Climate change speeds up bird molts- making them look older, faster

Molting patterns vary amongst different types of birds; some transition from their juvenile plumage to their adult feathers in one single molting cycle, while others may take years to reach their fully matured plumage.In the West Palearctic, encompassing Europe and parts of the Middle East and north Africa, songbirds typically lean towards the latter option, molting some of their feathers in one cycle and molting the rest at later points in time.3  As it is energetically costly to grow feathers, spreading molts out over longer periods of time can help offset energetic costs.  However, there is a reproductive tradeoff: the presence of juvenile feathers signal that the bird is young and not as competitively fit as an older bird with a whole set of adult feathers.  Interestingly, however, climate change may be changing up these molt patterns.3

The relationship between climate change and migration patterns has been well-studied; for short-distance migrants like many of the West Palearctic passerines, warming temperatures have led to them leaving for their wintering grounds later.2  Kiat et al. (2019) looked at the plumages of juvenile birds over 212 years and saw that their molting grew more extensive with climate change.  As they molt right after the breeding season, before migrating to their winter range, this change in migration timing may be giving birds more time to molt.3  They also saw that female birds have been molting more extensively than males in recent years, a reversal of past trends.3


Figure 1.  Diagram representing the increase in molt over time in two West Palearctic songbirds.  Adapted from Kiat et al. (2019)

     For birds, these changes in molting may affect their reproductive and social interactions.  A bird that molts its nest-grown feathers faster may look mature sooner than they did in past years.  On one hand, as Kiat et al. note, this may give younger birds an advantage in the reproductive scene, as quickly replacing their juvenile feathers allows them to compete with the older birds with regards to the attractiveness of their plumage.  On the other hand, looking more mature may also attract attention in the form of aggression from older birds, something that the juveniles may not be prepared to handle.3

The effects of this trend are in many ways still unstudied, and the effect of climate change may operate differently depending on a bird’s molt pattern and the climate conditions in which it lives.  For instance, birds like gulls and eagles may need as many as five years to reach their adult plumage, while smaller songbirds reach their mature plumage much sooner and may feel the effects of climate change more strongly.1  Either way, this phenomenon shows just how all-encompassing climate change can be, and how there are even more effects that researchers have yet to discover.

  1. All About Birds (2008) The Basics: Feather Molt. (last accessed 23 April 2022).
  2. Jenni L and Kéry M (2003) Timing of autumn bird migration under climate change: advances in long–distance migrants, delays in short–distance migrants.  R.  Soc.  Lond.  B.  270:1467–1471.  doi:10.1098/rspb.2003.23942.
  3. Kiat Y, Vortman Y and Sapir N (2019) Feather moult and bird appearance are correlated with global warming over the last 200 years.  Commun.  10, 2540(2019).  doi: 10.1038/s41467-019-10452-1.


Electro Sensory and Turbidity: American Paddlefish’s Decline and Outlook

Polyodon spathula

Figure 1: American Paddlefish (image courtesy of U.S. Fish and Wildlife Service)


The American Paddlefish (Polyodon spathula) or spoonbill as they are often referred to due to their paddlelike snout, is a large and ancient fish that has survived relatively unchanged since the late cretaceous period around 68 million years ago when dinosaurs walked the earth. They can be found throughout North American in the Mississippi River Basin. While they are a protected and rare state threatened species in Ohio, they are found most commonly in Ohio River tributaries downstream of the first dams; particularly in the Scioto River south of Columbus (Rice and Zimmerman 2019). In Ohio, they can grow to a maximum size of 5′ and 184lbs, however fish ranging from 2-4′ and around 20-30lbs are much more common (Rice and Zimmerman 2019). The cause for their decline was attributed to increased turbidity, or suspended particles like clay and silt, and being cutoff from suitable spawning areas to reproduce due to the construction of dams (Rice and Zimmerman 2019). In order to understand why turbidity has impacted these fish so much and why their populations are beginning to rebound as water quality improvements t0 the rivers has been made, you must first understand how they feed.

