mobbing the predator and driving it away. Yet researchers have now found that who the caller is will affect the level of response.

In playback experiments Woods et al (2018) that the highest response was to nestbox residents who would be highly familiar with the caller. The level of response to an anti-predator call diminished as familiarity decreased from colony members to non-colony members and then to rooks (a species that often lives alongside jackdaws).

Original research: http://dx.doi.org/10.1038/s41598-018-25793-y

 

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Sqeamish ossifrage by John Norwood

Delectable mouse

in defiance, stands to face

sqeamish ossifrage

The ossifrage, more commonly known as the bearded vulture, prefers to feed on dead animals, feeding predominantly on the bone marrow as opposed to the meat. It will on occasion kill living animals, with its main prey being tortoises which it drops onto rocks to break them open.

This haiku celebrates a defiant mouse but was inspired by a secondary meaning. In my study of cryptography, I recently de-crypted a challenge with the solution: ‘the magic words are squeamish ossifrage’ which, as it turns out, is a phrase frequently incorporated into the solution of cryptographic puzzles since 1977.

Further reading: The Magic Words Are Squeamish Ossifrage

John Norwood is a Mechanical Engineer working with Carbon, Inc. to revolutionize how things are made. His interests include old houses, yoga, baking, cryptography, and bluegrass music. You can follow him on Twitter under the handle @pryoga

Enjoyed this sciku? Check out some of John’s other work: Universal truth, The answer is none, God may be defined, With enough data, and Rivers cut corners.

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Beak trimming distaste

Beak trimming distaste,

yet long beaks lead to poor health.

Best of a bad bunch?

 

Sometimes it’s better to cause harm for the right reasons rather than allowing worse harm to occur. Egg-laying barn hens typically have their beaks trimmed to reduce pecking damage but this practice results in pain and sensory loss for the birds. As a result the practice of beak trimming is being debated worldwide and some countries have already banned it based on welfare concerns.

Riber and Hinrichsen (2017) compared the welfare of trimmed and non-trimmed flocks of hens across 10 separate farms and across 62 weeks. They found that beak trimming actually resulted in higher conditions of hen plumage, skin and keel bones, as well as decreased mortality. Whilst beak trimming seems distasteful, this evidence suggests that it may be the best option after all.

Original research: https://doi.org/10.3389/fvets.2017.00222

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Little peepers

Nocturnal Kiwi.

Redundant little peepers –

can survive blindness.

 

Most birds have excellent vision, even those that are active under low light conditions. In contrast the kiwi has the smallest eyes relative to body mass of any bird and poor vision. In fact, kiwis have been observed surviving in good condition in the wild despite being completely blind (Moore et al, 2017). Kiwis instead have sensitive auditory, olfactory and tactile somatosensory systems which they use to navigate the world and survive.

Original research: https://doi.org/10.1186/s12915-017-0424-0

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Their noses know

How do shearwaters

navigate across oceans?

Their noses know ¿no?

 

Many birds travel hundreds of miles across oceans with no obvious sign posts to help them find their way. So how do they navigate?

Padget et al (2017) manipulated the olfactory ability of shearwaters and then tracked them as they made free-ranging foraging trips across the Mediterranean Sea. Shearwaters that were anosmic behaved as normal whilst foraging but on their return trips they were not oriented towards their colony – they found the coastline within 40 km from their colony and travelled the rest of the way along the coast. In contrast the control birds found their colony with a significantly greater degree of accuracy. This suggests that shearwaters use an olfactory map to navigate across open water successfully.

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The kids help out

Staying at home, the

kids help out. Breeding becomes

cooperative.

 

In cooperatively breeding species individuals help to raise offspring that are not their own, but how did this costly behaviour evolve? By comparing 3,005 species using phylogenetic analyses Griesser et al (2017) suggest that cooperative breeding in birds occurred in two stages.

First, families formed by the prolonging of parent-offspring associations, with chicks not leaving the nest when nutritionally independent. This appears to have occurred in productive environments where the cost of the offspring remaining at home for longer is less.

Second, the offspring remaining at the home nest then start to help out. In contrast to the formation of family units, the researchers suggest that this happened in more variable environments where the retained helpers can buffer in harsh years.

This theory helps to explain the geographic distribution of cooperatively breeding bird species too – areas where these species are found have often experienced historical declines in productivity. The pre-decline environment may have fostered family formation whilst the decline may have then resulted in the step to cooperative breeding.

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Pray, are you a predator?

Have we met before?

Pray, are you a predator?

I am so naive!

 

Predators are a threat for most animals and gauging whether a novel species is dangerous or not can be a life or death judgment. Whilst some species may have a degree of innate predator recognition, research suggests other species require prior experience of the predator to learn of its danger.

Great and blue tits were tested with novel and familiar predators. Tits from populations familiar with both sparrowhawks and little owls reacted towards the stimuli as expected, mobbing the predators equally. But tits from populations only familiar with sparrowhawks did not treat the little owl stimulus as a threat, suggesting it wasn’t recognised as a predator. Prior experience of predator species is therefore important in great and blue tits. Carlson et al, 2017.

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Tiny migration

The dusky grouse wait,

girding their loins for the trip –

Tiny migration.

 

As the seasons change many species migrate across hundreds or even thousands of miles to reach fertile breeding or feeding grounds. In contrast, the North American dusky grouse (a species of blue grouse) may sometimes migrate less than a mile, with females travelling shorter distances than males (Cade & Hoffman, 1993). Often these tiny distances are travelled on foot rather than flying.

The migration is so small that the species is recognised by Guinness World Records as being the shortest bird migration at 300 meters (although individual birds have been recorded as travelling even shorter distances) and has featured on the BBC quiz show QI.

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Just a warm up

Oh how sweet dawn’s song!

Yet this choral crescendo

is just a warm up.

 

Many of us enjoying waking up to the sound of birdsong. But whilst we might enjoy the various trills and tweets as the sun rises, the Adelaide’s warbler’s song actually improves over the course of the morning. To appreciate the best of its voice, perhaps the early bird doesn’t catch the worm! Schraft et al, 2017.

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Unhappy Whio

Unhappy Whio –

Your populations estranged,

split by the Cook strait.

 

The rare blue duck (named the Whio in Maori after the male call) is found on the North and South islands of New Zealand. The genetics suggest that the populations on the two islands diverged in the late Pleistocene, with very limited gene flow since. The current conservation strategy not to translocate individuals between the populations is therefore sensible so as to avoid potentially negative issues arising from crossing distant genetic pools. Grosser et al, 2016.

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When courting

When courting with song

do take turns with your neighbour –

Gentlemen hermits!

 

Male long-billed hermits (a sub-group of humming birds) form leks to attract mates by singing, but competing birds close together could overlap singing and confuse each other’s song. To counter this, males close together coordinate to alternate singing bouts whilst males further away from each other (and not at danger from vocal obscuration) overlap their songs. Araya-Salas et al, 2017.