Honey I Forgot The Kids

Parent investment strategies across the animal kingdom

By Hunter Doughty

It is not uncommon for potential parents to think about the amount of time, money, or attention, they could provide to their future children. We all want the best for our kids, right? But is this desire to give our offspring the greatest chances for success, or even survival, limited to human beings? Most definitely not. In fact, all animals have strategies for reproducing. And each one of them is attempting to optimize the survival rate of their offspring given their particular circumstances. In ecology, we refer to these evolutionarily refined tactics as ‘parent investment strategies’.

In general, all animals can be placed along a spectrum spanning two opposing approaches to reproduction. These two approaches are known as R strategists, and K strategists. In essence, an R strategist values quantity over quality. They are animals that use sheer numbers of offspring to increase their overall chance of having successful progeny. K strategists, on the other hand, value quality over quantity. These animals invest more energy into fewer offspring to increase each individual offspring’s chance of success. The letters R and K are derived from the mathematical formulas that show biological population trends, but we won’t go into all of that today.¹

Let’s first start with a true R strategist to understand some of the factors at play. Musca domestica, better known as the common housefly, is an insect found across every inhabited continent. Its life cycle includes the following stages: egg, larva, pupa, and adult. On average, a female will lay between 75 to 150 eggs in a single batch, and will lay multiple batches throughout her adult life, totaling an approximate 500 eggs. Each egg contains a single offspring that can go from egg to adult in 6.5 days, and at most, in 58 days. Once an adult, it will reach sexual maturity in as little as 36 hours, and will survive between 15 to 60 days. Astonishingly, this means that in theory “a pair of flies beginning reproduction in April, may be progenitors, under optimal conditions and if all were to live, of 191,010,000,000,000,000,000 flies by August.” ^{2, 3, 4}

Musca domestica (Ref 10)

The common housefly illustrates a number of key traits associated with R strategists: extremely fast maturation time, large number of offspring produced, precocial offspring (meaning they do not need to learn behavior from their parents in order to survive), high mortality rate of offspring, almost no parental care, and a very short life span. This combination of traits makes for a species that is highly adaptable due to their fast generational turnover. And this fact is why R strategists are usually extremely successful in disturbed habitats such as cleared forests, or temporary habitats such as a pile of trash. As shown by the ubiquitous housefly, many invasive pest species fall under the category of R strategists. ^{1, 5, 6}

On the complete opposite end of the spectrum, we find our K strategists. A prime K strategist example is our very own Elephas maximus, a.k.a. the Asian elephant. A female Asian elephant carries her calf for 18 to 22 months before giving birth (that’s almost two years, and its the longest gestation period of any mammal!). The calf then takes an average of three to five years to fully wean off of its mother’s milk, and will not reach sexual maturity until its teens. A male usually reaches sexual maturity around age 14 to 15 and is then known as a bull. At this point he will join a bachelor herd, and will likely not have access to females until he is around age 30, due to the dominance of other older males. A female will reach sexual maturity at about age 14-16, and will usually have her first calf around age 18 to 20. An adult female, known as a cow, can give birth to a single calf every two to four years under optimal conditions, and on average has five to six (and a max of ten) calves throughout her lifetime. A female will stay in her mother’s herd for her entire life, continually learning from the older females. ^{7, 8}

Boonjan and baby Denra here in the Golden Triangle

The Asian elephant’s long-term parenting is a clear depiction of what it means to be a K strategist: very slow maturation time, a few number of offspring produced, larger offspring relative to R strategists, altricial offspring (meaning they must rely on their parents for survival when they are born), lower mortality rate of offspring relative to R strategists, immense parental care, and a long potential life span. ^{1, 9}

How this particular parental investment strategy relates to conservation is important. Because of the life history traits associated with K strategists, these species are often the ones most impacted by human induced change such as loss of habitat due to development, or direct population declines due to hunting. And unfortunately, these same life history traits also mean that these species tend to be the most difficult to save once their numbers have been significantly depleted.

