Kulasisi

 

I have occasional fantasies of blogging or even column-writing, but remind myself that neither of these endeavors will pay the bills. And as an academic, I simply do not have the time. But once in awhile, I indulge the fantasy. 

Gentle Reader, please be kind with me.  I write drafts then don't publish. This particular text draft is from 4 years ago,  I think. It was written when we were still living in the lovely lush campus of UP Visayas. Now my family and I living in the grey concrete jungle of Quezon City. There are many upsides, but I do miss the campus and our wild neighbors. 

This particular wild neighbor is from an even earlier time, waayy back in 2018. It would be nice to believe he stuck around and made more babies -- all I know is that I never saw the Kulasisi in our banana tree again. Long live the UPV kulasisi.

- - - - 

[from 2021ish (text) and 2018 (photos)]

 Forgive me for a terrestrial post this time! While I’m a marine biologist, there’s so much amazing terrestrial fauna where I currently live that I can’t help but share some of it.

So I’m a city kid. I grew up in the urban jungle of Metro Manila. But I always pined for nature, and now that I live in a rural part of the Philippines, I get excited about critters that rural and suburban folk take for granted. Like the ubiquitous tuko (Gekko gecko or tockay gecko)! I can’t get over how beautiful and huuuge and LOUD they are. And all the birds!  From our house windows alone, I’ve spotted 21 species!! We had moved to Iloilo from the small Pacific island of Guam. The native flora and fauna of Guam have been ravaged by colonial activities, the endemic birds in particular wiped out by the invasive brown tree snake. At our house on Guam we only had Eurasian tree sparrows around. So to see and hear so many birds around the home every day is something I do not take for granted.

Here’s one of my favorite window bird sightings. It’s the kulasisi (or colasisi, Loriculus philippinensis subsp. regulus)! Endemic to the Philippines and listed as critically endangered on the Philippine Red List, this hanging parrot is nonetheless considered ‘common*’, even making appearances in cities. When I shared my spotting with my birder friends, they ho-hummed at my excitement. Whatever. Common it may be for birders, but for a city slicker like me, it was still a terribly exciting wildlife spotting!

I got to know this particular individual rather well. Like clockwork, ‘Kulas’ would show up on this banana heart (infloresence) every morning at 8h30. He (I know he’s male because of the red throat patch) would land on the heart and root around the new blossoms, causing them to fall.

On this particular day, a male tamsi (Cinnyris jugularis or olive backed sunbird) also wanted to feed on the sweet, sticky banana nectar, and got pretty upset with the green visitor. Here’s some shots of the tamsi trying to shoo the kulasisi away. It didn’t work, the parrot just ignored the littler guy.

When the banana heart got small, Kulas stopped visiting. I was hopeful he would come back because another banana flowered soon after. Alas, Kulas hasn’t made a reappearance. I hope he is still out there somewhere. And that he’s making more kulasisi babies on campus. I read that they make their nests on dead wood - this is a bit of a worry, as wood is harvested for firewood or charcoal around here.

*the reason why the kulasisi is listed as critically endangered despite being common is because of the 10 geographically separated subspecies, the Cebu and Mindoro ones have very small populations. Perhaps one day ornithologists will split the subspecies up into new species.

Source: Philippine Red List of 2020, freely available here: http://www.biodiversity.ph/wp-content/uploads/2020/08/PRLC-Book-vertebrates.pdf

[guest student post] Ecological Corridors in Fragmented Urban Habitats

 

As she arrived at the bushes, she started preparing a refuge. Pieces of herbaceous plants and dried leaves were lodged steadily. Soon enough, she was joined by her mate. Putting strips of plastic and twigs together took weeks to finish.

The first egg was laid on the nest. One more egg was laid the next day.  The mother was keen on incubating both eggs. It lasted a few days. 

After some time, one four-day-old chick was gaping to be fed. The other would crane its neck up. Both parents were tirelessly looking for food, and once one meal was delivered, they flew off to find more.