Filter Feeding:

Despite their massive size and tough exterior, these fish are filter feeders that prey mostly on small plankton crustaceans, which are small organisms that float freely in the water. You may be wondering how it is possible for the paddlefish to eat enough of these organisms to grow to such a large size. Luckily for the paddlefish, they are excellent filter feeders like Humpback Whales. Having been described by early naturalists as “A living plankton net” these fish have hundreds of gill rakers that form a tight mesh that collects plankton as they swim around with their large gaping mouths open as seen in Figure 2.

Figure 2: Paddlefish gill rakers (Courtesy of John Lyons of Virigina Tech)

But what purpose does the paddle serve?


The paddle or rostrum was once thought to have been used to dig through the stream substrate foraging for food, but research has proven that it is actually an electro sensory organ covered in sensory pores (Figure 3) used by the paddlefish to detect the weak electrical currents plankton give off (Wilkens and Hofmann 2007). In a study published in 2007, researchers ran feeding experiments on juvenile paddlefish where they placed the paddlefish in dark tanks and witnessed them able to seek out single small crustaceans that were placed in the tank (Wilkens and Hofmann 2007). They also noted that they would avoid metallic objects in the tank, even in the dark, as this likely interfered with their perception of electrical currents which may also hint at a further impact locks and dams could have on paddlefish by disrupting their ability to navigate rivers and access spawning habitat after dams were constructed (Wilkens and Hofmann 2007). If paddlefish can locate food even in the dark or muddy waters, then why has increased turbidity impacted them so much?

Figure 3: Paddlefish rostrum and closeup of electro sensory pores (Helfman et al. 2007)


The issue with increased turbidity is largely due to their ability to finely filter feed. Some studies have shown that 50% of the gut content of some paddlefish was detritus (decomposing organic material like small leaves) and sand (Pyron et al 2019). Under highly turbid conditions, paddlefish gill rakers may become clogged with materials that are suspended in the water, making them unable to filter feed plankton effectively. In addition to not being able to filter feed as effectively, other studies have linked high turbidity to reduced growth of plankton species (Kirk and Gilbert 1990). Despite the paddlefish’s ability to find food solely using electroreception, they’d still struggle to find food as plankton growth can be reduced, leaving them less food in water with high turbidity.


At present, water quality in Ohio has been steadily improving after legislation like the Clean Water Act in 1972 and many fish species have since begun to bounce back after having been impacted by habitat and water quality degradation (Pyron et al 2019). As water quality continues to improve and many old and outdated dams are removed; granting these fish access to places to spawn, we can be hopeful that conservation efforts to protect this ancient Ohio fish will be successful and future paddlefish will be free to filter feed all they want.



Helfman, G., Collette, B. B., Facey, D. E., & Bowen, B. W. (2009). The diversity of fishes: biology, evolution, and ecology. John Wiley & Sons.

Kirk, K. L., & Gilbert, J. J. (1990). Suspended clay and the population dynamics of planktonic rotifers and cladocerans. Ecology71(5), 1741-1755. Lon A. Wilkens, Michael H. Hofmann, The Paddlefish Rostrum as an Electrosensory Organ: A Novel Adaptation for Plankton Feeding, BioScience, Volume 57, Issue 5, May 2007, Pages 399–407.

Pyron, M., Mims, M. C., Minder, M. M., Shields, R. C., Chodkowski, N., & Artz, C. C. (2019). Long-term fish assemblages of the Ohio River: Altered trophic and life history strategies with hydrologic alterations and land use modifications. Plos one14(4), e0211848.

Rice, D. L., Zimmerman, B.. (2019). A naturalist’s guide to the fishes of Ohio. Ohio Biological Survey.


The maned wolf is undeniably an interesting animal; it’s the largest canid of South America, looks like a fox while being called a wolf, but is in reality neither a fox nor a wolf, and is the only member of its genus. The maned wolf is found in central and eastern South America, and monogamous pairs occupy  a territory of approximately 10 square miles, and due to their size, they remain protected from other carnivores surrounding them. The only animals that have been found to prey on the maned wolf are the puma and domestic dogs. Despite their size and omnivorous status, the number of maned wolves is rapidly declining, with less than 5,000 believed to live outside of Brazil. The main cause for the rapid decline of this animal is human interaction (The Smithsonian’s National Zoo and Conservation Biology Institute n.d.).

The maned wolf. Picture credit: The Smithsonian’s National Zoo and Conservation Biology Institute, 2020.

