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.

References:

The Smithsonian’s National Zoo and Conservation Biology Institute. No date. The maned wolf. Retrieved April 24 2022 from https://nationalzoo.si.edu/animals/maned-wolf.

The Smithsonian’s National Zoo and Conservation Biology Institute. 2020. A Heart to Heart with Maned Wolves . Retrieved April 24 2022 from  https://nationalzoo.si.edu/conservation/news/heart-heart-maned-wolves.

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.

 

 

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 https://www.allaboutbirds.org/news/parthenogenesis-in-california-condors-stuns-scientists/

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.

References

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 https://www.allaboutbirds.org/news/parthenogenesis-in-california-condors-stuns-scientists/

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.

 

Sources:

Ho, Leonard. 2017. Austin company behind glow-in-the-dark fish in pet stores sells IP for $50 million. Austin Business Journal. https://reefs.com/how-much-is-glofish-worth/

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: https://www.rivm.nl/bibliotheek/rapporten/609021118.html

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.

References

Joosse, T. (2022, February 17). Nearly half of bald eagles have lead poisoning. Science. Retrieved April 25, 2022, from https://www.science.org/content/article/nearly-half-bald-eagles-have-lead-poisoning

Preidt, R. (2022, February 21). Eagles are being poisoned by environmental lead. HealthDay. Retrieved April 25, 2022, from https://consumer.healthday.com/b-2-18-eagles-are-being-poisoned-by-environmental-lead-2656673156.html

Hypoxia in the Mississippi River Delta

The Mississippi River Delta is one of the most biologically diverse areas in the United States, teeming with fish, waterfowl, and dense vegetation. The Mississippi River is essential for the maintenance of this estuarine environment, depositing nutrients and sediment into the delta and Gulf of Mexico. However, this mass nutrient deposition causes eutrophic conditions and a large hypoxic zone every year. This “dead zone” can exceed 20,000 square km and can leave potential habitat within the zone uninhabitable.

Hypoxic zone formation is a eutrophication process . Excess nutrients, primarily nitrogen and phosphorus, often enter the river from sources of agricultural runoff and waste. As nutrients flow down the Mississippi River, levels of primary production increase along with organic matter (Rabalais et.al. 2002). Degradation of the organic matter is mostly done by oxygen-consuming microbes which deplete dissolved oxygen.

Excess nutrients and affected primary production have the potential to change the dynamic of an entire ecosystem. One of the most noticeable effects is displacement of aquatic organisms. Fish breathe by buccal pumping where oxygen is filtered out of water by the gills, so depleted oxygen in water decreases survivability, and many swimming organisms cope by simply leaving the hypoxic area (Rabalais et.al. 2002, Bryant 2010). Shifts in partial oxygen can increase the oxygen-binding affinity of hemoglobin. Direct mortality also negatively affects the ecosystem. Fish populations that feed mainly on primary producers increase, while others decrease due to oxygen deficiency and depleted food sources (Rabalais et.al. 2002).

 

References

Rabalais, N. N., R. E. Turner, and W. J. Wiseman. 2002. Gulf of mexico hypoxia, a.k.a. “The dead zone.” Annual Review of Ecology and Systematics 33:235–263.

Bryant, M.D. 2010. Past and present aquatic habitats and fish populations of the Yazoo-Mississippi Delta. Gen. Tech. Rep. SRS–130.

Wildlife Crossings Cross One Risk Off the List

As urbanization spreads and the human population of earth grows, roads and highway systems are expanding to keep up with urban sprawl. It is well known that habitat loss is one of the more detrimental anthropogenic impacts to wildlife. But what about roads specifically can be so harmful to animals? And is there anything we can do to mitigate these impacts?