When trying to save a K strategist species, like the elephant, a conservationist has to deal with the fact that an individual of this species is only going to reproduce a few select times over many years. Furthermore, that group of progeny will then take another many years in order to reach sexual maturity so that they may produce the subsequent generation. Which means, that if protection measures are to be effective, they have to be successfully implemented throughout the duration of a vastly large temporal scale. They require the investment and cooperation of many groups, governments, and citizens, to maintain efforts long enough for a species to increase its population to a stable, and self-sustaining, level.

Herd of African elephants (Ref 11)

Across the animal kingdom there are a variety of species that fall somewhere between our two extreme examples. A leatherback sea turtle for example has a long life span, but still lays many eggs at a time that must hatch unprotected and immediately fend for themselves. While a grey wolf, who has a much shorter life span, produces fewer offspring over the course of its lifetime and instead chooses to invest more energy into each young. With all of these parenting tactics in mind, if you yourself are debating whether to have many children with hopes that at least one of them will make it to the professional big leagues, or to only have a single child so that you can afford the best coaches in the country to optimize their training, then just remember that you are not alone in strategizing how best to reproduce.

Leatherback sea turtle hatch-lings, Costa Rica

References:

¹ jaredreser.com/Background/Biology/randkstrategies.htm

² hentnemdept.ufl.edu/creatures/urban/flies/house_fly.HTM

³ the-piedpiper.co.uk/th6a.htm

⁴ en.wikipedia.org/wiki/Housefly

⁵ llink.springer.com/chapter/10.1007/978-1-4020-8644-1_18#page-2

⁶ britannica.com/EBchecked/topic/487821/r-selected-species

⁷ http://library.sandiegozoo.org/factsheets/asian_elephant/asian_elephant.htm

⁸un.or.id/documents_upload/publication/Giants%20on%20our%20hands.%20Proceedings%20of%20the%20International%20workshop%20on%20the%20domesticated%20Asian%20elephant.pdf#page=205

⁹ britannica.com/EBchecked/topic/309092/K-selected-species

¹⁰ howsyourrobot.com/wp-content/uploads/2013/02/wp-House-fly-1680x1050.jpg

¹¹ cache1.asset-cache.net/gc/453691-001-african-elephant-herd-kenya-gettyimages.jpg?v=1&c=IWSAsset&k=2&d=x5iQdYk1Kw%2FnAnImWLpHeJN1UgwER5wTTq9RXS240c4%3D

An Anecdote to Accompany our Assessment of Anthropomorphism

By: Elise Gilchrist

This blog is written as a follow-up to a piece I wrote recently about anthropomorphism and whether or not it is negative to anthropomorphize in the scientific world (http://bit.ly/1t9cfL7).

I was at a press conference recently with Dr. Plotnik, the founder of Think Elephants International. We were at an event in Bangkok and a small conference had been set up to give the journalists some background information about elephants. There were three ‘elephant experts’ available, each at their own table. The journalists essentially had the opportunity to speed date each of the experts by sitting with them and asking questions for a brief period of fifteen minutes before being shuffled on to the next speaker. The panel of experts was made up of Dr. Plotnik, to discuss elephant cognition and conservation, John Roberts, the head of the Golden Triangle Asian Elephant Foundation to discuss captive elephant management, and Tony Nevin, an elephant osteopath to talk about elephant physiology and health.

I was shadowing Dr. Plotnik at the press conference, something I always find beneficial because he has a way of talking about our organization and discussing the research in a way that is scientific but also relatable. That was not what I found most interesting, however. Dr. Plotnik, because he was speaking to three different groups for a short amount of time, wanted to get across the same information in each round, but because this was not a rehearsed speech, there were slight variations each time in how he presented the work. He described the elephant cognition research to each group and I noticed something interesting when he talked about the study on cooperation. For one of the groups he noted, “The elephant had to learn to stand and hold the rope without pulling, waiting for its partner to walk over.” The reporters were intrigued and asked more questions about the implications of the work. We moved on to the next group, but this time when describing the same study, Dr. Plotnik said, “The elephant had to learn to stand and hold the rope without pulling, waiting for its friend to walk over.” Instantly the group reacted with smiles, laughs and questions. It was a palpable emotional response from the group. I believe this might have been due to the phrasing he used, and specifically attributing our anthropocentric notion of friendship to the elephants engaging in the task.

Dr. Plotnik speaking at a different event. This was at the International Primatological Society's Conference in Hanoi, Vitenam.