The maned wolf’s natural range in Brazil overlaps more with agricultural land than protected land, meaning these animals are surrounded by human activity as they go about their daily lives. The close interaction with people, as well as the expansion of agricultural land, puts the maned wolf at risk for elevated stress levels which could contribute to decreasing population numbers. When studying hormone levels from fecal samples, it was found that thyroid hormone levels were elevated in agricultural areas indicating better nutrition, progesterone levels decreased as maned wolves moved away from protecting lands, indicating a dropping level of reproductive success, and glucocorticoid levels increased as wolves moved into areas with more human activity, indicating elevated and prolonged stress. Despite the ease of finding food, the increased human activity is primarily negatively affecting the maned wolf (Vynne et al. 2014).

The heart rate of maned wolves in captivity has also been a subject researchers have been interested in recently. The maned wolf’s heart rate can drop as low as 30 beats per minute, but in moments of extreme stress their heart rate can increase to over 330 beats per minute. Researchers have been observing their reactions and heart rates in response to various activities and loud noises in order to better understand what activities specifically stress these wolves out (The Smithsonian’s National Zoo and Conservation Biology Institute, 2020). As habitat loss continues, the maned wolf is being forced to interact with humans, and gaining a better understanding of how human activity is impacting this unique animal will hopefully contribute to the continued conservation efforts.


The Smithsonian’s National Zoo and Conservation Biology Institute. No date. The maned wolf. Retrieved April 24 2022 from

The Smithsonian’s National Zoo and Conservation Biology Institute. 2020. A Heart to Heart with Maned Wolves . Retrieved April 24 2022 from

Vynne, C., R. K. Booth, S. K. Wasser. 2014. Physiological implications of landscape use by free-ranging maned wolves (Chrysocyon brachyurus) in Brazil. Journal of Mammalogy 95: 696-706.



Big City Bats

An LED Floodlight, Image by Leon Brooks. Retrieved from

Throughout the world, more and more people are living in urban areas. We’re called by the glimmering lights, the whirlwind of activity, the sights and sounds of the big city. Some of these same factors that draw people to cities are what drive other animals away–or, in many cases, cause harm to the animals who stay.

For bats, who are most active at night, urban light pollution can pose some major issues (Laforge et al., 2019; Langley, 2019; Seewagen and Adams, 2021). Artificial light can be disorienting for nocturnal animals, disrupting their circadian cycles and changing their typical activity levels throughout the day (Seewagen and Adams, 2021). Further, high levels of light leave species that are used to the cover of darkness vulnerable to predators (Cravens and Boyles, 2018; Laforge et al., 2019). Still, some bats–individuals or entire species–choose to spend more time foraging in lighter areas because UV lights attract their preferred food choice: insects (Cravens and Boyles, 2018; Langley, 2019; Seewagen and Adams, 2021).

So how does the presence of light impact the bats who choose to stay?

Seewagen and Adams (2021) found that several species of bats reacted to the presence of LED floodlights by greatly reducing their foraging activity. Migratory tree bats tended to not be impacted by light or even be attracted to it, while nonmigratory species tended to avoid light areas (Seewagen and Adams, 2021). Little brown bats (Myotis lucifugus) have been found to have difficulty avoiding obstacles in highly-illuminated areas, indicating that light may have some impact on their sensory systems, including systems involved in orientation (Seewagen and Adams, 2021).

Little Brown Bat, Image by Moriarty Marvin, USFWS. Retrieved from

Cravens and Boyles (2018) focused on the differences between levels of the blood metabolite beta-hydroxybutyrate in bats found in lit and unlit conditions. Beta-hydroxybutyrate is a fasting metabolite, and is used for energy in metabolic processes when triglyceride fat storage is low. Interestingly, this is not the exact case in bats: beta-hydroxybutyrate levels spike after feeding–so they are correlated with periods of intense exercise (Cravens and Boyles, 2018). For red bats (Lasiurus borealis), beta-hydroxybutyrate levels were highest just after sunset in highly-lit sites, while the opposite was true in dark sites (Cravens and Boyles, 2018). Cravens and Boyles (2018) suggest that red bats have altered their foraging activity to prey on insects at lit sites just after sunset, while other bats may forage throughout the night. Also, red bats captured at lights late at night had low levels of these blood metabolites, suggesting that they were able to gain more energy from well-lit areas with less work (Cravens and Boyles, 2018).