First of all, the sheer stress that traffic noise elicits can have quite the negative impact. Birds are one unlucky recipient of the brunt of negative effects of roads. Obviously, most birds do not need to cross a busy street on foot and can instead just fly right over. However, birds often have to compete with the loud, low hum of traffic noise when emitting calls to find a mate or defend their territories. Traffic noise has even been shown to cause changes in breeding patterns, increase stress levels, and change how birds interact with their offspring (Halfwerk et al., 2011).

Furthermore, roadways by design fragment wildlife habitat and act as a literal barrier for animals that can prove fatal to attempt to cross on foot. Collisions with vehicles are all too common in cities, as I am sure we all are familiar with seeing an animal laying on the side of the road after an unfortunate encounter with a car or truck. Deer, opossums, squirrels, and even mountain lions (among many other animals) are all examples of creatures who too often meet unfortunate ends while trying to cross a street to find food, a mate, new territory or to escape predation.

So, what can be done to mitigate the impacts roadways have on wildlife? While the impacts from traffic noise are harder to alleviate, there is a solution to help with the fragmentation roads cause and danger associated with attempts to cross them. Enter: wildlife crossings!

Wildlife crossings are exactly what they sound like: a corridor designed to link habitats on either side of a roadway or other barrier, which will help restore landscape connectivity and give wildlife a safe way to cross the street. The first wildlife crossing was built over 60 years ago in Florida. Now, wildlife crossings are often incorporated into early highway planning stages and may even be added as retrofits to existing highways (Clevenger, 2005).

“Wildlife crossing 3” by afagen is marked with CC BY-NC-SA 2.0. To view the terms, visit https://creativecommons.org/licenses/by-nc-sa/2.0/?ref=openverse

Construction has recently started on what will be the world’s largest wildlife crossing, which will span 10 lanes of Highway 101 traffic in Los Angeles. The $87 million project is expected to be completed in 2025 and was primarily designed to give mountain lions a safe way to pass from the Santa Monica mountains, over the freeway, and into the Simi Hills of the Santa Susana mountain range. The population of mountain lions in this area also is suffering from inbreeding and a resulting lack of genetic diversity due to being surrounded by roadways and isolated to their “urban island”, which further underscores the importance of this project (Mossburg, 2022).

California Governor Gavin Newsom has pledged to contribute $50 million to other similar projects around the state (Mossburg, 2022). This project will also likely kick forward other wildlife crossing projects across the country (and perhaps the world). It is time to start incorporating wildlife considerations into our roadway plans to allow for safe passages. Next up, how to deal with all that traffic noise…

 

REFERENCES:

Clevenger AP. (2005) Conservation Value of Wildlife Crossings: Measures of Performance and Research Directions. GAIA 14(2):124-129.

Halfwerk W, Holleman LJ, Lessells CM and Slabbekoorn H. (2011) Negative impact of traffic noise on avian reproductive success. Journal of Applied Ecology 48:210-219.

Mossburg C. (2022, April 25). Construction starts on world’s largest wildlife crossing to let animals roam over 10 lanes of L.A. highway. CNN. Retrieved from https://www.cnn.com/2022/04/23/us/california-wildlife-crossing-scn-trnd/index.html.

Animals are gaining longer appendages in the face of Climate Change

Ectotherms, or animals that regulate their own body heat, have recently been shown having longer legs, tails, or beaks due to increased temperatures (Fearon, 2021). This may seem like a weird adaptation for animals to get on board with, but it makes sense. Endotherms shed heat through their beaks and tails, so having a larger surface area means these animals are able to cool off quicker (Fearon, 2021). Physiologically speaking, as temperatures continue to warm, these individuals will need to find ways to keep their bodies at optimal temperatures because once their body temperatures increase to a certain point they will have other problems to contend with.

Figure 1: The North American dark-eyed junco with a longer then usual beak (modified from Fearon, 2021).