There are certainly other factors that may be at play in this one instance. For example, it is highly likely that the groups we were talking to were comprised of different human personalities that were predisposed to react differently to the information. It is also conceivable that it was something else in the way Dr. Plotnik presented the information. Regardless, there was one specific difference between the two speeches, the only one I picked up on, and it was the slight variance in wording. It was a difference that made the study relatable to human behavior.

I have also witnessed this effect as a result of information I was presenting about elephants. Here at Think Elephants International, we interact quite a bit with guests at the Anantara Golden Triangle Resort and Spa. A part of what we do is teach guests about all things elephant. During one of these experiences I was describing the social structure of wild Asian elephants. At first I used the term “matriarch” and described her important role as ‘the oldest living female.’ This did not get much of a response from the family I was talking to. Time to try another tactic. I tried again and this time described the family group of all related females, with the oldest living female as the leader, sort of like a grandmother taking care of her daughters and granddaughters. Instantly they understood and were maybe able to relate their family life to elephant family life.

Again these are merely anecdotes, but they do potentially offer a trend. Maybe as scientists talking to the general public, we should be less worried about giving information as it’s presented in a peer-reviewed journal or textbook and instead try to find ways to talk about science so it is comprehendible and even relatable to our audience. The more ways we can find to better communicate science and conservation messages, the better equipped we will be as a global community to make decisions about our world. If used with careful consideration, maybe anthropomorphism is a tool that can be utilized do just that.

Technology in Conservation

Technology permeates most aspects of modern human society, and in recent years, this has come to include methods that specifically address our surrounding ecosystems as well. Several technologies have been developed of late that have both direct and indirect applications in conservation. These range from the monitoring of animal populations using radio collars or unmanned airplanes, to websites that allow important information about human activities within an ecosystem to be readily accessible. And all of these technologies have proven useful tools for the protection of elephants among other species.

Global Positioning System (GPS) collars have been widely used as a conservation tool for over 50 years. The collars allow scientists to track animal movements in order to determine migration routes and habitat use. Animals are immobilized, fitted with collars, and the data from their movements is collected at intermittent periods. Then, using this information, a picture of their locations over time can be generated to show a map of the animal’s home range. This technology is useful in conservation, especially for animals inhabiting dense forested areas where human observation is limited. In more recent years however, real-time monitoring of animal movements has become possible with technological advances. Instead of collecting stored data about animal positions every week, the data can be streamed continuously for analysis. This allows an analyst to visualize the position or trajectory of a collared animal in a geographical information system (GIS) within minutes of its occurrence¹. This technology has the potential to better protect species that are either under immediate risk of hunting or are likely to frequently interact with humans as a threat.

The home range of a white-tailed deer based on GPS information⁷

Particularly in African elephant conservation, real-time monitoring with GPS collars has enabled researchers to monitor the safety of individual elephants and the communities that surround elephant habitat. There are currently over 90 elephants across Africa being tracked². Rangers can use the acquired knowledge of elephant movements within a particular ecosystem to best design their patrol routes in order to protect against poachers. Additionally, the technology can also recognize immobility of a collared elephant. This means that if the individual does not move out of a critical radius an alert can be made to wildlife managers about the possibility of an injured elephant, likely due to poaching¹. Rangers can then be deployed to the site of immobility in an attempt to arrest any present poachers and potentially save the injured elephant.

A bull elephant wearing a GPS collar in Samburu, Kenya

This tracking technology can also be used to prevent human-elephant conflict. This is accomplished through the analysis of geographic intersections, or geofencing. A geofence is a virtual fence line erected around human settlements that can send alerts to wildlife managers if a collared elephant approaches within a certain distance of the line¹. This allows communities to be notified if potential crop-raiding elephants are close. Farmers and rangers can then attempt to deter elephants from eating crops, and drive them away from their village, before the elephant’s damage to a farmers’ livelihood incurs the anger of the farmer. Over time elephants may also learn to avoid these areas where they are harassed and to travel through safer corridors³.