Then there was a low, distant hum and it grew louder like a rattling sound. The trees began to fall in different directions, and the young birds were startled by the noise. Because of the perceived danger, they thought of flying, but they were too young.

Chirp! Chirp!

The parents came back shocked. One hatchling was lying on the ground. Trees were falling everywhere but they must find the other one, so they kept on looking. In despair, the female bird cried and left after all of the chaos around her.

Not everybody will hear her. No one would know that she just lost her child. Everyone is juggling with paperwork and deadlines. Someone’s got to pay rent, find a job, and feed a family. Why would they ever notice a bird’s agony?

Do you know that they are warm-blooded animals and have a four-chambered heart, just like us? A similarity often overlooked. But birds don’t really look like us—they have feathers. They lay eggs. Definitely, not us! Unless you lay eggs, too.

When a bird’s natural habitat is altered by urbanization, it can cause some dramatic problems. There is noise from road traffic and construction machinery. Obviously, there is plastic consumption from fast-moving consumer goods. Concrete absorbs more heat, causing warmer temperatures, an “urban heat island effect.” Excessive artificial lights installed in the city cause light pollution.

The pressure of living in the city takes a toll on some birds, while others cope well with the new conditions. Noise may disturb communication between songbirds and affect their breeding productivity¹, causing a decline in their abundance². Chinese bulbuls can use plastics as nesting material, showing adjustment to the materials available in the city³. While birds from temperate regions can benefit from urban heating⁴, urban heat islands can cause heat stress and dehydration to some birds in the tropics⁵. Changes to the behavioral patterns of nocturnally migrating birds due to urban lights can also be energetically expensive⁶.

Aside from altering bird behavior, urbanization increases habitat fragmentation. Habitat fragmentation is when a large expanse of habitat is converted into smaller, isolated patches. After the transformation, the properties of the remaining habitat are also changed⁷. Habitat fragmentation is estimated to be responsible for habitat degradation and 75% of terrestrial biodiversity loss⁸.

Habitat fragmentation also reduces ecological connectivity. It impedes the movement of species, as well as the flow of natural processes⁹. Connectivity loss will limit birds’ dispersal abilities, affecting their breeding activities and reproductive success¹⁰. Birds are also seed dispersal agents that maintain plant communities, and the loss of connectivity may eventually result in loss of green space¹¹.

Loss of connectivity highlights the importance of identifying potential safety passages known as “ecological corridors.” These ecological corridors (see figure below) provide links to restore and maintain ecological connectivity to areas that have become isolated due to fragmentation. They are not a substitute for protected areas, but should nonetheless be established to maintain connectivity between isolated patches¹².

Typical components of terrestrial ecological networks.¹³

Recently, researchers have deduced effective parameters for identifying and designing potential ecological corridors by using target species like birds. Birds are mobile organisms that can provide links or flow between fragmented habitats. Their likelihood or unwillingness to move through a land cover can be mapped and used in connectivity analysis¹⁴.

Some planners use patch size as a basis in identifying priority corridors for birds like Maya because these birds prefer larger patches as nesting, foraging, and breeding sites, while corridors for Bulbul are based on vegetation types since their nesting and breeding sites are located near urban gardens and food resources¹⁵.

Yellow-vented Bulbul (Pycnonotus goiavier)
Tigayon, Kalibo, Aklan
8 April 2021 11:32 AM
Nikon D3200 ISO1600, 300mm, f/5.06 1/250

These birds are commonly found in different parts of Southeast Asia. They are well adapted in the city but prefer densely vegetated areas. They are mostly recognized by their bright yellow vent—hence their name, Yellow-vented Bulbuls.
Bulbuls are frugivorous. They can swallow whole fruits and berries of 8-10 millimeters. They adjust their nesting and breeding sites near food resources and make their untidy nests in urban gardens and trees near wetland and farmland. For bulbuls, the important parameter for designing ecological networks is the vegetation type.¹⁶

Eurasian tree sparrow (Passer montanus)
Tigayon, Kalibo, Aklan
22 May 2021 04:43 PM
Nikon D3200 ISO400, 85mm, f/4.0, 1/400