Despite this positive impact on foraging in some bat species, high levels of light pollution can negatively impact bat diversity and species abundance in urban areas (Laforge et al., 2019; Langley, 2019; Seewagen and Adams, 2021). Seewagen and Adams (2021) were only able to detect little brown bats on 14% of light nights, while they were able to hear little brown bats calling on 65% of dark nights. Laforge et al. (2019) had similar results, with artificial light being a significant predictor of bat presence and activity, as well as their ability to move through their landscapes.

While artificial nighttime light can provide light-tolerant bats with novel foraging opportunities, finding ways to mitigate the impacts of nighttime light can greatly improve bat biodiversity. The most obvious solution is to turn out the lights–reducing nighttime light can help bats expand their species range by providing opportunities to safely move between habitat patches (Laforge et al., 2019). With less light, bats will be better able to avoid predators, and their sensory systems and circadian cycles may fall back in line. However, reducing light is not enough to truly improve bats’ habitat quality (Laforge et al., 2019)–and it is not the only option. Increasing urban greenspace can provide bats with shelter from predators in the form of tree canopy cover (Langley, 2019). Bats may even be able to strike a balance–enjoying the benefits of insects attracted to UV lights while remaining safely covered (Langley, 2019).

Whatever the solution may be, one thing is for sure: providing safe habitats for bats is necessary for supporting pollination, controlling insect populations, and preserving biodiversity in a changing world.

Works Cited

Cravens, ZM & Boyles, JG (2019) Illuminating the physiological implications of artificial light on an insectivorous bat community. Oecologia 189:69-77. doi: 10.1007/s00442-018-4300-6

Laforge, A, Pauwels, K, Faure, B, Bas, Y, Kerbiriou, C, Fonderflick, J, & Besnard, A (2019) Reducing light pollution improves connectivity for bats in urban landscapes. Landsc Ecol 34:793-809. doi: 1o.1007/s10980-019-00803-0

Langley, L (2019, April 17) Light pollution hurts urban bats. Trees can help. National Geographic.

Seewagen CL & Adams, AM (2021) Turning to the dark side: LED light at night alters the activity and species composition of a foraging bat assemblage in the northeastern United States. Ecol Evol 11(10):5635-5645

Image 1 source:

Image 2 source:

The California condor can reproduce asexually

Parthenogenesis, a form of asexual reproduction in which females produce viable offspring without male contribution, is not typically associated with species of birds – more so with amphibians, fish, and reptiles. In fact, it has only been documented in a few species, including domestic chickens and turkeys1. However, a recent study has found that two female California condors in captivity had each produced a chick via this process, despite being continuously housed with males with whom they had previously produced offspring1.

California condor. Photo by Patrick Sysiong, from

The California condor (Gymnogyps californianus) is a critically endangered bird native to California, whose numbers dropped all the way to 22 individuals in 19821. Thanks to a robust breeding program, the number of California condors in captivity steadily increased, and birds were being successfully released back to the wild – in 2019, there were 219 individuals in captivity and 306 in the wild1. Of course, with such a small starting population there is a genetic bottleneck – a very limited pool of genes available for breeding, which could result in genetic defects. Scientists kept careful track of each bird and its genes to avoid this as much as possible, and this allowed the discovery in 2021 of two chicks which had been produced by parthenogenesis2. The mothers of these chicks had been housed consistently with reproductively capable males, who had fathered many of their other chicks – but not these particular chicks, who were both male and had been released into the wild2. Parthenogenesis is difficult to assess in wild birds because it requires a good understanding of an individual’s genes, as well as their parent(s) and the parents’ genes in order to identify2. The identification of these two chicks as products of parthenogenesis is a step towards better understanding factors that trigger this process in birds, and in establishing it as a mechanism of reproduction in some avian species.

Unfortunately, the two chicks produced by parthenogenesis both died relatively young compared to average California condor lifespans in the wild, and neither were able to father offspring in that time2. Further studies involving more birds produced by parthenogenesis would be necessary to gain a better understanding of how this method of reproduction could impact a bird’s ability to survive in the wild and whether this is a viable option for increasing population numbers for the California condor. However, it’s possible that this may be another mechanism by which population size can be increased in some species including the California condor when access to breeding pairs may be limited.