A text message alert from an elephant crossing a geofence²

Drone technology, historically used in the military, has also recently been adapted for use in conservation. One NGO, Conservation Drones, is working to promote the use of these unmanned aerial vehicles in surveying wildlife, mapping ecosystems, and supporting the enforcement of protected areas. The conservation drones are small motorized planes with navigation systems and high definition cameras. The major advantage of this technology is that it can reduce the cost and time associated with traditional ground surveys, especially in dense forest where human access is difficult. Several of these drones have already been used to conduct a census of the orangutans living in a national park in Sumatra, and to monitor seabird-nesting activities along the coast of Australia. They have also been used to protect elephants in Nepal, and several countries in Africa, by expanding surveillance of illegal activity such as poaching⁴.

                Although drones seem to be a beneficial, low-cost conservation tool, a lot of skepticism exists about their use as surveillance technology. The success of conservation projects depends greatly on the support of the surrounding communities, and using drones could alienate the local people. If they feel as though they are being spied upon, then this technology could make relationships with local communities worse, undermining their desire to cooperate in conservation projects⁵. There is also a fear of the technology falling into the opponents’ hands. If poachers are able to hack into the drone technology, they could find target animals even easier. Security of this technology is therefore extremely important to maintain in order for them to be considered an effective surveillance tool. The public stigma associated with drones may have to change for them to prove successful in conservation efforts.

Photographs of orangutan nests in Sumatra taken by a drone⁸

                Information is widely available in the current digital age and more platforms for publically available information are being created with conservation in mind. One of these global databases is a website called WildLeaks, which provides a secure platform for users to share anonymous information regarding wildlife and forest crime. The organization is composed of professionals with backgrounds in law enforcement, security, and investigations. They analyze and evaluate the information received, then decide to launch an investigation or share the information with law enforcement and the media. The goal of the organization is to encourage the sharing of information without the fear of losing anonymity, so that enforcement agencies can more successfully break down the coordinated criminals of wildlife trafficking⁶. WildLeaks has even recently received three separated tips related to the ivory trade in East Africa allowing them to start investigations into the ivory trafficking that is endangering elephants in this area³.

                To further promote awareness through technology, other organizations have embraced a public platform where they can provide transparency about conservation issues. One of these groups is Eyes on the Forest, which has partnered with Google Earth and multiple NGOs in Indonesia to create maps of the deforestation occurring on the island of Sumatra. This island is one of the only places where Asian elephants, tigers, and orangutans co-exist, so it is a critically important habitat to preserve. Eyes on the Forest has created these maps for the public to clearly see where the locations of wildlife ranges, national parks, and legal logging or palm oil plantations occur. They hope this transparency will both allow the community to identify where illegal activities may be occurring, and to place greater public pressure on companies driving deforestation³.

A map of Sumatra showing forest cover in 1985 (light green) compared to 2009 (dark green) created by Eyes on the Forest ⁹

                The combination of technology at work on the ground, in the sky, and via online platforms, is an exciting new hope for the future of many species. It is allowing for conservationists to take alternate and possibly more effective measures to protect individuals at immediate risk, and take-down larger scale networks of environmental threats. Both the African and the Asian elephant are among these species. Through the use of these technologies we can improve our knowledge of their habitat use, implement better techniques to protect them from poaching, and develop management practices that reduce conflict between humans and these magnificent animals.

               

 Resources

¹ Wall, J., Wittemeyer, G., Klinkenberg, B., & Douglas-Hamilton, I. 2014. Novel opportunities for wildlife conservation and research with real-time monitoring. Ecological Applications, 24, 593-601.

² savetheelephants.org

³ thedianerehmshow.org/shows/2014-08-21/how-technology-transforming-conservation-efforts-worldwide/transcript

⁴ conservationdrones.org/mission/

⁵ theguardian.com/environment/blog/2014/jun/26/using-drones-save-elephants-rhinos-backfire

⁶ news.nationalgeographic.com/news/2014/02/140210-wildleaks-wildlife-crime-trafficking-whistleblower/

⁷wildlife.followit.se/projects/tellus-gpsgsm-study-of-white-tailed-deer-in-suburban-philadelphia

⁸ blogs.scientificamerican.com/extinction-countdown/2012/09/27/drones-help-conserve-sumatran-orangutans-wildlife/

⁹ http://maps.eyesontheforest.or.id/