They are commonly called Maya in most parts of our country. Although these birds are found almost everywhere in the Philippines, they are believed to be introduced by the Spaniards.
Mayas are chestnut-capped with black patches on cheeks. They are mainly granivorous, feeding on grains or seeds on the ground, but they can even feed on garbage.
They build nests in hollows of buildings and trees and prefer larger patches for movement and forage. For Maya, the important parameter for designing ecological networks is the patch size.¹⁷

Apart from patch size and vegetation type, patch distance is also used. Planners identify how far a bird can disperse a seed from one place to another, or move to breed or nest. Both Maya and Bulbul have a dispersal capability of 1 km. Their seed dispersal ability, breeding, and nesting behavior depend on many factors. For example, they are most likely to choose shorter pathways near food sites, to spend less time traveling and avoid fewer hazards¹⁸.

Patch distance, size, and vegetation are some of the parameters that represent how birds behave in a habitat. These are measured to identify potential corridors. Visualizing them on a larger scale like in an urban landscape can be very difficult.

To resolve this issue, urban planners use models to predict how these birds might “move” between patch sites. In modeling, they use software applications like Circuitscape to map and estimate these movements by incorporating parameters like patch size and vegetation types. The model can also predict “which route” will facilitate greater movements for birds by calculating the distance traversed by birds between habitat patches¹⁹.

Today, most urban planners are developing better models to further understand how ecological connectivity works in different habitats. Each habitat has a different set of species, vegetation, and size. Such variations seek to address different strategic plans that will effectively establish and implement appropriate ecological corridors, especially in areas that require protection and conservation management that is greatly affected by habitat fragmentation.

These corridors could just be a small pathway of bushes and trees that may seem of no value to you—but they are important to those birds that are impacted by large-scale clearing operations that build residential houses, roadways, power plants, and malls. Those birds constantly move to look for resources — find shelter, food, and nesting grounds. A little bit of habitat will give them enough space to move around but if we continuously block their way, we could end up losing their population. Just like how the female bird lost both her children.

About the Author: Jessica Carlos grew up in Taguig and now lives in Kalibo. In her spare time, she enjoys taking photographs and watercolor painting as creative pursuits.

Literature Cited:

[guest student post] Parasite Eve in Eden: Modelling Anisakis Distribution in the Marine Environment

 

Guest post by Earl Jeroh Bacabac

 

 

Figure 1. The life cycle of Anisakiasis-causing worms. Courtesy of the Centers for Disease Control and Prevention of the US Government.

 

            You had Kinilaw earlier today and you were invited to eat with friends later. Your barkada decided to eat Sashimi. You experienced a tingling sensation as you savor the dish and you were wondering why. You recalled that you’ve just had two raw fish dishes, and you know there are risks to eating food raw. Things were normal as you go your way, but within 12 hours, the tingling was accompanied by nausea and you are discomforted by abdominal pain. Any time now, you might feel like vomiting.

What I presented to you, ladies and gentlemen, is the common mode of entry by which a person might get infected by marine parasitic worms and some symptoms that manifest with the condition “Anisakiasis”.

Anisakiasis is named after the nematode which causes the disease. Worms of the genus Anisakis are common parasites of a wide range of aquatic organisms. Public interest with them can be phrased as the following question: “How the hell did it get into the fish in my dish?”

We know for a fact that parasites rely on their hosts to be able to complete their life cycles. To understand how Anisakis infections are acquired and to be able to manage them, Kuhn and colleagues (2016) modelled the distribution of nine Anisakis species using the Maxent approach.

When we lack of knowledge on how an organism is distributed in the environment, we turn to models to predict how they “might” occur in nature. Maxent is one approach by which we can predict the distribution of organisms. Maxent is a software program that aims to predict where species occur by finding the distribution where they are most spread out, while taking into account the environmental variables of their known locations and prioritizing them in terms of their influence on distribution. Maxent is useful for Anisakis as the development and dispersal of its eggs are influenced by environmental factors such as salinity, temperature, and ocean currents (Kuhn et al., 2016).