1 Ryder OA, Thomas S, Judson JM, Romanov MN, Dandekar S, Papp JC, Sidak-Loftis LC, Walker K, Stalis IH, Mace M, Steiner CC and Chemnick LG. (2021). Facultative Parthenogenesis in California Condors. Journal of Heredity 112:569-574.

2 Powell H. (2021). Parthenogenesis In California Condors Stuns Scientists. All About Birds. From

New Zealand Tourism Consequences on Yellow-eyed Penguins

Yellow-eyed penguins at Katiki Point in New Zealand. Photo taken by Iain McGregor. Retrieved from


The yellow-eyed penguin is endemic to New Zealand and is also a popular cultural icon in New Zealand (Katz, 2017). However, over the years these penguins have faced population declines and are now considered to be endangered. Human disturbance has a large impact on the population of yellow-eyed penguins. A large cause of population declines comes from unregulated tourism (McClung et al., 2004). Since these penguins do not have many habituation opportunities, they are more sensitive to human tourism (French et al., 2018).

Tourism impacts stress, reproduction, and behavior in yellow-eyed penguins (Ellenberg et al., 2007). The presence of humans around these penguins causes an increase in stress-induced corticosterone. If this stress is prolonged or frequent, it can result in decreased fitness and survival in adults (Ellenberg et al., 2007). This increased stress can also impact the behavior of adults and their reproductive success (French et al., 2018).

Tourists often will ignore fences and signs in order to get closer to the penguins (Huffadine, 2018). Penguins in these touristed areas have lower breeding success and lower fledgling weights (McClung et al., 2004). A large reason for this is that the presence of tourism will cause the stressed penguins to change their behavior to avoid the humans. These changes in behavior include a decrease in the time spent at their nest, an increase in travel time, and an increase in the likelihood of nest abandonment (French et al., 2018). These changes in the behavior of adults cause negative impacts on the survival of their children.

Parental care is an important factor in the growth of fledglings. However, with the adult penguins spending more time avoiding the nests because of tourism, the fledglings receive lower provisions. Continuously missing meals or missing a meal during a year with poor food supply can lead to lighter fledgling weights and even death (Huffadine, 2018). Lower fledgling weight can have long-term population consequences like lower survival and recovery rates (McClung et al., 2004). It is important for humans to better mitigate the impacts of tourism in order to help protect this endangered species.


Ellenberg U., Setiawan A. N., Cree A., Houston D. M., Seddon P. J. (2007) Elevated hormonal stress response and reduced reproductive output in Yellow-eyed penguins exposed to unregulated tourism. General and Comparative Endocrinology, 152(1):54-63.

French R., Muller C., Chilvers B.,  Battley P. (2019). Behavioural consequences of human disturbance on subantarctic Yellow-eyed Penguins Megadyptes antipodes. Bird Conservation International, 29(2), 277-290.

McClung M. R., Seddon P. J., Massaro M., Setiawan A.N. (2004) Nature-based tourism impacts on yellow-eyed penguins Megadyptes antipodes: does unregulated visitor access affect fledging weight and juvenile survival?, Biological Conservation, 119(2):279-285.

Katz B. (2017) New Zealand’s Yellow-Eyed Penguins May Be in Trouble.

Huffadine L. (2018) People with selfie sticks are harming endangered yellow-eyed penguins.

The Growing and Glowing Threat to Native Brazilian Freshwater Fish

By: Ashlyn Halseth

Glow-in-the-dark fish were first created in the late 1990s by the National University of Singapore by genetically modifying zebrafish (Danio rerio) with fluorescent proteins obtained from sea anemones (Entacmaea quadicolor) and jellyfish (Aequorea victoria; Wan et al. 2002). In 2001, an Austin-based company began to commercialize these fluorescent zebrafish, and rebranded them with the name, GloFish. GloFish took the exotic pet trade by storm and was sold to Spectrum Brands for $50 million in 2017 and is continuing to grow in popularity (Ho 2017). As of 2022, the Glofish company has expanded its collection of fluorescent fish, and now produces and distributes genetically modified bettas (Betta splendens), short-fin and long-fin tetras (Gymnocorymbus ternetzi), barbs (Puntius tetrazona), and sharks (Epalzeorhynchos frenatum), together known as the GloFamily.

