Tuesday, January 31, 2017

How to Get Animal Experience

Who wouldn't want to do this??
Photo provided by Bridget Walker.
Many of us grow up dreaming of someday becoming a veterinarian or animal trainer or zoo keeper. We raise pets and try to save the baby animals we find in the yard. We work hard in school and are mesmerized by Animal Planet. But what does it really take to make it into one of these coveted fields? A key factor to being competitive in any of these jobs is having lots of experience working with animals in lots of different ways. But there is a catch: to get a position working with animals, you need to have experience working with animals. So how are you supposed to get your foot in the door?

Snuggles! Photo by Jenna Buley.
The most reliable way to get animal experience is to volunteer, since most paid positions that work with animals are out of reach for those that do not have significant animal-handling experience. There are many different places that need volunteers to help with animal care. Local pet shelters, such as the Humane Society, are always looking for volunteers. For large animal experience, stables and animal farm sanctuaries are often looking for help. If you are looking for wildlife experience, many local wildlife rehabilitation centers and zoos will also accept volunteers. And if you are the adventurous type, there are ecotourism groups that can connect you with wildlife sanctuaries abroad that are looking for temporary volunteers (some are even geared towards pre-vet students). Granted, these volunteer positions are not glamorous: they don’t pay, they are hard work, and they generally involve cleaning lots of poop. But generally, the more you do, the more you will be allowed to do. And if you commit to at least 6 months to a year, you will make yourself competitive for other positions that work with animals.

Awww... as tempting as it is to pick up an adorable baby skunk,
don't do it unless you are a trained and licensed wildlife rehabilitator
(like this woman is). Image by AnimalPhotos at Wikimedia.
If you already have some animal experience under your belt, you may want to apply for some paid positions that work with animals. Zoos, aquariums, sanctuaries, and rehabilitation centers frequently have paid internships. Animal hospitals hire veterinary assistants, animal caretakers and receptionists with little to no animal experience. Stables and farms hire staff to care for their animals as well. In all of these cases, the larger and more famous the institution, the more competitive the applications will be and the more experience you will need to get a paid position.

Once your foot is in the door, you can move up the ranks into more exciting and fulfilling positions. Keep in mind that employers and veterinary schools are looking for both breadth and depth when it comes to animal experience. Having experiences at a variety of different places with a range of species will make you more competitive. Also, you want to stay in the same place for a long time (months to years) to gain the depth of animal-handling knowledge that employers and vet schools are looking for. But, if this is the career path for you, you may not want to leave anyway.

For more advice on working with animals, check this out.

Sunday, January 22, 2017

Nature Shapes Faithful and Unfaithful Brains

Among monogamous animals, some individuals are more faithful than others. Could these differences in fidelity be, in part, because of differences in our brains? And if so, why does this diversity in brain and behavior exist?

A snuggly prairie vole family. Photo from theNerdPatrol at Wikimedia Commons.

Prairie voles are small North American rodents that form monogamous pair bonds, share parental duties, and defend their homes. Although prairie voles form monogamous pairs, that does not mean they are sexually exclusive. About a quarter of prairie vole pups are conceived outside of their parents’ union.

Not all male prairie voles cheat on their partners at the same rates. In fact, some males are very sexually faithful. It turns out, there are both costs and benefits to being faithful and to cheating. Mariam Okhovat, Alejandro Berrio, Gerard Wallace, and Steve Phelps from the University of Texas at Austin, and Alex Ophir from Cornell University used radio-telemetry to track male prairie voles for several weeks to explore what some of these costs and benefits might be. Compared to males that only sired offspring with their own partner, unfaithful males had larger home ranges, intruded on more territories of other individuals, and encountered females more often. However, these unfaithful males were also more likely to be cheated on when they were away (probably because they were away more). I guess even rodents live by The Golden Rule.

Maps of how paired male voles in this study used space. The solid red/orange/yellow peaks show where a faithful male (in the left map) and unfaithful male (in the right map) spent their time in relation to where other paired males spent their time (showed by open blue peaks). Image from the Okhovat et al. Science paper (2015).

Vasopressin is a hormone that has been found to affect social behaviors such as aggression and pair bonding when it acts in the brain. Mariam, Alejandro, Gerard, Alex, and Steve all set out to determine how vasopressin in the brain may relate to sexual fidelity in prairie voles. They found that faithful males had lots of a particular type of vasopressin receptor (called V1aR) in certain brain areas involved in spatial memory. Surprisingly, faithful males did not have more V1aR in brain regions typically associated with pair bonding and aggression. A male that has more V1aR in spatial memory regions might better remember where his own mate is and where other males have been aggressive, which would decrease the chances that he would intrude on other territories in search of other females and increase the time that he spends home with his own mate. A male that has less V1aR in spatial memory regions might be less likely to learn from his negative experiences and more likely to sleep around.

Photos of a brain section from a faithful male (left) and unfaithful male (right). The dark shading shows the density of V1aR vasopressin receptors. The arrows show the location of the retrosplenial cortex (RSC), a brain area involved in spatial memory. Faithful males had significantly more V1aR receptors in the RSC compared to unfaithful males. Image from the Okhovat et al. Science paper (2015).

The research team then found genotype variations that related to having lots or not much V1aR in one of these spatial memory regions (called retrosplenial cortex … but we’ll just call it RSC). They confirmed these findings with a breeding study, in which they reared siblings that were genetically similar, but some had the genotype they predicted would result in lots of V1aR in RSC and some had the genotype they predicted would result in very little V1aR in RSC. They confirmed that these genetic variations correspond with the amount of vasopressin receptor in this specific spatial memory area.

The researchers then looked closer at the different versions of this vasopressin receptor gene in the RSC brain region to see if differences in the amount of vasopressin receptors in RSC may be caused by the epigenetic state of the gene (i.e. how active the gene is). They found that the genotype that results in very little V1aR in RSC had many more potential methylation sites, which can repress gene activity.

All of this data together tells a very interesting story. Male prairie voles that have the genotype for more V1aR vasopressin receptors in their RSC part of their brain are more likely to remember where their home and mate are and to remember where other aggressive prairie voles are, which will make them more likely to spend more time with their partner, to be sexually faithful and to have sexually faithful partners. Male prairie voles that have the genotype for less V1aR in their RSC are more likely to forget where their home and mate are and where other aggressive prairie voles are, which will make them more likely to cheat and to be cheated on. Overall, faithful and unfaithful male prairie voles have roughly the same number of offspring, but advantages may emerge with changes in population density. Prairie vole populations vary anywhere from 25 to 600 voles per hectare from year to year. When population densities are high, you (and your partner) are more likely to encounter more potential mates and it may benefit you to cheat (and have a “cheater’s brain”). When population densities are low, you (and your partner) are less likely to encounter more potential mates and it may benefit you to be faithful (and have a “faithful brain”). But when populations fluctuate between high and low densities, both faithful and unfaithful genotypes will get passed along from generation to generation.

Want to know more? Check this out:

Okhovat, M., Berrio, A., Wallace, G., Ophir, A., & Phelps, S. (2015). Sexual fidelity trade-offs promote regulatory variation in the prairie vole brain Science, 350 (6266), 1371-1374 DOI: 10.1126/science.aac5791