To refine their model, the authors included data on each parasite’s definitive hosts, or the host organisms where the parasite is able to reproduce. This is because the distribution of the intermediate and adult stages of Anisakis is shaped by the movement of its different hosts in those life stages; which are crustaceans, fishes, and ultimately, marine mammals as definitive hosts. The resulting Maxent model would then map the distribution of each Anisakis species as influenced by both their environment and their specific hosts.

Six environmental factors were found to be important drivers of distribution in the Anisakis species: distance from land, mean sea surface temperature, depth, salinity, range of sea surface temperature; as well as primary productivity (or how fast producers convert energy from the environment into food for different organisms).

Among these variables, temperature-related factors and salinity highly influence distribution because they affect how eggs of Anisakis hatch and how long they live. Higher temperatures favor faster egg hatching but shorten their life spans, while salinity lengthens the lives of the individuals. Meanwhile, distance from land is linked directly to the definitive hosts rather than the parasites.

The “hotspots” where most of the Anisakis species are located are in waters of the Mediterranean, around Japan, the North American coasts, as well as in the waters of the North Atlantic; areas with extensive fishing and where many economically-important fishes are caught.

 

Figure 2. Pseudoterranova decipiens, one of the Anisakiasis-causing parasites. Courtesy of Matthieu Deuté under Creative Commons BY-SA 3.0.

 

            You might think immediately that where the hosts are located should overlap exactly with those of Anisakis, right? Apparently, the distribution of the parasites doesn’t always overlap with the diversity hotspots of its definitive hosts and vice versa. This is very interesting as this suggests that the Anisakis species are located in more areas, or have a wider distribution than presently recorded.

One species they modelled, Anisakis simplex, has never been reported in the South Atlantic even if the area is highly suited to the species, based on their model. These can be due to limitations of egg dispersal in A. simplex or its associated definitive host species, which is a marine mammal.

Fish are intermediate hosts of the parasites and in a way, anisakiasis can be framed as if we are mistaken by the parasites as their definitive hosts, which if you recall, are also mammals. Thus, we end as “accidental hosts” of the parasites.

Reliable data on the intermediate hosts’ locations often come from areas which are more accessible and studied. These regions do not always overlap with those where the parasites are obtained, and this disparity affects the mapping of the parasite’s distribution.

Sampling disparities are also the reason why the authors emphasized that the inputted data on parasite and hosts distributions affect the Maxent model, regardless of its promise. Since some regions are more studied than others, this affects Maxent’s algorithm, which builds upon the known distribution of the parasite and host species being examined.

Hence, the authors warned that the diversity hotspots for Anisakis and its hosts might differ from the actual occurrences in nature. This inaccurate representation would then reduce the reliability of their model, and so they reminded that interpretation of the results of any approach or model should be handled carefully.

Nonetheless, this study provides valuable insight into the biogeography of marine parasites; a field brimming with questions (Rohde, 2016) waiting to be answered.

Literature Cited

Kuhn T, Cunze S, Kochmann J, Klimpel S. (2016). Environmental variables and definitive host distribution: a habitat suitability modelling for endohelminth parasites in the marine realm. Scientific Reports. 6: 30246. doi: 10.1038/srep30246.

Rohde, K. (2016). Ecology and Biogeography, Future Perspectives: Example Marine Parasites. Geoinformatics & Geostatistics: An Overview. 4. 10.4172/2327-4581.1000140.

 

Blog owner's note: As a culminating activity to my MS Biology class in Biogeography, I asked my students to write a blog post on a topic in biogeography. We welcome constructive comments on this student piece.

 

About the Writer

EARL JEROH I. BACABAC

Earl’s love for the sea fueled his goal to become a marine biologist. He obtained his Bachelor’s Degree in Biology from the University of the Philippines Visayas while also being a Department of Science and Technology scholar. His passion for the marine environment is rivaled by his diverse interests in music, the arts, and video games.

 

He is also a freelance content writer and can be commissioned through the following social media platforms:

 

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