Photo is property of GloFish

The entire GloFamily is available for purchase in the USA and Canada, but is prohibited for sale in Mexico, South Africa, India, Indonesia, Australia, New Zealand and throughout the entire European Union (Van Den Akker & Wassenaar 2012). Most recently, Brazil has prohibited the commercialization of the first species of GloFish, the green-fluorescent zebrafish, after hearing reports of this fish making its way out of aquariums and into the local waterways (Tuckett et al. 2017). The non-fluorescent species of zebrafish, from which the GloFish is modified from, is native to the freshwater streams and rivers of the Western Ghats and parts of the Himalayas in India (Magalhaes et al. 2021). It was previously thought that the GloFish wouldn’t be able to survive outside of its native home ranges or controlled aquariums as they were modeled to be unable to forage for food or reproduce efficiently (Khee 2006). However, since the GloFish introduction to Brazilian waterways within the past decade, this has not been the case.


Brazil is home to the Muriae Ornamental Aquaculture Center, the largest Brazilian fisheries establishment that has 250 different species of aquarium fish, 350 fish farms, and 4,500 production ponds (Magalhaes et al. 2021). In practice to maintain these facilities, routine pond drains happen eight times a year, only 1-6 meters away from local waterways full of native fish. Many fish farms have physical barriers to prevent the introduction of non-native fish into local waterways; however, the Muriae Ornamental Aquaculture Center has no retention or detention ponds and is hypothesized to be the source for some non-native introductions (Magalhaes et al. 2020). As mentioned above, the green variant of the zebrafish, referred to as GloFish, has been detected in Brazil’s streams and rivers, and are thriving.

GloFish, in their native home range, are prompted to start reproducing in response to the South Asian monsoons; however, the GloFish have easy acclimated to Brazil’s climate, as the summer months experience similarly high levels of rainfall as well (Magalhaes et al. 2021). This increase in water levels allows for easier communication between breeding pairs and even allows for increases in breeding grounds and food availability for their young after they hatch. In fact, the climate of Brazil is so favorable, that the GloFish breeding season ranges from 8 months to the entire year. Furthermore, GloFish are generalist feeders, meaning they have the ability to consume almost any species of prey to meet their energetic demands. With this natural history tactic, GloFish can feed across the entire Brazilian water column, with the dominant prey source being aquatic insects, but also algae, zooplankton, terrestrial prey, and more (Magalhaes et al. 2021).

Although more studies need to be conducted to understand the full impact GloFish have on their introduced community, it is thought that this non-native species could be detrimental to the native freshwater fish populations found in Brazil’s waterways. Being a generalist feeder, Glofish have the potential to consume large quantities of small prey species, harming the invertebrate community and therefore putting a strain on other species of fish that consume the same prey (Magalhaes et al. 2021). Furthermore, GloFish in laboratory settings have been documented to be aggressive towards other fish, through nipping and biting (Karga & Mandal 2017). Their large diversity of diet and aggression towards other species could lead to them out-competing native Brazilian fish, which serve important ecological and economic roles (Magalhaes et al. 2021).

While the individual species of GloFish in Brazil’s waterways still need to be addressed, there is hope for preventing the introduction of introduced species in the future. In Brazil, it is illegal to release genetically modified species, intentionally or unintentionally, like GloFish, into the environment. Also, many biologists, like Magalhaes et al. (2021) have proposed steps to prevent future introductions. Education remains at the forefront of this plan, with a push towards the production of native species instead of non-natives for aquariums, installation of filters to prevent unintentional introductions, introducing native predators into contaminated areas, and more legislative bans to prevent the commercialization of non-native species. With all of these practices and more innovative approaches, highlighting the impacts GloFish have on native fish communities, one can hope that GloFish will remain a sought-after pet, and not an ecosystem terror.



Ho, Leonard. 2017. Austin company behind glow-in-the-dark fish in pet stores sells IP for $50 million. Austin Business Journal.