So, as temperatures continue to rise, we may just see more birds like The North American dark-eyed junco showing longer beaks. Or individuals like the Wood Mouse showing longer tails. Or even animals like the Masked Shrew adapting larger legs. So why do we, as humans, care about these changes? It’s important to know that some animals are able to adapt to the quick changes in temperature that we are currently seeing. However, it is important to know that this is not an indication that animals are doing well in the face of climate change (Fearon, 2021). It means they are surviving by adapting in these ways. Climate change is happening quickly, and in most cases, it may be happening too quickly for animals to adapt to (Fearon, 2021).

This is not the only way we see animals adapting to the effects of Climate Change. It is, however, one of the most interesting to see. The adaptations mentioned above are happening at faster rates then we usually see, but they are among the multiple adaptations we will likely be seeing moving forward (Fearon, 2021).

 

References

Fearon, R. (2021). Shape-shifting is how some animals adapt to climate change. Retrieved April 25, 2022, from https://www.discovery.com/nature/shape-shifting-is-how-some-animals-adapt-to-climate-change

Tree Squirrels and Habitat Fragmentation

An American red squirrel. Credit: Gettyimages/iStockphoto

Let’s talk about tree squirrels. More precisely, their habitats.

Tree squirrels are widely distributed across the globe and like to live in wooded areas. As their name suggests, tree squirrels are dependent on trees for food and habitat, often making a leaf nest or living in cavities of trees.

One of the biggest problems tree squirrels face is habitat fragmentation. Habitat fragmentation happens when a habitat gets broken up into smaller disconnected pieces. Sometimes this happens naturally but is usually caused by human activity. Fragmentation can cut individuals or population off from resources in their habitat, and from other organisms, even when quality habitat is available (North Carolina Wildlife Resources Commission).

Photo by Georg Gerster

Here’s an example. You’re a squirrel living in the southern part of a forest, and you often go to the northern part of the forest to because there is more available food and available mates. Some roads and houses get built that block off your access to the other parts of the forest. Now you no longer have access to that source of food and mates. What do you do? Stay where you are, or try to move? Trying to cross a road may be the last time you do it, so choose carefully.

One of the largest problems associated with habitat fragmentation is a loss of genetic diversity. Let’s look at a study done on red squirrels. Loss of genetic diversity can reduce the chances of survival for isolated populations and influence population dynamics (Wauters, 1994). Maintaining genetic diversity is difficult for isolated populations; genetic diversity is still lost when at least one individual joins an isolated population every year (Wauters). However, measuring immigration rate is not always easy. It can be difficult to distinguish between residents and immigrants, and the immigration rate is responsible for genetic diversity in isolated populations, not population size (Wauters).

Squirrels have a very important role in their habitats. They have a habit of taking seeds, burying them, and forgetting where they are. By inadvertently planting seeds, over time squirrels can expand a forest and change the plant composition (Grenrock, 2018). Fragmentation is not just bad for animal populations, but it can affect plant communities over time as well without that method of dispersal.

 

References

“Fox Squirrel – Ncwildlife.org.” Fox Squirrel, North Carolina Wildlife Resources Commission ,2017.

Grenrock, Samantha. “Why Should You Love Squirrels? Here Are Six Reasons.” University of Florida News , 17 Jan. 2018.

Wauters, Luc A., et al. “The Effects of Habitat Fragmentation on Demography and on the Loss of Genetic Variation in the Red Squirrel.” Proceedings of the Royal Society of London. Series B: Biological Sciences, 22 Feb. 1994.

Image 1 Credit: Gettyimages/iStockphoto https://media.npr.org/assets/img/2017/04/25/istock-115796521-fcf434f36d3d0865301cdcb9c996cfd80578ca99-s1200-c85.webp

Image 2 Credit: Georg Gerster Aerial Photography http://www.georggerster.com/en/aerial-photography-worldwide

Ohio’s Newest Vector

As we transition into spring arthropods are starting to make an appearance on humans, domestic pets, and wildlife again. Make sure to keep your eyes peeled for the newest vector of disease infiltrating Ohio, the Asian Longhorned Tick!