Noisy Birds

So here is an interesting one. A new study is being conducted about the effects of urban noise on nestlings.

No one ever really thinks about the effects of the noise we make; cars, factories and even just regular household noises like children playing or loud music. Birds are just a part of everyday life. Seeing nests (at least for me, and I know definitely for kids) is super exciting. If you find a nest that is low enough, I know most are tempted to look inside to see what kind of fun stuff is in there. All the shuffling people do. Driving and noise making.

Imagine yourself as a bird. Naturally nesting and residing in woodlands. The only noise is the rain, wind and other animals. Then humans come and bring strange smells, substances and sounds. Birds now need to compete with us, calling and communicating over every day noises we unwittingly create.

                So now to the study. It was hypothesized that urban noise would have an effect on the efficiency of communication between parents and their nestlings. Birds have certain calls to communicate whether there is danger in the area or they are coming home with goodies for the babies. The nestlings react accordingly when they hear these different calls. The test was conducted by presenting sparrow tree nestlings noises adult sparrows make when approaching the nest with food and warning for a predator. Background noise was added to the calls and the reactions of the nestlings were compared. It was found that nestlings failed to beg when there was background noise as well as failed to stop begging and crouch down when predator calls were made.

(Picture of a tree swallow taken by  Hugh M. Vandervoort)

This effect is significant since birds are just as important as deer and wolves and even insects. They contribute to the ecosystem, balancing the world around us, and even enrich our lives. The mis- communication between mother and chick puts the lives of the nestlings in danger. Kills by predators may pose a greater risk in birds that nest within human communities than that once thought  when compared to birds raised in the wilderness.

With our populations growing exponentially, we could see less and less of Mr. and Mrs. Robin visiting our feeder in the back yard. Less of those adorable barn swallows flying around eating bugs as you mow the lawn.

Horn made an important statement that ‘most people think that the physical destruction of habitat is what is the biggest factor when the decline of animal species is brought up, but noise is another factor that is becoming apparent and we can’t ignore it.’

Fuzzy, Conniving and Smart

            Squirrels. Cute, fuzzy and sometimes very annoying. Such a pain to find your garbage has been picked apart by your friendly neighborhood squirrel. Although irritating, they are very enjoyable to watch. They are very common as well so you can see them almost anywhere there are trees. The way they twitch. The noises they make. Their fluffy tails. Kinda makes up for their devilish deeds.

(McRae posing with his remote controlled cat)

So while you are watching the twitchy little things, have you ever noticed any patterns? Dr. McRae at the University of Miami did. He was curious as to what caused certain movements and what kind of predators resulted in different reactions? During his two year study on the adorable creatures, he listened to the noises made as well as tail movements when the squirrels were presented with a possible threat. McRae used several fun props to mimic predators, such as the cat car pictured above. He theorizes that the two forms of communication are to warn others that danger is near as well as let the predator know that it has been spotted. The article did not specify which calls and tail movements were correlated to a specific predator so I guess we will have to wait till that paper comes out! Or, make observations yourself! You may think science is boring or that everything has already been done but you would be surprised how fun it can be and how many different things have not been studied yet.

           This study is still being conducted and expanded to study the reactions of other squirrels when a danger signal is called.

Breathalyzers for Dolphins?

                The oceans we have are vast. Full of vibrant life by the masses. From bright corals and lively reef fish to huge whale sharks and narwhals. It is a wonderful place that many see as mysterious. Cetaceans (marine mammals) are seen as a good way to measure the ocean’s health. They have a blubber layer that not only stores fat but also toxins in its environment. Older methods of obtaining data from marine mammals included blood samples and skin biopsies which are hard to acquire (A. Askenov et al.2014)

(Photo from American Chemical Society)

                Here is the fun part. Scientists have come up with a form of breathalyzer test for dolphins. The reason being that you can tell a lot about the health of an animal by a single exhale (not just alcohol content).  Cetaceans have separated digestive and respiratory systems so the breath exhaled is not contaminated with anything from the digestive system. They also have more alveoli in their lungs. This means that more metabolites are exhaled, giving a better reading on individual health of the dolphin. With this new strategy, it makes it easier to study causes of mortality patterns and spread of disease. Who knew? Breathalyzers for bottleneck dolphins.

Shark Love

So many people have had the wonderful experience of owning fish. Whether it was a simple goldfish or more complicated saltwater fish. Everyone knows that sharks are basically the coolest fish to own (definitely bragging material). I have owned sharks. They are definitely hard work.

Well, a recent study was done on small sharks about social behavior. The study was done at the University of Exeter as well as the Marine Biological Association. Social interactions were tested in small sharks placed in several different environments. It was observed that when the group size was altered, sharks that had a strong social connection to other specific individual sharks tended to stay close to those ‘friends’. Their behavior was consistent throughout the whole experiment. The concept of fish friends among sharks is almost foreign since when you think about sharks, most tend to think about individual sharks who choose to stay solitary until mating.

Dr. David Jacoby stated that the behavior was repeated throughout different habitats. He also mentioned that these social behaviors seemed to reflect survival tactics where social groups sought shelter in the comfort of masses, decreasing odds of being attacked by a predator. Individuals who chose not to be social would change their colors to blend in with their surroundings (David M. P. Jacoby 2014). 

                When you own fish, you usually have to get around three to make sure that the dominance among the fish is not too intense. Imagine getting a whole group, and being able to observe social behavior yourself! Friends galore!

David M. P. Jacoby, Lauren N. Fear, David W. Sims, Darren P. Croft. Shark Personalities? Repeatability of social network traits in a widely distributed predatory fish. Behavioral Ecology and Sociobiology, 2014; DOI:10.1007/s00265-014-1805-9

University of Exeter. “Sharks have personality traits, study suggests.” ScienceDaily. Science Daily, 2 October 2014. <www.sciencedaily.com/releases/2014/10/141002084343.htm.>