Karga J, Mandal S. 2017. Effect of different feeds on the growth, survival and reproductive performance of zebrafish, Danio rerio (Hamilton, 1822). Aquac. Nutr. 23(2):406–413.

Khee SW. 2006. Possible ecological impacts caused by GFP transgenic zebrafish, Danio rerio [PhD Thesis].

Tuckett QM, Ritch JL, Lawson KM, Hill JE. 2017. Landscape-scale survey of non-native fishes near ornamental aquaculture facilities in Florida, USA. Biol Invasions. 19(1):223–237.

Magalhães ALB, Daga VS, Bezerra LAV, Jacobi CM, Silva LGM. 2020. All the colors of the world: biotic homogenization-differentiation dynamics of freshwater fish communities on demand of the Brazilian aquarium trade. Hydrobiologia. 847(2):3897–3915.

Magalhães ALB, Brito MFG, Silva LGM. 2021. The fluorescent introduction has begun in the southern hemisphere: presence and life-history strategies of the transgenic zebrafish Danio rerio (Cypriniformes: Danionidae) in Brazil. Studies on Neotropical Fauna and Environment: 1-13.

Van Den Akker HCM, Wassenaar ALM. 2012. Potential introduction of unapproved GM animals and GM products in the Netherlands (RIVM report 609021118). Bilthoven: National Institute for Public Health. No. 609021118:

Wan H, He J, Ju B, Yan T, Lam TJ, Gong Z. 2002. Generation of two-color transgenic zebrafish using the green and red fluorescent protein reporter genes gfp and rfp. Mar Biotechnol. 4(2):146–154.

Lead Poisoning in Bald Eagles

Nearly driven to extinction in the 1960 due to the use of the pesticide DDT, the Bald Eagle has a long history of facing incredible struggles to their populations. After their listing on the Endangered Species Act and the banning on DDT, Bald Eagle populations made an impressive recovery (Joosse, 2022). However, lead poisoning has been increasingly imperiling this species in recent decades. Bald Eagles often consume remnants of lead gun ammunition and angling gear when consuming their prey, which has led to a dramatic increase in lead poisoning (Preidt, 2022).

A recent study that involved surveying eagles from 38 states found that nearly half of all Bald Eagles have lead poisoning (Joosse, 2022). Upon consumption, lead travels through the eagle’s bloodstream and through the liver, and can build up in their bones (Joosse, 2022). Symptoms of lead poisoning in Bald Eagles include seizures, diarrhea, impaired motor function, and even death.

Another study found that lead poisoning has resulted in a 3.8% decrease in population growth for Bald Eagles (Preidt, 2022). Additionally, it was found that lead poisoning is more common in older individuals, which could have impacts on population dynamics.

Lead poisoning is becoming a more pressing threat to Bald Eagles, and could have long-term impacts on population dynamics and growth. While populations of Bald Eagles are still growing, it is important to ensure we don’t make the same mistakes we did before with this symbolic species.


Joosse, T. (2022, February 17). Nearly half of bald eagles have lead poisoning. Science. Retrieved April 25, 2022, from

Preidt, R. (2022, February 21). Eagles are being poisoned by environmental lead. HealthDay. Retrieved April 25, 2022, from

Stressed Out Doggies

Did you know that your hair can indicate how stressed out you are? A recent study from Utrecht University found that dogs in shelters have higher levels of the stress hormone cortisol in their hair than non-shelter dogs. Regardless of how well the shelters treat their animals, they are often still stressed out, which is a great excuse to go rescue a dog in my opinion!

A Thankful Rescued Pit Bull. Photo by Luke Holben (2022).

The researchers examined the hair of many shelter dogs when they arrived, during their stay, and once they were adopted and placed into their new forever-homes. They found that the dogs were more stressed out during their stay than when they arrived, but after they were adopted the stress levels began to drop to normal levels. The dogs were so relieved to be in their new homes! Adopting dogs from shelters is extremely rewarding, but only adopt if you are sure you can care for your new best friend. I have personally adopted two dogs, one of which is the beautiful pit bull pictured above, and I would not trade them for the world.



Utrecht University. (2022, April 21). Cortisol in shelter dog hair shows signs of stress. ScienceDaily. Retrieved April 25, 2022 from